Himalayan Leap for Yak Genomic Science

Context

For the first time ever, scientists in India have successfully assembled the complete chromosome-level genome of the Indian yak (Bos grunniens). This significant achievement was led by specialists from four institutions under the Indian Council of Agricultural Research (ICAR).

**About Indian Yak (Bos grunniens)**

The Indian yak, often called the "ship of the Himalayas," is a large herbivore ungulate species.
It inhabites remote areas of high-elevation alpine tundra, grasslands and cold desert of the Tibetan plateau.
The native populations of wild yak in Bhutan and Nepal are believed to be extinct and their range is confined to China and India.
It is a vital animal for people living in the high-altitude Himalayan regions such as Arunachal Pradesh, Ladakh, Sikkim, and Himachal Pradesh.
These animals provide essential resources including meat, milk, and serve as pack animals for transport in difficult mountainous terrain.
Yaks are uniquely adapted to survive in extreme conditions — freezing cold, low oxygen, and rugged terrain — which makes them indispensable for the livelihoods of Himalayan communities.
However, yaks face growing threats from shrinking grazing areas, climate change, diseases, and loss of genetic diversity.
Understanding the yak’s genome—the complete set of its DNA—helps scientists learn how these animals thrive in such harsh environments and how to protect and improve their populations.
Conservation status:
- IUCN Red List: Vulnerable
- CITES: Appendix I
- Indian WildLife (Protection) Act, 1972: Schedule II

Chromosome-level genome assembly

Genome assembly is the process of mapping out an organism’s complete DNA sequence.
A chromosome-level genome assembly means that the DNA sequence is organized precisely along each chromosome, providing a detailed and accurate genetic blueprint of the species.
To create this genome, scientists used advanced technologies such as long-read sequencing, which reads long stretches of DNA with high accuracy, and powerful computer analysis (bioinformatics) to organize this information into a complete, structured form.

Chromosomes:

Chromosomes are thread-like structures located inside the nucleus of animal and plant cells.
Each chromosome is made of protein and a single molecule of deoxyribonucleic acid (DNA).
Passed from parents to offspring, DNA contains the specific instructions that make each type of living creature unique.
Function:

The unique structure of chromosomes keeps DNA tightly wrapped around spool-like proteins, called histones.
For an organism to grow and function properly, cells must constantly divide to produce new cells to replace old, worn-out cells.
During cell division, it is essential that DNA remains intact and evenly distributed among cells.
Chromosomes are a key part of the process that ensures DNA is accurately copied and distributed in the vast majority of cell divisions.
It is also crucial that reproductive cells, such as eggs and sperm, contain the right number of chromosomes and that those chromosomes have the correct structure.

If not, the resulting offspring may fail to develop properly. For example, people with Down syndrome have three copies of chromosome 21, instead of the two copies found in other people.