Quantitative trait loci associated with fatness in a broiler-layer cross

Area of Science:

• Animal Genetics
• Quantitative Genetics
• Poultry Breeding

Background:

• Abdominal fat and serum lipid concentrations are key economic traits in poultry.
• Understanding the genetic basis of these traits is crucial for improving production efficiency.

Purpose of the Study:

• To map quantitative trait loci (QTL) associated with abdominal fat weight, abdominal fat percentage, and serum lipid concentrations (cholesterol and triglycerides).
• To identify potential genetic regions influencing fat deposition and lipid metabolism in chickens.

Main Methods:

• Utilized an F2 population derived from crossing broiler and layer lines.
• Applied two genetic models (line-cross and half-sib) with the regression interval method for QTL analysis.
• Analyzed data for abdominal fat weight, abdominal fat percentage, serum cholesterol, and triglyceride concentrations.

Main Results:

• Mapped a total of five QTL for abdominal fat weight and six QTL for abdominal fat percentage.
• Identified four QTL for triglyceride concentration, including new loci on GGA5, GGA23, and GG27.
• Observed significant parent-of-origin effects for several QTL on GGA3 and GGA12 related to fat traits.

Conclusions:

• Successfully mapped multiple QTL influencing fat deposition and lipid metabolism in chickens.
• Identified novel QTL for serum triglyceride concentration, providing targets for further investigation.
• The identified QTL regions align with previous studies, suggesting conserved genetic architecture and potential for fine-mapping and candidate gene discovery.