massive-ovulation-mammals-techniques-for-analyzing-natural

Massive Ovulation in Mammals: Techniques for Analyzing Natural Spontaneous Polyovulation and Induced Polyovulation in <em>Lagostomus maximus</em>

The South American plains vizcacha, Lagostomus maximus, is recognized as the mammalian species with the highest ovulation rate, which can reach as many as ...

Universidad Maimónides

Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)

The South American plains vizcacha, Lagostomus maximus, displays an exceptional ovulation rate of up to 800 eggs per cycle, the highest rate recorded for a mammal. Massive polyovulation arises from the overexpression of the apoptosis-inhibiting BCL2 gene leading to a suppression of apoptotic pathways responsible for follicular atresia in mammals. We analyzed the ovarian histology, ovarian apoptosis, and apoptosis-related protein expression with special emphasis in corpora lutea throughout the 5-mo-long gestation period, at parturition day and early postpartum, in L. maximus. Corpora lutea were abundant throughout gestation with no sign of structural regression even at the end of gestation. Both immunohistochemistry and Western blot analysis showed strong signals for apoptosis-inhibiting BCL2 protein, whereas the proapoptotic BAX protein was just detected in isolated luteal cells in gestating females and postpartum females. Apoptosis-associated DNA fragmentation detected by TUNEL was very scarce and occasional and correlated with BAX detection in luteal cells. Marked expression of progesterone and alpha-estrogen receptors in luteal cells was found at early, mid-, and late gestation as well as at parturition day and early postpartum samples. Additionally, serum level of progesterone increased markedly to reach maximal values at late gestation and decreasing at parturition to levels found at early gestation, suggesting that corpora lutea remained functional throughout gestation. These results point out that the unusual ovarian environment of L. maximus in which germ cell demise is abolished through antiapoptotic BCL2 gene overexpression also preserves structural integrity and functionality of corpora lutea during the whole gestation. Overexpression of antiapoptotic BCL2 gene may represent a strategy for an essential need of ovary and corpora lutea in order to maintain pregnancy until term.

The ovary of the gestating South American plains vizcacha (Lagostomus maximus): suppressed apoptosis and corpora lutea persistence.

Lagostomus maximus is a notable mammalian model for reproductive studies. Females have an extremely high ovulation rate, which is due to down-regulation of the follicular apoptosis pathway, which ensures a large pool of developing follicles. This large pool is supported by the convoluted anatomy of the mature ovary, whose germinal tissue is found in irregularly curved ridges throughout the cortex. Medullary tissue is restricted to a minimum. Lyso Tracker Red reconstruction under confocal laser scanning microscopy was used to recognize and measure all follicular stages from primordial to antral. Unlike most mammals in which early primordial follicles are just found in fetal life, the adult ovary shows regions packed with early primordial follicles. Follicle size ranged from 24 to 316 microm. We discuss the relationships of L. maximus follicles size with regard to other species of mammals and propose that the physiology of the adult viscacha ovary obeys to a neoteny process in the evolution of this species.

The ovary of Lagostomus maximus (Mammalia, Rodentia): an analysis by confocal microscopy.

&#x96C4;&#x6FC0;&#x7D20;&#x548C;&#x96C4;&#x6FC0;&#x7D20;&#x53D7;&#x4F53;&#x53D1;&#x6325;&#x5728;&#x7CBE;&#x5B50;&#x53D1;&#x751F;&#x8FC7;&#x7A0B;&#x4E2D;&#x7684;&#x5173;&#x952E;&#x4F5C;&#x7528;&#x548C;&#x80A5;&#x529B;&#x7684;&#x54FA;&#x4E73;&#x52A8;&#x7269;&#xFF0C;&#x5E76;&#x53CA;&#x5176;&#x53D7;&#x4F53;&#x4E0E;&#x96CC;&#x6FC0;&#x7D20;&#x6709;&#x52A9;&#x4E8E;&#x8C03;&#x8282;&#x777E;&#x4E38;&#x529F;&#x80FD;&#x901A;&#x8FC7;&#x53D1;&#x8D77;&#x548C;&#x7EF4;&#x6301;&#x7CBE;&#x5B50;&#x53D1;&#x751F;&#x548C;&#x751F;&#x6B96;&#x7EC6;&#x80DE;&#x53F8;&#x548C;&#x751F;&#x5B58;&#x3002;&#x7136;&#x800C;&#xFF0C;&#x4ECE;&#x4E0D;&#x540C;&#x7269;&#x79CD;&#x7684;&#x7ED3;&#x679C;&#x662F;&#x4ECD;&#x8FDC;&#x672A;&#x5EFA;&#x7ACB;&#x6E05;&#x695A;&#x5730;&#x4E86;&#x89E3;&#x8FD9;&#x4E9B;&#x53D7;&#x4F53;&#x5728;&#x777E;&#x4E38;&#x4E2D;&#x7684;&#x4E0D;&#x540C;&#x5355;&#x5143;&#x683C;&#x7C7B;&#x578B;&#x3002;&#x6211;&#x4EEC;&#x5206;&#x6790;&#x4E86;&#x96C4;&#x6FC0;&#x7D20;&#x53D7;&#x4F53;&#x3001; &#x514D;&#x75AB;&#x7EC4;&#x5316;&#x548C;&#x5B9E;&#x65F6;&#x8367;&#x5149;&#x5B9A;&#x91CF; PCR&#xFF0C;&#x6240;&#x8868;&#x8FBE;&#x7684;&#x589E;&#x6B96;&#x7EC6;&#x80DE;&#x6838;&#x6297;&#x539F; (PCNA) &#x548C;&#x80DA;&#x7684;&#x8EAB;&#x4EFD;&#x8DDF;&#x74E6;&#x8428;&#x86CB;&#x767D;&#x3001; Lagostomus&#x3001; &#x6301;&#x7EED;&#x7684;&#x751F;&#x7CBE;&#x7EC6;&#x80DE;&#x589E;&#x6B96;&#x4E0E;&#x556E;&#x9F7F;&#x7C7B;&#x52A8;&#x7269;&#x548C;&#x8D8A;&#x6765;&#x8D8A;&#x591A;&#x7684;&#x53D1;&#x5C55;&#x4E2D;&#x56FD;&#x5BB6;&#x7684;&#x5375;&#x5DE2;&#x5728;&#x534E;&#x4FA8;&#x57CE; 4 &#x8868;&#x793A; gonocytes &#x80CE;&#x513F;&#x3001; &#x56F4;&#x4EA7;&#x671F;&#x3001; &#x9752;&#x6625;&#x671F;&#x524D;&#x548C;&#x6210;&#x4EBA;&#x777E;&#x4E38;&#x4E2D;&#x7684;&#x6269;&#x6563;&#x4E0E;&#x96CC;&#x6FC0;&#x7D20;&#x53D7;&#x4F53; &alpha; &#x548C; &beta; &#x548C;&#x82B3;&#x9999;&#x5316;&#x9176;&#x86CB;&#x767D;&#x7684;&#x8868;&#x8FBE;&#x3002;AR &#x8868;&#x8FBE;&#x9650;&#x4E8E;&#x777E;&#x4E38;&#x95F4;&#x8D28;&#x7EC6;&#x80DE;&#x53CA;&#x7BA1;&#x5468;&#x7EC6;&#x80DE;&#x524D;&#x6027;&#x6210;&#x719F;&#xFF0C;&#x6B64;&#x65F6;&#x5B83;&#x8FD8;&#x6210;&#x4E86;&#x8868;&#x793A;&#x652F;&#x6301;&#x7EC6;&#x80DE;&#x4E2D;&#x3002;ER&alpha; &#x548C; ER&beta; &#x4E2D;&#xFF0C;&#x8868;&#x793A;&#x751F;&#x7CBE;&#x5C0F;&#x7BA1;&#x53CA;&#x95F4;&#x8D28;&#xFF0C;&#x5206;&#x522B;&#x5728;&#x80CE;&#x513F;&#x548C;&#x9752;&#x6625;&#x671F;&#x524D;&#x777E;&#x4E38;&#x3002;&#x6210;&#x4EBA;&#x777E;&#x4E38;&#xFF0C;ER&alpha; &#x548C; ER&beta; &#x7EF4;&#x777E;&#x4E38;&#x95F4;&#x8D28;&#x53CA;&#x5FAE;&#x8840;&#x7BA1;&#x4E2D;&#x7684;&#x5355;&#x5143;&#x683C;&#x3002;&#x82B3;&#x9999;&#x5316;&#x9176;&#xFF0C;&#x8FD9;&#x4E00;&#x8F6C;&#x6362;&#x96CC;&#x6FC0;&#x7D20;&#x96C4;&#x6FC0;&#x7D20;&#x524D;&#x4F53;&#xFF0C;&#x63A2;&#x6D4B;&#x5206;&#x6790;&#x7684;&#x5404;&#x4E2A;&#x53D1;&#x5C55;&#x9636;&#x6BB5;&#xFF0C;&#x4EC5;&#x9650;&#x4E8E;&#x777E;&#x4E38;&#x95F4;&#x8D28;&#x7EC6;&#x80DE;&#x3002;&#x589E;&#x6B96;&#x7EC6;&#x80DE;&#x6838;&#x6297;&#x539F;&#x6027;&#x6210;&#x719F;&#x4E4B;&#x524D;&#x4ECD;&#x7136;&#x5F88;&#x9AD8;&#x3002;ER&alpha; &#x6838;&#x63A2;&#x6D4B;&#x751F;&#x7CBE;&#x7EC6;&#x80DE;&#x548C;&#x777E;&#x4E38;&#x95F4;&#x8D28;&#x7EC6;&#x80DE;&#x589E;&#x6B96;&#x7EC6;&#x80DE;&#x6838;&#x6297;&#x539F;&#x9633;&#x6027;&#x7EC6;&#x80DE;&#x4E2D; AR &#x8868;&#x660E;&#x96CC;&#x6FC0;&#x7D20;&#x5BF9;&#x7CBE;&#x539F;&#x7EC6;&#x80DE;&#x589E;&#x6B96;&#x523A;&#x6FC0;&#x4F5C;&#x7528;&#x7684;&#x53EF;&#x80FD;&#x6027;&#x3002;&#x8FD9;&#x79CD;&#x6548;&#x679C;&#x53EF;&#x80FD;&#x89E3;&#x91CA;&#x7684;&#x589E;&#x52A0;&#x5728;&#x74E6;&#x8428;&#x8868;&#x793A;&#x5355;&#x5143;&#x683C;&#x5728;&#x6210;&#x4EBA;&#x7684;&#x777E;&#x4E38;&#x4E2D;&#x53D1;&#x73B0;&#x3002;

