The fourth Daphnia Genomics Consortium Meeting was held from July 7th through July 9th, 2007 at Indiana University (Bloomington, IN, USA). This year’s meeting was entitled The Genome Biology of the Model Crustacean Daphnia and was highlighted by the initial public release of the draft version of the Daphnia pulex genome. In collaboration with the US Department of Energy Joint Genome Institute (...

When individuals from multiple populations colonize a new habitat patch, intraspecific trait variation can make the arrival order of colonists an important factor for subsequent population and community dynamics. In particular, intraspecific priority effects (IPEs) allow early arrivers to limit the growth or establishment of later arrivers, even when competitively inferior on a per-capita basis...

Paland and Lynch (Reports, 17 February 2006, p. 990) showed that in Daphnia pulex, the ratio of amino acid replacement to silent substitution in mitochondrial genes is higher in asexual lineages than in sexual lineages. If this base-composition bias is maintained by selection, it too should alter following transitions in reproductive mode. Analysis reveals no such change in the genomes of D. pu...

Ultraviolet radiation is known to be highly variable in aquatic ecosystems. It has been suggested that UV-exposed organisms may demonstrate enough phenotypic plasticity to maintain the relative fitness of natural populations. Our long-term objective is to determine the potential photoprotective effect of vitamin D3 on Daphnia pulex exposed to acute or chronic UV radiation. Herein we report our ...

The cladoceran Daphnia lumholtzi has invaded many US rivers and lakes. To better understand the ecological factors and consequences associated with D. lumholtzi invasion, we carried out a microcosm experiment evaluating competition of D. lumholtzi with a widespread native daphnid, D. pulex. We applied two light treatments to these two different microcosms and found strong context-dependent comp...

Understanding nucleotide variation in natural populations has been a subject of great interest for decades. However, many taxonomic groups, especially those with atypical life history attributes remain unstudied, and Drosophila is the only arthropod genus for which DNA polymorphism data are presently abundant. As a result of the recent release of the complete genome sequence and a wide variety ...

The molecular mechanisms leading to asexuality remain little understood despite their substantial bearing on why sexual reproduction is dominant in nature. Here, we examine the role of hybridization in the origin and spread of obligate asexuality in Daphnia pulex, arguably the best-documented case of contagious asexuality. Obligately parthenogenetic (OP) clones of D. pulex have traditionally be...

Daphnia pulex is quickly becoming an attractive model species in the field of ecological genomics due to the recent release of its complete genome sequence, a wide variety of new genomic resources, and a rich history of ecological data. Sequences of the mitochondrial NADH dehydrogenase subunit 5 and cytochrome c oxidase subunit 1 genes were used to assess the global phylogeography of this speci...

An attempted proteomic study of Daphnia pulex response to sodium chloride exposure revealed an unexpected result: very strong proteome degradation previously observed in D. pulex is halted when animals have been exposed to elevated salinity prior to protein extraction. Further characterization of conditions controlling proteome degradation shows that the proteolytic factor(s) is/are present in ...