Short Tandem Repeat (STR) based assessment of genetic diversity of Alambadi - A draught cattle breed of Tamil Nadu

Abstract

Alambadi is one of the five indigenous draught type cattle breeds of Tamil Nadu. The present study was undertaken to establish baseline genetic diversity information and evaluate its genetic relationship with Bargur cattle. The results suggested moderate levels of allelic diversity and observed heterozygosity with an overall mean of 6.52 and 0.666 respectively. Estimates of FIS showed significant heterozygosity deficit (0.056) indicating relatively higher levels of inbreeding in Alambadi cattle. The test for Hardy-Weinberg equilibrium revealed 11.1% (3 out of 27) of the investigated loci showing significant deviations due to heterozygosity deficit. Estimation of global F statistics revealed low genetic differentiation between Alambadi and Bargur cattle. The global FST indicated only 3% of the total variation being explained by between breed differences, while the remaining 97% was explained by within breed variability. Principal components analysis revealed separate clustering of Alambadi and Bargur cattle, although admixture was observed among few animals from both the breeds. The test for mutation drift equilibrium revealed no evidences for the occurrence of genetic bottleneck in Alambadi and Bargur cattle in the recent past. Considering the rapid decline in the population of Alambadi cattle, the results of the present study is expected to help planning the strategy for genetic conservation and breed improvement.

Keywords

• Diversity
• Microsatellite
• Mutation Drift Equilibrium
• Principal Components