&#x96C4;&#x6FC0;&#x7D20;&#x53D7;&#x4F53;&#x3001; &#x96CC;&#x6FC0;&#x7D20;&#x53D7;&#x4F53; &alpha; &#x548C; &beta; &#x548C;&#x80CE;&#x513F;&#x3001; &#x56F4;&#x4EA7;&#x3001; Prepubertal &#x548C;&#x6210;&#x4EBA;&#x777E;&#x4E38;&#x7684;&#x5357;&#x7F8E;&#x6D32;&#x5E73;&#x539F; Vizcacha&#xFF0C;Lagostomus &#x9C7C; (&#x54FA;&#x4E73;&#x7EB2;&#xFF0C;&#x556E;&#x9F7F;&#x7C7B;) &#x4E2D;&#x82B3;&#x9999;&#x5316;&#x9176;&#x7684;&#x8868;&#x8FBE;&#x3002;

Androgens and androgen receptor play a critical role in spermatogenesis and fertility in mammals, and estrogens and their receptors contribute to regulation of testicular function through initiation and maintenance of spermatogenesis and germ cell division and survival. However, results from different species are still far from establishing a clear understanding of these receptors in the different cell types from the testis. We analyzed the expression of androgen receptor, estrogen receptors Î± and Î² and aromatase protein by immunohistochemistry and real-time PCR, in relation to proliferation followed by the expression of proliferation cell nuclear antigen (PCNA) and germinal identity by VASA protein, in fetal, perinatal, prepubertal and adult testes of Lagostomus maximus, a rodent with sustained germ cell proliferation and an increasing number of OCT-4-expressing gonocytes in the developing ovary. AR expression was restricted to Leydig cells and peritubular cells before sexual maturity, at which point it also became expressed in Sertoli cells. ERÎ± and ERÎ² were expressed in seminiferous tubules and the interstitium, respectively, in both fetal and prepubertal testes. In adult testes, both ERÎ± and ERÎ² co-localized in Leydig and peritubular cells. The aromatase enzyme, which converts androgenic precursors into estrogens, was detectable in all developmental stages analyzed and was restricted to Leydig cells. PCNA remained high until sexual maturity. ERÎ± nuclear detection in germ cells and AR in Leydig cells in PCNA-positive cells suggest the possibility of a stimulatory effect of estrogens on spermatogonia proliferation. This effect might explain the increase found in VASA-expressing cells in the adult testis.

Expression of Androgen Receptor, Estrogen Receptors Alpha and Beta and Aromatase in the Fetal, Perinatal, Prepubertal and Adult Testes of the South American Plains Vizcacha, Lagostomus maximus (Mammalia, Rodentia).

Androg&egrave;nes et r&eacute;cepteur des androg&egrave;nes jouent un r&ocirc;le essentiel dans la spermatogen&egrave;se et la fertilit&eacute; chez les mammif&egrave;res, et des oestrog&egrave;nes et leurs r&eacute;cepteurs contribuent &agrave; la r&eacute;gulation de la fonction testiculaire &agrave; travers l&#39;ouverture et l&#39;entretien de la division de la spermatogen&egrave;se et des cellules germinales et de survie. Cependant, les r&eacute;sultats provenant de diff&eacute;rentes esp&egrave;ces sont encore loin d&#39;&eacute;tablir une compr&eacute;hension claire de ces r&eacute;cepteurs dans les diff&eacute;rents types de cellules du testicule. Nous avons analys&eacute; l&#39;expression du r&eacute;cepteur des androg&egrave;nes, oestrog&egrave;nes r&eacute;cepteurs &alpha; et &beta; et l&#39;aromatase prot&eacute;ine par immunohistochimie et PCR en temps r&eacute;el, en ce qui concerne la prolif&eacute;ration, suivie par l&#39;expression de l&#39;antig&egrave;ne nucl&eacute;aire de cellules de prolif&eacute;ration (PCNA) et identit&eacute; germinale prot&eacute;ine VASA, dans les testicules foetus, p&eacute;rinatales, pr&eacute;pub&egrave;res et adultes de Lagostomus maximus, un rongeur &agrave; une prolif&eacute;ration des cellules germinales soutenue et un nombre croissant de gonocytes exprimant l&#39;OCT-4 dans l&#39;ovaire en d&eacute;veloppement. Expression AR &eacute;tait limit&eacute;e aux cellules de Leydig et cellules p&eacute;ritubulaires avant la maturit&eacute; sexuelle, &agrave; quel point il est devenu aussi exprim&eacute; dans les cellules de Sertoli. ER&alpha; et RE&beta; ont &eacute;t&eacute; exprim&eacute;es dans les tubules s&eacute;minif&egrave;res et l&#39;interstitium, respectivement, dans les testicules fois foetales et pr&eacute;pub&egrave;res. Dans les testicules adultes, ER&alpha; tant RE&beta; localis&eacute;e dans les cellules de Leydig et p&eacute;ritubulaire. L&#39;enzyme aromatase, qui convertit des pr&eacute;curseurs androg&egrave;nes en oestrog&egrave;nes, a &eacute;t&eacute; d&eacute;tect&eacute; dans tous les stades de d&eacute;veloppement analys&eacute;s et se limitait &agrave; cellules de Leydig. PCNA est demeur&eacute;e &eacute;lev&eacute;e jusqu&#39;&agrave; la maturit&eacute; sexuelle. D&eacute;tection nucl&eacute;aire ER&alpha; dans les cellules germinales et AR dans les cellules de Leydig dans des cellules positives PCNA sugg&egrave;rent la possibilit&eacute; d&#39;un effet stimulant des oestrog&egrave;nes sur la prolif&eacute;ration des spermatogonies. Cet effet pourrait expliquer l&#39;augmentation dans les cellules exprimant le VASA dans le testicule adult.

