Selective incorporation of selenium-75 into a polypeptide of the rat sperm tail

✍ Scribed by Calvin, Harold I.

• Publisher: John Wiley and Sons
• Year: 1978
• Tongue: English
• Weight: 319 KB
• Volume: 204
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1402040315

✦ Synopsis

Abstract

Selenium is necessary for normal sperm tail development in the rat. The biochemical locus of this requirement was investigated by intratesticular administration of (^75^Se)Se0~3~^−2^. Sperm were labeled primarily in tail keratin, a disulfide‐stabilized fraction obtained by extracting isolated tails with sodium dodecyl sulfate (SDS). By incubation in 1% SDS−0.2 mM dithiothreitol, followed by sonication and centrifugation, the ^75^Se was separated from a residue rich in S and Zn, composed of dense fibers and connecting pieces. The extracted ^75^Se‐labeled material was non‐dialyzable, sensitive to pronase, retained most of its bound isotope following carboxymethylation, and displayed only one radioactive component, of 17,000 daltons, during SDS‐polyacrylamide gel electrophoresis. It is suggested that the labeled moiety is a selenopolypeptide whose function is critical for normal assembly of the sperm tail.