HISTOCHEMICAL OBSERVATION OF NUCLEOPROTEIN TRANSITION IN SPERMATOGENIC CELLS OF RAT TESTIS / 解剖学报

ABSTRACT

During spermatogenesis, lysine-rich histones in spermatogenic cells are progressively replaced by arginine-rich protamine. In this study, the nucleoprotein transition in spermatogenic cells of Wistar rat was investigated using aniline blue staining, PTA staininig (both to demonstrate lysine-proteins) and NQS (1, 2-naphthoquinone4-sodium sulfonate) staining (to demonstrate arginine-protein). Under light microscope, the nuclei of spermatogonia and spermatocytes were intensely aniline blue positive and the nuclei of young spermatids moderately positive, while the nuclei of late elongated spermatids and spermatozoa were aniline blue negative. The nuclei of spermatogonia and young spermatids were basicallyy NQS negative and there were a few granules of weak NQS positive in the nuclei of primary spermatocytes, while the nuclei of late elongated spermatids and spermatozoa were NQS positive. Under the electron microscope, the PTA positive chromatin in the nuclei of early spermatids with round nucleus (steps 1 to 8)was fibrillar or granular in appearance. Along with the condensation of nuclei of spermatids(steps 9 to 13), the nuclear stain ability increased. The positive chromatin in the nuclei of spermatids (steps 14, 15) was disappeared progressively, in the direction from cranial to caudal along with the further condensation of nuclei. The nuclei of late spermatids with elongated nucleus (steps 18, 19) and spermatozoa were PTA negative. These observations suggest that the nucleoprotein transition from histones to protamine (S_1) occur during spermiogenesis and that this process could be divided into two consecutive steps, i. e. from histones through an intermediate phase of transition proteins to protamine.