Posukh Olga V, Shloma Victor V, Skrypnik Polina A, Maksimov Daniil A, Antoshina Polina A, Kalashnikova Daria A, Nurislamov Artem, Lukyanchikova Varvara A, Torgunakov Nikita, Battulin Nariman R, Fishman Veniamin S, Vyatkin Yuri V, Smelova Arina A, Romanov Stanislav E, Laktionov Petr P, Valishayev Daulet, Belyakin Stepan N, Singh Prim B
Epigenetics Laboratory, Department of Natural Sciences, Novosibirsk State University, Pirogov Str. 2, 630090 Novosibirsk, Russia.
Institute of Molecular and Cellular Biology SD RAS, Lavrentyev Ave., 8/2, 630090 Novosibirsk, Russia.
Cells. 2025 Aug 12;14(16):1243. doi: 10.3390/cells14161243.
The term chromosomal imprinting was introduced to denote the parent-of-origin-dependent behavior of chromosomes in the fungus gnat originally named (current taxonomic name is ). Such behavior is observed in embryos, where paternal X chromosomes (X) are specifically eliminated during the 7th-8th cleavage divisions. Elimination is regulated by a controlling element (CE) that has been mapped to heterochromomere II (H2) within the sub-telomeric short arm of polytene X chromosomes. Here, using a combination of a new genome assembly, along with ChIP-Seq and MeDIP analyses, we show that a 1.2 Mb region within the CE locus has a repressive epigenetic signature that is characterised by enrichments of H3K9me3, H4K20me3 and 5'-methyl cytosine (5meC). These data provide evidence for a model where the H3K9me3/HP1/H4K20me3 pathway operates to assemble a heterochromatin- complex at the CE that renders it silent on X chromosomes that are not eliminated. In this regard, our findings support the idea that the H3K9me3/HP1/H4K20me3 pathway represents the most evolutionarily conserved mechanism linked to chromosomal imprinting in animals.
“染色体印记”这一术语最初是用来描述在一种最初被命名为（当前分类学名称为）的蕈蚊中，染色体依赖亲本来源的行为。这种行为在胚胎中可以观察到，其中父本的X染色体（X）在第7 - 8次卵裂时被特异性消除。消除过程由一个控制元件（CE）调控，该元件已被定位到多线X染色体亚端粒短臂内的异染色质节II（H2）上。在这里，我们结合新的基因组组装、ChIP - Seq和MeDIP分析，表明CE位点内一个1.2 Mb的区域具有抑制性表观遗传特征，其特点是H3K9me3、H4K20me3和5'-甲基胞嘧啶（5meC）富集。这些数据为一个模型提供了证据，即H3K9me3/HP1/H4K20me3途径在CE处组装异染色质复合物，使其在未被消除的X染色体上沉默。在这方面，我们的发现支持了这样一种观点，即H3K9me3/HP1/H4K20me3途径代表了动物中与染色体印记相关的最具进化保守性的机制。
