Study of genetic diversity and association analysis of single nucleotide polymorphism (SNP) with resistance to gastrointestinal parasites and prolificacy in Santa Ines sheep

Author(s)

Priscila Silva Oliveira

• Document type: Doctoral Thesis
• Press: Pirassununga.
• Institution: Universidade de São Paulo (USP). Faculdade de Zootecnica e Engenharia de Alimentos (FZE/BT)
• Defense date: 2014-02-21

Examining board members

José Bento Sterman Ferraz; Luiz Lehmann Coutinho; Marcelo Beltrão Molento; Arlindo Saran Netto

• Advisor: José Bento Sterman Ferraz

Abstract

The aim of this work was to evaluate the presence of polymorphisms and possible associations with characteristics associated with resistance to gastrointestinal parasites and prolificacy in Santa Ines sheep. To evaluate the resistance to gastrointestinal parasites, feces and blood samples of approximately 700 animals infected naturally and from four different properties, were collected between the months of October and November, 2011 to assess characteristics body condition, degree of anemia measured by FAMACHA card, the characteristics of the hair of sheep, feces consistency, egg counts per gram of feces, hematocrit, white blood cell count, red blood cell count, hemoglobin and platelets count. For the evaluation of prolificacy, 340 sheep were evaluated for the total number of lambs born, divided by the number of births from each dam, as well as the correlation of this feature with the average birth weight of their lambs and productive efficiency of dam. 28 single nucleotide polymorphisms (SNPs) were selected for the development of this study and were genotyped by Sequenom MassARRAY iPLEX platform. Allele and genotype frequencies, the Hardy-Weinberg equilibrium, the effects of allelic substitution, additivity and dominance deviation were analyzed. The results showed considerable variability of the characteristics evaluated in the population in study and in most of the polymorphisms. Significant effect was observed (p ≤ 0.05) or suggestive (0.05> p ≤ 0.10) for allelic substitution of at least one SNP for each of the evaluated traits, indicating that these polymorphisms may help in the selection processes of characteristics related to resistance to gastrointestinal parasites and prolificacy. (AU)

• FAPESP's process: 10/05516-7 - Study of genetic diversity and association analysis of single nucleotide polymorphisms(SNPs)with resistance to gastrointestinal endoparasites and prolificacy of sheep Santa Ines
• Grantee: Priscila Silva Oliveira
• Support Opportunities: Scholarships in Brazil - Doctorate