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Moss JA Burreson EM Cordes JF Dungan CF Brown GD Wang A Wu X Reece KS 《Diseases of aquatic organisms》2007,77(3):207-223
With the drastic decline of eastern oyster Crassostrea virginica populations in the Chesapeake Bay due to over-fishing, diseases and habitat destruction, there is interest in Maryland and Virginia in utilizing the non-native oyster species Crassostrea ariakensis for aquaculture, fishery resource enhancement, and ecological restoration. The International Council for the Exploration of the Sea (ICES) recommends that non-native species be examined for ecological, genetic and disease relationships in the native range prior to a deliberate introduction to a new region. Therefore, a pathogen survey of C. ariakensis and other sympatric oyster species was conducted on samples collected in the PR China, Japan and Korea using molecular diagnostics and histopathology. Molecular assays focused on 2 types of pathogens: protistan parasites in the genus Perkinsus and herpesviruses, both with known impacts on commercially important molluscan species around the world, including Asia. PCR amplification and DNA sequence data from the internal transcribed spacer region of the rRNA gene complex revealed the presence of 2 Perkinsus species not currently found in USA waters: P. olseni and an undescribed species. In addition, 3 genetic strains of molluscan herpesviruses were detected in oysters from several potential C. ariakensis broodstock acquisition sites in Asia. Viral gametocytic hypertrophy, Chlamydia-like organisms, a Steinhausia-like microsporidian, Perkinsus sp., Nematopsis sp., ciliates, and cestodes were also detected by histopathology. 相似文献
208.
T. Cordes D. Diesing S. Becker D. Fischer K. Diedrich M. Friedrich 《The Journal of steroid biochemistry and molecular biology》2007,103(3-5):326
1,25-Dihydroxyvitamin D3 (calcitriol) is the most active natural metabolite of Vitamin D3. It has strong antiproliferative and differentiating effects on various cell types including breast cancer cells. 25-Hydroxyvitamin D3-1α-hydroxylase (1α-hydroxylase, CYP27B1) is one of the key enzymes in the formation of calcitriol. It has been found in breast cancer cells suggesting an autocrine regulation of formation of calcitriol in these cells. Alternative splicing of the encoding genes for this enzyme can possibly play a role in regulating the enzyme level and can explain tissue specific variations of 1α-hydroxylase activity. Splice variants containing intron 1 may encode for truncated proteins with deletion of protein domains which are essential for its enzymatic activity. In order to obtain more information on the abundance of 1α-hydroxylase splice variants, we performed a highly specific nested touchdown PCR in MCF-7 cells. The full-length sequence of 1α-hydroxylase and two different splice variants of this enzyme containing intron 1 were isolated. By Western blot technique we then confirmed the protein products of the full-length enzyme and its splice variants. We hypothesize that that the expression of splice variants can lead to a quantitatively lower expression of the mRNA of the full-length enzyme. The abundance of less active 1α-hydroxylase protein variants can alter the local synthesis of calcitriol in the cells and may explain variations of enzymatic activity in different cells and tissues. 相似文献
209.
Leif Engqvist Nils Cordes Klaus Reinhold 《Evolution; international journal of organic evolution》2015,69(2):395-406
In many species, males possess conspicuous characteristics to attract females. These traits often attract predators as well, and males thus may have to balance the conspicuousness of their signals in relation to the prevailing predation risk. Here we develop a theoretical model of optimal signaling and risk‐taking behavior for males differing in the attractiveness of their signals. All else being equal, more attractive males should behave more cautiously. Yet this prediction may drastically change if males differ in any additional characteristic, especially if basal mortality rate or signaling costs are higher or if the vulnerability to predators is lower for attractive males. A key insight from our model is that male competition will create a positive feedback so that selection on male risk‐taking strategies is acting in opposite directions. If selection acts on one male type to behave more cautiously, this will strengthen selection on males of the other types to take higher risks and vice versa. Our results further demonstrate that the asset‐protection principle, which states that individuals with higher future expectations should behave more cautiously, may often be violated. We also offer an alternative to the handicap principle explaining the often found positive association between male ornamentation and viability: attractive males may simply behave more cautiously. 相似文献
210.
Abbie S. A. Chapman Stace E. Beaulieu Ana Colao Andrey V. Gebruk Ana Hilario Terue C. Kihara Eva Ramirez‐Llodra Joze Sarrazin Verena Tunnicliffe Diva J. Amon Maria C. Baker Rachel E. Boschen‐Rose Chong Chen Isabelle J. Cooper Jonathan T. Copley Laure Corbari Erik E. Cordes Daphne Cuvelier Sbastien Duperron Cherisse Du Preez Sabine Gollner Tammy Horton Stphane Hourdez Elena M. Krylova Katrin Linse P. A. LokaBharathi Leigh Marsh Marjolaine Matabos Susan Wier Mills Lauren S. Mullineaux Hans Tore Rapp William D. K. Reid Elena Rybakova Tresa Remya A. Thomas Samuel James Southgate Sabine Sthr Phillip J. Turner Hiromi Kayama Watanabe Moriaki Yasuhara Amanda E. Bates 《Global Ecology and Biogeography》2019,28(11):1538-1551