Detection of QTL associated with three skeletal deformities in gilthead seabream (Sparus aurata L.): Lordosis, vertebral fusion and jaw abnormality

The presence of skeletal deformities in farmed fish is a major problem affecting aquaculture industry. In this study, the first QTL analysis for three of the most frequent deformities in gilthead seabream (Sparus aurata L.) is reported. A F1 full-sibling family consisting of 152 fish was genotyped by using a set of 13 multiplex PCRs (ReMsa1-ReMsa13). This PCR includes 106 microsatellite markers from the genetic map of this species. For vertebral fusion, one significant QTL (located in linkage group LG 21) and two suggestive QTL (located in LG4 and LG13, respectively) were detected. For lordosis, one significant QTL (located in LG9) at chromosome and genome-wide level and one suggestive QTL (located in LG22) were detected. For jaw deformity, one significant QTL (located in LG13) and one suggestive QTL (located in LG16) were detected. The percentages of variance explained by the QTL effect ranged from 1.6 to 11.4%. Hd-46-T was the closest-to-vertebral-fusion-significant-QTL microsatellite marker and showed a statistical association between male allelic segregation and phenotype. CId-26-H and CId-03-F were the two closest-to-jaw-deformity-significant-QTL microsatellite markers and showed a statistical association with female allelic segregation. Considering these results can help to decrease the prevalence of these deformities in future by Marker Assisted Selection breeding and to solve one of the most important aquaculture industry problems. However, additional analyses in other gilthead seabream families are needed in order to confirm these QTL. Statement of relevance The results of the present study show the first QTL identified for skeletal deformities in gilthead seabream, which could help to decrease these deformity prevalence. These results, although in preliminary way, could help to solve one of the most important aquaculture industry problems. (C) 2015 Elsevier B.V. All rights reserved.