BACKGROUND Oviducts participate in fertilization and early embryo development, and they are influenced by systemic and local circulation. Local functional interplay between ovary, oviduct and uterus is important, as deduced from the previously observed differences in hormone concentrations, presence of sperm, or patterns of motility in the oviduct after unilateral ovariectomy (UO). However, the...

Many free-spawning marine invertebrates, such as sea urchins, lack any courtship or assortative mating behavior. Mate recognition in such cases occur at the gametic level, and molecules present on the sperm and egg are major determinants of species-specific fertilization. These molecules must also coevolve in relation to each other in order to preserve functional integrity. When sea urchins rel...

Sialic acids (Sias) mediate many biological functions, including molecular recognition during development, immune response, and fertilization. A Sia-rich glycocalyx coats the surface of sperm, allowing them to survive as allogeneic cells in the female reproductive tract despite female immunity. During capacitation, sperm lose a fraction of their Sias. We quantified shed Sia monosaccharides rele...

The centrioles of cnidarian sperm associate with striated specializations (pericentriolar processes) during spermiogenesis. Three functions have been proposed for the role of these structures: (a) an anchoring mechanism for the sperm flagellum, (b) a signal-transmitting mechanism for communication between sperm head and tal, and (c) a contractile mechanism involved in motor function of the sper...

fertility in the male is dependent on the proper production of sperm cells. this process, called spermatogenesis is very complex and involves the synchronization of numerous factors. the presence of pro–inflammatory cytokines, tumor necrosis factor-alpha (tnf–α), interleukin–1 alpha (il–1 α) and interleukin 1 beta (il–1 β) cytokines in the male reproductive tract (testis, epididymis and sperm) ...

spermatozoa generate reactive oxygen species (ros) in physiological amounts which play a role in sperm functions during sperm capacitation acrosome reaction (ar) and oocyte fusion. in addition damaged sperm are likely to be the source of ros. the most important ros produced by human sperm are hydrogen peroxide superoxide anion and hydroxyl radicals. besides human seminal plasma and sperm posses...

In flowering plants, the two sperm cells are embedded within the cytoplasm of the growing pollen tube and as such are passively transported to the embryo sac, wherein double fertilization occurs upon their release. Understanding the mechanisms and conditions by which male gametes mature and take part in fertilization are crucial goals in the study of plant reproduction. Studies of gene expressi...

Evidence supports the involvement of nitric oxide (NO) in a Varity of male reproductive processes such as spermatogenesis, spermiogenesis, sperm motion, sperm metabolism and sperm capacitation. However, Low concentration of NO is essential in biology and physiology of spermatozoa, but high amounts of NO is toxic and has negative effects on sperm functions. On the other hand, it is established t...

background: the availability of testis specific genes will be of help in choosing the most promising biomarkers for the detection of testicular sperm retrieval in patients with non-obstructive azoospermia (noa). testis specific chromodomain protein y 1 (cdy1) is a histone acetyltransferase which concentrates in the round spermatid nucleus, where histone hyperacetylation occurs and causes the re...