tag:blogger.com,1999:blog-496263467300370264.post98638228735919570..comments2022-03-26T17:52:14.434+00:00Comments on The Y.O.R.F.: Investigating the Smallest Bacterial GenomeCathttp://www.blogger.com/profile/08645968914831610862noreply@blogger.comBlogger7125tag:blogger.com,1999:blog-496263467300370264.post-49044448353261814552009-08-24T00:12:39.278+01:002009-08-24T00:12:39.278+01:00C. ruddii cells are actually stored in a specialis...<i>C. ruddii</i> cells are actually stored in a specialised organ called the bacteriome which is placed between the alimentary canal and the gonads of the psyllid. Psyllids only reproduce sexually and, before they do, endosymbiont cells travel from the bacteriome to the oocyte, which carries them onto the next generation. EMs seem to show that during this process the bacteria are actively taken up by the follicle cell via phagocytosis, demonstrating the extent of coevolution between the two organisms. This seems like the most opportune point in the life cycle for LGT to take place.<br /><br />So it's quite different from the gut symbiosis in humans, since we only acquire our bacteria during and after birth if I remember correctly. I remember at least one study claiming that the human genome contains bacterial genes. This was based on the fact that some genes are found in humans and bacteria but not in any other eukaryotes. I don't have much paper access at the moment unfortunately so I can't say whether they did an exhaustive search of eukaryotic genomes...<br /><br />Unfortunately the final year Immunology module didn't go into human endosymbionts as much as I'd hoped so I still don't know a great deal about them. My project for next year is examining a family of proteins that may regulate those types of bacteria though, so I'll hopefully be learning a lot more :)<br /><br />Your blog pictures look really cool btw, especially the beach. I hope you have a good time over there.Joseph Boylehttps://www.blogger.com/profile/16489640800322311480noreply@blogger.comtag:blogger.com,1999:blog-496263467300370264.post-89523309454173621832009-08-23T21:17:24.453+01:002009-08-23T21:17:24.453+01:00I take it that these endosymbionts live in the ins...I take it that these endosymbionts live in the insect gut. How can LGT be an explanation for the gene loss in the bacteria and the AS gene in the insect unless the endosymbionts live in or near the reproductive organs? Wouldn't LGT have to take place in the germline for this to be meaningful?<br /><br />Also, did you ever have a look at human (or mammalian) endosymbionts in terms of ORF count or LGT possibility? I remember a TED talk about how we have essentially been domesticated by bacteria (you can view it that way considering the number of bacteria outnumbers the number of "human" cells in a human body by orders of magnitude) and have been meaning to find out more about it. Obviously we are talking about gut microbes here so the germline transmission problem is still there but I'm sure we have some endosymbionts where it could happen?<br /><br />Fascinating post, btw, and quite an honour to be featured on MolBio Research Highlights!Menelaos Symeonideshttps://www.blogger.com/profile/05361581879935604330noreply@blogger.comtag:blogger.com,1999:blog-496263467300370264.post-56327538357248060902009-08-21T01:55:19.005+01:002009-08-21T01:55:19.005+01:00I don't know if the psyllid genome is being se...I don't know if the psyllid genome is being sequenced at the moment unfortunately. Most of the research in this area seems to be directed at a similar symbiosis between an aphid and an endosymbiont named <i>Buchnera aphidicola</i> and I believe the aphid genome is being sequenced and annotated right now. LGT has been implicated in this symbiosis but the smallest strains of <i>Buchnera</i> still have about 400 genes, so I don't think that that genome sequence will be as interesting as the psyllid one could be.<br /><br />As far as I know these endosymbionts have traditionally been thought of as genetically independent from their hosts, at least in insects, so I havn't read much about protein targeting in these cases. <br /><br />Interestingly though, <i>C. ruddii</i> has no cell membrane/wall metabolism so this must be provided by the host. If it has similar cell walls to mitochondria then it's possible it could use the same protein import mechanism. I tried to examine this at one point but I couldn't make much out from the available electron micrographs. Also of interest is whether <i>C. ruddii</i> has peptidoglycan cell walls (some early electron microscopy papers listed its cell wall as gram negative). If so this would also point to LGT because eukaryotes wouldn't normally have the necessary biosynthetic enzymes to make peptidoglycan.<br /><br />I'll have to catch up on the news in this area when I have access to papers again...<br /><br />'Organelle' is an interesting discussion point. Out of interest do you know who, if anyone, has the right to define the more ambiguous terms in biology, or is it just popular use in textbooks and papers? The definitions that I found around the internet were extremely varied. I think that the meaning of 'Life' has got to be the toughest definitions though :P<br /><br />Thanks Alejandro, that's very kind :)Joseph Boylehttps://www.blogger.com/profile/16489640800322311480noreply@blogger.comtag:blogger.com,1999:blog-496263467300370264.post-47199529967140291302009-08-21T00:45:09.273+01:002009-08-21T00:45:09.273+01:00Hi Joseph.
Very interesting post.
I selected you...Hi Joseph.<br /><br />Very interesting post. <br />I selected your post as one of my "picks of the week" in molecular biology over at my blog (http://amontenegro.blogspot.com/2009/08/my-weekly-picks-from-researchblogging-2.html).<br />Cheers,<br />-AAlejandro Montenegro-Monterohttps://www.blogger.com/profile/18078462764857337905noreply@blogger.comtag:blogger.com,1999:blog-496263467300370264.post-11348399943375265162009-08-20T23:22:30.345+01:002009-08-20T23:22:30.345+01:00really interesting. so any ETA on a genome sequenc...really interesting. so any ETA on a genome sequence of the insect so we can look for the enzyme in question and if it has a signal peptide sending it to the bacteria (maybe something similar to sending it to a mito)? anything known about protein targeting to these types of mircobes in other examples?<br /><br />it has always been one of my fav things to discuss the definitions of important things that no one can define like what is an organelle or life. no clear definitions means we cannot truly say what a virus is or an organelle etc.James Lloydhttps://www.blogger.com/profile/08219295648051788360noreply@blogger.comtag:blogger.com,1999:blog-496263467300370264.post-72680571841404384092009-08-17T00:49:05.345+01:002009-08-17T00:49:05.345+01:00So this is what you spent all your time doing down...So this is what you spent all your time doing downstairs... very interesting indeed!Cathttps://www.blogger.com/profile/08645968914831610862noreply@blogger.comtag:blogger.com,1999:blog-496263467300370264.post-76240163988202329382009-08-16T17:22:07.162+01:002009-08-16T17:22:07.162+01:00very nice post. Sounds like an exciting project wi...very nice post. Sounds like an exciting project with many implications.<br />ThanksAnonymousnoreply@blogger.com