PDF(Pubmed)
Abstract：
The genomic processes enabling speciation and species coexistence in sympatry are still largely unknown. Here we describe the whole-genome sequencing and assembly of 3 closely related species from the butterfly genus Morpho: Morpho achilles (Linnaeus, 1758), Morpho helenor (Cramer, 1776), and Morpho deidamia (Höbner, 1819). These large blue butterflies are emblematic species of the Amazonian rainforest. They live in sympatry in a wide range of their geographical distribution and display parallel diversification of dorsal wing color pattern, suggesting local mimicry. By sequencing, assembling, and annotating their genomes, we aim at uncovering prezygotic barriers preventing gene flow between these sympatric species. We found a genome size of 480 Mb for the 3 species and a chromosomal number ranging from 2n = 54 for M. deidamia to 2n = 56 for M. achilles and M. helenor. We also detected inversions on the sex chromosome Z that were differentially fixed between species, suggesting that chromosomal rearrangements may contribute to their reproductive isolation. The annotation of their genomes allowed us to recover in each species at least 12,000 protein-coding genes and to discover duplications of genes potentially involved in prezygotic isolation like genes controlling color discrimination (L-opsin). Altogether, the assembly and the annotation of these 3 new reference genomes open new research avenues into the genomic architecture of speciation and reinforcement in sympatry, establishing Morpho butterflies as a new eco-evolutionary model.
摘要：
使物种形成和物种共存的基因组过程在很大程度上仍然未知。在这里，我们描述了蝴蝶属Morpho：Morphoachilles（Linnaeus，1758),MorphoHelenor(Cramer,1776),和Morphodeidamia(Höbner，1819).这些大型的蓝色蝴蝶是亚马逊雨林的象征物种。它们在地理分布范围广泛，并表现出平行多样化的背翼颜色模式，暗示当地的模仿。通过排序，装配,并注释它们的基因组，我们的目标是发现防止这些同胞物种之间基因流动的前合子屏障。我们发现这3个物种的基因组大小为480Mb，而deidamia的染色体数量范围为2n=54，而achilles和helenor的染色体数量为2n=56。我们还在性染色体Z上检测到倒位，这些倒位在物种之间差异固定，表明染色体重排可能有助于它们的生殖隔离。基因组的注释使我们能够在每个物种中恢复至少12,000个蛋白质编码基因，并发现可能参与合子前分离的基因的重复，例如控制颜色区分的基因（L-视蛋白）。总之,这3个新的参考基因组的组装和注释开辟了新的研究途径，进入物种形成和同构强化的基因组结构，建立Morpho蝴蝶作为一种新的生态进化模型。
