Fertilization, a critical step in animal reproduction, is triggered by a series of specialized sperm-egg interactions. However, the molecular mechanisms underlying fertilization are not well understood. Here, we identify a sperm-enriched C. elegans TRPC homolog, TRP-3. Mutations in trp-3 lead to sterility in both hermaphrodites and males due to a defect in their sperm. trp-3 mutant sperm are mo...

BACKGROUND Improvement of baboon sperm capacitation is necessary for achieving high in vitro fertilization (IVF) rates in baboons. In this study, we evaluated separate and combined effects of caffeine and dbcAMP on baboon sperm capacitation. METHODS Sixteen male baboons (n = 16) were electroejaculated. Each sperm sample was divided into two aliquots: one for chemical activation and the other ...

Mammalian sperm acquire fertilizing capacity in the female tract in a process called capacitation. At the molecular level, capacitation requires protein kinase A activation, changes in membrane potential and an increase in intracellular calcium. Inhibition of these pathways results in loss of fertilizing ability in vivo and in vitro. We demonstrated that transient incubation of mouse sperm with...

BACKGROUND C. elegans male sexual behaviors include chemotaxis and response to hermaphrodites, backing, turning, vulva location, spicule insertion, and sperm transfer, culminating in cross-fertilization of hermaphrodite oocytes with male sperm. The LOV-1 and PKD-2 transient receptor potential polycystin (TRPP) complex localizes to ciliated endings of C. elegans male-specific sensory neurons and...

Abstract Study question How does sperm phospholipase C zeta (PLCζ) affect fertilization in conventional vitro (cIVF)? Summary answer Absence of PLCζ causes polyspermy, and a decline the proportion expressing is correlated with low rate (FR) after cIVF. What known already key sperm-borne factor that triggers Ca2+ oscillations subsequent oocyte activation following gamete fusion. Mutations PLCZ1,...

BACKGROUND There are no studies relating the apoptotic marker caspase-3 in human sperm to different degrees of abnormal sperm concentration, morphology and rapid progressive motility. METHODS Semen from 67 males with abnormal semen analyses (n = 61) and normozoospermia (n = 6) were used. In each case, sperm from the neat semen (semen fraction) and after gradient centrifugation and swim-up (sw...

Activation of mature oocytes initiates development by releasing the prior arrest of female meiosis, degrading certain maternal mRNAs while initiating the translation of others, and modifying egg coverings. In vertebrates and marine invertebrates, the fertilizing sperm triggers activation events through a rise in free calcium within the egg. In insects, egg activation occurs independently of spe...

The basal fungus Allomyces macrogynus (A. macrogynus) produces motile male gametes displaying well-studied chemotaxis toward their female counterparts. This chemotaxis is driven by sirenin, a sexual pheromone released by the female gametes. The pheromone evokes a large calcium influx in the motile gametes, which could proceed through the cation channel of sperm (CatSper) complex. Herein, we rep...

Human sperm have been documented to display apoptosis-like features such as externalization of phosphatidylserine (EPS), disruption of the transmembrane mitochondrial potential (MMP) and activation of caspases. Our aim was to evaluate possible association between activation of the apoptosis cascade in human sperm and its oocyte penetration capacity using the zona free hamster oocyte penetration...