Whole-genome resequencing of hybrid F1 and its parental inbred populations in the Pacific oyster (Crassostrea gigas)
The Pacific oyster (Crassostrea gigas) is a globally important aquaculture species. Through over ten generations of successive selection, we have developed two distinct lines (HD1 and OS) with differentiated genetic backgrounds. The maternal oysters (OS) were from an inbred breeding line selected for orange shell color, following a breeding program of two generations of family selection and eight generations of mass selection. The parental oysters (HD1) were from a new variety ("Haida No.1") selected for fast growth through thirteen consecutive generations. Their intraspecific hybrid (HD4) exhibits significant growth heterosis. Heterosis (hybrid vigor) has been widely exploited to improve its growth and survival, yet the underlying genomic mechanisms remain largely unexplored. This project presents a high-resolution genomic resource generated by whole-genome resequencing of a superior hybrid "Haida No.4" (F1) and its two parental inbred lines. The primary objectives are to: (1) identify genome-wide genetic variations (SNPs) distinguishing the hybrid and its parental populations; (2) detect signatures of selection and genomic regions associated with heterosis by comparative population genomics. This dataset provides a foundational resource for dissecting the genetic architecture of complex traits in oysters and facilitates marker-assisted breeding.