Oocyte production, maturation and ovulation must be coordinated with sperm availability for successful fertilization. In C. elegans this coordination involves signals from the sperm to the oocyte and somatic gonad, which stimulate maturation and ovulation. We have found that the C. elegans early growth response factor family member EGRH-1 inhibits oocyte maturation and ovulation until sperm are...

Intercellular cell-survival signals play a major role in animal development [1]. In the nematode Caenorhabditis elegans, however, the stereotyped cell deaths that occur reproducibly during development are regulated in a cell-autonomous fashion (or, in a few cases, by a death-inducing signal) [2]. We show here the existence of a cell-survival signal acting on the vulval precursor cells in two ne...

Mammalian sex-determination and differentiation are controlled by several genes, such as Sry, Sox-9, Dax-1 and Mullerian inhibiting substance (MIS), but their upstream and downstream genes are largely unknown. Ad4BP/SF-1, encoding a zinc finger transcription factor, plays important roles in gonadogenesis. Disruption of this gene caused disappearance of the urogenital system including the gonad....

Sea cucumber is presented as potential marine source of antimicrobial compounds. The purpose of this study is to evaluate antifungal effects of sea cucumber, Holothuria leucospilota, extracts on Aspergillus niger and Candida albicans. Methanol and chloroform extracts of the body wall, gonad and intestine of sea cucumber, H. leucospilota, collected from Persian Gulf, were evaluated for their ant...

Reproductive or neotenic soldiers of the Archotermopsid Zootermopsis nevadensisnevadensis (Hagen) are compared to sterile soldiers and primary male reproductives. Several head capsule morphometrics correlate significantly with gonad size across all forms and both sexes of soldiers. The easily observed field character of ratio of mandible length to labrum length is a consistent and reliable feat...

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 ...

Proses induk lele (Clarias gariepinus Burchell) betina menjadi matang gonad secara alami memakan waktu hingga 2-3 bulan, dengan tingginya permintaan benih diperlukan percepatan proses pematangan agar dapat terpenuhi, salah satunya melalui pemberian hormon ethinylestradiol. Kandungan optimum ethinylestradiol pada tubuh akan mempercepat vitellogenesis sehingga memacu pertumbuhan oosit dan kematan...

Gonad characteristics and reproductive cycle in the acmaeid Collisella subrugosa from Northeastern Brazil were investigated. The individuals were collected monthly from February 1993 to April 1994 at Farol do Mucuripe Beach, Fortaleza, Ceará, Brazil. There is no external characteristic on the shell and the soft body structures except the gonad that allows sex differentiation. The gonad of limpe...

The functional, nutritional, and antioxidative properties of hydrolyzed herring and herring byproducts (head and gonad) were evaluated. All freeze-dried herring fish protein hydrolysate (FPH) powders were light yellow and contained 77% to 87% protein. The degree of hydrolysis was 18.3%, 13%, 13%, and 10.1%, respectively, for head, whole fish, body, and gonad after 75 min digestion. All FPH powd...

The creation of sexual dimorphism in the gonads is essential for producing the male and female gametes required for sexual reproduction. Sexual development of the gonads involves both somatic cells and germ cells, which often undergo sex determination by different mechanisms. While many sex-specific characteristics evolve rapidly and are very different between animal species, gonad function and...