Changes of chromosomal basic proteins of rats have been followed during transformation of spermatids into spermatozoa in the testis and during maturation of spermatozoa in the epididymis. Rat testis chromatin has been fractionated on the basis of differing sensitivity to shearing, yielding a soluble fraction and a condensed fraction. The sperm histone is found in the condense fraction. Somatic-...

To study the chemotactic response of sperm to an egg and to characterize sperm motility, an annular laser trap based on axicons is designed, simulated with the ray-tracing tool, and implemented. The diameter of the trapping ring can be adjusted dynamically for a range of over 400 microm by simply translating one axicon along the optical axis. Trapping experiments with microspheres and dog sperm...

Sperm capacitation is a complex process that involves a protein kinase A (PKA)-dependent tyrosine phosphorylation of proteins. We studied the time-course, the modulation and the cellular localization of the phosphorylation of the Arginine-X-X-(Serine/Threonine) motif, characteristic of PKA substrates, in sperm proteins during capacitation. There was an increased phosphorylation of 80 (p80) and ...

In nematode, sperm activation (or spermiogenesis), a process in which the symmetric and non-motile spermatids transform into polarized and crawling spermatozoa, is critical for sperm cells to acquire fertilizing competence. SPE-8 dependent and SPE-8 independent pathways function redundantly during sperm activation in both males and hermaphrodites of Caenorhabditis elegans. However, the downstre...

We analyse a co-evolutionary sexual conflict game, in which males compete for fertilizations (sperm competition) and females operate sperm selection against unfavourable ejaculates (cryptic female choice). For simplicity, each female mates with two males per reproductive event, and the competing ejaculates are of two types, favourable (having high viability or success) or unfavourable (where pr...

Hermaphrodite self-fertilization is the primary mode of reproduction in the nematode Caenorhabditis elegans. However, when a hermaphrodite is crossed with a male, nearly all of the oocytes are fertilized by male-derived sperm. This sperm precedence during reproduction is due to the competitive superiority of male-derived sperm and results in a functional suppression of hermaphrodite self-fertil...

OBJECTIVE To determine the consequences of adjuvant testicular germ cell tumor treatment (TGCT) on sperm characteristics and sperm DNA, and to evaluate the predictors of sperm recovery. DESIGN Multicenter prospective longitudinal study of patients analyzed before treatment and after 3, 6, 12, and 24 months. SETTING University hospitals. PATIENT(S) One hundred twenty-nine volunteer TGCT pa...

The zona pellucida, which surrounds the mammalian oocyte, consists of the ZPA, ZPB, and ZPC glycoproteins and plays roles in species-selective sperm-egg interactions via its carbohydrate moieties. In the pig, this activity is conferred by tri- and tetraantennary complex type chains; in cattle, it is conferred by a chain of 5 mannose residues. In this study, porcine zona glycoproteins were expre...

Triosephosphate isomerase 1 (TPI1) is a member of the glycolytic pathway, which is a critical source of energy for motility in mouse sperm. By immunoblotting, we detected two male, germ line-specific TPI1 bands (Mr 33,400 and 30,800) as well as the somatic-type band (Mr 27,700). Although all three bands were observed in spermatogenic cells, somatic-type TPI1 disappeared from sperm during epidid...

OBJECTIVE To determine why patients with cancer stop storing semen in a sperm bank program. DESIGN Retrospective study. SETTING Hospital andrology laboratory. PATIENT(S) Cancer patients (n = 56) who discontinued sperm storage. INTERVENTION(S) A database of 342 patients with cryopreserved sperm was searched for disease diagnosis, marital status before and after diagnosis, type of therapy...