Investigating genetic heterogeneity using microsatellite markers after long term selection for egg production in Rhode Island Red chicken

Abstract

Genetic heterogeneity was investigated using 24 microsatellite markers and genomic DNA of 24 randomly selected birds from the selected and control lines of RIR chicken maintained at ICAR-Central Avian Research Institute, Izatnagar. The microsatellite alleles were determined on urea-PAGE, recorded using GelDoc system and the samples were genotyped. The complete genotypic data set was analyzed using POPGENE software. The observed heterozygosity (Ho) means were 0.6306±0.3901 and 0.6528±0.4345 in the selected and control line, respectively. Explicitly the control line contained more Ho mean and thus the more diverse than the selected population. The expected heterozygosity (He) ranged from 0.5053 (MCW0059) to 0.8421 (MCW0004) with mean of 0.7066±0.020 in the selected line, and from 0.2899 (MCW0059) to 0.9130 (ADL0136) with mean of 0.7095±0.030 in the control line. The Ho mean was less than the He mean in each population; the Chi square and G-square tests revealed significant deviations of almost all the loci from the Hardy-Weinberg equilibrium. The selected and control line populations had the corresponding genetic identity and genetic distance of 0.5264 and 0.6418 as original measures, and 0.5528 and 0.5928 as unbiased measures. The phylogenetic analysis revealed their moderate genetic diversity reflecting 29.64 to 32.09% common inheritance. This present investigation thus estimated genetic heterogeneity using a set of microsatellite markers after long term selection for egg production in RIR chicken and could be useful in the study of population dynamics under selection pressure.

Keywords

• Genetic identity and distance
• Hardy-Weinberg disequilibrium
• Heterozygosity
• Microsatellites
• Phylogeny
• RIR chicken