Differential localization of histone variant TH2B during the first round compared with subsequent rounds of spermatogenesis. Issue 6 (19th April 2019)

• Record Type: Journal Article
• Authors: Beedle, My‐Thanh; Topping, Traci; Hogarth, Cathryn; Griswold, Michael
• Is Part Of: Developmental dynamics. Volume 248:Issue 6(2019)
• Page Start: 488
• Page End: 500
• Publication Date: 2019-04-19
• Subjects: chromatin -- germ cells -- Hist1h2aa -- Hist1h2ba -- ID4‐eGFP -- neonatal -- spermatocyte -- spermatogenesis -- spermatogonia -- testis -- TH2A -- TH2B -- WIN 18446 -- ZBTB16; Morphogenesis -- Periodicals; Anatomy -- Periodicals; Anatomie -- Périodiques; Biologie du développement -- Périodiques; 571.833
• DOI: 10.1002/dvdy.33
• Languages: English
• ISSNs: 1058-8388

Abstract

Abstract: Background: Male germ cells are unique because they express a substantial number of variants of the general DNA binding proteins, known as histones, yet the biological significance of these variants is still unknown. In the present study, we aimed to address the expression pattern of the testis‐specific histone H2B variant (TH2B) and the testis‐specific histone H2A variant (TH2A) within the neonatal mouse testis. Results: We demonstrate that TH2B and TH2A are present in a testis‐enriched for undifferentiated spermatogonia. Co‐localization studies with an undifferentiated marker, ZBTB16, revealed that TH2B and ZBTB16 co‐localize in the neonatal testis. Upon the appearance of the primary spermatocytes, TH2B no longer co‐localized with the ZBTB16 positive spermatogonia but were instead detected within the differentiating spermatogonia. This pattern of expression where TH2B and ZBTB16 no longer co‐localize was maintained in the adult testis. Conclusion: These findings are in contrast to previous studies, which demonstrated that TH2B and TH2A were found only in adult spermatocytes. Our data are in support of a switch in the expression of these variants following the first round of spermatogonial differentiation. These studies reinforce current understandings that spermatogonia within the neonatal mouse testis are inherently different from those residing within the adult testis. Key Findings: Contrary to previous beliefs, testis specific histone variants TH2B and TH2A are also expressed expressed in undifferentiated spermatogonia in the neonatal mouse testis. Upon the appearance of the primary spermatocytes, TH2B switches its expression from spermatogonia to the spermatocyte population. This study reinforces the idea that spermatogonia in the neonatal mouse testis is inherently different than those residing within the adult.