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The water flea Daphnia--a 'new' model system for ecology and evolution?

Stollewerk A - J. Biol. (2010)

Bottom Line: Daphnia pulex is the first crustacean to have its genome sequenced.Availability of the genome sequence will have implications for research in aquatic ecology and evolution in particular, as addressed by a series of papers published recently in BMC Evolutionary Biology and BMC Genomics.

View Article: PubMed Central - HTML - PubMed

Affiliation: Queen Mary, University of London, School of Biological and Chemical Sciences, Mile End Road, London E1 4NS, UK. a.stollewerk@qmul.ac.uk

ABSTRACT
Daphnia pulex is the first crustacean to have its genome sequenced. Availability of the genome sequence will have implications for research in aquatic ecology and evolution in particular, as addressed by a series of papers published recently in BMC Evolutionary Biology and BMC Genomics.

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Scanning electron micrograph of a Daphnia larva shortly before hatching. Photograph courtesy of Petra Ungerer.
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Figure 1: Scanning electron micrograph of a Daphnia larva shortly before hatching. Photograph courtesy of Petra Ungerer.

Mentions: Daphnia are filter feeders that direct small suspended particles into their mouth by a water current produced by their leaf-like legs (Figure 1). Daphnia's common name of 'water flea' comes from its jump-like movement, which results from the beat of the large antennae used for swimming (Figure 1). In a normal growth season Daphnia generates diploid eggs by asexual reproduction (parthenogenesis). These eggs develop directly into larvae in the female brood chamber and are released into the water after about 3 days. In most species the larvae go through four to six larval stages before developing into sexually mature adults. However, the Daphnia life cycle is adapted to extreme environmental conditions such as cold winters or summer droughts. If triggered by external stimuli such as high population density and a scarcity of food, Daphnia can produce haploid resting eggs by meiosis; these require fertilization and a period of extended dormancy in order to develop [3]. Resting eggs are distributed by wind or animals and development is resumed in response to external stimuli (for example, rising temperature). Cyclic parthenogenesis, in which parthenogenesis and sexual reproduction alternate, is common in most Daphnia species, but lineages have been described that exclusively reproduce asexually (obligate parthenogenesis). Cyclic parthenogenetic Daphnia must contain the molecular tools for the production of both haploid gametes (by meiosis) and diploid eggs (by mitosis), the latter developing parthenogenetically into diploid zygotes. This makes Daphnia an ideal system to study the evolution of the molecular processes of parthenogenesis.


The water flea Daphnia--a 'new' model system for ecology and evolution?

Stollewerk A - J. Biol. (2010)

Scanning electron micrograph of a Daphnia larva shortly before hatching. Photograph courtesy of Petra Ungerer.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2871515&req=5

Figure 1: Scanning electron micrograph of a Daphnia larva shortly before hatching. Photograph courtesy of Petra Ungerer.
Mentions: Daphnia are filter feeders that direct small suspended particles into their mouth by a water current produced by their leaf-like legs (Figure 1). Daphnia's common name of 'water flea' comes from its jump-like movement, which results from the beat of the large antennae used for swimming (Figure 1). In a normal growth season Daphnia generates diploid eggs by asexual reproduction (parthenogenesis). These eggs develop directly into larvae in the female brood chamber and are released into the water after about 3 days. In most species the larvae go through four to six larval stages before developing into sexually mature adults. However, the Daphnia life cycle is adapted to extreme environmental conditions such as cold winters or summer droughts. If triggered by external stimuli such as high population density and a scarcity of food, Daphnia can produce haploid resting eggs by meiosis; these require fertilization and a period of extended dormancy in order to develop [3]. Resting eggs are distributed by wind or animals and development is resumed in response to external stimuli (for example, rising temperature). Cyclic parthenogenesis, in which parthenogenesis and sexual reproduction alternate, is common in most Daphnia species, but lineages have been described that exclusively reproduce asexually (obligate parthenogenesis). Cyclic parthenogenetic Daphnia must contain the molecular tools for the production of both haploid gametes (by meiosis) and diploid eggs (by mitosis), the latter developing parthenogenetically into diploid zygotes. This makes Daphnia an ideal system to study the evolution of the molecular processes of parthenogenesis.

Bottom Line: Daphnia pulex is the first crustacean to have its genome sequenced.Availability of the genome sequence will have implications for research in aquatic ecology and evolution in particular, as addressed by a series of papers published recently in BMC Evolutionary Biology and BMC Genomics.

View Article: PubMed Central - HTML - PubMed

Affiliation: Queen Mary, University of London, School of Biological and Chemical Sciences, Mile End Road, London E1 4NS, UK. a.stollewerk@qmul.ac.uk

ABSTRACT
Daphnia pulex is the first crustacean to have its genome sequenced. Availability of the genome sequence will have implications for research in aquatic ecology and evolution in particular, as addressed by a series of papers published recently in BMC Evolutionary Biology and BMC Genomics.

Show MeSH