Comparative genomics of bdelloid rotifers

Reuben Nowell’s paper compared genomes of multiple bdelloid rotifer species for the first time. Some previously reported features of bdelloid genomes that have been attributed as evidence for asexuality were not repeated in the new genomes. Some other features – notably the high prevalence of horizontally acquired genes from bacteria, plants and fungi etc – were confirmed, and shown to be the most unusual feature of bdelloids.

The paper is here

A comment “Full disclosure: genome assembly is still hard” is here

Contamination and horizontal gene transfer

With so called tardigate, there has been a lot of discussion recently about contamination as an explanation for evidence of horizontal gene transfer. Chris Wilson’s paper showed that inadvertent contamination explained a reported result of gene exchange between bdelloid rotifer individuals, using analyses of Sanger sequencing chromatograms that could be a useful general tool for exploring contamination.

The paper is here

and a comment is here

Note – this does not pertain to evidence that bdelloids have taken up lots of non-metazoan DNA – those results are robust to critical tests for contamination and have been confirmed now in multiple independent studies.

Horizontal gene transfer is ancient and ongoing in bdelloids

Isobel Eyres paper showing that horizontal gene exchange is ancient and common to bdelloid species at high levels of unto 10% of genes- much higher than observed in any other animal. Closely related species have picked up unique horizontally transferred genes, showing that the process is ongoing.

The paper was timely because evidence for high frequencies of horizontal transfer in tardigrades, published shortly before, was shown to result from contamination. Our work in this paper and subsequently rule out contamination as an explanation in bdelloids.

How Do Species Interactions Affect Evolutionary Dynamics Across Whole Communities?

This paper outlines verbal theory, existing evidence and future avenues for studying evolutionary interactions across whole communities. Many thanks to the Biodiversity Research Centre at the University of British Columbia (UBC) for hosting my sabbatical visit. Watching cedar waxwings and hummingbirds from my office window helped inspire this paper. We now need quantitative theory to guide our experiments – watch this space!