Arunachal: Genome study charts scientific plan to protect Siangmi Mithun

Guwahati: In a first for one of Northeast India’s most culturally treasured animals, scientists have completed the earliest whole-genome study of Arunachal Pradesh’s semi-domesticated mithun — a milestone that gives conservationists, for the first time, a genome-based foundation to protect and strengthen the prized bovine for generations to come.

Researchers from ICAR-National Research Centre on Mithun sequenced the complete genomes of 11 mithuns and identified nearly 5 million high-quality genetic markers, building the most detailed genomic profile of the animal ever assembled. The findings were published in the high impact factor scientific journal International Journal of Molecular Sciences.

Importantly, the sampled animals were drawn from five villages across two districts of the Siang region — East Siang and Lepa Rada — meaning the study offers a close-up genetic portrait of the mithun of the Siang belt rather than a survey of the entire state. 

Scientists are now working toward a fuller characterisation of this distinct regional population, provisionally referred to as the Siangmi mithun (having approximate population of 15,000-20,000), whose genetic signature reflects the long history and geographic isolation of the Siang communities that have reared these animals for centuries. 

The breed registration of this mithun population is pending after the team has characterized and registered world’s first mithun breed Nagami with ICAR – NBAGR, Karnal.

The study found that the Siang mithun retains moderate genetic diversity, and — crucially — showed no evidence of recent inbreeding but ancient inbreeding with moderation. 

The genetic patterns that do appear are largely ancient, the imprint of a breed that has remained genetically isolated across centuries of traditional village rearing rather than the result of any modern breeding pressure.

Researchers say this is an encouraging sign: it means the population’s genetic health can be actively strengthened through timely, science-guided intervention.

More than a local variety, the mithun of the Siang basin carries a gene pool shaped by centuries of geographic isolation. Whole-genome analysis shows its inbreeding signature is predominantly ancient rather than recent — the mark of a population that has bred largely within isolated village herds across the Siang belt for generations, evolving apart from mithun elsewhere in the Northeast. 

Confined to the Siang river basin and reared under the traditional free-ranging systems of the Siang communities, this population reflects a specific ecology and husbandry history rather than a state-wide average. That deep, stable distinctiveness is precisely what makes the Siangmi worth characterising and conserving as a population in its own right — and gives Arunachal a genetically unique lineage to safeguard.

Using the genome data, the team reconstructed the animal’s deep demographic history, tracing changes in its effective breeding population over thousands of generations. 

Scientists stress that this “effective” figure is a technical genetic measure of the breeding gene pool — not an actual head count — and that it reflects long-term historical trends rather than the current, far larger population on the ground.

The researchers frame the study as a tool for growth. With planned exchange of breeding bulls between villages, genome-informed breeding programmes, and proper pedigree records, they say the diversity and resilience of the mithun population can be actively expanded — turning centuries of isolation into an opportunity for carefully managed genetic enrichment.

India is home to around 3.84 lakh mithuns, with roughly 70 per cent found in Arunachal Pradesh, placing the state at the heart of efforts to conserve this globally unique bovine. Revered by the state’s indigenous tribes as a symbol of wealth, prestige and tradition, the mithun plays a central role in ceremonies and marriage customs and remains an important source of livelihood and nutrition.

By providing the first genome-based scientific foundation for conservation planning and selective breeding, the researchers say the study helps ensure that the Siang region’s — and Arunachal’s — most iconic livestock species remains genetically robust and thriving for future generations.

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