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Doppel gene polymorphisms in Portuguese sheep breeds: insights on ram fertility

R M Pereira1, P Mesquita, M Batista

  • 1L-INIA, Quinta da Fonte Boa, 2005-048 Vale de Santarém, Portugal. rosalnp@gmail.com

Animal Reproduction Science
|November 26, 2008
PubMed

Insights

The Doppel (Prnd) gene polymorphism was studied in Portuguese sheep breeds, revealing a link between the GG genotype and ram fertility. This finding suggests a potential role for Doppel in male reproduction and sheep breeding programs.

Area of Science:

  • Animal Genetics
  • Reproductive Biology
  • Sheep Breeding

Background:

  • The prion-like protein Doppel (Prnd) is essential for male fertility in mice, as its absence causes infertility.
  • Doppel-deficient mouse sperm exhibit impaired acrosome reaction, hindering oocyte penetration.
  • The specific function of Doppel in male fertility requires further elucidation.

Purpose of the Study:

  • To characterize Doppel (Prnd) gene polymorphisms in eight Portuguese sheep breeds.
  • To investigate the association between Prnd gene polymorphisms and ram fertility.
  • To assess the potential impact of Prnd genotypes on sheep reproductive success.

Main Methods:

  • Ovine genomic DNA from 364 animals across eight breeds was analyzed using multiple restriction fragment-single-strand conformation polymorphism (MRF-SSCP).
  • A synonymous G-->A substitution at codon 26 of the Prnd gene was identified.
  • Semen parameters and embryo production rates were used to develop a classification model for genotypes.

Main Results:

  • A single synonymous polymorphism (G-->A) in codon 26 of the ovine Prnd gene was detected across the studied breeds.
  • Churra Galega Mirandesa and Saloia breeds exhibited higher polymorphism rates, while Serra da Estrela and Merino Branco showed lower rates.
  • A classification model accurately identified the homozygous GG genotype with 86.7% accuracy using fertility traits, suggesting a relationship with male reproduction.

Conclusions:

  • A single Prnd gene polymorphism at codon 26 was identified in Portuguese sheep breeds.
  • The homozygous GG genotype appears to be associated with ram fertility, particularly in the Churra Galega Mirandesa breed.
  • Future research should explore the AA genotype's fertility impact and the Prnd gene's interaction with sheep breeding programs, including Scrapie eradication efforts.

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