High‐density interspecific genetic linkage mapping provides insights into genomic incompatibility between channel catfish and blue catfish

Citations Over TimeTop 10% of 2015 papers

Abstract

Catfish is the leading aquaculture species in the United States. The interspecific hybrid catfish produced by mating female channel catfish with male blue catfish outperform both of their parent species in a number of traits. However, mass production of the hybrids has been difficult because of reproductive isolation. Investigations of genome structure and organization of the hybrids provide insights into the genetic basis for maintenance of species divergence in the face of gene flow, thereby helping develop strategies for introgression and efficient production of the hybrids for aquaculture. In this study, we constructed a high-density genetic linkage map using the hybrid catfish system with the catfish 250K SNP array. A total of 26,238 SNPs were mapped to 29 linkage groups, with 12,776 unique marker positions. The linkage map spans approximately 3240 cM with an average intermarker distance of 0.25 cM. A fraction of markers (986 of 12,776) exhibited significant deviation from the expected Mendelian ratio of segregation, and they were clustered in major genomic blocks across 15 LGs, most notably LG9 and LG15. The distorted markers exhibited significant bias for maternal alleles among the backcross progenies, suggesting strong selection against the blue catfish alleles. The clustering of distorted markers within genomic blocks should lend insights into speciation as marked by incompatibilities between the two species. Such findings should also have profound implications for understanding the genomic evolution of closely related species as well as the introgression of hybrid production programs in aquaculture.

Related Papers

• → Introgressive hybridization of human and rodent schistosome parasites in western Kenya(2008)68 cited
• → Genetic and morphological data demonstrate hybridization and backcrossing in a pair of salamanders at the far end of the speciation continuum(2021)17 cited
• → Maintenance of species boundaries despite rampant hybridization between three species of reef fishes (Hexagrammidae): implications for the role of selection(2007)42 cited
• → Characterization of a contemporaneous hybrid zone between two darter species (Etheostoma bison and E. caeruleum) in the Buffalo River System(2013)22 cited
• → Hybrid Fertility, Introgression, and Backcrossing in Fish(1999)35 cited