expression-fluorescent-proteins-branchiostoma-lanceolatum-mrna

Expression of Fluorescent Proteins in <em>Branchiostoma lanceolatum</em> by mRNA Injection into Unfertilized Oocytes

We report here a robust and efficient protocol for the expression of fluorescent proteins after mRNA injection into unfertilized oocytes of the ...

Institut Pasteur

Centre de Recherche en Cancérologie de Marseille

The endemic Rhodanian percid Zingel asper (Linnaeus, 1758), is usually found throughout the Rhône basin, but this fish is now in sharp decline. Understanding its reproductive physiology is important so as to be able to artificially control its reproduction with a view to re-introducing it. This study was carried out on a population obtained by artificial fertilization and bred in external tanks. Fishes were observed from the juvenile stages through to adulthood. Patterns of testicular development were defined from histological observations. Testes of Z. asper were paired, elongated and fusiform dorsocaudal organs. The two lobes of each gonad joined together to form a duct that extended to the urogenital papillae. They showed a lobular structure. The testicular lobules were of the unrestricted spermatogonial type. Up to 10 months-old, most of the males were immature: their testes showed only type A spermatogonia. The appearance of type B spermatogonia in the lobules of a testis indicated the beginning of spermatogenesis in 10 months-old fish. Spermiogenesis occurred 24 months after the fertilization and, in 26 months-old fish, the cyst opened and released spermatozoa into the lumen of lobules. The spermiation belonged to a cystic type. During the third year, histological observations pointed to the same evolution of adult gonads as during the second year. Sexual maturity was reached in captive Z. asper after two years. The spawning occurred in May in the breeding conditions.

Reproductive biology of the endangered percid Zingel asper in captivity: a histological description of the male reproductive cycle.

The purpose of this study was to characterize testicular development in D'Man ram lambs, focusing primarily on androgen receptors (ARs) immunolocalization in the adenohypophysis and testis that is not still known in the D'Man ram lamb. Lambs (n = 12) were divided into four groups (three lambs per group). Adenohypophysis and testis were fixed and paraffin embedded; cross-section (3 μm) were stained and evaluated with immunohistochemistry. Testis weight increased at a greater rate between two and five months after birth, which was associated with remarkable changes in testicular histology, including significant increases in the diameter of seminiferous tubules. Spermatogenesis started between three and five months after birth; lumen and elongated spermatids were observed for the first time in three and four months-old animals respectively. ARs detected with immunohistochemistry were located in the nuclei and cytoplasm of adenohypophysis cells, and only in nuclei of testis cells (Leydig, Sertoli, peritubular myoid and germ cells).

Postnatal changes in testicular development and androgen receptors immunolocalization in D'Man ram lambs.

To study the cell behavior during morphogenesis of mouse surface ectoderm, skin, and hair follicles, we (1-3) have developed a new method to temporally induce clones that is based on a tamoxifen-dependent Cre recombinase. The classical protocol consisting in dissolving 4-hydroxy-tamoxifen or tamoxifen in corn oil to perform intraperitoneal (ip) injections (4) is not optimal to control the pharmacokinetic parameters of the induction as it leads to experimental variability in terms of timing and level of induction. We have developed a new protocol that consists in solubilizing 4-OHT or tamoxifen in an aqueous solvent using Cremophor(®) EL (5). This allows for intravenous (iv) and intraperitoneal injections.

Article	Year
Reproductive biology of the endangered percid Zingel asper in captivity: a histological description of the male reproductive cycle. Folia histochemica et cytobiologica / Polish Academy of Sciences, Polish Histochemical and Cytochemical Society\| PubMed ID: 22038230	2011
Postnatal changes in testicular development and androgen receptors immunolocalization in D'Man ram lambs. Folia histochemica et cytobiologica / Polish Academy of Sciences, Polish Histochemical and Cytochemical Society\| PubMed ID: 22532134	2012
Preparation and delivery of 4-hydroxy-tamoxifen for clonal and polyclonal labeling of cells of the surface ectoderm, skin, and hair follicle. Methods in molecular biology (Clifton, N.J.)\| PubMed ID: 24504929	2014

Christine Chevalier

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