Rapid turnover of the W chromosome in geographical populations of wild silkmoths, Samia cynthia ssp
Rapid turnover of the W chromosome in geographical populations of wild silkmoths, Samia cynthia ssp
复制标题
野生蚕蛾 (Samia cynthia ssp) 地理种群中 W 染色体的快速周转
DOI：
10.1007/s10577-013-9344-1
复制
发表时间：
2013
影响因子：
2.6
通讯作者：
Sahara K
中科院分区：
文献类型：
--
作者：
Yoshido A;Sichova J;Kubichova S;Marec F;Sahara K
我们之前的研究表明，野生蚕蛾（Samia cynthiassp）的染色体多态性水平相当高。(鳞翅目:天蚕蛾科)。该物种的地理居群在染色体数目上存在差异，并表现出包括Z0/ zzins在内的衍生性染色体系统。cynthia ricini（2n= 27/28；越南），neo-Wneo-Z/neo-Zneo-Z inS。cynthia walkeri（2n= 26/26；札幌，北海道）和neo-WZ1Z2/Z1Z1Z2Z2inS.cynthiasubsp。indet。（2n= 25/26；长野，本州）。在这项研究中，我们采集了s。日本九州岛、四国岛和本州岛，两性核型均为2n= 28，性染色体系统为WZ/ZZ，但有一个种群雌性失去了W染色体。然而,这些。cynthia pryeriW染色体表现出一种非常不寻常的形态：它由一个高度异色的体和一条类似于常染色质的“尾巴”组成，该体在整个细胞周期中保持凝聚。我们检测了W染色体和新W染色体的分子组成。利用激光显微解剖的W染色质制备的W染色体染色探针，采用比较基因组杂交和荧光原位杂交的方法鉴定了棘球蚴亚种。辛西娅pryeri。这些方法揭示了高异色部分的分子组成。cynthia pryeriW染色体在其他亚种的基因组中非常不同，缺乏同源性，而W染色体的常染色质样部分对应于新W染色体的异色部分。辛西娅walkeriandS.cynthiasubsp。indet。我们的发现表明s。辛西娅·普雷里玛可能代表了一种类群的祖先状态，但不排除其衍生起源的另一种假设。
Our previous studies revealed a considerably high level of chromosomal polymorphism in wild silkmoths,Samia cynthiassp. (Lepidoptera: Saturniidae). Geographical populations of this species complex differ in chromosome numbers and show derived sex chromosome systems including Z0/ZZ inS. cynthia ricini(2n= 27/28; Vietnam), neo-Wneo-Z/neo-Zneo-Z inS. cynthia walkeri(2n= 26/26; Sapporo, Hokkaido) and neo-WZ1Z2/Z1Z1Z2Z2inS.cynthiasubsp. indet. (2n= 25/26; Nagano, Honshu). In this study, we collected specimens ofS. cynthia pryeriin Japanese islands Kyushu, Shikoku and Honshu, with an ancestral-like karyotype of 2n= 28 in both sexes and a WZ/ZZ sex chromosome system, except for one population, in which females have lost the W chromosome. However, theS. cynthia pryeriW chromosome showed a very unusual morphology: It was composed of a highly heterochromatic body, which remained condensed throughout the whole cell cycle and of a euchromatin-like “tail.” We examined molecular composition of the W and neo-W chromosomes inS.cynthiasubspecies by comparative genomic hybridisation and fluorescence in situ hybridisation with W chromosome painting probes prepared from laser-microdissected W chromatin ofS. cynthia pryeri. These methods revealed that the molecular composition of highly heterochromatic part of theS. cynthia pryeriW chromosome is very different and lacks homology in the genomes of other subspecies, whereas the euchromatin-like part of the W chromosome corresponds to a heterochromatic part of the neo-W chromosomes inS. cynthia walkeriandS.cynthiasubsp. indet. Our findings suggest that the curious WZ system ofS. cynthia pryerimay represent an ancestral state of theSamiaspecies complex but do not exclude an alternative hypothesis of its derived origin.