In the red-eared slider turtle (Trachemys scripta), a species with temperature-dependent sex determination (TSD), the expression of the aromatase gene during gonad development is strictly limited to the female-producing temperature. The underlying mechanism remains unknown. In this study, we identified the upstream 5'-flanking region of the aromatase gene, gonad-specific promoter, and the tempe...

Like other organs, the C. elegans gonad develops from a simple primordium that must undergo axial patterning to generate correct adult morphology. Proximal/distal (PD) polarity in the C. elegans gonad is established early during gonadogenesis by the somatic gonad precursor cells, Z1 and Z4. Z1 and Z4 each divide asymmetrically to generate one daughter with a proximal fate and one with a distal ...

In wild-type Caenorhabditis elegans, the hermaphrodite gonad is a symmetrical structure, whereas the male gonad is asymmetric. Two cellular processes are critical for the generation of these sexually dimorphic gonadal shapes during early larval development. First, regulatory "leader" cells that control tube extension and gonadal shape are generated. Second, the somatic gonadal precursor cells m...

To culture germline stem cells in vitro, establishment of the cell lines that can be used as the feeder cells is a prerequisite. In this study, we tried to establish gonad-derived cell lines in Siberian sturgeon (Acipenser baerii). Five 1-year-old A. baerii were used as a donor of gonad tissues, and gonad-dissociated cells were cultured in vitro. Subsequently, determination of growth conditions...

Geoduck clams (Panopea generosa) are an increasingly important fishery and aquaculture product along the eastern Pacific coast from Baja California, Mexico, to Alaska. These long-lived clams are highly fecund, although sustainable hatchery production of genetically diverse larvae is hindered by the lack of sexual dimorphism, resulting in asynchronous spawning of broodstock, unequal sex ratios, ...

Coordination of animal behavior with reproductive status is often achieved through elaboration of hormones by the gonad. In the nematode Caenorhabditis elegans, adult males explore their environment to locate mates. Mate searching is regulated by presence of mates, nutritional status, and a signal from the gonad. Here we show that the gonadal signal acts via the nuclear receptor DAF-12, a prote...

During development, cells divide, differentiate into various cell types, and organize into functional tissues and organs. We are interested in understanding the cellular and molecular basis of organ formation in the nematode Caenorhabditis elegans. To this end, we are investigating two novel proteins that have a role in gonadogenesis, SYS-1 and NUD-1. SYS-1 was identified via a genetic screen f...

The mammalian sex-determining pathway is controlled by the presence or absence of SRY expression in the embryonic gonad. Expression of SRY in males is believed to initiate a pathway of gene expression resulting in testis development. In the absence of SRY, ovary development ensues. Several genes have now been placed in this pathway but our understanding of it is far from complete and several fu...

The Caenorhabditis elegans teneurin ortholog, ten-1, plays an important role in gonad and pharynx development. We found that lack of TEN-1 does not affect germline proliferation but leads to local basement membrane deficiency and early gonad disruption. Teneurin is expressed in the somatic precursor cells of the gonad that appear to be crucial for gonad epithelialization and basement membrane i...

During mouse development, the gonad begins to form shortly before 10. 5 days postcoitum (dpc) on the ventromedial side of the mesonephros. The XY gonad consists of germ cells and somatic cells. The origin of the germ cells is clearly established; however, the origin of the somatic cells, especially the epithelial supporting cell lineages, called Sertoli cells, is still unclear. Sertoli cells ar...