Comparative sequence analyses of genome and transcriptome reveal novel transcripts and variants in the Asian elephant Elephas maximus

J Biosci. 2015 Dec;40(5):891-907. doi: 10.1007/s12038-015-9580-y.

Abstract

The Asian elephant Elephas maximus and the African elephant Loxodonta africana that diverged 5-7 million years ago exhibit differences in their physiology, behaviour and morphology. A comparative genomics approach would be useful and necessary for evolutionary and functional genetic studies of elephants. We performed sequencing of E. maximus and map to L. africana at ~15X coverage. Through comparative sequence analyses, we have identified Asian elephant specific homozygous, non-synonymous single nucleotide variants (SNVs) that map to 1514 protein coding genes, many of which are involved in olfaction. We also present the first report of a high-coverage transcriptome sequence in E. maximus from peripheral blood lymphocytes. We have identified 103 novel protein coding transcripts and 66-long non-coding (lnc)RNAs. We also report the presence of 181 protein domains unique to elephants when compared to other Afrotheria species. Each of these findings can be further investigated to gain a better understanding of functional differences unique to elephant species, as well as those unique to elephantids in comparison with other mammals. This work therefore provides a valuable resource to explore the immense research potential of comparative analyses of transcriptome and genome sequences in the Asian elephant.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Elephants / genetics*
  • Gene Expression
  • Gene Expression Profiling
  • Genetic Variation*
  • Genome
  • Homozygote
  • Lymphocytes / physiology
  • Molecular Sequence Annotation
  • RNA, Long Noncoding
  • Sequence Analysis
  • Transcriptome*

Substances

  • RNA, Long Noncoding