CHARACTERIZATION AND EVALUATION OF PHYLOGENETIC STATUS OF KENGURI, MOULI AND YALAGA SHEEP OF KARNATAKA
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Date
2019-09
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SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517502. (A.P.) INDIA
Abstract
Karnataka state hosts five well adapted indigenous sheep breeds viz. Bellary,
Kenguri, Hassan, Deccani and Mandya. Apart from these recognized breeds, there are two
lesser known genetic groups viz., Mouli and Yalaga reared by farmers in North Karnataka
in Vijayapura and Bagalkote districts, respectively. The objective of the present research is
to document and compare the phenotypic traits of three genetic groups, Kenguri, Mouli
and Yalaga sheep of Karnataka and to study the genetic diversity existing in these genetic
groups, using mitochondrial and Y-chromosome markers. Data on morphological and morphometric traits were recorded in the three genetic groups from farmer's flocks in their breeding tracts. Data was classified based on their age and sex. It was observed that the Kenguri sheep were predominantly brown with white patch on forehead. Males are horned and ewes are polled in this breed. The animals are usually with black hooves, medium long drooping ears, short tail, straight face/fore-head or nose line in males and females. The Mouli sheep were generally white with brown patches all over the body, long tail, polled in both sexes, long drooping ears and typical convex face or bowed fore head with Roman nose. The Yalaga sheep were white in colour, with males being horned and females were polled. They have long tail, long drooping ears, straight forehead and straight nose line. The morphometric traits namely body length, height at withers, flank width and face length were longer in Mouli sheep compared to Kenguri and Yalaga sheep. Body weight is also larger in Mouli sheep compared to Kenguri and Yalaga sheep. The trend also holds good for age wise analysis among the three breeds. The genetic diversity and divergence among the three breeds were assessed using mitochondrial DNA. Metadata of fourteen Indian, Chinese, Caucasian breeds and wild Mouflon were also used for the analysis. The wild ancestor of sheep i.e. urial mitochondrial D-loop region was used as an outgroup for phylogenetic analysis. Mitochondrial DNA analysis indicated that there is high variation within these genetic groups but low differentiation between the genetic groups. Also there is high rate of gene flow among the three genetic groups, particularly between Mouli and Yalaga breeds. The observation is contrasting to the phenotypic differences between the two breeds. The phylogenetic analysis indicated that three genetic groups were predominantly clustered in clade A except one Kenguri sheep which is clustered in clade B. To understand paternal origin of the three breeds, the 611 bp promoter region of SRY gene was amplified and sequenced in the three genetic groups. Orthologous region for a total of 17 sheep representing domestic and wild sheep were obtained from the NCBI database. The three sheep breeds under study didn’t reveal any variation in the promoter region of the SRY chromosome, suggesting they are likely to have same paternal origin. Phylogenetic analysis of sequences indicated a plausible paternal lineage from European or Armenian Mouflon for the three genetic groups. The molecular clock analysis based on mitochondrial control region indicated that the Karnataka breeds must have diverged in the lineage A about 20000 yrs ago. A similar
number of years ago the Kenguri individual in clade B also might have diverged. This
estimate is slightly higher than the time of sheep domestication suggesting possibility of
multiple domestication events in the Indian subcontinent. The results in the present study indicate that phenotypically the three genetic groups are different. At molecular level the Mouli and Yalaga sheep are not differentiated based on the mitochondrial DNA analysis. The paternal source for the three genetic groups is likely from the European or Armenian Mouflon.
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