Monday, June 30, 2008

Foreign Dispatches: Reporting from the ASP Meeting in Texas

For my inaugural post, I'm relaying some info from the 83rd meeting of the American Society of Parasitologists, held this year in Arlington, Texas. Taxonomy and systematics have always been a large component of our society, though this year there seemed to be slightly fewer talks in these categories. Following the posts from the Evolution meetings, I have to say that parasitologists are still a little behind the curve. Most systematic studies being done were using the typical genes - 18S, coI - and doing concatenated analysis with parsimony plus one other method - sometimes Bayesian, sometimes ML. But, we have to be cut a little slack, I think. Parasites are notoriously difficult to do molecular biology on - often there's not much material to work with so you have limited ability to troubleshoot primers or methods. And sure, there are some genomes available for the parasites that infect humans, but often there's just the one and there is a lot of divergence in some of these groups. Nonetheless, progress is clearly happening and there are some cool things being done. Pete Olson, from the Natural History Museum in London, presented some really cool work exploring the expression of hox genes in tapeworms, animals that have a very different kind of segmentation. Janine Caira (UConn) and Kirsten Jensen (Kansas) and company once again dazzled us with how poorly the parasite fauna of the world is known, by showing how their field work in Borneo has revealed not only dozens of new species of tapeworms, but sometimes new species of hosts as well. Jessie Light (Florida) made us scratch with her work on the taxonomy and phylogeny of human lice, and Mark Siddall (AMNH) hinted that his recent work on EST's in leeches and their insight into paralogy may eventually explain some of the really bizarre findings of Dunn et al. in their recent animal phylogeny. Stay tuned.

5 comments:

Tom Near said...

Being a recovering parasitologist, I really loved the ASP meetings! Steve Nadler was my MS adviser.

Glor said...

I'm sure I'm going to see the bar for phylogenetic analysis lowered when I go to the Ichthyology/Herpetology meetings in July...

Tom Near said...

Yes, but only from the ichthyology side of the meeting. Mention BEST, and they will thing that you are talking about the most parsimonious tree(s).

Glor said...

Can you offer any more insight into the remark about the Dunn et al. manuscript and the implications of the ESTs and paralogy?

Susan Perkins said...

I don't want to get ahead of Mark before he has a chance to write this up, but his results from EST's have shown that in some cases (perhaps a lot - perhaps even most), genes that really do exist as paralagous copies might not all be expressed at a certain time in a certain tissue - perhaps for epigenetic or other reasons and so what can look like single-copy, orthologous genes really are paralogs. Now with all the genome projects, we should eventually get to a point where this isn't an issue, but it certainly could be for the data in Dunn et al.