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Topic: Bdelloid rotifers

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	Ludmila A. Kutikova. Variability in obligatory parthenogenetic rotifers (Rotifera, Bdelloida).
		Bdelloid rotifers have relatively uniform structure of body adapted to life, in spatially restricted water film of edaphon, in mosses, lichens, leaf and fir litter where they are mostly spread and also in the littoral and profundal of fresh waters, in benthos and among aquatic vegetation.
		Therefore it can be assumed that obligatory parthenogenetic bdelloid rotifers invaded terrestrial biotopes on the early stage of their evolution; they are characterized by slow evolution rates as compared to heterogonetic monogononts; the variability of bdelloids is of principally of different character and concerns morphological structures of a lower taxonomic rank.
		Kutikova, L.A. Kolovratki fauny SSSR [The rotifer fauna of USSR].
	www.zin.ru /annrep/2000/13.html (1399 words)

	Fresh Water Rotifers: A general introduction with photomicrographs of bdelloid rotifers. (Site not responding. Last check: 2007-09-09)
		Rotifers are small, mostly freshwater animals, and are amongst the smallest members of the Metazoa -- that group of multicellular animals which includes humans, and whose bodies are organized into systems of organs.
		When the rotifer is attatched, the current created by the corona brings food particles to the mouth, and when the rotifer releases the grip of its foot, they act as twin propellers, transporting the rotifer rapidly from one place to another.
		A bdelloid rotifer browses in a mass of decaying vegetation.
	www.micrographia.com /specbiol/rotife/homebdel/bdel0100.htm (893 words)

	www.amateurmicroscopy.net...Bdelloid Rotifers
		The foot terminates in 4 claws that the bdelloid rotifer uses to attach itself temporarily to the substrate.
		When traveling from one location to another, bdelloid rotifers anchor their toes to the substrate, extend their bodies fully, anchor the rostrum to the substrate, and then release the toes and pull the rest of the body forward to the rostrum.
		Bdelloid rotifers are not strictly filter feeders and can spend a considerable amount of time foraging for food particles, too.
	amateurmicroscopy.photomacrography.net /Articles/Rotifers/rotifers.htm (1344 words)

	Introduction to the Rotifera
		Rotifers are microscopic aquatic animals of the phylum Rotifera.
		Rotifers are also commonly found on mosses and lichens growing on tree trunks and rocks, in rain gutters and puddles, in soil or leaf litter, on mushrooms growing near dead trees, in tanks of sewage treatment plants, and even on freshwater crustaceans and aquatic insect larvae.
		The final region of the rotifer body is the foot; this foot ends in a "toe" containing a cement gland with which the rotifer may attach itself to objects in the water and sift food at its leisure.
	www.ucmp.berkeley.edu /phyla/rotifera/rotifera.html (1701 words)

	[No title]
		Bdelloid rotifers are small fresh-water invertebrates of cosmopolitan distribution classified in four families, 19 genera, and more than 350 species.
		If bdelloid rotifers have indeed evolved without sexual reproduction, the question arises as to what characteristics of the genome, in addition to the absence of closely homologous chromosomes, may be associated with ancient asexuality.
		As we have already shown that bdelloid PCR is unable to detect the major classes of retrotransposons in bdelloid rotifers, the only way to detect possible highly diverged relict transposons that may remain in their genomes would be sequence analysis.
	golgi.harvard.edu /meselson/NSF99.htm (5477 words)

	Welcome to the wonderfully weird world of rotifers
		An excellent reason for studying rotifers is that they are found in such a wide variety of environments, so that if you poke around a bit you're almost certain to have an encounter of the rotifer kind.
		Rotifers come in such an astonishing variety of sizes, shapes, and types that it is difficult to describe them.
		In orders other than the bdelloids in which males are known to occur, they are significantly smaller than the females and have a very short life span of just a day or two.
	www.microscopy-uk.org.uk /mag/artnov99/rotih.html (1611 words)

