Bacterial contribution to genesis of the novel germ line determinant oskar

Elife. 2020 Feb 24;9:e45539. doi: 10.7554/eLife.45539.


New cellular functions and developmental processes can evolve by modifying existing genes or creating novel genes. Novel genes can arise not only via duplication or mutation but also by acquiring foreign DNA, also called horizontal gene transfer (HGT). Here we show that HGT likely contributed to the creation of a novel gene indispensable for reproduction in some insects. Long considered a novel gene with unknown origin, oskar has evolved to fulfil a crucial role in insect germ cell formation. Our analysis of over 100 insect Oskar sequences suggests that oskar arose de novo via fusion of eukaryotic and prokaryotic sequences. This work shows that highly unusual gene origin processes can give rise to novel genes that may facilitate evolution of novel developmental mechanisms.

Keywords: D. melanogaster; Drosophila; LOTUS domain; de novo gene; developmental biology; evolutionary biology; germ plasm; horizontal gene transfer; orphan gene.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Physiological Phenomena*
  • Bayes Theorem
  • Drosophila Proteins / biosynthesis
  • Drosophila Proteins / genetics*
  • Drosophila melanogaster / genetics
  • Evolution, Molecular
  • Gene Transfer, Horizontal
  • Germ Cells / microbiology*
  • Likelihood Functions
  • Phylogeny


  • Drosophila Proteins
  • osk protein, Drosophila

Grant support

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.