2018/06/06 by Nicholas B. Stewart, Stewart, Nicholas B., Rebekah L. Rogers +1
Biochemistry, Genetics and Molecular Biology · Agricultural and Biological Sciences · Immunology and Microbiology · #Insect Resistance and Genetics #Entomopathogenic Microorganisms in Pest Control #Invertebrate Immune Response Mechanisms
paper · pdf · doi:10.48550/arxiv.1806.02205
The origins of new genes are among the most fundamental questions in\nevolutionary biology. Our understanding of the ways that new genetic material\nappears and how that genetic material shapes population variation remains\nincomplete. De novo genes and duplicate genes are a key source of new genetic\nmaterial on which selection acts. To better understand the origins of these new\ngene sequences, we explored the ways that structural variation might alter\nexpression patterns and form novel transcripts. We provide evidence that\nchromosomal rearrangements are a source of novel genetic variation that\nfacilitates the formation of de novo genes in Drosophila. We identify 52 cases\nof de novo gene formation created by chromosomal rearrangements in 14 strains\nof D. yakuba. These new genes inherit transcription start signals and open\nreading frames when the 5' end of existing genes are combined with previously\nuntranscribed regions. Such new genes would appear with novel peptide\nsequences, without the necessity for secondary transitions from non-coding RNA\nto protein. This mechanism of new peptide formations contrasts with canonical\ntheory of de novo gene progression requiring non-coding intermediaries that\nmust acquire new mutations prior to loss via pseudogenization. Hence, these\nmutations offer a means to de novo gene creation and protein sequence formation\nin a single mutational step, answering a long standing open question concerning\nnew gene formation. We further identify gene expression changes to 134 existing\ngenes, indicating that these mutations can alter gene regulation. Population\nvariability for chromosomal rearrangements is considerable, with 2368\nrearrangements observed across 14 inbred lines. More rearrangements were\nidentified on the X chromosome than any of the autosomes, suggesting the X is\nmore susceptible to chromosome alterations.\n