闽浙沿海棘头梅童鱼种群遗传分化的基因组解析OA

The Fujian-Zhejiang coastal region,located at the intersection of the East China Sea and South China Sea,represents a critical"hotspot"for marine biodiversity characterized by both species divergence and in-tegration.Collichthys lucidus,a shallow-sea teleost species,has diverged into distinct northern and southern linea-ges in this region.This species serves as an ideal model for investigating the genetic mechanisms underpinning speciation and adaptive evolution.To resolve the genetic structure at the interface of these lineages and elucidate the drivers of genetic differentiation,the whole-genome sequencing data from four geographically distinct popula-tions of C.lucidus(Zhoushan[ZS],Ruian[RA],Ningde[ND],and Xiamen[XM])was analyzed.Findings con-firmed significant genetic differentiation between the northern and southern populations,with the boundary local-ized between Ningde and Ruian,aligning with the historical Taiwan land bridge.Pairwise genetic differentiation(FST)analysis revealed that genetic divergence was greater between the geographically distant ZS-XM popula-tions than between the closer ND-RA populations.Among the chromosomes analyzed,sex chromosomes(Chr.1,Chr.7,and Chr.8)exhibited the highest levels of genetic differentiation.Sliding window analysis further revealed a pattern of elevated differentiation at one terminal of most chromosomes,except Chr.1.Selective sweep and func-tional enrichment analyses identified 997 highly differentiated genes significantly enriched in pathways related to energy metabolism,immune defense,and environmental stress response.These results suggest that geographic iso-lation,environmental selection,and the coordinated effects of sex chromosome divergence and centromeric struc-ture have collectively driven the genetic differentiation of C.lucidus'northern and southern lineages.