■ Abstract Most metazoans engage in recombination every generation. In theory this is associated with considerable cost, such as the production of males, so that asexual organisms, which do not pay this cost, should be able to invade populations of sexuals. Some asexuals depend on sperm of sexual males to trigger embryogenesis, a reproductive mode called gynogenesis. The genetic information of ...

No valid method is currently available to analyze the entire genome of sperm, including aneuploidies and structural chromosomal alterations. Here we describe the optimization and application of array-Comparative Genomic Hybridization (aCGH) on single human sperm. The aCGH procedure involves screening of the entire chromosome complement by DNA microarray allowing having a molecular karyotype, an...

BACKGROUND The effectiveness of varicocelectomy in restoration of fertility and improvement of semen parameters is still controversial. The purpose of this study was to determine the effect of age on semen parameters following varicocelectomy in a group of infertile men. METHODS Improvements in sperm count, morphology, and motility were studied in 67 infertile patients 4-10 months after varic...

BACKGROUND Identifying traits that reproductively isolate species, and the selective forces underlying their divergence, is a central goal of evolutionary biology and speciation research. There is growing recognition that postcopulatory sexual selection, which can drive rapid diversification of interacting ejaculate and female reproductive tract traits that mediate sperm competition, may be an ...

In the Ligurian Sea, northern part of Western Mediterranean sperm whales (Physeter macrocephalus Linnaeus, 1758) are historically sighted as solitary individuals or loose aggregations males, while social units extremely occasional. On 21 August 2020, two different were recorded in this area with an estimate total (12 first and nine second). The whale subpopulation is considered Endangered under I...

There is little information on the reproductive biology of the male Baird's tapir (Tapirus bairdii). In this study, we characterized the ejaculate traits and evaluated the efficacy of 2 cryodiluents on sperm cryosurvival. Ejaculates were assessed for volume, pH, sperm motility, forward progression, osmolality, sperm concentration, sperm morphology, and acrosomal integrity. For cryopreservation,...

Recent interest in sperm competition has led to a re-evaluation of the ‘cheap sperm’ assumption inherent in many studies of sexual selection. In particular, mounting evidence suggests that male sperm availability can be increased by the presence of females. However, there is little information on how this interacts with male traits presumably affected by female mate choice, such as larger size....

The separation of mammalian spermatozoa from seminal plasma is a practice routinely used in assisted reproductive technology applications and in sperm biomedical studies. The sperm isolation method is critically important for clinicians preparing sperm samples to be used in reproductive biotechnologies, veterinary medicine and animal husbandry. This practice has been used for several years in t...

I argue that several unusual aspects of spider sexual biology make them extremely promising subjects for future research on sperm competition and cryptic female choice, and outline promising lines for future research. The important traits include: double, bilaterally symmetrical genitalia (allowing the use of the same animal as experimental and control and thus providing unusually complete cont...

Our objective was to study the incidence of sperm-tail phosphotyrosine immunoreactivity in normozoospermic and asthenozoospermic human sperm samples, its association with sperm motion parameters, particularly hyperactivated motility, and its potential involvement in the pathogenesis of asthenozoospermia. The work was conducted as a prospective experimental study in the Sperm Biology and Androlo...