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排序方式: 共有147条查询结果,搜索用时 15 毫秒
1.
Benjamin B. Roa Frank Greenberg Preethi Gunaratne Christine M. Sauer Mark S. Lubinsky Chahira Kozma Jeanne M. Meck R. Ellen Magenis Lisa G. Shaffer J. R. Lupski 《Human genetics》1996,97(5):642-649
Autosomal dominant Charcot-Marie-Tooth type-1A neuropathy (CMT1A) is a demyelinating peripheral nerve disorder that is commonly
associated with a submicroscopic tandem DNA duplication of a 1.5-Mb region of 17p11.2p12 that contains the peripheral myelin
gene PMP22. Clinical features of CMT1A include progressive distal muscle atrophy and weakness, foot and hand deformities, gait abnormalities,
absent reflexes, and the completely penetrant electrophysiologic phenotype of symmetric reductions in motor nerve conduction
velocities (NCVs). Molecular and fluorescence in situ hybridization (FISH) analyses were performed to determine the duplication
status of the PMP22 gene in four patients with rare cytogenetic duplications of 17p. Neuropathologic features of CMT1A were seen in two of these
four patients, in addition to the complex phenotype associated with 17p partial trisomy. Our findings show that the CMT1A
phenotype of reduced NCV is specifically associated with PMP22 gene duplication, thus providing further support for the PMP22 gene dosage mechanism for CMT1A.
Received: 3 May 1995 / Revised: 1 August 1995 相似文献
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3.
The present study analyzed the drosophilid assemblages in different levels of urbanization in the city of Porto Alegre, Rio Grande do Sul, Brazil. Collections were carried out in 2008 in three different environments: a highly urbanized area????Jardim Botanico,?? a forested area with intermediary urbanization????Parque Gabriel Knijnik,?? and in a relatively well-preserved forested area, although threatened by the urban growth????Morro Santana.?? In Jardim Botanico, 36 species belonging to four genera were found, with high abundance of exotic species as Drosophila simulans Sturtevant and Zaprionus indianus (Gupta). In Parque Gabriel Knijnik, 33 species that belonged to four genera were found, with higher abundances of native species belonging to the Drosophila tripunctata species group and Drosophila willistoni species subgroup, and lower abundance of exotic species. As for Morro Santana, 32 species and three genera were found, with higher abundances of native groups, low representativeness of exotic species, and absence of Zaprionus indianus. The analysis of the Jaccard index showed higher similarity in the species composition between samples collected in summer and autumn, and between samples collected in winter and spring. On the other hand, the Morisita index differentiated Jardim Botanico from the other two studied sites. Our results show that Morro Santana is an important area of native biodiversity, reinforcing, therefore, the inclusion of this area in the project for the creation of an ecological corridor as proposed by the Ministry of the Environment of Brazil. 相似文献
4.
Background
Long-term benefits in animal breeding programs require that increases in genetic merit be balanced with the need to maintain diversity (lost due to inbreeding). This can be achieved by using optimal contribution selection. The availability of high-density DNA marker information enables the incorporation of genomic data into optimal contribution selection but this raises the question about how this information affects the balance between genetic merit and diversity.Methods
The effect of using genomic information in optimal contribution selection was examined based on simulated and real data on dairy bulls. We compared the genetic merit of selected animals at various levels of co-ancestry restrictions when using estimated breeding values based on parent average, genomic or progeny test information. Furthermore, we estimated the proportion of variation in estimated breeding values that is due to within-family differences.Results
Optimal selection on genomic estimated breeding values increased genetic gain. Genetic merit was further increased using genomic rather than pedigree-based measures of co-ancestry under an inbreeding restriction policy. Using genomic instead of pedigree relationships to restrict inbreeding had a significant effect only when the population consisted of many large full-sib families; with a half-sib family structure, no difference was observed. In real data from dairy bulls, optimal contribution selection based on genomic estimated breeding values allowed for additional improvements in genetic merit at low to moderate inbreeding levels. Genomic estimated breeding values were more accurate and showed more within-family variation than parent average breeding values; for genomic estimated breeding values, 30 to 40% of the variation was due to within-family differences. Finally, there was no difference between constraining inbreeding via pedigree or genomic relationships in the real data.Conclusions
The use of genomic estimated breeding values increased genetic gain in optimal contribution selection. Genomic estimated breeding values were more accurate and showed more within-family variation, which led to higher genetic gains for the same restriction on inbreeding. Using genomic relationships to restrict inbreeding provided no additional gain, except in the case of very large full-sib families. 相似文献5.
Biotic and abiotic factors that influence the avian distribution in a dry zone wetland was investigated by studying the distribution
of Asian Openbill (Anastomus oscitans), Cotton Pygmy-goose (Nettapus coromandelianus) and Pheasant-tailed Jacana (Hydrophasianus chirurgus) in Anavilundawa Ramsar sanctuary in Sri Lanka in 2006. Their distribution was recorded in Anavilundawa, Suruwila and Maiyawa
reservoirs, their catchments and respective paddy fields, through line transects. The floral cover of surface water was recorded
by floating quadrates. Water lily (Nymphea spp.) was the dominant flora in Anavilundawa reservoir, invasive water hyacinth (Eichhornia crassipes) in Suruwila reservoir and a native lotus (Nelumbo nucifera) in Maiyawa reservoir, respectively. Anavilundawa area had a higher distribution of birds than in the other two areas. Among
the three species observed, Asian Openbill distribution was mainly restricted to Anavilundawa whereas Pheasant-tailed Jacana
was present in all three areas. Nesting of Asian Openbill occurred only in Anavilundawa while nesting of Pheasant-tailed Jacana
was only observed in Maiyawa. Among the three species recorded, Cotton Pygmy-goose numbers were the least. Asian Openbill
preferred dead trees and trees with no leaves for nesting and perching over live trees. It is concluded that the spread of
invasives such as Water hyacinth and Salvinia (Salvinia molesta) forming mats over surface water have reduced the abundance of habitat specialists like Cotton Pygmy-goose. 相似文献
6.
