Epigenetic processes in a tetraploid mammal
Epigenetic processes in a tetraploid mammal
复制标题
DOI：
10.1007/s00335-008-9131-z
复制
发表时间：
2008-06-01
期刊：
影响因子：
2.5
通讯作者：
Gallardo, Milton H.
中科院分区：
文献类型：
--
作者：
Bacquet, Caroline;Imamura, Takuya;Gallardo, Milton H.
多倍体在动植物物种形成和进化中起着重要的作用。据认为，哺乳动物中多倍体的频率低是由于剂量不平衡，这会干扰哺乳动物多倍体的正常发育。第一个四倍体的哺乳动物，鼓鼠（Tympanoctomys barrectomy），似乎是一个例外，这一规则。本研究探讨了T.哺乳动物基因组中通常涉及剂量控制的两个表观遗传过程。Peg1基因的印迹状态由Peg1等位基因表达研究确定。通过使用针对Met3H3K27和macroH2A1的特异性抗血清通过免疫荧光在间期核上鉴定无活性的X染色体。采用定量PCR方法比较T.在其最密切相关的二倍体物种中，Octomys mimax。我们的数据表明，父母特异性沉默的至少一个基因和正常的X染色体剂量机制是保守的四倍体基因组。我们假设在这个四倍体基因组的功能性二倍体化过程中遗传和表观遗传机制的协同作用。
Polyploidy has played a most important role in speciation and evolution of plants and animals. It is thought that low frequency of polyploidy in mammals is due to a dosage imbalance that would interfere with proper development in mammalian polyploids. The first tetraploid mammal, Tympanoctomys barrerae (Octodontidae), appears to be an exception to this rule. In this study we investigated X chromosome inactivation (XCI) and genomic imprinting in T. barrerae, two epigenetic processes usually involved in dosage control in mammalian genomes. The imprinting status of the Peg1 gene was determined by Peg1 allelic expression studies. The inactive X chromosome was identified on interphase nuclei by immunofluorescence using specific antisera raised against Met3H3K27 and macroH2A1. Quantitative PCR was used to compare the Peg1/Dmd ratio in T. barrerae and in its most closely related diploid species, Octomys mimax. Our data demonstrate that parental-specific silencing of at least one gene and normal X chromosomal dosage mechanism are conserved in the tetraploid genome. We hypothesize a concerted action of genetic and epigenetic mechanisms during the process of functional diploidization of this tetraploid genome.