Microsatellite based molecular characterization of Nattukuttai- a unique short statured Bos indicus cattle population of southern India.

Molecular characterization was conducted to characterise 'Nattukuttai', a native cattle population of the north-eastern agro-climatic zone of Tamil Nadu (India), using thirty microsatellite markers. The analyses revealed a high level of genetic diversity, with a total of 294 alleles observed across all the loci, averaging 9.8 alleles per locus. The allele sizes ranged from 83 bp to 302 bp, with frequencies ranging from 0.010 to 0.875. The microsatellite markers demonstrated high polymorphism, as indicated by an average polymorphic information content (PIC) of 0.763. Deviation from Hardy-Weinberg equilibrium was observed in a significant number of loci, indicating possible genetic influences such as selection or population structure. Bottleneck analysis suggested that the Nattukuttai population did not undergo any recent significant population contraction. Comparative analyses with three other cattle populations (Kangayam, Malai Madu, and Malnad Gidda) revealed varying genetic distances. Nattukuttai showed a distinct genetic profile, diverging from a common source that also gave rise to the Kangayam and Malai Madu clusters. Multivariate statistical analyses and phylogenetic reconstruction supported the genetic differentiation of Nattukuttai from the other populations, while Malai Madu and Kangayam were found to be genetically closer to each other. Overall, these findings provide insights into the genetic structure and relationships of the Nattukuttai cattle population, highlighting its distinct genetic identity and potential conservation significance.