Correspondence Analysis to Visualize the Relationships between Alpha-S1 Casein and Beta-Lactoglobulin Gene Polymorphisms in Norduz Sheep

Abstract

Correspondence analysis (CA) is one of the multivariate statistical analysis techniques which examines the relationships between different nominal variable categories in two-way or contingency tables. The aim of this study is to investigate the relationships between Alpha-S1 casein and Beta-lactoglobulin gene polymorphisms in Norduz sheep by the CA method. In this study, genotype frequencies of CSN1S1 and BLG genes in Norduz sheep (n=102) were used as categorical variables. As a statistical method, descriptive statistics of characteristics were presented as count and percent and the chi-square ( 𝜒 2 ) test and CA in this study were performed to explore the relationships among the genotype frequencies of Beta-lactoglobulin and Alpha-S1 casein genes. The results of this study indicated that CA can be contributed to a graphical display for categories of nominal variables. Animal breeders can utilize CA as an analytical technique and graphical representation for categorical data. According to the results of this study, the first and second dimensions jointly accounted for 52.25% of the total inertia and "AA" allele of CSN1S1 has the greatest significance in the first dimension, while "BB" allele of BLG has the greatest significant in the second dimension. Therefore, it would be useful to investigate the effects of βLactoglobulin and αS1-Casein genotypes on various yield traits in larger population of Norduz sheep.