Expression du r&eacute;cepteur des androg&egrave;nes, oestrog&egrave;nes r&eacute;cepteurs Alpha et b&ecirc;ta et Aromatase foetal, p&eacute;rinatale, Prepubertal et testicules adultes de l&#39;Am&eacute;rique du sud des plaines Vizcacha, Lagostomus maximus (Mammalia, rongeurs).

Androgene und Androgenrezeptor spielen eine entscheidende Rolle bei der Spermatogenese und Fruchtbarkeit bei S&auml;ugetieren, und &Ouml;strogene und ihre Rezeptoren tragen zur Regulierung der Testikular-Funktion durch Einleitung und Aufrechterhaltung der Spermatogenese und Germ Cell Division und &uuml;berleben. Die Ergebnisse aus verschiedenen Arten sind jedoch noch weit von einer klaren Vermittlung dieser Rezeptoren in den verschiedenen Zelltypen aus den Hoden. Wir analysierten den Ausdruck der Androgenrezeptor, &Ouml;strogen-Rezeptoren-&alpha; und &beta; und Aromatase Protein durch Immunhistochemie und Echtzeit-PCR, in Bezug auf Verbreitung, gefolgt von dem Ausdruck der Verbreitung Zelle Nukle&auml;res Antigen (PCNA) und germinal Identit&auml;t durch VASA Protein im fetalen, Perinatale, Vorpubert&auml;r und Erwachsenen Hoden Lagostomus Maximus, ein Nagetier mit anhaltenden Germ Cell Proliferation und eine wachsende Zahl von OCT-4-Ausdruck Uranylionen in den Entwicklungsl&auml;ndern Eierstock. AR Ausdruck beschr&auml;nkte sich auf Leydig-Zellen und der Peritubular vor der Geschlechtsreife, an welcher Stelle sie auch in Sertoli-Zellen ausgedr&uuml;ckt wurde. ER&alpha; und ER&beta; wurden in seminiferous Tubules und das Interstitium bzw. sowohl fetale und pr&auml;pubert&auml;re Hoden ausgedr&uuml;ckt. Im Erwachsenen Hoden, ER&alpha; und ER&beta; co-localized in Zellen Leydig und Peritubular. Die Aromatase-Enzym, die Androgene Vorstufen in &Ouml;strogene umwandelt, war nachweisbar in allen Entwicklungsstadien analysiert und beschr&auml;nkte sich auf Leydig-Zellen. Hohe blieb PCNA sexuelle Reife. ER&alpha; nukleare Erkennung in Keimzellen und AR in Leydig-Zellen in PCNA-positiven Zellen schlagen die M&ouml;glichkeit, eine stimulierende Wirkung der &Ouml;strogene auf Spermatogonien Verbreitung. Dieser Effekt k&ouml;nnte erkl&auml;ren, dass den Anstieg in VASA-Ausdruck von Zellen in den Erwachsenen Hoden gefunden.

Ausdruck der Androgen-Rezeptor, &Ouml;strogen Rezeptoren Alpha und Beta und Aromatase im fetalen, Perinatal, Prepubertal und Erwachsenen Hoden der s&uuml;damerikanischen Plains Vizcacha, Lagostomus Maximus (Mammalia, Rodentia).

Androgeni e recettore degli androgeni svolgono un ruolo critico nella spermatogenesi e fertilit&agrave; nei mammiferi, e gli estrogeni e loro recettori contribuiscono alla regolazione della funzione testicolare attraverso l&#39;iniziazione e la manutenzione di divisione di spermatogenesi e la produzione delle cellule germinali e sopravvivenza. Tuttavia, risultati da diverse specie sono ancora lontani dallo stabilire una chiara comprensione di questi recettori nei tipi differenti delle cellule dal testicolo. Abbiamo analizzato l&#39;espressione del recettore degli androgeni, estrogeni recettori &alpha; e &beta; e dell&#39;aromatasi proteina da immunohistochemistry e PCR in tempo reale, in relazione alla proliferazione seguita dall&#39;espressione dell&#39;antigene nucleare delle cellule di proliferazione (PCNA) e germinale identit&agrave; di proteina VASA, nei testicoli fetali, perinatale, prepuberi e adulti Lagostomus maximus, un roditore con proliferazione delle cellule di germe sostenuta e un numero crescente di gonocytes OCT-4-esprimendo nell&#39;ovaio in via di sviluppo. Espressione di AR &egrave; stata limitata a cellule di Leydig e peritubulare cellule prima della maturit&agrave; sessuale, al punto che essa divenne espresso anche in cellule del Sertoli. ER&alpha; ed ER&beta; sono stati espressi nei tubuli seminiferi e l&#39;interstizio, rispettivamente, nei testicoli fetali e prepuberale. In adulti testicoli, sia ER&alpha; ed ER&beta; co-ha localizzato nelle cellule di Leydig e peritubulare. L&#39;enzima aromatasi, che converte i precursori androgeni in estrogeni, era rilevabile in tutte le fasi di sviluppo analizzate ed era limitata a cellule di Leydig. PCNA &egrave; rimasto alto fino alla maturit&agrave; sessuale. ER&alpha; rilevamento nucleare nelle cellule germinali e AR in cellule di Leydig in cellule positive PCNA suggeriscono la possibilit&agrave; di un effetto stimolante degli estrogeni sulla proliferazione di spermatogoni. Questo effetto potrebbe spiegare l&#39;aumento trovato in cellule che esprimono VASA nel testicolo adulto.

Espressione del recettore degli androgeni, estrogeni recettori alfa e Beta e aromatasi in fetale, perinatale, Prepubertal e adulti testicoli del sud americano pianure Vizcacha, Lagostomus maximus (Mammalia, Rodentia).

