Testis-specific chromatin protein that specifically binds histone H4 acetylated at 'Lys-5' and 'Lys-8' (H4K5ac and H4K8ac, respectively) and plays a key role in spermatogenesis (PubMed:12861021, PubMed:19794495, PubMed:22901802, PubMed:22922464). Required in late pachytene spermatocytes: plays a role in meiotic and post-meiotic cells by binding to acetylated histones at the promoter of specific meiotic and post-meiotic genes, facilitating their activation at the appropriate time. In the post-meiotic phase of spermatogenesis, binds to hyperacetylated histones and participates in their general removal from DNA (PubMed:22901802). Also recognizes and binds a subset of butyrylated histones: able to bind histone H4 butyrylated at 'Lys-8' (H4K8ac), while it is not able to bind H4 butyrylated at 'Lys-5' (H4K5ac) (PubMed:27105113). Also acts as a component of the splicing machinery in pachytene spermatocytes and round spermatids and participates in 3'-UTR truncation of specific mRNAs in post-meiotic spermatids (PubMed:22570411). Required for chromocenter organization, a structure comprised of peri-centromeric heterochromatin (PubMed:22020252). Interacts with SMARCE1 (By similarity). Interacts with mRNA splicing machinery proteins SRSF2, DDX5, HNRNPK and TARDBP. Interacts with the acetylated N-terminus of histone H1, H2, H3 and H4. Interacts with P-TEFb components CDK9 and CCNT1/cyclin-T1. Detected on chromatin (PubMed:19794495). Excluded from the chromocenter. Testis-specific. Expressed in germinal cells from the early meiotic (pachytene) spermatocytes and during spermiogenesis in the round and elongating spermatids until the condensed late spermatids. No expression seen in spermatogonia. First detected when type B spermatogonia give rise to early meiotic cells (preleptotene, leptotene and zygotene) at 10-12 days post partum (dpp), producing a clearly detectable protein at 12 dpp (at protein level). Bromo domains mediate interaction with histones that have acetylated lysine residues at specific positions. Bromo domain 1 mediates binding with histone H4 acetylated at 'Lys-5' and 'Lys-8' (H4K5ac and H4K8ac, respectively) (PubMed:19794495). The bromo domains also recognize and bind a subset of butyrylated histones: able to bind histone H4 butyrylated at 'Lys-8' (H4K8ac), while it is not able to bind H4 butyrylated at 'Lys-5' (H4K5ac) (PubMed:27105113). Mice are viable but males are sterile, producing fewer and morphologically abnormal sperm. Aberrant morphogenesis are first detected in step 9 elongating spermatids, and those elongated spermatids that are formed lack the distinctive foci of heterochromatin at the peri-nuclear envelope. Spermatid nuclei show a fragmented chromocenter. Brdt is a promising target for male contraception. Inhibition by thienodiazepine inhibitor (+)-JQ1 that binds Asn-108, prevents recognition of acetylated histone H4. Treatment of mice with JQ1 reduces seminiferous tubule area, testis size and spermatozoa number and motility without affecting hormone levels. JQ1 causes a complete and reversible contraceptive effect in male mice (PubMed:22901802). Asking life to be patient - Issue 144 of November 2012