This study is the first report on the ultrastructure of the sperm storage glands (spermathecae) in the salamander Rhyacotriton variegatus. The population studied is associated with cold-water, rocky streams of the redwood (Sequoia) zone in northern California. Males possess sperm in their vasa deferentia and undergo spermiation throughout the year, but mating is seasonal. Most females with larg...

To date, cultivated male Japanese eels have not matured sexually in captivity under normal conditions. However, spermatogenesis and spermiation can be induced by the injection of gonadotropins. During this study, most males spermiated after the fifth or sixth weekly injection of human chorionic gonadotropin (HCG; 1 IU/g BW/wk) and the milt weight gradually increased as the number of injections ...

BACKGROUND The dmrt1 and sox9 genes have a well conserved function related to testis formation in vertebrates, and the group of fish presents a great diversity of species and reproductive mechanisms. The lambari fish (Astyanax altiparanae) is an important Neotropical species, where studies on molecular level of sex determination and gonad maturation are scarce. METHODS Here, we employed molec...

A testicular feed back on the hypothalamo-pituitary system was studied in male rainbow trout (Salmo gairdneri) after bilateral castration and steroid or testicular supplementation. Experiments were carried out at various periods of the spermatogenetic cycle ; in March-April (resting stage), June (initiation of spermatogenesis), October (end of spermatogenesis and before spermiation), and Decemb...

In rat testes, the ectoplasmic specialization (ES) at the Sertoli-Sertoli and Sertoli-spermatid interface known as the basal ES at the blood-testis barrier and the apical ES in the adluminal compartment, respectively, is a testis-specific adherens junction. The remarkable ultrastructural feature of the ES is the actin filament bundles that sandwiched in between the cisternae of endoplasmic reti...

The blood-testis barrier (BTB), one of the tightest blood-tissue barriers in the mammalian body, creates an immune-privileged site for postmeiotic spermatid development to avoid the production of antibodies against spermatid-specific antigens, many of which express transiently during spermiogenesis and spermiation. However, the BTB undergoes extensive restructuring at stage VIII of the epitheli...

Disubstituted haloacid by-products of drinking water disinfection such as dibromoacetic acid and dichloroacetic acid have been shown to perturb spermatogenesis and fertility in adult male rats. In the present study we sought to establish whether equimolar exposure to bromochloroacetic acid (BCA), a prevalent by-product in finished drinking water, is also capable of disrupting these endpoints, a...

In epithelia, a primary damage of tight junctions (TJ) always leads to a secondary disruption of adherens junction (AJ), and vice versa. This response, if occurring in the testis, would disrupt spermatogenesis because the blood-testis barrier (BTB) must remain intact during the transit of spermatids in the seminiferous epithelium, which is associated with extensive apical ectoplasmic specializa...

As the number of fish reproduction studies has proliferated, so has the number of gonadal classification schemes and terms. This has made it difficult for both scientists and resource managers to communicate and for comparisons to be made among studies. We propose the adoption of a simple, universal terminology for the phases in the reproductive cycle, which can be applied to all male and femal...

Ž . In three separate experiments, non-spermiating male Atlantic salmon Salmo salar were Ž . injected with a commercial salmon gonadotropin releasing hormone analog GnRHa preparation Ž . or vehicle propylene glycol . After 6 days, fish were also injected with 17a-hydroxyprogesterone Ž . Ž . 17P , 17a ,20b-dihydroxy-4-pregnen-3-one 17,20bP or vehicle. Injections were repeated on day 7, and after...