Analysis of candidate genes for meat production traits in domestic rabbit breeds

A candidate gene approach has been already successfully applied to identify several DNA markers associated with production traits in livestock. The principle is based on the fact that variability within genes coding for protein products involved in key physiological mechanisms and metabolic pathways directly or indirectly involved in determining an economic trait (e.g. feed efficiency, muscle mass accretion, reproduction efficiency, disease resistance, etc.) might probably explain a fraction of the genetic variability for the production trait itself. Growth hormone (GH) and myostatin (MSTN) genes play important roles in animal growth, development and muscle mass accretion. For their functions, these two genes can be considered candidate genes for meat production traits. Here we resequenced parts of these two genes in four rabbit breeds (Belgian Hare, Burgundy Fawn, Checkered Giant and Giant Grey) in order to identify DNA markers useful for association studies with economic traits. On the whole, resequencing of the GH and MSTN genes generated sequence information for 9988 bp. No mutation was detected in the sequenced regions of the GH gene suggesting the absence of common polymorphisms in this rabbit gene. Resequencing of the rabbit MSTN gene identified only a single nucleotide polymorphism (C>T) in intron 2. A PCR-RFLP protocol was designed to investigate this mutation in a larger number of rabbits (15 Checkered Giant, 9 Giant Grey, 6 Dwarf, 4 Burgundy Fawn, 3 Giant White, 3 Lop, 2 Belgian Hare, 1 New Zealand White). Allele frequencies across breeds were 0.51 for allele C and 0.49 for allele T. Considering the breeds for which at least 5 animals were analysed, allele C frequency was 0.56 in Checkered Giant, 0.60 in Burgundy Fawn and Giant Grey and 0.83 in Dwarf. For its allele distribution the identified polymorphism seems an useful gene marker for association studies with production traits in rabbits.