2,098 research outputs found
A comparative analysis of Y chromosome and mtDNA phylogenies of the <it>Hylobates</it> gibbons
No full textAbstract Background The evolutionary relationships of closely related species have long been of interest to biologists since these species experienced different evolutionary processes in a relatively short period of time. Comparison of phylogenies inferred from DNA sequences with differing inheritance patterns, such as mitochondrial, autosomal, and X and Y chromosomal loci, can provide more comprehensive inferences of the evolutionary histories of species. Gibbons, especially the genus Hylobates, are particularly intriguing as they consist of multiple closely related species which emerged rapidly and live in close geographic proximity. Our current understanding of relationships among Hylobates species is largely based on data from the maternally-inherited mitochondrial DNAs (mtDNAs). Results To infer the paternal histories of gibbon taxa, we sequenced multiple Y chromosomal loci from 26 gibbons representing 10 species. As expected, we find levels of sequence variation some five times lower than observed for the mitochondrial genome (mtgenome). Although our Y chromosome phylogenetic tree shows relatively low resolution compared to the mtgenome tree, our results are consistent with the monophyly of gibbon genera suggested by the mtgenome tree. In a comparison of the molecular dating of divergences and on the branching patterns of phylogeny trees between mtgenome and Y chromosome data, we found: 1) the inferred divergence estimates were more recent for the Y chromosome than for the mtgenome, 2) the species H. lar and H. pileatus are monophyletic in the mtgenome phylogeny, respectively, but a H. pileatus individual falls into the H. lar Y chromosome clade. Conclusions Based on the ~6.4 kb of Y chromosomal DNA sequence data generated for each of the 26 individuals in this study, we provide molecular inferences on gibbon and particularly on Hylobates evolution complementary to those from mtDNA data. Overall, our results illustrate the utility of comparative studies of loci with different inheritance patterns for investigating potential sex specific processes on the evolutionary histories of closely related taxa, and emphasize the need for further sampling of gibbons of known provenance.</p
Mitochondrial Genome Sequences Effectively Reveal the Phylogeny of Hylobates Gibbons
No full textBACKGROUND: Uniquely among hominoids, gibbons exist as multiple geographically contiguous taxa exhibiting distinctive behavioral, morphological, and karyotypic characteristics. However, our understanding of the evolutionary relationships of the various gibbons, especially among Hylobates species, is still limited because previous studies used limited taxon sampling or short mitochondrial DNA (mtDNA) sequences. Here we use mtDNA genome sequences to reconstruct gibbon phylogenetic relationships and reveal the pattern and timing of divergence events in gibbon evolutionary history. METHODOLOGY/PRINCIPAL FINDINGS: We sequenced the mitochondrial genomes of 51 individuals representing 11 species belonging to three genera (Hylobates, Nomascus and Symphalangus) using the high-throughput 454 sequencing system with the parallel tagged sequencing approach. Three phylogenetic analyses (maximum likelihood, Bayesian analysis and neighbor-joining) depicted the gibbon phylogenetic relationships congruently and with strong support values. Most notably, we recover a well-supported phylogeny of the Hylobates gibbons. The estimation of divergence times using Bayesian analysis with relaxed clock model suggests a much more rapid speciation process in Hylobates than in Nomascus. CONCLUSIONS/SIGNIFICANCE: Use of more than 15 kb sequences of the mitochondrial genome provided more informative and robust data than previous studies of short mitochondrial segments (e.g., control region or cytochrome b) as shown by the reliable reconstruction of divergence patterns among Hylobates gibbons. Moreover, molecular dating of the mitogenomic divergence times implied that biogeographic change during the last five million years may be a factor promoting the speciation of Sundaland animals, including Hylobates species
Inferring the evolutionary histories of divergences in Hylobates and Nomascus gibbons through multilocus sequence data
No full textCapacitors
No full textThis webpage is part of a larger site by the author about electronic circuit engineering. This page introduces the reader to capacitors, including the principles behind how they work. Explanations of several different types of capacitors (including Electrolytic, Tantalum, and Mica) are accompanied by detailed color illustrations of the concepts
Lecideoid lichens of Prince Olav Coast and Soya Coast, Enderby Land, East Antarctica
No full textFive species of lecideoid lichens belonging to three genera are reported as new to the flora of the Prince Olav Coast and the Soya Coast, Enderby Land, East Antarctica; they are Carbonea capsulata (DODGE & BAKER) HALE, Lecidea andersonii R. FILSON, Lecidea cancriformis DODGE & BAKER, Lecidea soyaensis M. INOUE and Lecidella siplei (DODGE & BAKER) M. INOUE. All are endemic to Antarctica. An examination was made of the collections from the region, which were collected mainly by the author under the project of the 27th Japanese Antarctic Research Expedition (JARE-27,during January 1986 and February 1987). The type and authentic specimens of possibly related species have been restudied. Lecidea soyaensis M. INOUE is new to science and Lecidella siplei (DODGE & BAKER) M. INOUE is proposed as a new combination. Taxonomic and chemical data as well as a key to the known taxa are provided
The Hobby of Electronic Circuit Engineering
No full textThis website (originally created in Japanese and translated into English using translation software) by a Japanese systems engineer, Seiichi Inoue, provides an extensive overview of electronic circuit engineering. Topics covered include: Basic knowledge of Electronic parts, Basic knowledge of Engineering Instruments, an Introduction of Engineering Method, and the Assembly Process. A variety of electronic circuits and their uses are provided, as well as a separate section on PIC electronic circuits. The language may be difficult to follow at times given the translation, but still a gem of a site for anyone wanting to build some circuits! Keep in mind that in some sections, the author notes that he is "describing while studying, there seems to be mistakes in the contents. Do at your own risk." For some further browsing, he includes sections on his other interests, such as 3D photography, java programming, CAD, Japanese customs and the Japanese language
- …
