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Draft Genome Sequence of Rhodococcus sp. Strain ATCC 49988, a Quinoline-Degrading Bacterium.
We report here the 4.9-Mb genome sequence of a quinoline-degrading bacterium, Rhodococcus sp. strain ATCC 49988. The draft genome data will enable the identification of genes and future genetic modification to enhance traits relevant to heteroaromatic compound degradation
150,000-year palaeoclimate record from northern Ethiopia supports early, multiple dispersals of modern humans from Africa
Climatic change is widely acknowledged to have played a role in the dispersal of modern humans out of Africa, but the timing is contentious. Dispersal is often linked to climatic change at ~60,000 years ago, despite increasing evidence for earlier presence of modern humans in Asia. Here we report a deep seismic and near-continuous core record of the last 150,000 years from Lake Tana in the Ethiopian highlands, close to the earliest modern human fossil sites and to postulated dispersal routes. The record shows varied climate at the end of the penultimate glacial, followed by an abrupt change to relatively stable moist climate during the last interglacial. These conditions would have favored population growth and range expansion, supporting models of early, multiple dispersals of modern humans from AfricapublishersversionPeer reviewe
Concurrent Acquisition of a Single Nucleotide Polymorphism in Diverse Influenza H5N1 Clade 2.2 Sub-clades
Highly pathogenic Influenza A H5N1 was first identified in Guangdong Province in 1996, followed by human cases in Hong Kong in 1997. The number of confirmed human cases now exceeds 300, and the associated Case Fatality Rate exceeds 60%. The genetic diversity of the serotype continues to increase. Four distinct clades or sub-clades have been linked to human cases. The gradual genetic changes identified in the sub-clades have been attributed to copy errors by viral encoded polymerases that lack an editing function, thereby resulting in antigenic drift. We report here the concurrent acquisition of the same polymorphism by multiple, genetically distinct, clade 2.2 sub-clades in Egypt, Russia, and Ghana. These changes are not easily explained by the current theory of “random mutation” through copy error, and are more easily explained by recombination with a common source. This conclusion is supported by additional polymorphisms shared by clade 2.2 isolates in Egypt and Germany
Aggregation of Single Nucleotide Polymorphisms in a Human H5N1 Clade 2.2 Hemagglutinin
The evolution of H5N1 has attracted significant interest 1-4 due to linkages with avian 5,6 and human infections 7,8. The basic tenets of influenza genetics 9 attribute genetic drift to replication errors caused by a polymerase complex that lacks a proof reading function. However, recent analysis 10 of swine influenza genes identifies regions copied with absolute fidelity for more than 25 years. In addition, polymorphism tracing of clade 2.2 H5N1 single nucleotide polymorphisms identify concurrent acquisition 11 of the same polymorphism onto multiple genetic backgrounds in widely dispersed geographical locations. Here we show the aggregation of regional clade 2.2 polymorphisms from Germany, Egypt, and sub-Sahara Africa onto a human Nigerian H5N1 hemagglutinin (HA), implicating recombination in the dispersal and aggregation of single nucleotide polymorphisms from closely related genomes
Aggregation of Single Nucleotide Polymorphisms in a Human H5N1 Clade 2.2 Hemagglutinin
The rapid evolution of the H5N1 serotype of avian influenza has been explained by a mechanism involving the selection of single nucleotide polymorphisms generated by copy errors. The recent emergence of H5N1 Clade 2.2 in fifty countries, offered a unique opportunity to view the acquisition of new polymorphism in these evolving genomes. We analyzed the H5N1 hemagglutinin gene from a fatal human case from Nigeria in 2007. The newly emerged polymorphisms were present in diverse H5N1 isolates from the previous year. The aggregation of these polymorphisms from clade 2.2 sub-clades was not supported by recent random mutations, and was most easily explained by recombination between closely related sequences
Author Correction: 150,000-year palaeoclimate record from northern Ethiopia supports early, multiple dispersals of modern humans from Africa
A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper
A new species in the tree genus Polyceratocarpus (Annonaceae) from the Udzungwa Mountains of Tanzania
Polyceratocarpus askhambryan-iringae, an endemic tree species of Annonaceae from the Udzungwa Mountains of Tanzania, is described and illustrated. The new species is identified as a member of the genus Polyceratocarpus by the combination of staminate and bisexual flowers, axillary inflorescences, subequal outer and inner petals, and multi-seeded monocarps with pitted seeds. From Polyceratocarpus scheffleri, with which it has previously been confused, it differs in the longer pedicels, smaller and thinner petals, shorter bracts, and by generally smaller, less curved monocarps that have a clear stipe and usually have fewer seeds. Because Polyceratocarpus askhambryan-iringae has a restricted extent of occurrence, area of occupancy, and ongoing degradation of its forest habitat, we recommend classification of it as Endangered (EN) on the IUCN Red List
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