State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, 410081, Hunan, PR China.
BMC Genet. 2020 Mar 21;21(1):35. doi: 10.1186/s12863-020-00840-8.
Autotetraploid Carassius auratus (4nRCC, 4n = 200, RRRR) was derived from the whole genome duplication of diploid red crucian carp (Carassius auratus red var.) (2nRCC, 2n = 100, RR). To investigate the genetic effects of tetraploidization, we analyzed DNA variation, epigenetic modification and gene expression changes in the Sox9a-Amh-Cyp19a1a regulatory cascade between 4nRCC and 2nRCC.
We found that the Sox9a gene contained two variants in 2nRCC and four variants in 4nRCC. Compared with that in 2nRCC, DNA methylation in the promoter regions of the Amh and Cyp19a1a genes in 4nRCC was altered by single nucleotide polymorphism (SNP) mutations, which resulted in the insertions and deletions of CpG sites, and the methylation levels of the Sox9a, Amh and Cyp19a1a genes increased after tetraploidization. The gene expression level of the Sox9a-Amh-Cyp19a1a regulatory cascade was downregulated in 4nRCC compared with that in 2nRCC.
The above results demonstrate that tetraploidization leads to significant changes in the genome, epigenetic modification and gene expression in the Sox9a-Amh-Cyp19a1a regulatory cascade; these findings increase the extant knowledge regarding the effects of polyploidization.
四倍体金鱼（4nRCC，4n=200，RRRR）是由二倍体红鲫鱼（Carassius auratus red var.）（2nRCC，2n=100，RR）的全基因组复制而来。为了研究四倍体化的遗传效应，我们分析了四倍体金鱼和二倍体金鱼之间 Sox9a-Amh-Cyp19a1a 调控级联的 DNA 变异、表观遗传修饰和基因表达变化。
我们发现，Sox9a 基因在 2nRCC 中包含两个变体，在 4nRCC 中包含四个变体。与 2nRCC 相比，4nRCC 中 Amh 和 Cyp19a1a 基因启动子区域的 DNA 甲基化因单核苷酸多态性（SNP）突变而改变，导致 CpG 位点的插入和缺失，Sox9a、Amh 和 Cyp19a1a 基因的甲基化水平在四倍体化后增加。与 2nRCC 相比，4nRCC 中 Sox9a-Amh-Cyp19a1a 调控级联的基因表达水平下调。
上述结果表明，四倍体化导致 Sox9a-Amh-Cyp19a1a 调控级联中的基因组、表观遗传修饰和基因表达发生显著变化；这些发现增加了关于多倍体化影响的现有知识。
