In Drosophila species of the obscura group, males exhibit sperm-heteromorphism, simultaneously producing both long sperm, capable of fertilization, and short sperm that are not. The production of multiple sperm types calls into question whether mating system correlates, such as sperm length and number trade-offs and female remating behavior, are the same as previously described in sperm-monomor...

Experimental studies in insects have shown how sperm competition can be a potent selective force acting on an array of male reproductive traits . However, the role of sperm quality in determining paternity in insects has been neglected, despite the fact that sperm quality has been shown to influence the outcome of sperm competition in vertebrates . A recent comparative analysis found that males...

Potential sperm limitation has become a concern for blue crabs Callinectes sapidus in Chesapeake Bay. However, methods to quantify sperm in blue crabs are time intensive, which limits the sample size that can be obtained for sperm limitation studies. Our goal was to develop an efficient method for rapidly preparing spermathecae samples that more quickly quantifies sperm in blue crabs. Ultimatel...

The objective of this study was to analyze the gonadossomatic relation of males and females of Brycon opalinus (the Pirapitinga do Sul) in the Serra do Mar State Park--Núcleo Santa Virgínia. The study area included three rivers: Paraibuna, Ipiranga, and Grande. From the gonadossomatic relation, it was possible to determine the reproductive season and strategy of this species. The gonadossomatic...

background: nitric oxide (no) is synthesized from l-arginine by a family of enzymes known as nitric oxide synthases. low concentrations of no is essential in biology and physiology of spermatozoa, but high amounts of no is toxic and has negative effects on sperm functions. moreover, sperm membrane contains high concentrations of polyunsaturated fatty acids that are highly susceptible to oxidati...

MTT (3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay is commonly used to validate the viability of metabolically active cells. The study was conducted to examine and validate the MTT test to assess the sperm viability of Nili-Ravi buffalo bulls and compare the efficiency of the test with the supra-vital staining technique (eosin-nigrosine) and hypo-osmotic swelling test. F...

BACKGROUND Recent studies have shown that benzene extract of Ocimum sanctum (O. sanctum) leaves induces the ultrastructural changes in the epithelial cells of the cauda epididymis, its subsequent recovery in the seminiferous epithelium and fertility of male albino rats. OBJECTIVE Our aim was to investigate the effect of benzene extract of O.sanctum leaves on the cauda epididymal sperm paramet...

the present study was aimed to examine the association of bovine follicular stimulating hormone gene polymorphism with sperm quality traits including sperm volume (sv), sperm concentration (spco), total sperm (ts), fresh sperm motility (fsm), total fresh motile sperm (tfms), post thaw sperm motility (ptsm), total post thaw motile sperm (tptms), number of produced payout (npp), number of fresh m...

This study was conducted to clarify the toxic effects of sertraline (SRT) on the reproductive system of male rats and to elucidate the underlying mechanisms. Rats were treated orally with SRT at doses of 5, 10, and 20 mg kg-1 for 28 consecutive days. At the end of the treatment period, sperm concentration, sperm motility, and sperm morphology were investigated by computer-assisted sperm analysi...