Population density, sexual reproduction and diapause in monogonont rotifers: new data for Brachionus and a review

Gilbert, John J.

doi:10.4081/jlimnol.2004.s1.32

Cited by 58 publications

(40 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…as in monogonont rotifers (Snell 2011), and perhaps also by environmental factors (Pourriot and Clément 1975), descendants of both founders underwent Oenothera-like meiosis, both producing, as in monogonont rotifers (Gilbert 2004), shortlived haploid males and females carrying haploid eggs. Reciprocal fertilization (Suatoni et al 2006) and consequent restoration of heterozygosity might then impart enhanced fitness to the progeny while, as in monogononts, parental types that had entered the sexual cycle would be incapable of further reproduction.…”

Section: Hypothesismentioning

confidence: 99%

Allele Sharing and Evidence for Sexuality in a Mitochondrial Clade of Bdelloid Rotifers

et al. 2015

View full text Add to dashboard Cite

Rotifers of Class Bdelloidea are common freshwater invertebrates of ancient origin whose apparent asexuality has posed a challenge to the view that sexual reproduction is essential for long-term evolutionary success in eukaryotes and to hypotheses for the advantage of sex. The possibility nevertheless exists that bdelloids reproduce sexually under unknown or inadequately investigated conditions. Although certain methods of population genetics offer definitive means for detecting infrequent or atypical sex, they have not previously been applied to bdelloid rotifers. We conducted such a test with bdelloids belonging to a mitochondrial clade of Macrotrachela quadricornifera. This revealed a striking pattern of allele sharing consistent with sexual reproduction and with meiosis of an atypical sort, in which segregation occurs without requiring homologous chromosome pairs.KEYWORDS clonal erosion; cyclic parthenogenesis; meiosis; monogonont; Oenothera B DELLOID rotifers are minute freshwater invertebrates commonly found in lakes, streams, and ponds and in ephemerally aquatic environments such as rock pools and the water films on moss and lichens where they are able to survive because of their unusual ability to withstand desiccation. Although typically only several tenths of a millimeter in size, bdelloids have ganglia; muscles; reproductive, digestive, excretory, and secretory systems; photosensitive and tactile sensory organs; and structures for crawling, feeding, and swimming. Characterized by their ciliated head and bilateral ovaries and classified in four families and hundreds of morphospecies, their ancient origin is indicated by the considerable synonymous sequence divergence between families and by the finding of bdelloid remains in 35-to 40-million year old amber (Mark Welch et al. 2009).Despite much observation of field and laboratory populations and except for one heavily qualified account of having twice seen a male among many females in a sample from a lake (Wesenberg-Lund 1930), neither males, hermaphrodites, mating, nor meiosis have ever been reported within the class (Birky 2010). The only known mode of bdelloid reproduction is via eggs produced by two mitotic divisions from primary oocytes (Hsu 1956a,b). Most recently, further evidence suggestive of asexuality has come from genomic sequencing of the bdelloid Adineta vaga, showing it to be devoid of homologous chromosome pairs and therefore excluding the possibility of standard meiosis (Flot et al. 2013). Nevertheless, the possibility remains that bdelloids reproduce sexually under unknown or inadequately investigated conditions, employing a form of meiosis known in certain plants in which segregation occurs without homologous chromosome pairs-a possibility that can be tested by methods of population genetics.For any two individuals in a population descended from a common ancestor without sexual reproduction or any other sort of genetic transfer between individuals, the phylogenetic distance between a sequence in one individual and its Librar...

show abstract

Section: Hypothesismentioning

confidence: 99%

Allele Sharing and Evidence for Sexuality in a Mitochondrial Clade of Bdelloid Rotifers

et al. 2015

View full text Add to dashboard Cite

show abstract

“…In B. plicatilis, and probably the other species as well, this crowding effect is mediated by a protein released into the medium by the rotifers themselves (Stelzer & Snell, 2003;Snell et al, 2006). Here, data from experiments with five strains of B. calyciflorus and one strain each of B. angularis, B. variabilis, E. ukera, and R. frontalis (Gilbert, 2003a(Gilbert, , 2004Schröder & Gilbert, 2004) are used to address two hypotheses: females of a clone will vary significantly from one another in their propensity to produce mictic daughters in response to a mixis signal, and they will be less likely to produce mictic daughters as they age.…”

