Search results for "Sperm Midpiece"
showing 2 items of 2 documents
A novel pyruvate kinase (PK-S) from boar spermatozoa is localized at the fibrous sheath and the acrosome
2007
Boar spermatozoa contain a novel pyruvate kinase (PK-S) that is tightly bound at the acrosome of the sperm head and at the fibrous sheath in the principal piece of the flagellum, while the midpiece contains a soluble pyruvate kinase (PK). PK-S could not be solubilized by detergents, but by trypsin with no loss of activity. Purified PK-S as well as PK-S still bound to cell structures and soluble sperm PK have all kinetics similar to those of rabbit muscle PK-M1. The PK-S subunit had a relative molecular mass of 64 ± 1 × 103(n= 3), i.e. slightly higher than that of PK-M1, and carried an N-terminal extension (NH2-TSEAM-COOH) that is lacking in native PK-M1. Evidence is provided that PK-S is en…
Sperm morphological abnormalities appearing in the male rabbit reproductive tract
1996
The role of the excurrent duct system in producing and/or eliminating morphologically abnormal spermatozoa may modify the semen parameters and interfere with sperm fertilizing capacity. To study this process, changes in the morphology of spermatozoa during their transit through the reproductive tract in sexually mature rabbits were investigated. The incidence of head, midpiece and tail abnormalities as well as of multiple defects in a single spermatozoon, and the position of the cytoplasmic droplet along the sperm midpiece were evaluated in samples from the testis, 6 regions of the epididymis and the vas deferens. Spermatozoa were characterized by rapid migration of the cytoplasmic droplet …