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The only remaining self-sustaining native population of lacustrine Lahontan cutthroat trout ( Oncorhynchus clarki henshawi ) not affected by nonnative salmonids is in Summit Lake, Humboldt County, Nevada. Annual spawning runs in 1993 and 1994 were monitored at a fish trap on Mahogany Creek, the only spawning tributary for Summit Lake. Number of spawners was similar in both years, with 1290 upstream migrants observed in 1993 and 1255 in 1994. In 1993, 137 postspawners (10.6% of upstream migrants) returned to the lake, and in 1994, 434 postspawners (34.6% of upstream migrants) returned downstream through the fish trap. Two distinct groups of subadult Lahontan cutthroat trout were observed moving downstream in 1994. The first group passed downstream between 27 April and 29 July and included 1188 fish (average fork length = 90 mm). Between 1 August and 31 October, 1160 fish (average fork length = 42 mm) moved downstream. Size differences of these 2 groups suggest that the 1st group comprised fish that had overwintered in Mahogany Creek, while the 2nd group were probably young-of-the-year. 相似文献
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This paper reports on an action research study for the development of a common program on inspection and accreditation of blood collection establishments in the European Union member states. Using soft systems methodology to guide the study, we have developed the systems required and arrived at the actions that are necessary to realize and maintain them. 相似文献
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QI XueBin YANG Su ZHENG HongKun WANG YinQiu LIAO ChengHong LIU Ying CHEN XiaoHua SHI Hong YU xiaoJing Alice A. LIN Luca L. CAVALLI-SFORZA WANG Jun SU Bing 《科学通报(英文版)》2007,52(3):324-335
To understand the genetic basis that underlies the phenotypic divergence between human and non- human primates, we screened a total of 7176 protein-coding genes expressed in the human brain and compared them with the chimpanzee orthologs to identify genes that show evidence of rapid evolution in the human lineage. Our results showed that the nonsynonymous/synonymous substitution (Ka/Ks) ratio for genes expressed in the brain of human and chimpanzee is 0.3854, suggesting that the brain-expressed genes are under functional constraint. The X-linked human brain-expressed genes evolved more rapidly than autosomal ones. We further dissected the molecular evolutionary patterns of 34 candidate genes by sequencing representative primate species to identify lineage-specific adaptive evolution. Fifteen out of the 34 candidate genes showed evidence of positive Darwinian selection in human and/or chimpanzee lineages. These genes are predicted to play diverse functional roles in em- bryonic development, spermatogenesis and male fertility, signal transduction, sensory nociception, and neural function. This study together with others demonstrated the usefulness and power of phy- logenetic comparison of multiple closely related species in detecting lineage-specific adaptive evolu- tion, and the identification of the positively selected brain-expressed genes may add new knowledge to the understanding of molecular mechanism of human origin. 相似文献
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Two unusual types of behaviour (wandering and intraspecific aggressive behaviour) have been observed when rearing larvae of two species of the tribe Hyperini. Wandering of Hypera postica in search for food was observed in L1, L2 and L3 larvae, as well as in young L4 larvae. L1 larvae also disperse in response to crowding. Wandering of L2 to young L4 instars was a response to food shortage. Wandering of late L4 larva (‘prepupa’) occurs because of searching for a place to spin the cocoon and pupate. Encounters between the larvae may result in agonistic behaviour, and some larvae may die as a consequence of fighting. This aggression increases with food limitation. Agonistic intraspecific behaviour has not been described to date in weevil’s larvae and it probably may not occur under natural conditions when there is a plenty of food and larval densities are decreased by pathogens or parasitoids. 相似文献
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I Perrault S Hanein X Zanlonghi V Serre M Nicouleau S Defoort-Delhemmes N Delphin L Fares-Taie S Gerber O Xerri C Edelson A Goldenberg A Duncombe G Le Meur C Hamel E Silva P Nitschke P Calvas A Munnich O Roche H Dollfus J Kaplan JM Rozet 《Nature genetics》2012,44(9):975-977
