Abstract

Background:
Buffaloes (Bubalus bubalis) are a significant livestock in Indonesia, with approximately 36% (201,060 heads) of their breeding populations located on Sumatera Island, including Sijunjung Regency.

Aim:
This study aimed to ascertain the matrilineal lineage of swamp buffaloes in Sijunjung Regency, Indonesia, using the mitochondrial cytochrome b (Cyt-b) region.

Methods:
Blood samples were obtained from 23 adult female swamp buffaloes for DNA extraction and analysis. A total of 906 bp of bubaline Cyt-b amplicons was amplified for forward sequencing. Six bioinformatics programs (BioEdit, DNAsp, MEGA, STRUCTURE, BEAST, and R) were used for sequence alignment, haplotype diversity estimation, phylogenetic tree construction, pairwise genetic distance calculations, and genetic admixture analysis.

Results:
Seventeen mutation sites were identified in the Cyt-b region. Consequently, four haplotypes (H) of Cyt-b were identified: H1 (56%), H2 (22%), H3 (17%), and H4 (5%). The haplotype diversity (Hd) and nucleotide diversity (pi) for the partial Cyt-b analyzed were 0.645 ± 0.081 and 0.003 ± 0.001, respectively. Phylogenetic tree analysis indicated that the swamp buffaloes in Sijunjung Regency were classified within Haplogroup 1 and exhibited close genetic ties to buffaloes from South Asia (Bangladesh), Southeast Asia (Thailand, Laos, Vietnam, Philippines), and East Asia (Taiwan, China). No evidence of genetic introgression from Indian and Pakistani buffaloes was found in the studied population.

Conclusion:
The matrilineal origin of buffaloes in Sijunjung Regency may be traced back to the southeastern Chinese buffalo (Lineage A) via two migration routes: the land-bridge (China - IndoChina - Malaya Peninsula - Sumatra) and the insular pathway (China - Taiwan - Philippines - Borneo - Sumatra).

Key words: Buffaloes; Cyt-b region; Matrilineal; Sequencing; Sijunjung Regency.