FIG. 4.

Developmental stage- and cell type-specific recruitment of transcription factors to the Pgk1 and Pgk2 promoters. ChIP analyses were performed with relatively pure populations of specific spermatogenic cell types prior to, during, and following the period of active transcription of the Pgk2 gene, using antibodies specific for PBX1/2/3/4 (A), SP3 (B), and CREM (C). Precipitated DNA was subjected to real-time PCR with the use of specific primers for the Pgk2 (left side panels) and Pgk1 (right side panels) promoters, and enrichment of immunoprecipitated DNA (bound fractions, BO) relative to input (IP) DNA was calculated in each case. All results were normalized to values for normal rabbit IgG, with that level arbitrarily set to 1.0. Each error bar indicates standard error of the mean. Type A, type A spermatogonia; Type B, type B spermatogonia; Prelep, preleptotene spermatocytes; Lep/Zyg, leptotene plus zygotene spermatocytes; Ea Pachs, early (juvenile) pachytene spermatocytes; Pachs, pachytene spermatocytes; Round, round spermatids.