Genetic (co)variation in skin pigmentation patterns and growth in rainbow trout

Abstract

From a physiological-behavioral perspective, it has been shown that fish with a higher density of black eumelanin spots are more dominant, less sensitive to stress, have higher feed intake, better feed efficiency and therefore are larger in size. Thus, we hypothesized that genetic (co)variation between skin pigmentation patterns and growth exists and it is advantageous in rainbow trout. The objective of this study was to determine the genetic relationships between skin pigmentation patterns and BW in a breeding population of rainbow trout. We performed a genetic analysis of pigmentation traits including dorsal color (DC), lateral band (LB) intensity, amount of spotting above (SA) and below (SB) the lateral line, and BW at harvest (HW). Variance components were estimated using a multi-trait linear animal model fitted by restricted maximum likelihood. Estimated heritabilities were 0.08±0.02, 0.17±0.03, 0.44±0.04, 0.17±0.04 and 0.23±0.04 for DC, LB, SA, SB and HW, respectively. Genetic correlations between HW and skin color traits were 0.42±0.13, 0.32±0.14 and 0.25±0.11 for LB, SA and SB, respectively. These results indicate positive, but low to moderate genetic relationships between the amount of spotting and BW in rainbow trout. Thus, higher levels of spotting are genetically associated with better growth performance in this population.

Single-Step Genome-Wide Association Study for Resistance to Piscirickettsia salmonis in Rainbow Trout (Oncorhynchus mykiss)

“…This population was artificially selected for growth, appearance-related traits and carcass quality for three generations. For a detailed description about rearing conditions and population management please see Flores-Mara et al (2017), Rodríguez et al (2018) and Neto et al (2019).…”

Fish pigmentation and coloration: Molecular mechanisms and aquaculture perspectives

“…29,105 These genes are scattered throughout the genome and are involved in multiple cellular processes including melanocytes specification, proliferation, differentiation, migration and melanin biosynthesis. 106 However, of these potential targets, only a few genes have been identified as important contributors to colour variation. We present a list of genes that are closely related to the regulation of melanocytes, as well as their expression characteristics and molecular functions.…”

Genome-Wide Association Analysis for Resistance to Infectious Pancreatic Necrosis Virus Identifies Candidate Genes Involved in Viral Replication and Immune Response in Rainbow Trout (Oncorhynchus mykiss)

“…The fish belonged to 58 full-sib families generated from 58 females and 20 males of rainbow trout from the 2014 year-class. For more details on the description about rearing conditions and population management see Flores-Mara et al (2017), Neto et al (2019) and Rodríguez et al (2018).…”