&#x30A2;&#x30F3;&#x30C9;&#x30ED;&#x30B2;&#x30F3;&#x3068;&#x30A2;&#x30F3;&#x30C9;&#x30ED;&#x30B2;&#x30F3;&#x53D7;&#x5BB9;&#x4F53;&#x7CBE;&#x5B50;&#x5F62;&#x6210;&#x306B;&#x304A;&#x3044;&#x3066;&#x91CD;&#x8981;&#x306A;&#x5F79;&#x5272;&#x3068;&#x54FA;&#x4E73;&#x52D5;&#x7269;&#x3067;&#x3001;&#x4E0D;&#x598A;&#x6CBB;&#x7642;&#x3092;&#x518D;&#x751F;&#x3057;&#x3001;&#x30A8;&#x30B9;&#x30C8;&#x30ED;&#x30B2;&#x30F3;&#x3068;&#x305D;&#x306E;&#x53D7;&#x5BB9;&#x4F53;&#x306E;&#x7CBE;&#x5DE3;&#x6A5F;&#x80FD;&#x958B;&#x59CB;&#x3092;&#x4ECB;&#x3057;&#x3066;&#x8ABF;&#x7BC0;&#x3068;&#x7CBE;&#x5B50;&#x5F62;&#x6210;&#x3068;&#x751F;&#x6B96;&#x7D30;&#x80DE;&#x306E;&#x5206;&#x88C2;&#x3068;&#x751F;&#x5B58;&#x306E;&#x7DAD;&#x6301;&#x306B;&#x8CA2;&#x732E;&#x3002;&#x305F;&#x3060;&#x3057;&#x3001;&#x7D50;&#x679C;&#x306E;&#x7570;&#x306A;&#x308B;&#x7A2E;&#x304B;&#x3089;&#x7CBE;&#x5DE3;&#x304B;&#x3089;&#x7570;&#x306A;&#x3063;&#x305F;&#x7D30;&#x80DE;&#x306E;&#x30BF;&#x30A4;&#x30D7;&#x306E;&#x3053;&#x308C;&#x3089;&#x306E;&#x53D7;&#x5BB9;&#x4F53;&#x3092;&#x660E;&#x78BA;&#x306B;&#x7406;&#x89E3;&#x3092;&#x307E;&#x3060;&#x78BA;&#x7ACB;&#x3059;&#x308B;&#x3053;&#x3068;&#x304B;&#x3089;&#x9060;&#x3044;&#x3067;&#x3059;&#x3002;&#x30A2;&#x30F3;&#x30C9;&#x30ED;&#x30B2;&#x30F3;&#x53D7;&#x5BB9;&#x4F53;, &#x514D;&#x75AB;&#x7D44;&#x7E54;&#x5316;&#x5B66;&#x3068;&#x30F4;&#x30A1;&#x30FC;&#x30B5; &#x30BF;&#x30F3;&#x30D1;&#x30AF;&#x8CEA; Lagostomus &#x5927;&#x6BBF;&#x3001;&#x6301;&#x7D9A;&#x7684;&#x306A;&#x751F;&#x6B96;&#x7D30;&#x80DE;&#x5897;&#x6B96;&#x6301;&#x3064;&#x9F67;&#x6B6F;&#x52D5;&#x7269;&#x304A;&#x3088;&#x3073; OCT 4 &#x3092;&#x8868;&#x73FE;&#x3059;&#x308B; gonocyte &#x958B;&#x767A;&#x306E;&#x5375;&#x5DE3;&#x306E;&#x5897;&#x52A0;&#x3059;&#x308B;&#x6570;&#x306E;&#x5468;&#x7523;&#x671F;&#x3001;&#x601D;&#x6625;&#x671F;&#x524D;&#x80CE;&#x5150;&#x3001;&#x6210;&#x4EBA;&#x7CBE;&#x5DE3;&#x306B;&#x304A;&#x3051;&#x308B;&#x5897;&#x6B96;&#x7D30;&#x80DE;&#x6838;&#x6297;&#x539F; (PCNA) &#x3068;&#x80DA;&#x306E;&#x30A2;&#x30A4;&#x30C7;&#x30F3;&#x30C6;&#x30A3;&#x30C6;&#x30A3;&#x306E;&#x8868;&#x73FE;&#x306B;&#x3088;&#x3063;&#x3066;&#x7D9A;&#x3044;&#x3066;&#x5897;&#x6B96;&#x95A2;&#x9023;&#x306E;&#x30EA;&#x30A2;&#x30EB;&#x30BF;&#x30A4;&#x30E0; PCR &#x306B;&#x3088;&#x308B;&#x30A8;&#x30B9;&#x30C8;&#x30ED;&#x30B2;&#x30F3;&#x53D7;&#x5BB9;&#x4F53; &alpha; &#x3068; &beta; &#x3068;&#x30A2;&#x30ED;&#x30DE;&#x30BF;&#x30FC;&#x30BC;&#x86CB;&#x767D;&#x8CEA;&#x306E;&#x8868;&#x73FE;&#x3092;&#x5206;&#x6790;&#x3057;&#x307E;&#x3057;&#x305F;&#x3002;AR &#x5F0F;&#x524D;&#x306B;&#x6027;&#x7684;&#x306B;&#x6210;&#x719F;&#x3001;&#x305D;&#x306E;&#x6642;&#x70B9;&#x3067;&#x305D;&#x308C;&#x3082;&#x30BB;&#x30EB;&#x30C8;&#x30EA;&#x7D30;&#x80DE;&#x3067;&#x767A;&#x73FE;&#x3068;&#x306A;&#x3063;&#x305F;&#x30E9;&#x30A4;&#x30C7;&#x30A3;&#x30C3;&#x30D2;&#x7D30;&#x80DE;&#x3084;, &#x7BA1;&#x5468;&#x56F2;&#x7D30;&#x80DE;&#x306B;&#x5236;&#x9650;&#x3055;&#x308C;&#x307E;&#x3057;&#x305F;&#x3002;&#x305D;&#x308C;&#x305E;&#x308C;&#x3001;ER&alpha; &#x3068; ER&beta; &#x7CBE;&#x7D30;&#x7BA1;&#x3068;&#x3001;&#x6C17;&#x9053;&#x306E;&#x7CBE;&#x5DE3;&#x3067;&#x306F;&#x80CE;&#x5150;&#x3068;&#x601D;&#x6625;&#x671F;&#x524D;&#x304C;&#x8868;&#x73FE;&#x3055;&#x308C;&#x307E;&#x3057;&#x305F;&#x3002;&#x6210;&#x4EBA;&#x306E;&#x7CBE;&#x5DE3;&#x3067;&#x306F;&#x3001;ER&alpha; &#x3068; ER&beta; &#x306E;&#x4E21;&#x65B9;&#x30E9;&#x30A4;&#x30C7;&#x30A3;&#x30C3;&#x30D2;&#x3068;, &#x7BA1;&#x5468;&#x56F2;&#x7D30;&#x80DE;&#x3092; co-localized &#x3057;&#x307E;&#x3057;&#x305F;&#x3002;&#x30A2;&#x30F3;&#x30C9;&#x30ED;&#x30B2;&#x30F3;&#x524D;&#x99C6;&#x4F53;&#x30A8;&#x30B9;&#x30C8;&#x30ED;&#x30B2;&#x30F3;&#x306B;&#x5909;&#x63DB;&#x30A2;&#x30ED;&#x30DE;&#x30BF;&#x30FC;&#x30BC;&#x9175;&#x7D20;&#x5206;&#x6790;&#x3059;&#x3079;&#x3066;&#x306E;&#x767A;&#x9054;&#x6BB5;&#x968E;&#x3067;&#x691C;&#x51FA;&#x3055;&#x308C;&#x3001;&#x30E9;&#x30A4;&#x30C7;&#x30A3;&#x30C3;&#x30D2;&#x7D30;&#x80DE;&#x306B;&#x5236;&#x9650;&#x3055;&#x308C;&#x307E;&#x3057;&#x305F;&#x3002;PCNA &#x307E;&#x3067;&#x6027;&#x7684;&#x6210;&#x719F;&#x5EA6;&#x304C;&#x9AD8;&#x3044;&#x307E;&#x307E;&#x3067;&#x3057;&#x305F;&#x3002;ER&alpha; &#x6838;&#x691C;&#x51FA;&#x751F;&#x6B96;&#x7D30;&#x80DE;&#x306B;&#x304A;&#x3051;&#x308B; AR &#x306E;&#x30E9;&#x30A4;&#x30C7;&#x30A3;&#x30D2;&#x7D30;&#x80DE;&#x306E; PCNA &#x967D;&#x6027;&#x7D30;&#x80DE;&#x306E;&#x30A8;&#x30B9;&#x30C8;&#x30ED;&#x30B2;&#x30F3;&#x306E;&#x7CBE;&#x7956;&#x7D30;&#x80DE;&#x5897;&#x6B96;&#x4FC3;&#x9032;&#x52B9;&#x679C;&#x306E;&#x53EF;&#x80FD;&#x6027;&#x304C;&#x793A;&#x5506;&#x3055;&#x308C;&#x305F;.&#x3053;&#x306E;&#x52B9;&#x679C;&#x306F;&#x30F4;&#x30A1;&#x30FC;&#x30B5;&#x767A;&#x73FE;&#x7D30;&#x80DE;&#x6210;&#x4EBA;&#x306E;&#x7CBE;&#x5DE3;&#x3067;&#x306E;&#x5897;&#x52A0;&#x3092;&#x8AAC;&#x660E;&#x3059;&#x308B;&#x304B;&#x3082;&#x3057;&#x308C;&#x306A;&#x3044;&#x3002;

