The nuclear hormone receptor DAX1 has been implicated in mammalian gonad development and sex determination. The expression of the gene in the gonad follows a dynamic pattern in time and place in the embryo and the adult. We have undertaken the first in vivo study of the regulation of Dax1 expression. Using a transgenic mouse approach we have identified a novel 500-bp region 4 kb upstream of the...

The signalling molecule WNT4 has been associated with sex reversal phenotypes in mammals. Here we show that the role of WNT4 in gonad development is to pattern the sex-specific vasculature and to regulate steroidogenic cell recruitment. Vascular formation and steroid production in the mammalian gonad occur in a sex-specific manner. During testis development, endothelial cells migrate from the m...

Seasonal variation in the gonad weight and biochemical composition of the sea urchin Paracentrotus lividus from the Golf of Tunis (Tunisia) were studied between September 2003 and August 2004. The highest gonad indices occurred in March (16.71%). The spawning period occurred between April and July and resulted in a fall in gonad indices to low level (7.12 ± 0.12%). Protein constituted the main ...

Effects of representative mid-Michigan (USA) wastewater treatment plant (WWTP) effluents on the reproductive physiology of common goldfish (Carassius auratus) were assessed in situ by measuring plasma concentrations of vitellogenin (VTG), 17 beta-estradiol (E2), and testosterone (T), and evaluating gonad histology. Caged adult male and female goldfish were exposed for six weeks to WWTP effluent...

A study to investigate the reproductive biology of Aspidoparia jaya was conducted in Bangladesh where a total 80 fish samples were collected on monthly basis from Atrai River and Jamuna during period January 2022 December 2022. The highest values gonado-somatic index (GSI) recorded July (11.37±1.75%) (9.55±1.35%), whereas individual fecundity 6990±1280 5755±1050 ova diameter 0.55±0.05 0.52±0.03...

The present study was conducted to investigate the reproductive biology of Neotropius atherinoides in Bangladesh Fisheries Research Institute, Floodplain Sub-station, Santahar, Bogura, Bangladesh. A total number 70 fish samples were collected on monthly basis from Atrai River and Jamuna during period September 2021 August 2022. highest mean value gonado-somatic index (GSI) recorded July (12.55±...

Cartilaginous fish species have ecological importance. Besides, the ecotoxicological studies on these are pretty insufficient. In this study, Al, Cr, Mn, Fe, Cu, Zn, As, Pb, Cd, and Sr levels were determined in muscle, liver, gill, kidney, spleen, stomach, gonad tissues of Alopias superciliosus (Female, 240 cm TL) caught from Mersin Bay. Tissue metal analysis was by Inductively Coupled Plasma M...

This is the first study concerning the features of the reproduction process of the karyologically identified spined loach C. taenia (2n=48). The histology of 71 ovaries, and gonadosomatic index (GSI) of karyologically identified spined loach Cobitis taenia L. from Lake Klawój (Northern Poland) were examined. The absolute and relative fecundity of 25 females was estimated by gravimetric method. ...

Seasonal variations in fatty acid composition in several tissues of a 1-year-old population of giant lion's-paw scallop Nodipecten subnodosus were analyzed during gonad development. Samples were taken bimonthly from December 1999 to June 2000, a period in which gonad development was occurring. Fatty acid accumulation in neutral and polar lipids of the female gonad was concomitant to the gonad d...

BACKGROUND In birds as in mammals, a genetic switch determines whether the undifferentiated gonad develops into an ovary or a testis. However, understanding of the molecular pathway(s) involved in gonad differentiation is still incomplete. METHODOLOGY/PRINCIPAL FINDINGS With the aim of improving characterization of the molecular pathway(s) involved in gonad differentiation in the chicken embr...