tag:blogger.com,1999:blog-8341686541622227200.post1231008706720636717..comments2024-02-08T12:10:38.282+00:00Comments on Life of a Lab Rat: Trends in bacterial signalling pathwaysLab Rathttp://www.blogger.com/profile/07962574174521597312noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-8341686541622227200.post-48837064389354865782009-11-16T19:16:14.346+00:002009-11-16T19:16:14.346+00:00Heh, I never thought of the title that way, but it...Heh, I never thought of the title that way, but it does make sense, considering all the other 'trends' journals :)<br /><br />ooh...I never thought about gene-duplication in terms of gene size, at least it never occured to me in terms of this paper. It could be a potential way of getting so many signalling systems, and useful duplicates would be hugely selected for by motile bacteria with many environmental pressures.<br /><br />Obligate intracellular bacterial parasites tend to loose a lot of their genome as well, it's only the ones that can occupy a number of different niches that hang on to them. Andfor the same reason as any other parasites, they simply don't need them. <br /><br />Gram positive/Gram negative is still used routinely. It's not *wonderfully* evolutionarily taxonomic, but it is still one of the most useful things to know about bacteria. In terms of cell-wall/antibiotic interactions (where I am now) it's one of THE most useful things to know, same with people working on bacterial secretion as well. Even though it's based on a seemingly arbitary staining method the different membrane systems play a major part in how the bacteria will behave.<br /><br />I really need to look up these "Tom Cavalier-Smith" papers of which you speak...I just seem to have no time at the moment. heh.<br /><br />And please Spam away! I love answering questions, especially about bacteria :)<br /><br />(totally agree with you about signalling btw, i find it one of the most difficult areas to study. That's pretty much the reason I looked at this paper, I was hoping that generating interest in bacterial signalling might encourage me to start looking at euk pathways with some kind of enthusiasm)Lab Rathttps://www.blogger.com/profile/07962574174521597312noreply@blogger.comtag:blogger.com,1999:blog-8341686541622227200.post-49328122774694513442009-11-16T07:26:40.106+00:002009-11-16T07:26:40.106+00:00When I first glanced at the title, I thought Cell ...When I first glanced at the title, I thought Cell Press unveiled a new journal dedicated to bacterial signalling pathways...is that bad? <br /><br /><i>"the more genes a bacteria has, the more of them it will dedicate to monitoring its internal and external surroundings."</i><br /><br />Or, those genes involved in signalling have have been duplicated, and subsequently neo- or subfunctionalised. Large genomes tend to be a result of 'degradation', if you will: if there isn't much pressure towards streamlining, then it becomes excusable for an operation that previously required a single gene to be modified to require several. <br /><br />Interestingly, this seems to be reversed in intracellular parasites, and to some extent, gut endosymbionts as well (but not as much). If you no longer need certain metabolic (or signalling) pathways, they can (and will) go to [evolutionary] hell. The large effective population size in bacterial populations seems to promote streamlining, but it would be interesting if that's the case for all of them -- do you know anything about that?<br /><br />But I guess the main point is that in the case of large genomes, it's not that the organism now has a shitload more genes to play with, so it sits there and goes "hmmm, where should I invest them?", but the picture is more complex, and reversed: the genomes are larger largely <i>because</i> 'anti-streamlining' gene duplications and the rest of it were tolerated, not the other way around.<br /><br />Of course, those could later be exapted into something adaptive, but it's hard to see how a pathway duplication + modification can be adaptive <i>initially</i>...<br /><br /><br />Oooh, and another question for a bacteriologist: what's up with the adherence to the gram-negative vs. gram-positive categorisation? Isn't it horribly polyphyletic and painfully far from constituting any semblance of a natural classification? (then again, I do get most of my knowledge of prokaryotes from Tom Cavalier-Smith's papers, so I don't know what you guys think of his bacterial evolution theories)<br /><br />I've got more questions, but I'll avoid spamming your blog... >_><br /><br />Signalling is fascinating stuff*, so nice post! <br /><br />*until you have to painfully *memorise* pathways for a very medically-oriented biochem class >.<Psi Wavefunctionhttps://www.blogger.com/profile/10829712736757471647noreply@blogger.com