RESUMO
The understanding of marine microbial ecology and metabolism has been hampered by the paucity of sequenced reference genomes. To this end, we report the sequencing of 137 diverse marine isolates collected from around the world. We analysed these sequences, along with previously published marine prokaryotic genomes, in the context of marine metagenomic data, to gain insights into the ecology of the surface ocean prokaryotic picoplankton (0.1-3.0 µm size range). The results suggest that the sequenced genomes define two microbial groups: one composed of only a few taxa that are nearly always abundant in picoplanktonic communities, and the other consisting of many microbial taxa that are rarely abundant. The genomic content of the second group suggests that these microbes are capable of slow growth and survival in energy-limited environments, and rapid growth in energy-rich environments. By contrast, the abundant and cosmopolitan picoplanktonic prokaryotes for which there is genomic representation have smaller genomes, are probably capable of only slow growth and seem to be relatively unable to sense or rapidly acclimate to energy-rich conditions. Their genomic features also lead us to propose that one method used to avoid predation by viruses and/or bacterivores is by means of slow growth and the maintenance of low biomass.
Assuntos
Organismos Aquáticos/genética , Genômica , Metagenoma , Plâncton/genética , Células Procarióticas/metabolismo , Organismos Aquáticos/classificação , Organismos Aquáticos/isolamento & purificação , Organismos Aquáticos/virologia , Biodiversidade , Biomassa , Bases de Dados de Proteínas , Genoma Bacteriano/genética , Modelos Biológicos , Oceanos e Mares , Filogenia , Plâncton/crescimento & desenvolvimento , Plâncton/isolamento & purificação , Plâncton/metabolismo , Células Procarióticas/classificação , Células Procarióticas/virologia , RNA Ribossômico 16S/genética , Microbiologia da ÁguaRESUMO
Culex quinquefasciatus (the southern house mosquito) is an important mosquito vector of viruses such as West Nile virus and St. Louis encephalitis virus, as well as of nematodes that cause lymphatic filariasis. C. quinquefasciatus is one species within the Culex pipiens species complex and can be found throughout tropical and temperate climates of the world. The ability of C. quinquefasciatus to take blood meals from birds, livestock, and humans contributes to its ability to vector pathogens between species. Here, we describe the genomic sequence of C. quinquefasciatus: Its repertoire of 18,883 protein-coding genes is 22% larger than that of Aedes aegypti and 52% larger than that of Anopheles gambiae with multiple gene-family expansions, including olfactory and gustatory receptors, salivary gland genes, and genes associated with xenobiotic detoxification.
Assuntos
Cromossomos/genética , Culex/genética , Genes de Insetos , Genoma , Análise de Sequência de DNA , Aedes/genética , Animais , Anopheles/genética , Mapeamento Cromossômico , Culex/classificação , Culex/fisiologia , Elementos de DNA Transponíveis , Proteínas de Insetos/genética , Proteínas de Insetos/fisiologia , Insetos Vetores/genética , Dados de Sequência Molecular , Família Multigênica , Filogenia , Receptores Odorantes/genética , RetroelementosRESUMO
We present a draft sequence of the genome of Aedes aegypti, the primary vector for yellow fever and dengue fever, which at approximately 1376 million base pairs is about 5 times the size of the genome of the malaria vector Anopheles gambiae. Nearly 50% of the Ae. aegypti genome consists of transposable elements. These contribute to a factor of approximately 4 to 6 increase in average gene length and in sizes of intergenic regions relative to An. gambiae and Drosophila melanogaster. Nonetheless, chromosomal synteny is generally maintained among all three insects, although conservation of orthologous gene order is higher (by a factor of approximately 2) between the mosquito species than between either of them and the fruit fly. An increase in genes encoding odorant binding, cytochrome P450, and cuticle domains relative to An. gambiae suggests that members of these protein families underpin some of the biological differences between the two mosquito species.