The evolutionary conservation of H-Y antigen and its expression in the heterogametic sex regardless of whether this is male or female must mean that the antigen is associated with a common denominator underlying the development of mammalian testes and avian ovaries. It is suggested that one such common denominator is an enhanced growth rate of the dominant heterogametic gonad at a critical stag...

Introduction Black (H. cracherodii) and white abalone sorenseni) are federally listed as endangered species in the United States. Conservation efforts include captive breeding programs; however, determination of reproductive state individual is notoriously difficult using traditional visual assessments. Ultrasonography a well-recognized technology used to assess gonad condition accurately nonle...

Sex myoblast migration in the Caenorhabditis elegans hermaphrodite represents a simple, genetically amenable model system for studying how cell migration is regulated during development. Two separable components of sex myoblast guidance have been described: a gonad-independent mechanism sufficient for the initial anterior migration to the mid-body region, and a gonad-dependent mechanism require...

Abstract Chemical preservatives can alter stable isotope ratios in animal tissues. The effects of preservation on δ 13 C and 15 N values have been investigated a variety species, but not 2 H or the freshwater pearl mussel (FPM, Margaritifera margaritifera ) We evaluated effect ethanol (unpreserved vs preserved tissues) over 6 months C, FPM foot gonad Ethanol significantly increased (foot 0.4 ‰;...

shirbot ( barbus grypus ) is one of the species in south and southwest of iran which is greatly favorable to residents of the region. unfavorable ecological conditions in habitat of this species and overfishing have led to the reduction of the population of shirbot. therefore, to restore the natural stock of this species, identifying its reproductive cycle associated with its habitat is of a gr...

Somatic growth and reproduction were examined in individual laboratory-grown female Gambusia affinis fed with high (H), medium (M) and low (L) ration levels from birth to the first-time spawning. Results showed that the body length and weight, condition factor (CF), wet weight gain (WG(w)), specific growth rate in wet weight (SGR(w)) and ration levels in terms of energy (RL(e)) decreased signif...

background: gonad shielding has been recommended during pelvic x-rays since the 1950s. the popular method of gonad shielding is placement a lead shield in the midline of the pelvis. the aim of this study was to evaluate the prevalence and utility of gonad shielding in pediatrics undergoing pelvic x-rays.materials and methodsfollowing study approval, we retrospectively retrieved data from the di...

aquatics are a source of bioactive compounds that these compounds have different properties such as antimicrobial activity. in this study, antibacterial activity of methanol, chloroform and hexane extracts from body wall, gonad and intestine of sea cucumber holothuria leucospilota was evaluated against bacillus subtilis, pseudomonas aeruginosa and staphylococcus aureus. bioactive compounds of b...

this study presents the first details on morphological and histological characteristics of gonads, gonadal development stages and reproductive index of the persian loach, oxynoemacheilus persa (heckel, 1847), an iranian endemic species. sampling was done from april 2010 to april 2011 using electrofishing device and a total of 196 individuals were collected. the gonads of specimens were removed,...

Fragmented 18-day chick embryo gonads were explanted on synthetic media in the presence of hCG added to 24 h cultures at the beginning (0 h) and to 48 h cultures, only after 24 h or at 0 and 24 h. The production of seven steroids was assayed by RIA and compared to that of control cultures containing no hCG. The levels were expressed as in vitro production per gonad (after deduction of the non-e...