Govin Jérôme, Caron Cécile, Lestrat Cécile, Rousseaux Sophie, Khochbin Saadi
Laboratoire de Biologie Moléculaire et Cellulaire de la Différenciation, INSERM U309, Equipe Chromatine et Expression des gènes, Institut Albert Bonniot, Faculté de médecine, La Tronche, France.
Eur J Biochem. 2004 Sep;271(17):3459-69. doi: 10.1111/j.1432-1033.2004.04266.x.
One of the most dramatic chromatin remodelling processes takes place during mammalian spermatogenesis. Indeed, during the postmeiotic maturation of male haploid germ cells, or spermiogenesis, histones are replaced by small basic proteins, which in mammals are transition proteins and protamines. However, nothing is known of the mechanisms controlling the process of histone replacement. Two hints from the literature could help to shed light on the underlying molecular events: one is the massive synthesis of histone variants, including testis-specific members, and the second is a stage specific post-translational modification of histones. A new testis-specific 'histone code' can therefore be generated combining both histone variants and histone post-translational modifications. This review will detail these two phenomena and discuss possible functional significance of the global chromatin alterations occurring prior to histone replacement during spermiogenesis.
最显著的染色质重塑过程之一发生在哺乳动物精子发生过程中。事实上，在雄性单倍体生殖细胞的减数分裂后成熟过程中，即精子形成过程中，组蛋白被小的碱性蛋白所取代，在哺乳动物中这些小碱性蛋白是过渡蛋白和鱼精蛋白。然而，对于控制组蛋白替换过程的机制尚不清楚。文献中的两条线索可能有助于揭示潜在的分子事件：一是组蛋白变体的大量合成，包括睾丸特异性成员，二是组蛋白的阶段特异性翻译后修饰。因此，可以通过结合组蛋白变体和组蛋白翻译后修饰来生成一种新的睾丸特异性“组蛋白密码”。本综述将详细阐述这两种现象，并讨论精子形成过程中组蛋白替换之前发生的整体染色质改变的可能功能意义。