&#x30A2;&#x30F3;&#x30C9;&#x30ED;&#x30B2;&#x30F3;&#x53D7;&#x5BB9;&#x4F53;, &#x30A8;&#x30B9;&#x30C8;&#x30ED;&#x30B2;&#x30F3;&#x53D7;&#x5BB9;&#x4F53;&#x30A2;&#x30EB;&#x30D5;&#x30A1;&#x3068;&#x30D9;&#x30FC;&#x30BF;&#x80CE;&#x4ED4;, &#x5468;&#x7523;&#x671F;&#x3001;Prepubertal &#x304A;&#x3088;&#x3073;&#x5357;&#x30A2;&#x30E1;&#x30EA;&#x30AB;&#x306E;&#x5E73;&#x539F; Vizcacha&#x3001;&#x30DE;&#x30AF;&#x30B7;&#x30E0;&#x30B9; Lagostomus (&#x54FA;&#x4E73;&#x7DB1;, &#x9F67;&#x6B6F;&#x76EE;) &#x306E;&#x6210;&#x4EBA;&#x306E;&#x7CBE;&#x5DE3;&#x3067;&#x306F;&#x30A2;&#x30ED;&#x30DE;&#x30BF;&#x30FC;&#x30BC;&#x306E;&#x767A;&#x73FE;

&#xC548; &#xB4DC;&#xB85C; &#xAC90;&#xACFC; &#xC548; &#xB4DC;&#xB85C; &#xAC90; &#xC218;&#xC6A9; &#xCCB4; &#xD50C;&#xB808;&#xC774; spermatogenesis&#xC5D0; &#xC911;&#xC694; &#xD55C; &#xC5ED;&#xD560;&#xC744; &#xD558; &#xACE0; &#xD3EC;&#xC720;&#xB958;, &#xBD88; &#xC784; &#xBC0F; &#xAC1C;&#xC2DC;&#xB97C; &#xD1B5;&#xD574; &#xACE0;&#xD658; &#xAE30;&#xB2A5; &#xADDC;&#xC815;&#xACFC; spermatogenesis &#xBC0F; &#xC0DD;&#xC2DD; &#xC138;&#xD3EC; &#xBD84;&#xC5F4;&#xACFC; &#xC0DD;&#xC874;&#xC758; &#xC720;&#xC9C0;&#xC5D0; &#xAE30;&#xC5EC; &#xD558;&#xB294; &#xC5D0;&#xC2A4;&#xD2B8;&#xB85C;&#xAC90;&#xACFC; &#xADF8;&#xB4E4;&#xC758; &#xC218;&#xC6A9; &#xCCB4;. &#xADF8;&#xB7EC;&#xB098;, &#xC885;&#xC5D0;&#xC11C; &#xACB0;&#xACFC; &#xACE0;&#xD658;&#xC5D0;&#xC11C; &#xC11C;&#xB85C; &#xB2E4;&#xB978; &#xC138;&#xD3EC; &#xC720;&#xD615;&#xC5D0;&#xC774; &#xC218;&#xC6A9; &#xCCB4;&#xC5D0; &#xBD84;&#xBA85;&#xD788; &#xC774;&#xD574;&#xB97C; &#xC218;&#xB9BD; &#xBA40;&#xC9C0;&#xB294;. &#xC6B0;&#xB9AC;&#xB294; &#xC548; &#xB4DC;&#xB85C; &#xAC90; &#xC218;&#xC6A9; &#xCCB4;, &#xC5D0;&#xC2A4;&#xD2B8;&#xB85C;&#xAC90; &#xC218;&#xC6A9; &#xCCB4; &alpha;&#xC640; &beta; aromatase &#xB2E8;&#xBC31;&#xC9C8; &#xAE30;&#xC220; &#xBC0F; Lagostomus &#xB9C9;&#xC2DC;&#xBB34;&#xC2A4;, &#xC9C0;&#xC18D;&#xC801;&#xC778;&#xB41C; &#xC138;&#xADE0; &#xC138;&#xD3EC; &#xC99D;&#xC2DD;&#xACFC; &#xC950; &#xADF8;&#xB9AC;&#xACE0; &#xAC1C;&#xBC1C; &#xB09C;&#xC18C;&#xC5D0; 10 &#xC6D4; 4 &#xD45C;&#xD604; gonocytes&#xC758; &#xC99D;&#xAC00; &#xC218;&#xC758; &#xD0DC;&#xC544;, perinatal prepubertal &#xBC0F; &#xC131;&#xC778; testes&#xC5D0;&#xC11C; &#xBC14;&#xC0AC; &#xB2E8;&#xBC31;&#xC9C8;&#xC5D0; &#xC758;&#xD574; &#xC99D;&#xC2DD; &#xC138;&#xD3EC; &#xD575; &#xD56D; &#xC6D0; (PCNA)&#xC640; &#xC0C8;&#xC2F9; &#xC815;&#xCCB4;&#xC131;&#xC758; &#xD45C;&#xD604; &#xC774;&#xC5B4;&#xC11C; &#xD655;&#xC0B0; &#xAD00;&#xB828; &#xC2E4;&#xC2DC;&#xAC04; PCR&#xC5D0; &#xC758;&#xD574;&#xC758; &#xC2DD;&#xC744; &#xBD84;&#xC11D; &#xD588;&#xB2E4;. &#xC544;&#xCE78;&#xC18C; &#xC2DD; &#xC5B4;&#xB290; &#xC2DC;&#xC810;&#xC5D0;&#xC11C; &#xADF8;&#xAC83;&#xC740; &#xB610;&#xD55C; &#xB418;&#xC5C8;&#xB2E4; &#xD45C;&#xD604; Sertoli &#xC138;&#xD3EC;&#xC5D0;&#xC11C; &#xC131;&#xC801; &#xC131;&#xC219; &#xD558;&#xAE30; &#xC804;&#xC5D0; Leydig &#xC138;&#xD3EC; &#xBC0F; peritubular &#xC140;&#xC744; &#xC81C;&#xD55C; &#xD588;&#xB2E4;. ER&alpha; &#xBC0F; ER&beta; &#xD588;&#xB2E4; &#xD45C;&#xD604; seminiferous tubules &#xADF8;&#xB9AC;&#xACE0; interstitium, &#xAC01;&#xAC01;, &#xD0DC;&#xC544; &#xBC0F; prepubertal testes&#xC5D0;&#xC11C;. &#xC131;&#xC778; testes&#xC5D0;&#xC11C; ER&alpha; &#xBC0F; ER&beta; co-localized Leydig &#xBC0F; peritubular &#xC140;. &#xC5D0;&#xC2A4;&#xD2B8;&#xB85C;&#xAC90;&#xC73C;&#xB85C; androgenic &#xC804;&#xC870;&#xB97C; &#xBCC0;&#xD658; &#xD558;&#xB294; aromatase &#xD6A8;&#xC18C; &#xBD84;&#xC11D; &#xD558;&#xB294; &#xBAA8;&#xB4E0; &#xAC1C;&#xBC1C; &#xB2E8;&#xACC4;&#xC5D0;&#xC11C; &#xAC10;&#xC9C0; &#xB418;&#xC5C8;&#xACE0; Leydig &#xC138;&#xD3EC;&#xB85C; &#xC81C;&#xD55C; &#xD588;&#xB2E4;. PCNA &#xC131;&#xC801; &#xC131;&#xC219;&#xAE4C;&#xC9C0; &#xB192;&#xC740; &#xC720;&#xC9C0;. &#xC138;&#xADE0; &#xC138;&#xD3EC;&#xC5D0;&#xC11C; ER&alpha; &#xD575; &#xAC10;&#xC9C0; &#xBC0F; PCNA &#xC591;&#xC131; &#xC138;&#xD3EC;&#xC758; Leydig &#xC138;&#xD3EC;&#xC5D0; &#xC544;&#xCE78;&#xC18C; spermatogonia &#xD655;&#xC0B0;&#xC5D0; &#xC5D0;&#xC2A4;&#xD2B8;&#xB85C;&#xAC90;&#xC758; stimulatory &#xD6A8;&#xACFC;&#xC758; &#xAC00;&#xB2A5;&#xC131;&#xC744; &#xC81C;&#xC548; &#xD569;&#xB2C8;&#xB2E4;. &#xC774; &#xD6A8;&#xACFC; &#xBC14;&#xC0AC; &#xD45C;&#xD604; &#xC140; &#xC131;&#xC778; &#xACE0;&#xD658;&#xC5D0; &#xC788;&#xB294; &#xC99D;&#xAC00; &#xC124;&#xBA85;&#xD560; &#xC218; &#xC788;&#xC2B5;&#xB2C8;&#xB2E4;.

