…as targets for genome sequencing in order to avoid bias in what we discover about gene regulation from sequenced genomes, because so far only small genomes have been sequenced. Such is the message reported at the HHMI based on a recent paper by Michael Eisen. I have written about the major problem of drawing broad conclusions from the biased sequenced genome dataset, and I am very excited to see someone else noting that we really need to examine more diversity. I have been meaning to write a paper on why we need large-scale genome size surveys and why sequencing people should be enthusiastic about it (maybe even help fund it). Here is another great reason that I will cite.
It so happens that a student in my lab will soon be initiating a project on dipteran genome sizes — this gives it even broader significance. I might point out that tephritids do not have “big genomes” for insects by my reckoning (for that, you would need to get beyond holometabolous orders). If you’re wondering why Drosophila genomes are so streamlined, it actually looks like development may constrain how large they can be.
And speaking of small genomes, our paper on megabats was published online yesterday. It’s free to access at the moment. Turns out megas have even more constrained genomes than microbats.
AbstractIt has long been recognized that bats and birds contain less DNA in their genomes than their non-flying relatives. It has been suggested that this relates to the high metabolic demands of powered flight, a notion that is supported by the fact that pterosaurs also appear to have exhibited small genomes. Given the long-standing interest in this question, it is surprising that almost no data have been presented regarding genome size diversity among megabats (family Pteropodidae). The present study provides genome size estimates for 43 species of megabats in an effort to fill this gap and to test the hypothesis that all bats, and not just microbats, possess small genomes. Intriguingly, megabats appear to be even more constrained in terms of genome size than the members of other bat families.
Have you thought of looking at genome size in carabids? There are both winged and wingless species of carabid, so would provide a nice test of the flight leads to smaller genomes hypothesis: lots of replication! I guess other beetles might work too.
I have done a little bit with them (and other beetles), still unpublished. I expect that I will have a student work on beetles sometime in the not too distant future. Grant gods willing.
I don’t have any insight on genome size, I just wanted to say that “megabat” is one of the coolest species names ever.