sperms are highly specialized cells for delivering dna from male to the ovum. incredibly, wide degree of diversity in sperm morphology in their basic structures i.e. head, middle piece and tail is found across species. differences in terms of overall size of the sperm, shape and number of sperm produced are also incredible. one of the key for this variations or diversity in sperm may be associa...

The mammalian CatSper ion channel family consists of four sperm-specific voltage-gated Ca2+ channels that are crucial for sperm hyperactivation and male fertility. All four CatSper subunits are believed to assemble into a heteromultimeric channel complex, together with an auxiliary subunit, CatSperbeta. Here, we report a comprehensive comparative genomics study and evolutionary analysis of CatS...

PROBLEM Semen is a heterogeneous and complex cell suspension in a protein-rich fluid with different functions, some of them well known, others still obscure. METHOD OF STUDY This paper reviews, comparatively, our current knowledge on the growing field of proteomics of the SP and its relevance in relation to the in vivo situation, for the sake of reproductive biology, diagnostics and treatment...

Structural changes inside the head of Thyone sperm undergoing the acrosomal reaction were followed with a high-resolution, differential interference contrast (DIC) video microscope . The beating sperm, adhering by their midpiece to the cover slip of a wedge perfusion chamber, were activated by a calcium ionophore (201uM A23187) suspended in sea water containing 50 mM excess CaC12. Before activa...

background: danae racemosa is a strong antioxidant and antioxidants have significant effects on spermatogenesis, sperm biology and oxidative stress, and changes in antioxidant capacity are considered to be involved in the pathogenesis of chronic diabetes mellitus. objective: because stz causes testicular dysfunction and degeneration under situations of experimentally induced diabetes in animal ...

What in your view is the distinguishing feature of developmental biology with respect to other natural sciences? It is the source of causality, the genome. Developmental biology differs from other sciences, physics, for example, most profoundly because of the organizing role of the primary informational content of the genome. The genomes of animals are the unique products of a billion years of ...

There are contrary reports of association of lead and cadmium with the decline in semen quality. This study evaluates whether seminal lead (Pb) and cadmium (Cd) at environmental concentration are associated with altered semen quality. We conducted a study of healthy fertile and infertile men 20-43 years of age attending the Andrology Laboratory of Reproductive Biology Department for semen analy...

Understanding whether the sperm of older males has a diminished capacity to produce successful offspring is a key challenge in evolutionary biology. We investigate this issue using 10 years of reproductive data on captive long-lived houbara bustards (Chlamydotis undulata), where the use of artificial insemination techniques means parents can only influence offspring quality via their gametes. H...

A fundamental problem in biology is to understand how fertilization initiates reproductive development. Higher plant reproduction is unique because two fertilization events are required for sexual reproduction. First, a sperm must fuse with the egg to form an embryo. A second sperm must then fuse with the adjacent central cell nucleus that replicates to form an endosperm, which is the support t...

One of the most complex and important problems in modern evolutionary biology remains to explain the evolution and persistence of sexual reproduction given the costs of sexuality. One way to study the relative strengths and weaknesses of sexuality and asexuality is to study the dynamics of the coexistence of sexual and asexual organisms. An excellent model system for such an approach is the uni...