In addition to its activity in nicotinamide adenine dinucleotide (NAD(+)) synthesis, the nuclear nicotinamide mononucleotide adenyltransferase NMNAT1 acts as a chaperone that protects against neuronal activity-induced degeneration. Here we report that compound heterozygous and homozygous NMNAT1 mutations cause severe neonatal neurodegeneration of the central retina and early-onset optic atrophy in 22 unrelated individuals. Their clinical presentation is consistent with Leber congenital amaurosis and suggests that the mutations affect neuroprotection of photoreceptor cells. 相似文献
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Briggs TA Rice GI Daly S Urquhart J Gornall H Bader-Meunier B Baskar K Baskar S Baudouin V Beresford MW Black GC Dearman RJ de Zegher F Foster ES Francès C Hayman AR Hilton E Job-Deslandre C Kulkarni ML Le Merrer M Linglart A Lovell SC Maurer K Musset L Navarro V Picard C Puel A Rieux-Laucat F Roifman CM Scholl-Bürgi S Smith N Szynkiewicz M Wiedeman A Wouters C Zeef LA Casanova JL Elkon KB Janckila A Lebon P Crow YJ 《Nature genetics》2011,43(2):127-131
We studied ten individuals from eight families showing features consistent with the immuno-osseous dysplasia spondyloenchondrodysplasia. Of particular note was the diverse spectrum of autoimmune phenotypes observed in these individuals (cases), including systemic lupus erythematosus, Sj?gren's syndrome, hemolytic anemia, thrombocytopenia, hypothyroidism, inflammatory myositis, Raynaud's disease and vitiligo. Haplotype data indicated the disease gene to be on chromosome 19p13, and linkage analysis yielded a combined multipoint log(10) odds (LOD) score of 3.6. Sequencing of ACP5, encoding tartrate-resistant acid phosphatase, identified biallelic mutations in each of the cases studied, and in vivo testing confirmed a loss of expressed protein. All eight cases assayed showed elevated serum interferon alpha activity, and gene expression profiling in whole blood defined a type I interferon signature. Our findings reveal a previously unrecognized link between tartrate-resistant acid phosphatase activity and interferon metabolism and highlight the importance of type I interferon in the genesis of autoimmunity. 相似文献
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Stoetzel C Laurier V Davis EE Muller J Rix S Badano JL Leitch CC Salem N Chouery E Corbani S Jalk N Vicaire S Sarda P Hamel C Lacombe D Holder M Odent S Holder S Brooks AS Elcioglu NH Silva ED Da Silva E Rossillion B Sigaudy S de Ravel TJ Lewis RA Leheup B Verloes A Amati-Bonneau P Mégarbané A Poch O Bonneau D Beales PL Mandel JL Katsanis N Dollfus H 《Nature genetics》2006,38(5):521-524
Bardet-Biedl syndrome (BBS) is a genetically heterogeneous ciliopathy. Although nine BBS genes have been cloned, they explain only 40-50% of the total mutational load. Here we report a major new BBS locus, BBS10, that encodes a previously unknown, rapidly evolving vertebrate-specific chaperonin-like protein. We found BBS10 to be mutated in about 20% of an unselected cohort of families of various ethnic origins, including some families with mutations in other BBS genes, consistent with oligogenic inheritance. In zebrafish, mild suppression of bbs10 exacerbated the phenotypes of other bbs morphants. 相似文献
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Haiman CA Patterson N Freedman ML Myers SR Pike MC Waliszewska A Neubauer J Tandon A Schirmer C McDonald GJ Greenway SC Stram DO Le Marchand L Kolonel LN Frasco M Wong D Pooler LC Ardlie K Oakley-Girvan I Whittemore AS Cooney KA John EM Ingles SA Altshuler D Henderson BE Reich D 《Nature genetics》2007,39(5):638-644
After the recent discovery that common genetic variation in 8q24 influences inherited risk of prostate cancer, we genotyped 2,973 SNPs in up to 7,518 men with and without prostate cancer from five populations. We identified seven risk variants, five of them previously undescribed, spanning 430 kb and each independently predicting risk for prostate cancer (P = 7.9 x 10(-19) for the strongest association, and P < 1.5 x 10(-4) for five of the variants, after controlling for each of the others). The variants define common genotypes that span a more than fivefold range of susceptibility to cancer in some populations. None of the prostate cancer risk variants aligns to a known gene or alters the coding sequence of an encoded protein. 相似文献