Studies of the structural polymorphism exhibited by block copolymers in the presence of selective solvents are relatively recent, but very promising in terms of fundamental understanding and practical applications. Highlighting recent advances, this review progresses from ‘dry’ ordered ( ) copolymers to solvated ordered gel-like copolymers and ( ) lastly to solvated disordered but locally organ...

Capacitation is an important physiological pre-requisite before the sperm cell can acrosome react and fertilize the oocyte. Recent reports from several laboratories have amply documented that the protein phosphorylation especially at tyrosine residues is one of the most important events that occur during capacitation. In this article, we have reviewed the data from our and other laboratories, a...

Traditional interpretations of mating behaviors assume cooperation between the sexes. The field of sexual conflict provides a contrasting view: The sexes are commonly in conflict because they diverge in benefits/costs of reproduction. Precopulatory mate guarding, wherein males attempt to monopolize mates by physically pairing before fertilization, is one expected case of conflict. Initial guard...

Capacitation is defined as the series of transformations that spermatozoa normally undergo during their migration through the female genital tract, in order to reach and bind to the zona pellucida, undergo the acrosome reaction, and fertilize the egg. During this process, extensive changes occur in all sperm compartments (head and flagellum; membrane, cytosol, cytoskeleton), factors originating...

Environmental shifts and lifestyle changes may result in formerly adaptive traits becoming non-functional or maladaptive. The subsequent decay of such traits highlights the importance of natural selection for adaptations, yet its causes have rarely been investigated. To study the fate of formerly adaptive traits after lifestyle changes, we evaluated sexual traits in five independently derived a...

In this introduction to the special issue on critical performativity and alternative organization we provide a brief historico-theoretical sketch of key concepts involved point ongoing pertinent debates in field management studies. We also present articles included issue, which all explore aspects how may cross-fertilize each other. doing so, collection provides interesting vantage points outsi...

Mammalian spermatozoa leave the testis as immature cells unable to fertilize until they have traversed the epididymis. Sperm maturation is an orchestrated series of sequential events occurring at different levels of the epididymis : sperm-zona pellucida binding ability in the proximal epididymis, progressive motility and the ability to penetrate and fertilize the oocyte in the middle epididymis...

Sperm competition is expected to favour the evolution of traits that influence the performance of sperm when they compete to fertilize a female's eggs. While there is considerable evidence that selection favours increases in sperm numbers, much less is known about how sperm quality contributes towards competitive fertilization success. Here, we determine whether variation in sperm quality influ...

Lepidopteran males produce eupyrene (nucleate) and apyrene (anucleate) spermatozoa, but in the female only eupyrene spermatozoa leave the spermatheca and fertilize the eggs. Both kinds of spermatozoa lack intrinsic motility in the male genital duct. They become motile in the spermatophore, in a process involving proteases from the male duct. In vitro, trypsin induces immotile spermatozoa to bec...

The present study aimed to compare the in vitro fertilizing capacity of frozen-thawed ejaculated and epididymal spermatozoa in order to standardize the semen preparation protocol for camel in vitro fertilization (IVF). Semen samples were collected from 7 Dromedary camels by means of artificial vagina (AV). Ten cauda epididymes were obtained from slaughtered adult camels, isolated, incised and r...