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Genetic analysis of housekeeping genes reveals a deep‐sea ecotype of Alteromonas macleodii in the Mediterranean Sea
Author(s) -
LópezLópez Arantxa,
Bartual Sergio G.,
Stal Lucas,
Onyshchenko Olga,
RodríguezValera Francisco
Publication year - 2005
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/j.1462-2920.2005.00733.x
Subject(s) - biology , ecotype , alteromonas , housekeeping gene , genetic diversity , mediterranean sea , rpob , gene , evolutionary biology , 16s ribosomal rna , mediterranean climate , genetics , ecology , bacteria , population , gene expression , demography , sociology
Summary The genetic diversity of 19 strains belonging to Alteromonas macleodii isolated from different geographic areas (Pacific and Indian Ocean, and different parts of the Mediterranean Sea) and at different depths (from the surface down to 3500 m) has been studied. Fragments of the 16S rRNA gene, the internal transcribed spacer (ITS) between 16S and 23S rDNA genes, the gyrB and the rpoB genes, have been sequenced for each strain. Amplified fragment length polymorphisms were used to characterize similarity at the level of the whole genome. Most of the diversity reflected the existence of a cluster of strains isolated from deep Mediterranean waters and two isolates from the Black Sea. Particularly the isolates from the deep sites were consistently different from all the others indicating the existence of a specific ecotype adapted to these conditions. Amplification of gyrB gene and ITS directly from DNA retrieved from deep Mediterreanean waters and one Atlantic sample showed that presence of this deep‐sea ecotype is widespread and is not a product of culture bias. On the other hand, strains isolated from surface tropical waters showed a remarkable level of resemblance to the first isolate of this species obtained from Hawaii in 1972. The results indicate the existence of both lineages of global distribution and ecotypes adapted to specific conditions such as deep or more diluted (the Black Sea) waters.