Section: Introductionmentioning

confidence: 87%

Intraclonal variation in propensity for mixis in several rotifers: variation among females and with maternal age

Gilbert

Schröder

2007

Hydrobiologia

Self Cite

View full text Add to dashboard Cite

In 14 previously published experiments with clones of three species of Brachionus, Epiphanes ukera, and Rhinoglena frontalis, females cultured singly in small volumes from birth through most of their reproductive period usually produced some mictic daughters. Here, these data are analyzed to test two hypotheses: the propensity of females in a clone to produce mictic daughters will vary significantly among females, and will decrease with female age. Significant heterogeneity (v 2 ) among replicate females was demonstrated in two clones of B. calyciflorus from Florida, in single clones of this species from Georgia, Texas, Spain, and Australia, in a clone of B. angularis from Argentina, and in single clones of E. ukera and R. frontalis from Germany. No significant heterogeneity was found in two other clones of B. calyciflorus from Florida and in a clone of B. variabilis from Spain. Significant heterogeneity among females of a clone could be caused by chance fluctuations during development, differences in birth order, or epimutations. This heterogeneity is an important component of a bet-hedging strategy to balance production of diapausing fertilized eggs and future population growth by female parthenogenesis. The propensity of a female to produce mictic daughters did not decrease with her age. In experiments with six different clones from four strains of B. calyciflorus, and with single clones of E. ukera and R. frontalis, only one clone of B. calyciflorus showed significant variation (ANOVA) in the proportion of mictic daughters produced in three or four successive one-or two-day periods. In this clone the proportion of mictic daughters increased with maternal age.

show abstract

“…However, experimental nutrient enrichment in peatlands did not change rotifer biomass (Gilbert et al 1998b). Rotifers are able to survive unfavourable conditions in diapause (Gilbert 2004;Schröder 2005;etc. ), which could enable them to withstand perturbations such as water level decreases.…”

Section: Relative Importance Of Water Chemistry and Substratummentioning

confidence: 94%

“…We therefore chose three different taxonomic groups of micro-organisms: diatoms, testate amoebae and monogonont rotifers, which we studied along a gradient of mineral richness, from extremely mineral-rich spring-fens to mineral-poor Sphagnum-fens. Diatoms are unicellular, silica-forming autotrophic organisms which can fix energy from the sun and thus form the base of the food chain (Round et al 1990); testate amoebae represent a group of unicellular, heterotrophic protists producing different types of shells or plates, which often contain silica (Warner 1990); monogonont rotifers are small multicellular aquatic animals characterised by the ability to withstand unfavourable periods in diapause, and by female parthenogenesis allowing rapid population growth under favourable environmental conditions (Ricci 2001;Gilbert 2004;Schröder 2005).…”

Section: Introductionmentioning

confidence: 99%

Disentangling the effects of water chemistry and substratum structure on moss-dwelling unicellular and multicellular micro-organisms in spring-fens

Hájková¹,

Bojková²,

Fránková³

et al. 2011

J Limnol

View full text Add to dashboard Cite

show abstract

Population density, sexual reproduction and diapause in monogonont rotifers: new data for Brachionus and a review

Abstract: ABSTRACT

Cited by 58 publications

References 25 publications

Allele Sharing and Evidence for Sexuality in a Mitochondrial Clade of Bdelloid Rotifers

Allele Sharing and Evidence for Sexuality in a Mitochondrial Clade of Bdelloid Rotifers

Intraclonal variation in propensity for mixis in several rotifers: variation among females and with maternal age

Disentangling the effects of water chemistry and substratum structure on moss-dwelling unicellular and multicellular micro-organisms in spring-fens

Contact Info

Product

Resources

About