"Evolution of mercury resistance genes in Bacilli: vertical divergence,convergence and horizontal gene transfer" Prof. Simon Silver

Dear All, 

Trans-membrane Trafficking Unit would like to invite you a talk by Prof.Simon Silver from University of Illinois, Chicago. I hope to see many of you at the seminar on coming Thursday the 25th. 

Date: Thursday, February 25

Time: 14:00 - 15:00

Venue: Meeting Room C015, Lab1

Speaker: Prof. Simon Silver 

Title: Evolution of mercury resistance genes in Bacilli: vertical divergence,convergence and horizontal gene transfer

Abstract: 

The evolution of cellular life is well understood to have proceeded in Darwinian fashion from the early prokaryote microbial cells with all functions shared by all cells to form a "tree of life", descending from the original cell to complex multicellular eukaryotes, including humans.Two additional (less familiar) evolutionary processes confound this simple Darwinian view.  These are firstly convergent evolution, which is the independent evolutionary invention of quite equivalent cellular functions more than once, for example for animal eyes and vision and the wings of birds and of insects.  Finally the horizontal gene transfer occurs, assembling new complexes of genes across species, genus and higher species cluster lines.  Horizontal gene transfer has occurred sufficiently frequently in bacteria to even cause some (mistakenly) to question the existence of natural bacterial species.  All three processes (divergent and convergent Darwinian evolution and horizontal gene transfer) are found in the cluster of less than 10 genes determining mercury and organomercurial resistances in the Gram positive spore-forming bacteria of the family Bacilli. Trees of MerA (mercuric reductase enzyme), MerB(organomrcurial lyase enzyme), MerR (transcriptional regulatory protein) and MerT, MerP and MerE (3 proteins involved in transport of mercurial across the cell membrane) illustrate that each of these proteins (and their genes) has different evolutionary lessons for us to learn.