&#xC548; &#xB4DC;&#xB85C; &#xAC90; &#xC218;&#xC6A9; &#xCCB4;, &#xC5D0;&#xC2A4;&#xD2B8;&#xB85C;&#xAC90; &#xC218;&#xC6A9; &#xCCB4; &#xC54C;&#xD30C;&#xC640; &#xBCA0;&#xD0C0;&#xC640; &#xD0DC;&#xC544;, Perinatal Prepubertal, &#xB0A8;&#xBBF8; &#xD3C9;&#xC6D0; Vizcacha Lagostomus &#xB9C9;&#xC2DC;&#xBB34;&#xC2A4; (&#xD3EC;&#xC720;&#xB958;, Rodentia)&#xC758; &#xC131;&#xC778; Testes Aromatase&#xC758; &#xD45C;&#xD604;.

Los andr&oacute;genos y receptor de andr&oacute;genos juegan un papel cr&iacute;tico en la espermatog&eacute;nesis y la fertilidad en los mam&iacute;feros, y los estr&oacute;genos y sus receptores contribuyen a la regulaci&oacute;n de la funci&oacute;n testicular a trav&eacute;s de la iniciaci&oacute;n y el mantenimiento de la espermatog&eacute;nesis y la c&eacute;lula de germen de la divisi&oacute;n y la supervivencia. Sin embargo, resultados de diferentes especies son a&uacute;n muy lejos de establecer una comprensi&oacute;n clara de estos receptores en los diferentes tipos celulares del test&iacute;culo. Hemos analizado la expresi&oacute;n del receptor de andr&oacute;genos, estr&oacute;genos receptores &alpha; y &beta; y aromatasa prote&iacute;na por inmunohistoqu&iacute;mica y PCR en tiempo real, en relaci&oacute;n con la proliferaci&oacute;n, seguida por la expresi&oacute;n del ant&iacute;geno nuclear de proliferaci&oacute;n celular (PCNA) e identidad germinal prote&iacute;na VASA, en test&iacute;culos fetales, perinatales, prep&uacute;beres y adultas de Lagostomus maximus, un roedor con proliferaci&oacute;n de la c&eacute;lula de germen sostenido y un n&uacute;mero creciente de OCT-4-expresi&oacute;n gonocytes en el ovario en desarrollo. Expresi&oacute;n de AR se restringi&oacute; a las c&eacute;lulas de Leydig y c&eacute;lulas peritubular antes de la madurez sexual, momento en el que tambi&eacute;n se convirti&oacute; en expres&oacute; en c&eacute;lulas de Sertoli. ER&alpha; y ER&beta; fueron expresados en los t&uacute;bulos semin&iacute;feros y el intersticio, respectivamente, en tanto fetales como prepubertal test&iacute;culos. En los test&iacute;culos adultos, ER&alpha; tanto ER&beta; co-localized en las c&eacute;lulas de Leydig y peritubular. La enzima aromatasa, que convierte a precursores androg&eacute;nicos en estr&oacute;genos, era perceptible en todas las etapas del desarrollo analizadas y se limita a las c&eacute;lulas de Leydig. PCNA se mantuvo alta hasta la madurez sexual. Detecci&oacute;n nuclear ER&alpha; en c&eacute;lulas germinales y AR en las c&eacute;lulas de Leydig en c&eacute;lulas PCNA positivas sugieren la posibilidad de un efecto estimulante de los estr&oacute;genos sobre proliferaci&oacute;n de espermatogonias. Ello podr&iacute;a explicar el aumento que se encuentra en las c&eacute;lulas VASA-expresando en el test&iacute;culo adulto.

Expresi&oacute;n del Receptor de andr&oacute;genos, estr&oacute;genos receptores alfa y Beta y aromatasa Fetal, Perinatal, Prepubertal y test&iacute;culos para adultos de la Vizcacha de llanuras de Am&eacute;rica del sur, Lagostomus maximus (Mammalia, Rodentia).

