Genomic and phenotypic consequences of two independent secondary contact zones between allopatric lineages of the anadromous ice goby Leucopsarion petersii

摘要

a Photograph (scale bar: 10 mm) of mature females of the Japan Sea (JS) and Pacific Ocean (PO) lineages of Leucopsarion petersii (reproduced with permission from Kokita et al. 2017). b Sampling locations for this study in the Japanese archipelago. The JS and PO lineages are mainly distributed in each sea region except that JS lineage has spread to the northern part of the Pacific Ocean side (Kokita and Nohara 2011). Closed and open circles indicate sampling locations of pure JS and PO lineages, respectively. Stars show introgressed populations in Seto Inland Sea and Joban-Kashimanada. These symbols were used in the following figures. Tsuruga population of the JS lineage used for the NPY analysis was shown by “z.” c. Pie graphs show proportions of mitochondria genome of JS (black) and PO (white) lineages. ADMIXTURE plots showing individual genotype membership in K clusters based on RAD sequencing. Assuming K = 2, the cluster of PO lineage (black) and JS lineage (white) were estimated. If we assume K = 3, Joban-Kashimanada populations were assigned to the third cluster (gray). Hybrid index was calculated based on divergent SNP loci (hybrid index becomes 0 if all SNP loci have homozygous PO alleles). Horizontal gray lines indicate 0.1 and 0.9 thresholds