HAT1 participates in spermatogenesis of Eriocheir sinensis by regulating chromatin aggregation

Abstract

Abstract Chinese mitten crab, Eriocheir sinensis, is a decapod crustacean with a special, non-condensated nucleus in the sperm. Studies has shown that this is closely related to histone modification. To explore the possible role of histone acetyltransferase 1 (HAT1) in the non-condensation mechanism of sperm nucleus and the spermatogenesis of E. sinensis, we took the testis tissues of adult and juvenile crabs as the objects of study and analyzed their biological functions by whole transcriptome sequencing and bioinformatics, then further analyzed the expression and distribution of HAT1 through RT-qRCR, western blotting, and immunofluorescence. The results showed that HAT1 was up-regulated in adult testes compared with in the juvenile ones (n = 3, P < 0.05). Besides, HAT1 was mainly located in the nucleus of the male germ cell of E. sinensis. With the development of spermatogonia, the expression of HAT1 decreased (n = 3, P < 0.05), and the sperm nucleus of E. sinensis also gradually become non-condensed. Bioinformatics analysis shows that HAT1 and proteins such as Asf1b, Chaf1b and Hist1h3f are involved in biological processes such as DNA conformational changes and DNA replication-dependent nucleosome assembly. It follows that HAT1 is an important regulator of maintaining histone acetylation at specific levels. During the spermatogenesis of E. sinensis, HAT1 first loosens the chromatin structure of sperm nucleus by acetylating histone, while the reduction of HAT1 expression in the later stage effectively avoids excessive acetylation, and maintains histone acetylation at a specific level, which protects the nuclear chromatin state of non-condensed sperm and is important in the spermatogenesis of E. sinensis.