The Asian elephant joins the ever-growing list of animals with sequenced genomes. Recent analyses throws light on the genetic bases of evolution in these intelligent, social animals. Researchers at the Indian Institute of Science Education and Research (IISER) Pune and the Indian Institute of Science (IISc) Bangalore have analyzed the genome and transcriptome sequences of an Asian elephant in their report to be published in the December issue of the Journal of Biosciences.
India is home to the largest population of the Asian elephant, Elephas maximus, an endangered species with less than 50,000 individuals remaining in the wild. The Asian and the African elephants are the largest living land mammals; have a shared evolutionary history dating back about 7 million years ago, yet exhibit species-specific differences. Most of the research on elephants so far has been focused on themes such as ecology, behavior, demography, reproductive biology, welfare and conservation. However, there have been very few studies on understanding the genetic bases of evolutionarily important traits and processes. This study demonstrates the power of next generation sequencing and comparative genomics and transcriptomics in the study of functional genetics in a non-model species.
By sequencing the genome of the Asian Elephant, the team has identified more than 1500 genes that set it apart from its African counterpart. One of the most significant subset of these genes were found to be involved in olfaction (the sense of smell), and possibly indicate an evolutionary adaptation to differences in the chemical signals that the Asian elephant lineage encountered after it moved out of Africa. The team has also reported and analyzed the first transcriptome sequence from blood lymphocytes in the Asian elephant. Proteins with domain architectures unique to elephants in comparison with three other related species of the superorder Afrotheria were identified in this study.
This study offers a foundation upon which future research could be directed towards studying evolutionary relationships trait-/species-specific evolutionary processes both within the elephantids, as well as between elephants and other mammals.
This paper titled “Comparative sequence analyses of genome and transcriptome reveal novel transcripts and variants in the Asian elephant Elephas maximus” was authored by Reddy PC, Sinha I, Kelkar A, Habib F, Pradhan SJ, Sukumar R and Galande S. and has appeared in the Journal of Biosciences this week.