tag:blogger.com,1999:blog-5460788270738656369.post5531881922923983188..comments2023-12-24T07:02:43.274+08:00Comments on Catalogue of Organisms: Amoeba: Much Wierder than You ThinkChristopher Taylorhttp://www.blogger.com/profile/11075565866351612441noreply@blogger.comBlogger12125tag:blogger.com,1999:blog-5460788270738656369.post-90283435460368163202010-05-25T10:18:33.583+08:002010-05-25T10:18:33.583+08:00At the rate of 20,000 base pairs replicated per se...At the rate of 20,000 base pairs replicated per second (which intuitively seems to be a rather high replication rate, even with many polymerases working in parallel), the time needed to replicate 670 Gbp is just over one year...<br />Would it be reasonable to assume that the organism is "vulnerable" during division (or during interphase)?<br />It appears as if in the polychaos case, the number of base pairs is estimated as a function of total chromosome weight, in pg. Could it be that the rather high polychaos estimate is due to an erroneous assumption regarding the relation chromosome weight/number of base pairs?Henry Normanhttps://www.blogger.com/profile/07818971016888907427noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-35406303705593805042010-05-25T09:43:29.908+08:002010-05-25T09:43:29.908+08:00I don't have the answer, but I would be surpri...I don't have the answer, but I would be surprised if dividing time was directly related to genome size. The cell's DNA doesn't all get replicated at the time of division; rather, replication happens while the cell is in interphase (the period of disassociated chromosomes between divisions). I expect that total genome size would only affect the obvious division time if it affects the time it takes to line the chromosomes up.Christopher Taylorhttps://www.blogger.com/profile/11075565866351612441noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-71568287894137137492010-05-24T18:06:11.985+08:002010-05-24T18:06:11.985+08:00Does anyone know (or have a reference to) the time...Does anyone know (or have a reference to) the time a 670 Gbp cell might need to divide?Henry Normanhttps://www.blogger.com/profile/07818971016888907427noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-67529394871467050222009-12-21T10:29:13.447+11:002009-12-21T10:29:13.447+11:00After being a biology student for many four years,...After being a biology student for many four years, my teacher did not even mention this special characteristics of amoebas! Thanks for this post and I am waiting for more of these!usb copierhttp://www.runtechmedia.com/noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-17195397157341542932009-09-04T15:23:04.979+08:002009-09-04T15:23:04.979+08:00The answer to that is hidden in the next post (sec...The answer to that is hidden in <a href="http://catalogue-of-organisms.blogspot.com/2009/09/amoebozoan-classification-putting.html" rel="nofollow">the next post</a> (second paragraph, excluding the footnote).Christopher Taylorhttps://www.blogger.com/profile/11075565866351612441noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-13752124767806104922009-09-04T12:34:17.546+08:002009-09-04T12:34:17.546+08:00How can you slice a single-celled organism in half...How can you slice a single-celled organism in half -- wouldn't the cytoplasm spill all over?T.T.noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-22121652457364277632009-09-04T09:43:11.420+08:002009-09-04T09:43:11.420+08:00The amoeboid with the biggest genome is sometimes ...The amoeboid with the biggest genome is sometimes called "<i>Amoeba dubia</i>", but the species' describer apparently decided ten years later to make it the type species of a new genus called <i>Polychaos</i>, which is one of my all-time favorite generic names. So today the critter is usually called <i>Polychaos dubium</i>.<br />A few links:<br />http://www.eol.org/pages/62532<br />http://amoeba.ifmo.ru/species/amoebidae/polydub.htm<br />http://protist.i.hosei.ac.jp/PDB/Images/Sarcodina/Polychaos/dubium.htmlGeorge Xnoreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-87279111714353705652009-09-04T02:59:06.694+08:002009-09-04T02:59:06.694+08:00Could there be a causal connection between the (pr...Could there be a causal connection between the (presumable) amount of cruft in Amoeba's genome, and its total lack of sexual reproduction?AWJhttps://www.blogger.com/profile/13729562595081825281noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-48864759888780049592009-09-03T15:56:27.888+08:002009-09-03T15:56:27.888+08:00I take it the ciliate can't come toward us or ...<i>I take it the ciliate can't come toward us or go away from us because the amoeba is squished flat on a slide?</i><br /><br />If I read the site that I got the picture from correctly, the amoeba will also cover the ciliate from above before it's finished. On the other hand, I don't think that the majority of ciliates and other acquatic micro-organisms normally swim freely through the water column. They're mostly concentrated on substrate surfaces, and if the ciliate doesn't have the wherewithal to swim straight upwards in the first place, then there's less problem for the amoeba.<br /><br /><i>How meaningful is the raw basepair count for polyploid nuclei?</i><br /><br />I tried to make sure I was accounting for polyploidy - the next contender in total genome size I could find was <i>Psilotum nudum</i> (which I think is multiploid) with about 250 billion bp in total.<br /><br />As for the significance of this amount, I tried to find out but couldn't. Answering that would (for a start) require some sort of idea of just how much of what types of DNA the amoeba carries. Does it actually contain a proportionally high amount of functional genes, or is it loaded to the gunnels with stuff like transposons and microsatellites?Christopher Taylorhttps://www.blogger.com/profile/11075565866351612441noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-34320074384954330252009-09-03T04:36:23.525+08:002009-09-03T04:36:23.525+08:00I share the relief that "undulipodium" h...I share the relief that "undulipodium" hasn't caught on. Rationally, about the only fault with the word is it's a mouthful, but it just bugs me for some reason.<br /><br />How meaningful is the raw basepair count for polyploid nuclei? I mean, the <i>total</i> basepair count in a human is humongous - a polyploid protist just keeps its (much smaller) number of duplicates in the same sell. Of course, if <i>Amoeba</i> is 3ish-ploid, it's still got a much larger amount of irreducible genetic material than humans do, but the difference is not quite so vast, and it migh affect genome size ranking in other cases if duplicates are counted or not.Andreas Johanssonhttps://www.blogger.com/profile/08802392912541974977noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-40786480524496574082009-09-03T04:28:02.597+08:002009-09-03T04:28:02.597+08:00Fascinating post.
I take it the ciliate can't...Fascinating post.<br /><br />I take it the ciliate can't come toward us or go away from us because the amoeba is squished flat on a slide? This probably seems trivial to you, but I haven't really thought much about how our popular images of microbes are based on ones which have been squished flat. It never occurred to me that it might have a different form (i.e., "radiosa") in 3D space.Mike Keeseyhttps://www.blogger.com/profile/00147156174467903264noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-59244103316923173592009-09-02T18:39:38.338+08:002009-09-02T18:39:38.338+08:00Three hundred billion base pairs. Holy crap.
I kn...Three hundred billion base pairs. Holy crap.<br /><br />I knew Amoeba was weird, but didn't know just HOW weird. You'd think that for such a model organism we'd have some of this stuff figured out now.<br /><br />What an awesome enigma. What hath Emergence wrought?<br /><br />~KaiAnonymousnoreply@blogger.com