UNUSUAL CHROMATIN STRUCTURAL ORGANIZATION IN THE SPERM HEAD OF A MURID RODENT FROM SOUTHERN AFRICA - THE RED VELD RAT, AETHOMYS-CHRYSOPHILUS TYPE-B

The structural organization of the chromatin of cauda epididymal sperm atozoa of the red veld rat Aethomys chrysophilus type B was investigat ed by fluorescence microscopy after staining with DNA specific dyes an d by transmission electron microscopy after incubation with Triton X10 0, dithiothreitol, and SDS. Staining with DNA dyes showed variation in intensity of fluorescence of the sperm chromatin, with an anterior sp herical region staining far more intensely than the surrounding chroma tin. Transmission electron microscopy of these spermatozoa indicated t hat this region was composed of cords and fibres. This chromatin regio n dispersed more readily than the surrounding chromatin when spermatoz oa were incubated with the detergents, and it is suggested that, unlik e the rest of the sperm chromatin, it may be a histone-rich region, wi th protamine(s) being either scarce or absent.