A genome-wide linkage map and QTL mapping for growth traits of Asian rice-field eel (Monopterus albus)

Abstract

Abstract The rice-field eel (Monopterus albus) is showing increasingly important economic value as a freshwater aquaculture fish in Asia. It is necessary to strengthen the genetic breeding research to ensure the quantity and quality of fry supply for the expanding production of rice-field eel. However, the genetic breeding research of this species is still in its infancy. In this study, a genome-wide linkage analysis was carried out to locate its growth-related genes, which may provide guidance for high-yield breeding. In addition, the linkage map was used to mount the supercontigs of the draft genome of rice-field eel. A couple of adults and their 199 six-month-old offspring were used to construct the first ultra-high density linkage map by genome-wide resequencing. The consensus map with a total length of 5161\xa0cM includes 1,603,560 SNPs distributed in 11,522 bins, covering almost all recombination events in the population. Using this map, up to 97.91% of the supercontigs were mounted to chromosomes, which show a good collinearity with the draft genome of rice-field eel. Based on the growth-related traits of the offspring, 37 quantitative trait loci (QTLs) were identified in 18 regions of 4 linkage groups. These QTLs contained SNPs belonging to 58 candidate growth-related genes, among which anks1a, brpf3, plch2, creld1, fry, slc9a1, rragc, mst1r, pfkfb2 and dgkb are worthy of attentions.