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...

Gonadogenesis in the Drosophila embryo is a complex process involving numerous cellular migratory steps and cell-cell interactions. The mechanisms guiding germ cells to move through, recognize and adhere to specific cell types are poorly understood. In order to identify genes that are required for these processes, we have conducted an extensive mutagenesis of the third chromosome and screened f...

Profiles for plasma gonadotropin, estradiol, and vitellogenin were obtained in female brown trout during the seasonal reproductive cycle. The accumulation of yolk lipophosphoprotein (phosvitin) in the gonad was also followed. Plasma estradiol and vitellogenin concentrations rose progressively and parallel increases in ovary yolk phosvitin were observed. Gonad development continued while plasma ...

The gonads arise on the ventromedial surface of each mesonephros. In most birds, female gonadal development is unusual in that only the left ovary becomes functional, whereas that on the right degenerates during embryogenesis. Males develop a pair of equally functional testes. We show that the chick gonads already have distinct morphological and molecular left-right (L-R) characteristics in bot...

SIR,-A man aged 40 was admitted in July 1967 with a reducible right inguinal hernia and an undescended left testis. The right testis, normal in size and consistency, was present in the scrotum. Exploration of the right inguinal canal revealed a completely patent processus vaginalis with the testis inside the sac. On applying traction to the testis, an oval mass, apparently intra-abdominal, was ...

We report on the characterization of RNF-121, an evolutionarily conserved E3 ligase RING finger protein that is expressed in the endoplasmic reticulum (ER) of various cells and tissues in Caenorhabditis elegans. Inactivation of RNF-121 induced an elevation in BiP expression and increased the sensitivity of worms to ER stress. Genetic analysis placed RNF-121 downstream of the unfolded protein re...

The colonial ascidian Botryllus schlosseri is an ideal model organism for studying gonad development and hermaphroditism. B. schlosseri has been reared in laboratories for over half a century, and its unique biology allows investigators to probe the processes of germ cell migration and gonad formation, resorption, and regeneration. Following metamorphosis, colonies of B. schlosseri show a synch...

This study evaluates the influence of different states of energy balance, positive and negative, on the accumulation and utilisation of energy reserves during the period of gonad development in the clam Ruditapes decussatus (L.). Our results show a clear sexual differentiation in the biochemical composition of the clams. The differences were associated with gonad development and were particular...

In chicken, the bipotential embryonic gonad differentiates into either a pair of testes or an ovary, but few genes that underlying the gonadal sex differentiation have been identified and the sex-determination gene is still unknown. To identify more genes involved in chicken sex differentiation, we employed suppression subtractive hybridization to isolate differentially expressed genes between ...