Casting histone variants during mammalian reproduction

Abstract

During mammalian reproduction, germ cell chromatin packaging is key to prepare parental genomes for fertilization and to initiate embryonic development. While chromatin modifications such as DNA methylation and histone post-translational modifications are well known to carry regulatory information, histone variants have received less attention in this context. Histone variants alter the stability, structure and function of nucleosomes and, as such, contribute to chromatin organization in germ cells. Here, we review histone variants expression dynamics during the production of male and female germ cells, and what is currently known about their parent-of-origin effects during reproduction. Finally, we discuss the apparent conundrum behind these important functions and their recent evolutionary diversification.

Transcriptomics and Spatial Proteomics for Discovery and Validation of Missing Proteins in the Human Ovary

“…It has been established that H1–8 is necessary for bovine subjects during the preimplantation stage . More recently, a review concluded that H1–8 is activated during the germinal vesicle stage, effectively replacing core histone H1 until the oocyte reaches full maturity (MII) in mice . A study published in 2023 demonstrated a correlation between H1–8 expression and oocyte maturity in humans.…”

“… 15 More recently, a review concluded that H1–8 is activated during the germinal vesicle stage, effectively replacing core histone H1 until the oocyte reaches full maturity (MII) in mice. 16 A study published in 2023 17 demonstrated a correlation between H1–8 expression and oocyte maturity in humans. Until now, its presence at the protein level has not yet been confirmed, but here we present for the first time convincing evidence of existence for H1–8 protein expression in human oocytes.…”

Roles of Histone H2A Variants in Cancer Development, Prognosis, and Treatment

“…The H2A family, with 19 mammalian variants reported to date, is the most diverse histone family among the other core histones ( Table 1 ). The amino acid sequences of the 19 histone H2A variants vary greatly from one another but remain highly conserved during evolution, indicating that they all carried out indispensable functions [ 17 , 21 , 22 ]. In contrast to the other three classes of canonical histones, H2A proteins have both N– and C–terminal tails.…”

“…3.4. Short H2A (sH2A)-H2A.R Short H2A histone (sH2A) is a group of H2A variant which displayed a testis-restricted transcription pattern and are expressed exclusively during mammalian spermatogenesis [21]. sH2A is one of the most rapidly evolving group of histone variants and was originated from placental mammals.…”