Background
In the analysis of complex traits, genetic effects can be confounded with non-genetic effects, especially when using full-sib families. Dominance and epistatic effects are typically confounded with additive genetic and non-genetic effects. This confounding may cause the estimated genetic variance components to be inaccurate and biased.Methods
In this study, we constructed genetic covariance structures from whole-genome marker data, and thus used realized relationship matrices to estimate variance components in a heterogenous population of ~ 2200 mice for which four complex traits were investigated. These mice were genotyped for more than 10,000 single nucleotide polymorphisms (SNP) and the variances due to family, cage and genetic effects were estimated by models based on pedigree information only, aggregate SNP information, and model selection for specific SNP effects.Results and conclusions
We show that the use of genome-wide SNP information can disentangle confounding factors to estimate genetic variances by separating genetic and non-genetic effects. The estimated variance components using realized relationship were more accurate and less biased, compared to those based on pedigree information only. Models that allow the selection of individual SNP in addition to fitting a relationship matrix are more efficient for traits with a significant dominance variance. 相似文献7.
Gunaratne PH Wu JQ Garcia AM Hulyk S Worley KC Margolin JF Gibbs RA 《Comptes rendus biologies》2003,326(10-11):971-977
We describe a high-throughput cDNA sequencing pipeline (http://www.hgsc.bcm.tmc.edu/projects/cdna) built in response to the emerging need for rapid sequencing of large cDNA collections. Using this strategy cDNA inserts are purified and joined through concatenation into large molecules. These 'pseudo-BACs' are subjected to random shotgun sequencing whereby the majority of cDNA inserts in the pool are sequenced. Using this concatenation cDNA sequencing platform, we have contributed more than 13000 full-length cDNA sequences from human and mouse to the Mammalian Gene Collection (MGC). 相似文献
8.
Summary The use of reticulated polyurethane foam as a support material for the immobilization of methanogenic associations and its application to the anaerobic treatment of fine particulate solid wastes was investigated. The colonization of polyurethane support particles in a continuous upflow reactor fed on a mixture of acetate, propionate and butyrate, was both rapid and dense. The combination of rumen microorganisms and colonized support particles in a two-phase digester resulted in an efficient anaerobic decomposition of papermill sludge. 相似文献
9.
Anjana Bhardwaj Nivetha Ganesan Kazunoshin Tachibana Kimal Rajapakshe Constance T. Albarracin Preethi H. Gunaratne Cristian Coarfa Isabelle Bedrosian 《PloS one》2015,10(5)
IntroductionAnnexin A1 (ANXA1) is an anti-inflammatory protein reported to play a role in cell proliferation and apoptosis, and to be deregulated in breast cancer. The exact role of annexin A1 in the biology of breast cancer remains unclear. We hypothesized that the annexin A1 plays an oncogenic role in basal subtype of breast cancer by modulating key growth pathway(s).MethodsBy mining the Cancer Genome Atlas (TCGA)-Breast Cancer dataset and manipulating annexin A1 levels in breast cancer cell lines, we studied the role of annexin A1 in breast cancer and underlying signaling pathways.ResultsOur in-silico analysis of TCGA-breast cancer dataset demonstrated that annexin A1 mRNA expression is higher in basal subtype compared to luminal and HER2 subtypes. Within the basal subtype, patients show significantly poorer overall survival associated with higher expression of annexin A1. In both TCGA patient samples and cell lines, annexin A1 levels were significantly higher in basal-like breast cancer than luminal and Her2/neu-positive breast cancer. Stable annexin A1 knockdown in TNBC cell lines suppressed the mTOR-S6 pathway likely through activation of AMPK but had no impact on the MAPK, c-Met, and EGFR pathways. In a cell migration assay, annexin A1-depleted TNBC cells showed delayed migration as compared to wild-type cells, which could be responsible for poor patient prognosis in basal like breast cancers that are known to express higher annexin A1.ConclusionsOur data suggest that annexin A1 is prognostic only in patients with basal like breast cancer. This appears to be in part due to the role of annexin A1 in activating mTOR-pS6 pathway. 相似文献
10.
Martinus AM van Boekel Erik R Vossenaar Frank HJ van den Hoogen Walther J van Venrooij 《Arthritis research & therapy》2001,3(2):1-7
This review focuses on the mechanisms of stress response in the synovial tissue of rheumatoid arthritis. The major stress factors, such as heat stress, shear stress, proinflammatory cytokines and oxidative stress, are discussed and reviewed, focusing on their potential to induce a stress response in the synovial tissue. Several pathways of stress signalling molecules are found to be activated in the synovial membrane of rheumatoid arthritis; of these the most important examples are heat shock proteins, mitogen-activated protein kinases, stress-activated protein kinases and molecules involved in the oxidative stress pathways. The expression of these pathways in vitro and in vivo as well as the consequences of stress signalling in the rheumatoid synovium are discussed. Stress signalling is part of a cellular response to potentially harmful stimuli and thus is essentially involved in the process of synovitis. Stress signalling pathways are therefore new and promising targets of future anti-rheumatic therapies. 相似文献