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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Animal Biosciences & Biotechnology Laboratory » Research » Publications at this Location » Publication #345867
Title: Parallel evolution of early and late feathering in turkey and chicken, same gene, different mutation

Author
item DERKS, MARTIJN - Wageningen University And Research Center
item HERRERO-MEDRANO, JUAN - Wageningen University And Research Center
item CROOIJMANS, RICHARD - Wageningen University And Research Center
item VEREIJKEN, ADDIE - Hendrix Genetics
item Long, Julie
item MEGENS, HENDRIK-JAN - Wageningen University And Research Center
item GROENEN, MARTIEN - Wageningen University And Research Center

Submitted to: Genetics Selection Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/22/2018
Publication Date: 12/5/2018
Citation: Derks, M.F., Herrero-Medrano, J.M., Crooijmans, R.P., Vereijken, A., Long, J.A., Megens, H., Groenen, M.A. 2018. Parallel evolution of early and late feathering in turkey and chicken, same gene, different mutation. Genetics Selection Evolution. 50:1-7. https://doi.org/10.1186/s12711-018-0380-3.
DOI: https://doi.org/10.1186/s12711-018-0380-3

Interpretive Summary: In poultry, it is important to determine whether newly hatched birds are male or female. This can be determined using by examining the feathering rate, and is a non-intrusive approach to separate male and females at hatch. The dominant gene for this feathering trait in the chicken is found on the female (Z) chromosome, and females exhibit faster feather growth than males. Although much is known about how this gene functions in chickens, limited information is available for turkeys. In this study, genetic data from slow-feathering and fast-feathering turkeys was examined to determine where the gene was located and how the gene functions. Similar to chickens, the gene locus was found on the Z chromosome in turkeys; however, the mutation for slow feathering rate in the turkey was found to be caused by a five base-pair deletion in the gene for prolactin receptor (PRLR). The consequence, a truncated PRLR protein, is strikingly similar to the slow feathering gene in the chicken, and provides a clear example of parallel evolution caused by applying identical breeding goals for two different domesticated species (chicken and turkey).

Technical Abstract: The sex-linked slow (SF) and fast (FF) feathering rate at hatch has been widely used in poultry breeding for autosexing at hatching. In chicken, the sex-linked K (SF), and k+ (FF) alleles are responsible for the feathering rate phenotype in chicken. The K allele is dominant and a partial duplication of the prolactin receptor has been identified as the causal mutation. Interestingly, some domesticated turkey lines exhibit similar slow- and fast feathering phenotypes. For turkey, however, the underlying genetic components and causal mutation have never been investigated. In this study we aim to investigate the molecular basis of feathering rate at hatch in domestic turkey. We performed a sequence based case-control association study and revealed a genomic region on chromosome Z statistically associated with the rate of feathering at hatching in turkey. We identified a hemizygous 5-bp frameshift deletion in the prolactin receptor (PRLR) as the polymorphism for the slow feathering at hatch phenotype. All the female cases (SF turkeys) were hemizygous for this deletion, while 188 controls (FF turkeys) were hemizygous or homozygous for the reference allele. The frameshift mutation induces an early stop codon including six novel amino acids producing a truncated PRLR protein lacking 98 C-terminal amino acids (AA). This study presents the causal mutation for feathering rate in turkey resulting in a partial C-terminal loss of the prolactin receptor. The consequence, a truncated PRLR protein, is strikingly similar to the slow feathering K allele in chicken, a clear example of parallel evolution.