Parent-of-Origin Effects on Egg Production Traits in Chickens: A Research Review
Quick Look
Researchers investigated whether the parent contributing an allele influences economically important production traits in chickens.
The study examined parent-of-origin effects using reciprocal crosses between two commercial chicken lines.
Several quantitative trait loci (QTL) showed parent-of-origin effects that would not have been detected using traditional Mendelian genetic models.
Significant parent-of-origin QTL were identified for body weight, egg production, egg weight, age at first egg, feed intake, and egg quality traits.
The findings suggest that some production traits are influenced by more than simple additive inheritance.
The study demonstrates that reciprocal crosses can reveal genetic effects that may otherwise remain undetected.
The authors conclude that parent-of-origin effects should be considered when mapping quantitative traits in poultry.
Why This Research Matters
Traditional poultry breeding assumes that an allele has the same effect regardless of whether it is inherited from the sire or the dam. However, some traits may be influenced by parent-of-origin effects, meaning the same allele produces different outcomes depending on which parent contributed it.
Understanding these effects is important because they may influence breeding decisions, reciprocal cross performance, and the interpretation of genetic studies. If parent-of-origin effects exist, conventional genetic analyses may overlook chromosome regions that contribute to economically important traits.
Study Summary
Objective
The objective of this study was to determine whether parent-of-origin effects influence quantitative trait loci associated with economically important production traits in chickens.
Study Design
Researchers analyzed an Fâ resource population developed from reciprocal crosses between two commercial chicken lines.
Using previously developed genetic linkage maps, the investigators compared conventional QTL analysis with statistical models that incorporated parent-of-origin effects.
Multiple production traits were evaluated throughout the study.
Traits Evaluated
Body weight
Egg weight
Egg production
Age at first egg
Feed intake
Egg quality traits
Methods
The researchers performed genome-wide QTL analysis using models that allowed the effect of an allele to differ depending on whether it was inherited from the sire or the dam.
These models were then compared with conventional Mendelian analyses to determine whether additional QTL could be detected.
Major Findings
Several significant QTL demonstrated parent-of-origin effects.
Importantly, a number of these QTL were not detected when traditional Mendelian models were used. Only after incorporating parent-of-origin effects into the statistical analysis did these chromosome regions become significant.
The study identified parent-of-origin QTL affecting several economically important traits, including:
Egg weight
Egg production
Age at first egg
Body weight
Feed intake
Egg quality
The authors also evaluated whether these observations could be explained by known mechanisms such as sex-linked inheritance, maternal effects, W chromosome inheritance, or mitochondrial inheritance. Their analyses suggested that these factors alone were unlikely to explain all of the observed parent-of-origin effects.
Practical Takeaways for Breeders
This study demonstrates that inheritance of production traits may be more complex than simple dominant and recessive genetics.
The research suggests that, for some traits, the biological effect of an allele may depend on whether it was inherited from the sire or the dam. This has important implications for reciprocal crosses and may explain why two breeding combinations using the same parental lines can sometimes produce different performance.
The findings also highlight the importance of choosing appropriate genetic models when studying complex traits. Conventional analyses may fail to detect biologically important chromosome regions if parent-of-origin effects are ignored.
Limitations of the Study
This research was conducted using an experimental chicken population developed from two commercial breeding lines. The identified QTL may not be present, or may have different effects, in other poultry populations.
The study identified chromosome regions associated with parent-of-origin effects but did not identify the specific genes responsible.
Although significant associations were detected, the biological mechanisms underlying these parent-of-origin effects remain uncertain. Additional molecular studies are required to determine how these effects influence gene expression.
Finally, the study focused on chickens. While the findings contribute to a broader understanding of poultry genetics, similar studies are needed in other species, including Japanese quail.
Original Research
de Koning DJ, Haley CS, Windsor D, Hocking PM, Griffin H, Morris A, Vincent J, Burt DW.
Quantitative Trait Loci with Parent-of-Origin Effects in Chicken.
Genetics Research. 2004.
DOI: 10.1017/S0016672304006950
Original publication:
How to cite this review: Poultry Nerds. (2026). Parent-of-Origin Effects in Chicken Genetics: Research Review. Poultry Nerds Research Library. Retrieved July 13, 2026, from https://www.poultrynerdspodcast.com/research-library/parent-of-origin-effects-chicken-genetics
Research Review
This article summarizes a peer-reviewed scientific publication and explains its practical application for poultry keepers, breeders, and educators. It is an original review written by Poultry Nerds and is not a reproduction of the original manuscript. Readers are encouraged to review the complete publication using the original publisher link provided above.