quantification-autoreactive-antibodies-mice-upon-experimental

Quantification of Autoreactive Antibodies in Mice upon Experimental Autoimmune Encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) is a disease model that recapitulates the autoimmune disorder multiple sclerosis (MS) at histopathological ...

East Carolina University

Adamts9 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 9) is one of a few metalloproteinases structurally conserved from C. elegans to humans and is indispensable in germ cell migration in invertebrates. However, adamts9's roles in germ cell migration in vertebrates has not been examined. In the present study, we found zygotic expression of adamts9 started around the germ ring stage and reached peak levels at 3 days post fertilization (dpf) in zebrafish. The migration of primordial germ cells (PGC) was completed within 24 hours (h) in wildtype siblings, while a delay in PGC migration was found at 15 and 24-h post-fertilization (hpf) in the Adamts9 knockout (KO). However, the delayed PGC migration in Adamts9 KO disappeared at 48 hpf. Our study suggests a conserved function of Adamts9 in germ cell migration among invertebrates and vertebrates. In addition, our results also suggest that Adamts9 is not essential for germ cell migration as reported in C. elegans, possibly due to expansion of Adamts family members and compensatory roles from other metalloproteinases in vertebrates. Further studies are required in order to elucidate the functions and mechanisms of metalloproteinases in germ cell migration and gonad formation in vertebrates.

Delay in primordial germ cell migration in adamts9 knockout zebrafish.

Publisher Correction: Delay in primordial germ cell migration in adamts9 knockout zebrafish.

Aggression is a fundamental behavior displayed universally among animal species, but hyper- or hypo-aggressiveness can be maladaptive with negative consequences for individuals and group members. While the social and ecological significance of aggression is well understood, the specific neurobiological and hormonal mechanisms responsible for mediating aggression have not been fully elucidated. Previous studies have shown a relationship between aggressive acts and circulating gonadal steroids, but whether classical nuclear steroid receptors regulate aggression in animals is still uncertain. We examined whether the nuclear androgen receptor (Ar) and nuclear progestin receptor (Pgr) were necessary for aggressive behaviors and maintenance of a dominance relationship in male zebrafish (Danio rerio). Dyadic social interactions of Ar knockout (ArKO), Pgr knockout (PgrKO) and wildtype (WT) controls were observed for two weeks (2-weeks). ArKO zebrafish were significantly less aggressive and had a less defined dominance relationship, whereas PgrKO dominant zebrafish were significantly and persistently more aggressive with a robust dominance relationship. Our results demonstrate the importance of nuclear steroid hormone receptors in regulating aggression of adult male zebrafish and provide new models for understanding of the mechanisms of aggression.

Nuclear androgen and progestin receptors inversely affect aggression and social dominance in male zebrafish (Danio rerio).

Development of a functional gonad includes migration of primordial germ cells (PGCs), differentiations of somatic and germ cells, formation of primary follicles or spermatogenic cysts with somatic gonadal cells, development and maturation of gametes, and subsequent releasing of mature germ cells. These processes require extensive cellular and tissue remodeling, as well as broad alterations of the surrounding extracellular matrix (ECM). Metalloproteases, including MMPs (matrix metalloproteases), ADAMs (a disintegrin and metalloproteinases), and ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs), are suggested to have critical roles in the remodeling of the ECM during gonad development. However, few research articles and reviews are available on the functions and mechanisms of metalloproteases in remodeling gonadal ECM, gonadal development, or gonadal differentiation. Moreover, most studies focused on the roles of transcription and growth factors in early gonad development and primary sex determination, leaving a significant knowledge gap on how differentially expressed metalloproteases exert effects on the ECM, cell migration, development, and survival of germ cells during the development and differentiation of ovaries or testes. We will review gonad development with focus on the evidence of metalloprotease involvements, and with an emphasis on zebrafish as a model for studying gonadal sex differentiation and metalloprotease functions.

Metzincin metalloproteases in PGC migration and gonadal sex conversion.

Previous studies showed that Adamts9 is involved in multiple functions including ovulation, spine formation, primordial germ cell migration, and development of primary ovarian follicles in animals. However, systemic examination and high-resolution analyses of adamts9 expression are missing due to lack of a sensitive reporter assay.

Article	Year
Delay in primordial germ cell migration in adamts9 knockout zebrafish. Scientific reports\| PubMed ID: 33879810	2021
Publisher Correction: Delay in primordial germ cell migration in adamts9 knockout zebrafish. Scientific reports\| PubMed ID: 33980960	2021
Nuclear androgen and progestin receptors inversely affect aggression and social dominance in male zebrafish (Danio rerio). Hormones and behavior\| PubMed ID: 34153924	2021
Metzincin metalloproteases in PGC migration and gonadal sex conversion. General and comparative endocrinology\| PubMed ID: 36191636	2023
Dynamic and broad expression of adamts9 in developing and adult zebrafish. Developmental dynamics : an official publication of the American Association of Anatomists\| PubMed ID: 37436116	2023

Jonathan J. Carver

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