BIOLOGICAL-ACTIVITY IN THE REPOPULATING RAT SPERMATOCYTE AFTER THE WITHDRAWAL OF GOSSYPOL TREATMENT .6. ALTERATION IN NUCLEAR FACTORS FOR INTERACTION WITH HISTONE GENE PROMOTER

This article reports the effects of gossypol at the genomic level in r at spermatogenic cells. After gossypol treatment for various times (8, 12, and 19 weeks), the spermatogonial cells were allowed to rest for 2 to 4 weeks. The function of histone H-4 gene promoter (H(4)GP) in th e repopulating pachytene spermatocytes (RPS) was investigated. The seq uences of the oligonucleotides for the H(4)GP binding sites 2 and 2 we re synthesized by an ABI-392 DNA synthesizer. RPS and the control pach ytene spermatocytes (CPS) were obtained by centrifugal elutriation and subsequently they were used for the preparation of nuclear protein ex tracts (NPE). The NPE interaction with the DNA fragment of site I or 2 was studied by an electrophoresis mobility shift assay (EMSA). EMSA w ith NPE-CPS revealed ten major gel shift bands for site I and 2. The p resence of extra unlabeled DNA fragments competed with 6 of the bands. After 2 to 4 weeks recovery from 8, 12, and 19 weeks of gossypol trea tment, NPE-RPS failed to shift four bands (b through e) in site 1. The se results suggested that gossypol treatment affected the transcriptio n factors for interaction with site 1. On the contrary, no effect was demonstrated in NPE that interacted with site 2. Furthermore, gossypol treatment did not change the nucleotide sequence in the H(4)GP site 1 and 2.