	New_Scientist_1996
		Nor, it turns out, are the bdelloid rotifers the only sexless organisms that seem to have dug their evolutionary heels in and survived against the odds.
		And the painful truth is that the discovery of just one male bdelloid, fossilised or alive, would instantly tarnish the bdelloid's reputation and dent biologists' hopes of using these ancient virgins to crack the mystery of sex.
		It's probably no accident, either, that notorious asexuals like the bdelloid rotifers and Darwinulid ostracods live in freshwater habitats: dispersal to avoid parasites and found new colonies might be easier in water.
	courses.missouristate.edu /mcb095f/bio370/papers/virginal_rotifers.htm (3090 words)

	Life Without Sex. - Unexplained - IN SEARCH FOR TRUTH - RIN.RU (Site not responding. Last check: 2007-09-09)
		This group of tiny water creatures, called bdelloid rotifers, is thriving in fresh water and soggy land worldwide despite, seemingly, no sex for at least 40 million years.
		Biologists have mused that there might be something funny about the sexual history of bdelloid rotifers, one of the classes of a phylum of little stalk-like water animals crowned with a characteristic circle of hairlike cilia.
		Bdelloids seem to be getting rid of menacing transposable elements, but so far as biologists know, don't seem bothered by an abundance of other mutations.
	istina.rin.ru /eng/ufo/text/89.html (1668 words)

	Meselson Laboratory - The Bay Paul Center Portal
		Bdelloid rotifers are small fresh-water invertebrates comprising four families, 19 genera, and some 360 described species.
		This would be consistent with the lack of retrotransposons in bdelloids and suggests that bdelloids either lost such elements close to the time when sex was lost, either by chance or else by some active mechanism of suppression or removal.
		Further opportunities for utilizing bdelloid rotifers in the study of basic genetic problems include investigations of DNA repair, genetic silencing, heterosis, population genetic diversity, and response to selection.
	jbpc.mbl.edu /labs-meselson.html (1250 words)

	TEA: Schulz- -- 1.20.1997
		The rotifers are thought to be the top of the food chain in these small ponds and perhaps even in the lakes.
		Bdelloid rotifers are all female and lay eggs - very strange.
		While I was working on the rotifers in the lab, Maria Stenzland, a photographer from National Geographic magazine came in.
	tea.armadaproject.org /schulz/1.20.1997.html (836 words)

	Topics
		Rotifers in saltwater environments, re-evaluation of an inconspicuous taxon.
		Starve and survive: stress tolerance and life-history traits of a bdelloid rotifer.
		The biology and ecology of lotic rotifers and gastrotrichs.
	users.unimi.it /ricci/html/papers.htm (538 words)

	rotifers
		In these sessile rotifers the anterior part is markedly transformed, for the wheel organ, the mouth and the gullet have been combined into a gaping funnel whose margin may be smooth, or equipped with lobes which bear long stiff cilia (as in this case).
		A bdelloid rotifer with a pronounced wheel organ.
		A rotifer with a rigid cuticle forming an ellipsoid case in which the body resides.
	www.microimaging.ca /rotifer.htm (422 words)

	Rotifera :: Animalia
		Rotifers get their name (derived from Latin and meaning "wheel-bearer"; they have also been called wheel animalcules) from the corona, which is composed of several ciliated tufts around the mouth that in motion resemble a wheel.
		Meselson Laboratory Rotifer Research: Current research and information on their studies of bdelloid rotifers and the mechanisms maintaining recombination in evolution.
		Rotifer Systematic Database: Rotifer taxonomy, anatomy, reproduction and behavior.
	science.gourt.com /Biology/Flora-and-Fauna/Animalia/Rotifera.html (620 words)

