A total of 27 microsatellite primer sets specific for sheep were used in the study. The number of observed alleles ranged from three to eight with a mean of 6.8890.85 across all loci. The most frequent number of alleles was five (41%) and the least frequent number of alleles was three, seven and eight (7%). The size of alleles ranged from 72-220 bp. In total, 143 alleles were observed on 27 loci. The frequency of the alleles ranged from 0.0166-0.7245. Of the 27 loci, the effective number of alleles ranged from 3.72-6.33. The mean number of effective alleles was 4.93250.60 across all loci. The Polymorphism Information Content (PIC) values in the present study ranged from 0.3966-0.8096.

Based on the PIC values, it was found that 93% of these markers showed values of more than 0.5, indicating that these microsatellite markers can be effectively used for molecular characterization and genetic diversity studies. The results of the X² test of goodness of fit revealed that the population was in Hardy-Weinberg Equilibrium (HWE) proportions for 19 microsatellite loci. The remaining eight loci departed from HWE. The observed heterozygosity ranged from 0.6250-0.8462 with a mean of 0.74040.06 while the expected heterozygosity ranged from 0.7211-0.8422 with a mean of 0.81060.03. Population inbreeding estimate (F_IS) indicates heterozygote deficiency was observed to be 0.0666 with a range from - 0.0063 (OarHH72)-0.2233 (OarJMP29). Though positive F_IS values were observed in 20 loci, they reflect inbreeding in Coimbatore sheep. The markers used in the study were highly informative and high heterozygosity value is indicative of the higher amount of genetic variability that can be exploited for their improvement.

In India, there are 42 recognized breeds of sheep distributed in different agroclimatic zones of the country. Tamil Nadu state is endowed with eight breeds of sheep, of which five are hairy meat type viz., Madras Red, Mecheri, Kilakarsal, Ramnad White and Vembur and three are wool type viz., Coimbatore, Trichy Black and Nilagiri
(Acharya, 1982).

Coimbatore sheep, also known by the synonyms, Kurumbai Adu and Coimbatore Kurumbai, produce coarse carpet wool in addition to their use mainly as meat animals. The breeding tract of Coimbatore sheep is Coimbatore district of Tamilnadu, flocks are highly migratory and medium-sized animals with compact body are penned for manure. They are white in color with varying extent of black or tan coat and fleece in the head and neck, which may also extend up to the shoulder or back (Figure 1). They are docile and hardy with faster growth rate and early maturity.

The first step towards conservation of livestock genetic resources is the genetic characterization with respect to phenotypic parameters, unique qualities and utility. Subsequently, finding out the genetic architecture through molecular means and evolutionary relationship with other related breeds would provide valuable information about the breed for taking up conservation measures. Considering these facts, the present study was carried out to characterize the Coimbatore breed of sheep using the molecular marker, such as microsatellites.

Genetics & Evolution Journal, Animal Genetics and Breeding, Polymorphism Information Content, PIC, Microsatellites, Phenotypic Parameters, Nonenzymatic Method, Spectrophotometric Measurements, Food and Agriculture Organization, FAO,Microsatellite Mutation Model, Microsatellite Analysis, Non-Enzymatic Method.