UNTANGLE

Understanding the role of transposons as novel forces in genomic landscapes

Jumping genes, also called mobile or transposable elements (TEs), are universal features of all eukaryotic genomes. TEs are considered major evolutionary players and can be linked to fast adaptations and stress responses. Notwithstanding their huge importance, knowledge of TE dynamics and effects on their hosts is still very limited although this knowledge is essential to predict the impact of climate change on natural populations.

Here, we will investigate the possible effects of TEs on evolution and adaptions of the non-marine ostracod Darwinula stevensoni (Crustacea). This species has a wide geographic distribution and can survive a surprisingly broad range of salinities and temperatures. It is also one of the few remaining examples of putative ancient asexuals, having lost sex and recombination at least 20 million years ago. How D. stevensoni can survive and adapt in the apparent absence of sex, remains an evolutionary puzzle. Diverse TEs cover at least 26% of D. stevensoni’s genome, and some are still actively transposing. TE activity might in part compensate for the absence of meiosis and sex, which are generally the main generator of genetic variation for selection to act on.

Objectives and methodology:

UNTANGLE will generate a high-quality reference genome for D. stevensoni with cutting edge technology. Ostracod genomes from five additional populations will be re-sequenced with long read technologies; this is the first time that such an approach is used in non-model organisms. By innovatively combing different statistical and bioinformatic methods, we will test for adaptive TE effects in the genome of D. stevensoni with 4 different ways. 

Funding

Belspo, BRAIN program, project number B2/223/P1/UNTANGLE