Structural and functional characterization of a putative de novo gene in Drosophila
Comparative genomic studies have repeatedly shown that new protein-coding genes can emerge de novo from noncoding DNA. Still unknown is how and when the structures of encoded de novo proteins emerge and evolve. Combining biochemical, genetic and evolutionary analyses, we elucidate the function and structure of goddard, a gene which appears to have evolved de novo at least 50 million years ago within the Drosophila genus. Previous studies found that goddard is required for male fertility. Here, we show that Goddard protein localizes to elongating sperm axonemes and that in its absence, elongated spermatids fail to undergo individualization. Combining modelling, NMR and circular dichroism (CD) data, we show that Goddard protein contains a large central α-helix, but is otherwise partially disordered. We find similar results for Goddard’s orthologs from divergent fly species and their reconstructed ancestral sequences. Accordingly, Goddard’s structure appears to have been maintained with only minor changes over millions of years.
Marie Skłodowska-Curie Actions | Individual Fellowship awarded to Dr. Bertrand Fouks
How genomes evolve and drive novelty is a central question in biology. Some of the most puzzling genomic innovations, for example the development of placenta in mammals, are triggered by Transposable Elements (TEs). TEs are small genome fragments that can move and insert in other areas of the genome, which can create or impair gene functions. Organisms have adapted mechanisms to counteract the harmful effects of TEs, notably small RNAs (e.g. piwi-interacting RNA, piRNAs). Despite increasing knowledge on the effects of TEs on genome evolution and the apparition of novel traits, how and which TEs along with their interactions with piRNAs can promote novelty remain unclear. The project of Dr. Fouks will shed light on this issue by investigating how TEs and piRNAs evolved and interacted in cockroaches and termites alongside the evolution of their incredible biodiversity, with an emphasis on sociality and wood feeding. Dr. Fouks will generate several high-resolution genomes and transcriptomes from cockroach and termite species to locate and categorize TEs and piRNAs., This will allow him to unravel their role in the adaptation of cockroaches and termites to different social levels and diets.
Humboldt Fellowship for Dr. Anna Grandchamp
Since several years it is known that new proteins not only arise via gene duplication and variation of the duplicates but also de novo, i.e. from previously non-coding DNA. An important first step in the creation of these de novo genes is that some of the zillions of randomly generated transcripts have some, though very weak, inherent function or are at least not toxic to the cell and are not quickly lost again. In her project, Dr. Grandchamp will investigate how often new random transcripts are created, by which mechanisms they are created and what the initial function of the new proteins might be.She plans to use in-bred lines of fly populations collected from all over Europe as well as of closely related fly species and map their transcriptomes onto the newly sequenced genomes to precisely characterise the creation and loss of de novo genes.