Identification and evolution of the orphan genes in the domestic silkworm, Bombyx mori

• Published in: FEBS letters Vol. 589; no. 19; pp. 2731 - 2738
• Main Authors: Sun, Wei, Zhao, Xin-Wei, Zhang, Ze
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 14.09.2015
• Subjects: Animals; Bombyx - genetics; Bombyx - growth & development; Evolution; Evolution, Molecular; Expression; Gene Expression Profiling; Genes, Insect - genetics; isoelectric point; OGs; Orphan gene; orphan genes; Phylogeny; RNA interference; RNAi; Silkworm; transposable element; TE; RNAi; Expression; pI; Evolution; OGs; Orphan gene; Silkworm
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/j.febslet.2015.08.008

•Seven hundred and thirty-eight OGs identified in the silkworm genome.•OGs have different features compared with non-OGs.•About 30.9% silkworm OGs were derived from TE.•Most of the silkworm OGs was expressed in limited tissues.•All five de novo genes are not essential to the silkworm. Orphan genes (OGs) which have no recognizable homology to any sequences in other species could contribute to the species specific adaptations. In this study, we identified 738 OGs in the silkworm genome. About 31% of the silkworm OGs is derived from transposable elements, and 5.1% of the silkworm OGs emerged from gene duplication followed by divergence of paralogs. Five de novo silkworm OGs originated from non-coding regions. Microarray data suggested that most of the silkworm OGs were expressed in limited tissues. RNA interference experiments suggested that five de novo OGs are not essential to the silkworm, implying that they may contribute to genetic redundancy or species-specific adaptation. Our results provide some new insights into the evolutionary significance of the silkworm OGs.