Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Life Sciences
Ornithine Decarboxylase Encoded By Chlorella Virus Pbcv-1, Tiara A. Morehead,, James R. Gurnon, Byron Adams, Kenneth Nickerson, Lisa A. Fitzgerald, James L. Van Etten
Ornithine Decarboxylase Encoded By Chlorella Virus Pbcv-1, Tiara A. Morehead,, James R. Gurnon, Byron Adams, Kenneth Nickerson, Lisa A. Fitzgerald, James L. Van Etten
Byron Adams
Sequence analysis of the 330-kb genome of chlorella virus PBCV-1 revealed an open reading frame, A207R, which encodes a protein with 37–41% amino acid identity to ornithine decarboxylase (ODC) from many eukaryotic organisms. The a207r gene was cloned and the protein was expressed as a His-A207R fusion protein in Escherichia coli. The recombinant protein catalyzes pyridoxal 5’-phosphate-dependent decarboxylation of ornithine to putrescine, the first step in the polyamine biosynthetic pathway The enzyme has a pH optimum of 9.0 and a temperature optimum of 42°C, and it requires dithiothreitol for maximal activity. The enzyme has a Km, for ornithine of 0.78 …
Co-Variation In Soil Biodiversity And Biogeochemistry In Northern And Southern Victoria Land, Antarctica, Byron J. Adams, J. E. Barrett, Ross A. Virginia, Diana H. Wall, S. C. Cary, A. L. Hacker, J. M. Aislabie
Co-Variation In Soil Biodiversity And Biogeochemistry In Northern And Southern Victoria Land, Antarctica, Byron J. Adams, J. E. Barrett, Ross A. Virginia, Diana H. Wall, S. C. Cary, A. L. Hacker, J. M. Aislabie
Byron Adams
Data from six sites in Victoria Land (72-77degrees S) investigating co-variation in soil communities (microbial and invertebrate) with biogeochemical properties show the influence of soil properties on habitat suitability varied among local landscapes as well as across climate gradients. Species richness of metazoan invertebrates (Nematoda, Tardigrada and Rotifera) was similar to previous descriptions in this region, though identification of three cryptic nematode species of Eudorylaimus through DNA analysis contributed to the understanding of controls over habitat preferences for individual species. Denaturing Gradient Gel Electrophoresis profiles revealed unexpectedly high diversity of bacteria. Distribution of distinct bacterial communities was associated with specific …
Comparative Phylogeography Of Codistributed Species Of Chilean Liolaemus (Squamata: Tropiduridae) From The Central-Southern Andean Range, Byron J. Adams, Pedro F. Victoriano, Juan Carlos Ortiz, Edgar Benavides, Jack W. Sites
Comparative Phylogeography Of Codistributed Species Of Chilean Liolaemus (Squamata: Tropiduridae) From The Central-Southern Andean Range, Byron J. Adams, Pedro F. Victoriano, Juan Carlos Ortiz, Edgar Benavides, Jack W. Sites
Byron Adams
In this study, we used a recently developed supertrees method to test for shared phylogeographical signal in partially overlapping geographical ranges of lizards of the genus Liolaemus from the Andean Range in south-central Chile. We reconstruct mtDNA gene trees for three partially codistributed species (Liolaemus tenuis, L. lemniscatus and L. pictus), and our sampling effort is sufficient to allow statistical tests of shared signal between the combinations L. tenuis-L. pictus, and L. tenuis-L. lemniscatus. For both combinations, standardized maximum agreement subtrees scores showed statistically significant signal for shared pattern in regions of overlap, as evaluated by randomization tests (P < 0.001 and < 0.05, respectively). The matrix representation with parsimony tree obtained from the combination of the three different gene trees revealed concordant phylogeographical associations of all species, and was consistent with the geographical association of intraspecific haploclades with three Chilean bioclimatic zones. A multidimensional scaling analysis of several climate variables showed highly significant differences among these zones, which further suggests that they may have contributed to similar patterns of intraspecific divergence across all three species. In the mesomorphic zone in Central Chile, the species L. tenuis and L. lemniscatus may have codiverged in response to shared orogenic vicariant events, which likely predominated over climatic events associated with cycles of glacial advance and retreat. In the hygromorphic zone in southern Chile, however, glacial cycles likely predominated in structuring the phylogeographical histories of L. tenuis and L. pictus, although important ecological differences between these two caution against broad generalizations at this point.