Testis-specific Histone H1 t Is Antigenically Distinct among H1 Subtypes

Abstract

Histone Hlt has been purified from rat testes and antibodies were elicited in rabbits. Immunoblotting studies with anti-histone Hlt-IgG have shown that it reacted specifically with histone Hlt but not with other histone H1 subtypes, namelyH la, -b, -c, -d, -e and HlO. The anti-histone Hlt-IgG also did not react with chicken erythrocyte histone H5. Immunoblotting studies have also revealed that the polyclonal anti-histone Hlt-IgG reacted with (a) two polypeptide fragments, NBS-N and NBS-C, derived from N-bromosuccinimide cleavage of histoneH lt, (b)t wo polypeptide fragments, CT-N and CT-C, derived from a-chymotrypsinc leavage of histone Hlt, and (c) GHlt, globular domain of histone Hlt obtained after trypsin cleavage. The indirect immunofluorescence studies on nuclei isolated from adult ratet stes with anti-histoneH lt-IgG showed that the fluorescence, particularly, of the pachytene nucleus was the brightest. On the other hand, antihistone Hlt-IgG did not stain nuclei from either liver or nuclei isolated fromth e testes of 10-day-old rats.