In mammals, elevated levels of progesterone (P4) throughout gestation maintain a negative feedback over the hypothalamic-hypophyseal-gonadal (H-H-G) axis, avoiding preovulatory follicular growth and preventing ovulation. Recent studies showed that in the South American plains vizcacha (Lagostomus maximus) folliculogenesis progresses to preovulatory stages during gestation, and an ovulatory process seems to occur at midgestation. The aim of this work was to analyze hypothalamic gonadotropin-releasing hormone (GnRH) and P4 receptors (PR) expression and luteinizing hormone (LH) secretion and correlate these with the functional state of the ovary in nonovulating and ovulating females and gestating females with special emphasis in the supposedly ovulating females at midgestation. We investigated P4 and LH serum levels as well as the distribution, localization, and expression of PR and GnRH in the hypothalamus of L. maximus at different time points during gestation and in nongestating, ovulating and nonovulating, females. A significant increment in GnRH, P4, and LH was detected in midpregnant vizcachas with respect to early-pregnant and to ovulating females. PR was also significantly increased in midpregnant animals. PR was detected in neurons of the preoptic and hypothalamic areas. Coexistence of both PR and GnRH in neurons of medial preoptic area and supraoptic nucleus was detected. Midpregnant animals showed increased number of PR immunoreactive cells at median eminence, localized adjacently to GnRH immunoreactive fibers. High expression of hypothalamic GnRH and PR, despite an increased level of P4, was correlated with the presence of antral, preovulatory follicles, and luteinized unruptured follicles at midgestation that suggest a possible role of the H-H-G axis in the modulation of ovulation during gestation in L. maximus.

Variation in progesterone receptors and GnRH expression in the hypothalamus of the pregnant South American plains vizcacha, Lagostomus maximus (Mammalia, Rodentia).

Gonadotropin-releasing hormone (GnRH) is the key regulator of the hypothalamic-pituitary-gonadal axis. Estradiol (E) affects GnRH synthesis and delivery. Hypothalamic estrogen receptors (ER) modulate GnRH expression acting as transcription factors. The South American plains vizcacha, Lagostomus maximus, is able to ovulate up to 800 oocytes per reproductive cycle, and shows continuous folliculogenesis with pre-ovulatory follicle formation and an ovulatory event at mid-gestation. The aim of this work was to analyze the hypothalamic expression of ER in the vizcacha at different gestational time-points, and its relationship with GnRH expression, serum luteinizing hormone (LH) and E. The hormonal pattern of mid-gestating vizcachas was comparable to ovulating-females with significant increases in GnRH, LH and E. Hypothalamic protein and mRNA expression of ERα varied during pregnancy with a significant increase at mid-gestation whereas ERβ mRNA expression did not show significant variations. Hypothalamic immunolocalization of ERα was observed in neurons of the diagonal band of Brocca, medial preoptic area (mPOA), periventricular, suprachiasmatic, supraoptic (SON), ventromedial, and arcuate nuclei, and medial eminence, with a similar distribution throughout gestation. In addition, all GnRH neurons of the mPOA and SON showed ERα expression with no differences across the reproductive status. The correlation between GnRH and ERα at mid-gestation, and their co-localization in the hypothalamic neurons of the vizcacha, provides novel information compared with other mammals suggesting a direct action of estrogen as part of a differential reproductive strategy to assure GnRH synthesis during pregnancy.

ERα and GnRH co-localize in the hypothalamic neurons of the South American plains vizcacha, Lagostomus maximus (Rodentia, Caviomorpha).

The gene network controlling primordial germ cell (PGC) specification in eutherian mammals has been exhaustively investigated in mice. The egg-cylinder morphology of the mouse embryo is the key event enabling inductive signals from the extra-embryonic ectoderm (ExE) to specify epiblast cells as PGCs early on. We investigated the embryonic development and the spatiotemporal localization of PGC-associated proteins in the basal Hystricognathi rodent Lagostomus maximus. L. maximus develops through a flat-disc epiblast far apart from the ExE. In the primitive streak stage, OCT4-positive cells are detected in the posterior pole of the embryo disc in the mesoderm of the proximal epiblast. In the neural plate stage, a reduced 8 to 12 OCT4-positive cell population transiently expresses FRAGILIS, STELLA and SOX17 in the posterior streak. Soon after translocation to the hindgut, pluripotent OCT4 cells start expressing VASA, and then, STELLA and FRAGILIS are turned on during migration toward the genital ridge. L. maximus shows a spatiotemporal pattern of PGC-associated markers divergent from the early PGC restriction model seen in mice. This pattern conforms to alternative models that are based on a pluripotent population in the embryonic axis, where PGCs are specified later during development.

Early embryonic development and spatiotemporal localization of mammalian primordial germ cell-associated proteins in the basal rodent Lagostomus maximus.

The South American plains vizcacha, Lagostomus maximus, is the only mammal described so far that shows expression of estrogen receptors (ERs) and progesterone receptors (PRs) in gonadotropin-releasing hormone (GnRH) neurons. This animal therefore constitutes an exceptional model for the study of the effect of steroid hormones on the modulation of the hypothalamic-pituitary-ovarian (HPO) axis. By using both in vivo and ex vivo approaches, we have found that pharmacological doses of progesterone (P4) and estradiol (E2) produced an inhibition in the expression of hypothalamic GnRH, while physiological doses produced a differential effect on the pulsatile release frequency or genomic expression of GnRH. Our ex vivo experiment indicates that a short-term effect of E2 modulates the frequency of GnRH release pattern that would be associated with membrane ERs. On the other hand, our in vivo approach suggests that a long-term effect of E2, acting through the classical nuclear ERs-PRs pathway, would produce the modification of GnRH mRNA expression during the GnRH pre-ovulatory surge. Particularly, P4 induced a rise in GnRH mRNA expression and protein release with a decrease in its release frequency. These results suggest different levels of action of steroid hormones on GnRH modulation. We conclude that the fine action of E2 and P4 constitute the key factor to enable the hypothalamic activity during the pregnancy of this mammal.

The key action of estradiol and progesterone enables GnRH delivery during gestation in the South American plains vizcacha, Lagostomus maximus.

Follicular atresia is a cell death event that occurs in the great majority of follicles before ovulation in the mature mammalian ovary. Germ cell loss has been mainly associated to apoptosis although autophagy also seems to be at play. Aimed to increase our understanding on the possible cooperating role of autophagy and apoptosis in follicular atresia and/or follicular survival, we analyzed both programmed cell death mechanisms in a rodent model, the South American plains vizcacha, Lagostomus maximus. Female vizcacha shows highly suppressed apoptosis-dependent follicular atresia in the adult ovary, with continuous folliculogenesis and massive polyovulation. This strategy of massive ovulation requires a permanent remodeling of the ovarian architecture to maintain the availability of quiescent primordial follicles throughout the individual's reproductive lifespan. We report here our analysis of autophagy (BECN1, LAMP1 and LC3B-I/II) and apoptosis (BCL2 and ACTIVE CASPASE-3) markers which revealed interactive behaviors between both processes, with autophagy promoting survival or cell death depending on the ovarian structure. Strong BECN1, LC3B-II and LAMP1 staining was observed in atretic follicles and degenerating corpora lutea that also expressed nuclear ACTIVE CASPASE-3. Healthy follicles showed a slight expression of autophagy proteins but a strong expression of BCL2 and no detectable ACTIVE CASPASE-3. Transmission electron microscopy revealed a high formation of autophagosomes, autolysosomes and lysosomes in atretic follicles and degenerating corpora lutea and a low number of autophagic vesicles in normal follicles. The co-expression of LC3B-BECN1, LC3B-LAMP1 and LC3B-ACTIVE CASPASE-3 was only detected in atretic follicles and degenerating corpora lutea, while co-expression of BCL2-BECN1 was only observed in normal follicles. We propose that autophagy could act as a mechanism to eliminate altered follicles and remnant corpora lutea providing the necessary space for maturation of primordial follicles that continuously enter the growing follicular pool to sustain massive ovulation.

