Identification of quantitative trait loci associated with caviar yield and ovarian adiposity in white sturgeon (Acipenser transmontanus)

The continued deterioration of sturgeon abundance worldwide has prompted the development of sturgeon aquaculture in which caviar is harvested from captive-reared fish.  One common problem that threatens the efficiency and success of caviar farming in the United States is highly variable roe yield associated with the accumulation of fat in the ovaries of white sturgeon.  White sturgeon with lean ovaries tend to produce a greater yield of superior quality roe compared to those with fatty ovaries.  The purpose of this study is to (1) determine the genetic contribution to caviar yield and ovarian adiposity and (2) identify quantitative trait loci (QTL) that are significantly correlated with these traits.  The role of genetics in determining caviar yield and ovarian adiposity will be assessed by calculating narrow-sense heritability in mature female white sturgeon under different environmental conditions at a caviar farm in California.  Restriction site-associated DNA sequencing (RADseq) using the Illumina platform will be used to identify thousands of single nucleotide polymorphisms (SNPs) throughout the white sturgeon genome.  As sturgeon are complex polyploids, the dosage of each SNP will be estimated and single-dose markers will be used to construct a linkage map from which QTLs associated with high caviar yield and lean ovaries will be identified.  We expect that caviar yield and ovarian adiposity will be highly heritable, as similar traits are in other species, and anticipate that the SNP markers detected here will be used by caviar farmers in selective breeding to improve the efficiency of caviar production.