	SNAIL'S TALES: The thing from the birdbath
		The rotifer is crawling, like an inchworm, by alternately attaching the toes at the end of its foot and the rostrum on the substrate.
		Bdelloid rotifers live in ponds, lakes, creeks, wet soil, mosses, leafy lichens, bird baths and any other place where water may accumulate even intermittently.
		Bdelloid rotifers (class Bdelloidea), with about 350 or so known species, have one characteristic that makes them stand out among all other animals: they are the largest group of animals that reproduce exclusively by parthenogenesis
	snailstales.blogspot.com /2005/10/thing-from-birdbath.html (673 words)

	Education World® - *Science : Life Science : Zoology : Invertebrates : Microscopic Invertebrates
		An Introduction to the Bdelloid Rotifers Aydin Örstan's article provides detailed information about the anatomy, taxonomy, ecology and evolution of bdelloid rotifers, as well as information on how to study them.
		Rotifers in Bromeliad Phytotelmata This article describes and lists the rotifers found associated with bromeliads in Jamaica.
		Rotifers of Cootes Paradise and Hamilton Harbour Information about rotifers in general, as well as lists of rotifers from this locale.
	db.education-world.com /perl/browse?cat_id=11314 (244 words)

	MBL researchers probe how an ancient microbe thrives and evolves without sex
		To learn more about the bdelloid rotifers' unique ability to evolve without sex, Arkhipova and Meselson studied portions of different bdelloid rotifer genomes and surveyed the diversity, structural organization, and patterns of evolution of DNA transposons.
		The scientists found that DNA transposons in bdelloid rotifers are in a different, perhaps less damaging, location than those found in other creatures.
		Indeed, many of them appear to be located at the tip of the chromosome in an area called the telomere, different from the gene-rich portions of the genome, whereas most species tend to have DNA transposons dispersed throughout their genome.
	www.eurekalert.org /pub_releases/2005-08/mbl-mrp080405.php (472 words)

	Fresh Water Rotifers: Bdelloid: Philodina species. (Site not responding. Last check: 2007-09-09)
		The yellow body is the loricate alga Trachelomonas, and a nearly developed egg of the rotifer Lecane is seen in the upper left of the picture.
		They are native to the Antarctic, and apart from the unusual bright red colouring of their bodies, are representative of bdelloid rotifers as a whole.
		The well-known ability of rotifers, particularly the bdelloids, to survive long periods in the frozen state is clearly a survival necessity for P. gregaria, and the specimens in these pictures may be many years or even decades in age -- there is no way of telling.
	www.micrographia.com /specbiol/rotife/homebdel/bdel01ph.htm (850 words)

	Anhydrobiosis without trehalose in bdelloid rotifers. (Site not responding. Last check: 2007-09-09)
		Eukaryotes able to withstand desiccation enter a state of suspended animation known as anhydrobiosis, which is thought to require accumulation of the non-reducing disaccharides trehalose (animals, fungi) and sucrose (plants), acting as water replacement molecules and vitrifying agents.
		We now show that clonal populations of bdelloid rotifers Philodina roseola and Adineta vaga exhibit excellent desiccation tolerance, but that trehalose and other disaccharides are absent from carbohydrate extracts of dried animals.
		Furthermore, trehalose synthase genes (tps) were not found in rotifer genomes.
	www.cryonet.org /cgi-bin/dsp.cgi?msg=22738 (135 words)

	"An Evolutionary Scandal" (Site not responding. Last check: 2007-09-09)
		There are no males among the 360 described species of bdelloid rotifers, and no evidence of sexual reproduction has ever been found.
		Using standard rates of mutation in other animals, they estimate that the common female ancestor of all bdelloid rotifers lived 50 million to 100 million years ago.
		Cabot professor of the natural sciences Matthew Meselson and David Mark Welch, Ph.D. '99, have found evidence that bdelloid rotifers, a class of multicelled animals, have survived for 50 million to 100 million years without sexual reproduction.
	www.harvard-magazine.com /on-line/1100113.html (722 words)