A dual death/survival role of autophagy in the adult ovary of Lagostomus maximus (Mammalia- Rodentia).

The corpus luteum (CL) is a transient endocrine gland that plays a crucial role in establishing and maintaining pregnancy. Although autophagy and apoptosis have been suggested as cooperative mechanisms, their interaction within the CL of pregnant mammals has not been thoroughly investigated. To understand the collaborative function of autophagy and apoptosis in the CL, we analyzed both mechanisms during pregnancy in the South American plains vizcacha, Lagostomus maximus. This rodent undergoes a decline in progesterone levels during mid-gestation, a reactivation of the hypothalamus-hypophysis-gonadal axis, and the incorporation of new functional secondary CL. Our analysis of autophagy markers BECLIN 1 (BECN1), SEQUESTOSOME1 (SQSTM1), Microtubule-associated protein light chain 3 (LC3B), and lysosomal-associated membrane protein 1 (LAMP1) and anti- and pro-apoptotic markers BCL2 and ACTIVE CASPASE 3 (A-C3) revealed interactive behaviors between both processes. Healthy primary and secondary CL exhibited positive expression of BECN1, SQSTM1, LC3B, and LAMP1, while regressed CL displayed enhanced expression of these autophagy markers along with nuclear A-C3. Transmission electron microscopy revealed a significant formation of autophagic vesicles in regressed CL during full-term pregnancy, whereas healthy CL exhibited a low number of autophagy vesicles. The co-localization between LC3B and SQSTM1 and LC3B with LAMP1 was observed in both healthy and regressed CL during pregnancy, while co-localization of BECN1 and BCL2 was only detected in healthy CL. LC3B and ACTIVE CASPASE 3 co-localization were detected in a subset of luteal cells within the regressing CL. We propose that autophagy could act as a survival mechanism in the CL, allowing the pregnancy to progress until full-term, while also serving as a mechanism to eliminate remnants of regressed CL, thereby providing the necessary space for subsequent follicular maturation.

Autophagy favors survival of corpora lutea during the long-lasting pregnancy of the South American plains vizcacha, Lagostomus maximus (Rodentia, Caviomorpha).

The plains vizcacha, Lagostomus maximus, is a precocial hystricomorph rodent with a gyrencephalic brain. This work aimed to perform a time-lapse analysis of the embryonic brain cortical development in the plains vizcacha to establish a species-specific temporal window for corticogenesis and the gyrencephaly onset. Additionally, a comparative examination with evolutionarily related rodents was conducted. Embryos from 40 embryonic days (ED) until the end of pregnancy (  154 ED) were evaluated. The neuroanatomical examination determined transverse sulci at 80 ED and rostral lateral and caudal intraparietal sulci around 95 ED. Histological examination of corticogenesis showed emergence of the subplate at 43 ED and expansion of the subventricular zone (SVZ) and its division into inner and outer SVZs around 54 ED. The neocortical layers formation followed an inside-to-outside spatiotemporal gradient beginning with the emergence of layers VI and V at 68 ED and establishing the final six neocortical layers around 100 ED. A progressive increment of gyrencephalization index (GI) from 1.005 ± 0.003 around 70 ED, which reflects a smooth cortex, up to 1.07 ± 0.009 at the end of gestation, reflecting a gyrencephalic neuroanatomy, was determined. Contrarily, the minimum cortical thickness (MCT) progressively decreased from 61 ED up to the end of gestation. These results show that the decrease in the cortical thickness, which enables the onset of neocortical invaginations, occurs together with the expansion and subdivision of the SVZ. The temporal comparison of corticogenesis in plains vizcacha with that in relative species reflects a prenatal long process compared with other rodents that may give an evolutionary advantage to L. maximus as a precocial species.

Corticogenesis and folding process of the neopallium in the South American plains vizcacha, Lagostomus maximus.

The South American plains vizcacha, Lagostomus maximus, is recognized as the mammalian species with the highest ovulation rate which can reach as many as 800 ova. This remarkable polyovulation phenomenon was first reported in the 1970s and has remained unchanged in its findings ever since. We conducted an extensive re-evaluation of ovulation in L. maximus by examining natural ovulation, ovulation induced through the administration of exogenous hormones and autologous seminal plasma, while also categorizing the morphological characteristics and maturation stages of the released ova. Our results confirm L. maximus as the foremost polyovulatory mammalian species, albeit with a mean of 154 ± 87, ranging from 29 to 326 oocytes per oestrous cycle. We observed the concurrent presence of spontaneous ovulation, serving as a mechanism to eliminate defective oocytes, alongside induced ovulation, referred to as "euovulation," that promotes the release of cumulus-oocyte complexes suitable for fertilization. In addition, we provide evidence for the involvement of seminal plasma in the process of induced ovulation and show that the "pseudovulation" phenomenon occurring at mid-gestation, which contributes to the formation of secondary corpora lutea, does not entail the release of oocytes into the oviducts. Our analysis also revealed the presence of spontaneous parthenogenetic oocyte activation and subsequent development, which occurred both during oocyte release in the ovulatory phase and within unruptured follicles in the ovary.

Article	Year
The ovary of the gestating South American plains vizcacha (Lagostomus maximus): suppressed apoptosis and corpora lutea persistence. Biology of reproduction\| PubMed ID: 18448845	2008
The ovary of Lagostomus maximus (Mammalia, Rodentia): an analysis by confocal microscopy. Biocell : official journal of the Sociedades Latinoamericanas de Microscopia Electronica ... et. al\| PubMed ID: 22128588	2011
Expression of Androgen Receptor, Estrogen Receptors Alpha and Beta and Aromatase in the Fetal, Perinatal, Prepubertal and Adult Testes of the South American Plains Vizcacha, Lagostomus maxim... The Journal of reproduction and development\| PubMed ID: 22813597	2012
Variation in progesterone receptors and GnRH expression in the hypothalamus of the pregnant South American plains vizcacha, Lagostomus maximus (Mammalia, Rodentia). Biology of reproduction\| PubMed ID: 24089203	2013
ERα and GnRH co-localize in the hypothalamic neurons of the South American plains vizcacha, Lagostomus maximus (Rodentia, Caviomorpha). Journal of molecular histology\| PubMed ID: 28317066	2017
Early embryonic development and spatiotemporal localization of mammalian primordial germ cell-associated proteins in the basal rodent Lagostomus maximus. Scientific reports\| PubMed ID: 28377629	2017
The key action of estradiol and progesterone enables GnRH delivery during gestation in the South American plains vizcacha, Lagostomus maximus. The Journal of steroid biochemistry and molecular biology\| PubMed ID: 32070756	2020
A dual death/survival role of autophagy in the adult ovary of Lagostomus maximus (Mammalia- Rodentia). PloS one\| PubMed ID: 32469908	2020
Autophagy favors survival of corpora lutea during the long-lasting pregnancy of the South American plains vizcacha, Lagostomus maximus (Rodentia, Caviomorpha). Scientific reports\| PubMed ID: 38755206	2024
Corticogenesis and folding process of the neopallium in the South American plains vizcacha, Lagostomus maximus. The Journal of comparative neurology\| PubMed ID: 38813760	2024
Polyovulation in the South American Plains Vizcacha, Revisited: Coexistence of Spontaneous and Induced Ovulation. Journal of experimental zoology. Part A, Ecological and integrative physiology\| PubMed ID: 40165530	2025

Noelia P. Leopardo

Biography

JoVE Journal Publications

Other Publications