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IISER Bhopal scientists decode peacock genome

Fitness: ‘Perhaps during the time of environmental changes, peacock was able to adapt its genes in order to evolve and survive’, explains Prof. Vineet Sharma (extreme right).  

To understand what gives peacock its ornamental plumage, long-train of tail feathers and disease-free long life, researchers from Indian Institute of Science Education and Research (IISER), Bhopal, sequenced the whole genome of the bird. This the first time the complete genome of peacock has been sequenced. They found several adaptive changes in its genes compared with five other related birds which contribute to these traits. A preprint version of the study is now available on bioRxiv.

Studying the complete set of genes gives crucial information regarding the development, physiology and evolution of the species.

To carry out the sequencing, blood sample was drawn from a peacock from Van Vihar National park in Bhopal. The whole genome sequencing yielded 153.7 Gb (Gigabit) of sequence data and contains about 15,970 genes with a data size of 1.1 GB (Gigabyte). As a handy reference the size of human genome is 3.2 GB, and contains more than 20,000 genes.

Comparitive analysis

After sequencing, the researchers compared peacock genes with those of five other related birds — chicken, turkey, duck, flycatcher and zebra finch. Evolutionary analysis showed that peacock was a close relative of chicken. It also revealed that the bird had suffered two bottlenecks (sudden decline in population) around 4,000 million and 450,000 years ago.

They also found a total of 99 genes that showed beneficial changes in peacock in comparison to other five birds.

Functional analysis revealed that genes that played important roles in early development, cell proliferation and differentiation showed changes in their sequences. “This kind of adaptive evolution suggest that perhaps during the time of environmental changes, it was able to adapt its genes in order to evolve and survive,” explains Prof. Vineet Sharma from the Department of Biological Sciences, IISER Bhopal, and corresponding author of the paper.

Robust immune system

“The changes in the genes of the immune system explain the possible way the bird has become resistant to many diseases compared with other birds. Peacock is resistant to many pathogens including some viruses. Its relative, the chicken, lives only for seven–eight years, while the peacock can live for 10-25 years,” explains Shubham K. Jaiswal, Ph.D scholar at the institute and one of the first authors of the paper.

Several genes that were involved in early development pathways that regulate the feather, bone and muscle development also showed adaptive changes. This adaptive evolution may have helped the bird diverge from the other birds and favour its survival.

“We have further planned to analyse the sequence to understand in detail about the specific genes that give the unique traits to the bird. It will also help in devising better strategies for the conservation of the species. We also wish to create a database for all India specific indigenous species,” says Ankit Gupta, Ph.D scholar at the institute and one of the first authors of the paper.

“Recently, genome sequencing has been used for the possible revival of New Zealand’s indigenous Moa bird. Similarly, the genomic data of peacock generated in this study will also help save our species in case it declines,” says Jaiswal. The genomic understanding of peacock will also help to develop better breeding and conservation programmes and may help tackle any pathogen attacks.

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Printable version | Nov 20, 2020 5:44:32 AM | https://www.thehindu.com/sci-tech/science/iiser-bhopal-scientists-decode-peacock-genome/article23865350.ece

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