	Anhydrobiosis in Bdelloid Species, Populations and Individuals -- Ricci and Caprioli 45 (5): 759 -- Integrative and ...
		Bdelloid rotifers are aquatic microinvertebrates common in water
		Örstan, A. Desiccation survival of the eggs of the rotifer Adineta vaga (Davis, 1873).
		Desiccation of rotifer (Macrotrachela quadricornifera): Survival and reproduction.
	icb.oxfordjournals.org /cgi/content/full/45/5/759 (2454 words)

	Trehalose and suspended animation
		Some plants and animals can easily enter a state of suspended animation, during which the metabolic activity of their cells can effectively be stopped, and the delicate architecture of the plasma membranes and intracellular organelles protected against extremes of cold, heat, radiation and other insults.
		Examples which we can easily observe are dried yeast, brine shrimp eggs, tardigrades and certain metazoa such as bdelloid rotifers, which I have chosen to illustrate the process.
		The bdelloids in fig.1 are encysted - left to dry out on a slide, and they have been in this state for several weeks, lying on a slide on my desk.
	www.microscopy-uk.org.uk /mag/artnov02/hbjtrehalose.html (934 words)

	Rates of nucleotide substitution in sexual and anciently asexual rotifers -- Welch and Meselson 98 (12): 6720 -- ... (Site not responding. Last check: 2007-09-09)
		Bdelloid rotifers are abundant invertebrate animals of worldwide distribution, mainly in fresh-water and moist-terrestrial
		It might be supposed that bdelloids have reduced their nucleotide mutation rate to a value substantially below that of monogononts.
		for hsp82 are applicable to bdelloid and monogonont genomes in
	www.pnas.org /cgi/content/full/98/12/6720 (3178 words)

	Literature: Why Do Bdelloid Rotifers Reproduce Only Asexually?
		The LINE-1 and gypsy sequences were absent in the bdelloid rotifers, however.
		Arkhipova and Meselson reported sequences in the mariner family in 24 of 34 taxa studied, including all five species of bdelloid rotifers.
		In asexual species such as bdelloid rotifers, retroposons will be transmitted chiefly vertically.
	wps.prenhall.com /esm_freeman_evol_3/0,8018,849314-,00.html (551 words)

	Bdelloid rotifers revisited -- Birky 101 (9): 2651 -- Proceedings of the National Academy of Sciences (Site not responding. Last check: 2007-09-09)
		Bdelloid rotifers revisited -- Birky 101 (9): 2651 -- Proceedings of the National Academy of Sciences
		one such group, the bdelloid rotifers, and raised some new questions.
		The bdelloids are believed to descend from a parthenogenetic
	www.pnas.org /cgi/content/full/101/9/2651 (1548 words)

	Evidence for the Evolution of Bdelloid Rotifers Without Sexual Reproduction or Genetic Exchange -- Welch and Meselson ... (Site not responding. Last check: 2007-09-09)
		Diverse DNA transposons in rotifers of the class Bdelloidea.
		From The Cover: Cytogenetic evidence for asexual evolution of bdelloid rotifers.
		Rates of nucleotide substitution in sexual and anciently asexual rotifers.
	www.sciencemag.org /cgi/content/abstract/288/5469/1211 (670 words)

	bdelloid rotifers evolution
		Posted: Sun Feb 06, 2005 3:40 pm Post subject: bdelloid rotifers evolution
		When dead lethal bacteria was injected along with living non lethal bacteria, the benign bacteria exchanged DNA with the dead and caused the mice to die.
		Posted: Wed Feb 09, 2005 2:35 am Post subject: Re: bdelloid rotifers evolution
	www.biology-online.org /biology-forum/about224.html (673 words)

	Search
		Forum: Cell Biology Posted: Tue Feb 08, 2005 4:44 am Subject: bdelloid rotifers evolution
		Forum: Cell Biology Posted: Sun Feb 06, 2005 3:40 pm Subject: bdelloid rotifers evolution
		If they are reproducing asexually, shouldn't there be trillions of "species"?
	www.biology-online.org /biology-forum/search.php?search_author=jozersky (69 words)

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