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1.
Zhong H Li XL Li M Hao LX Chen RW Xiang K Qi XB Ma RZ Su B 《Arthritis research & therapy》2011,13(6):R186
Introduction
Recent genome-wide and candidate gene association studies in large numbers of systemic lupus erythematosus (SLE) patients have suggested approximately 30 susceptibility genes. These genes are involved in three types of biological processes, including immune complex processing, toll-like receptor function and type I interferon production, and immune signal transduction in lymphocytes, and they may contribute to the pathogenesis of SLE. To better understand the genetic risk factors of SLE, we investigated the associations of seven SLE susceptibility genes in a Chinese population, including FCGR3A, FCGR2A, TNFAIP3, TLR9, TREX1, ETS1 and TNIP1. 相似文献2.
Background
Many genes involved in the sex determining cascade have indicated signals of positive selection and rapid evolution across different species. Even though fruitless is an important gene involved mostly in several aspects of male courtship behavior, the few studies so far have explained its high rates of evolution by relaxed selective constraints. This would indicate that a large portion of this gene has evolved neutrally, contrary to what has been observed for other genes in the sex cascade. 相似文献3.
4.
Robert E Lintner Pankaj K Mishra Poonam Srivastava Betsy M Martinez-Vaz Arkady B Khodursky Robert M Blumenthal 《BMC microbiology》2008,8(1):60
Background
Bacterial genome sequences are being determined rapidly, but few species are physiologically well characterized. Predicting regulation from genome sequences usually involves extrapolation from better-studied bacteria, using the hypothesis that a conserved regulator, conserved target gene, and predicted regulator-binding site in the target promoter imply conserved regulation between the two species. However many compared organisms are ecologically and physiologically diverse, and the limits of extrapolation have not been well tested. In E. coli K-12 the leucine-responsive regulatory protein (Lrp) affects expression of ~400 genes. Proteus mirabilis and Vibrio cholerae have highly-conserved lrp orthologs (98% and 92% identity to E. coli lrp). The functional equivalence of Lrp from these related species was assessed. 相似文献5.
Zhenqiu Liu Laurence S Magder Terry Hyslop Li Mao 《Algorithms for molecular biology : AMB》2010,5(1):30
It has been demonstrated that genes in a cell do not act independently. They interact with one another to complete certain
biological processes or to implement certain molecular functions. How to incorporate biological pathways or functional groups
into the model and identify survival associated gene pathways is still a challenging problem. In this paper, we propose a
novel iterative gradient based method for survival analysis with group L
p
penalized global AUC summary maximization. Unlike LASSO, L
p
(p < 1) (with its special implementation entitled adaptive LASSO) is asymptotic unbiased and has oracle properties [1]. We first extend L
p
for individual gene identification to group L
p
penalty for pathway selection, and then develop a novel iterative gradient algorithm for penalized global AUC summary maximization
(IGGAUCS). This method incorporates the genetic pathways into global AUC summary maximization and identifies survival associated
pathways instead of individual genes. The tuning parameters are determined using 10-fold cross validation with training data
only. The prediction performance is evaluated using test data. We apply the proposed method to survival outcome analysis with
gene expression profile and identify multiple pathways simultaneously. Experimental results with simulation and gene expression
data demonstrate that the proposed procedures can be used for identifying important biological pathways that are related to
survival phenotype and for building a parsimonious model for predicting the survival times. 相似文献
6.
Background
The novel chimeric open reading frame (orf) resulting from the rearrangement of a mitochondrial genome is generally thought to be a causal factor in the occurrence of cytoplasmic male sterility (CMS). Both positive and negative correlations have been found between CMS-associated orfs and the occurrence of CMS when CMS-associated orfs were expressed and targeted at mitochondria. Some orfs cause male sterility or semi-sterility, while some do not. Little is currently known about how mitochondrial factor regulates the expression of the nuclear genes involved in male sterility. The purpose of this study was to investigate the biological function of a candidate CMS-associated orf220 gene, newly isolated from cytoplasmic male-sterile stem mustard, and show how mitochondrial retrograde regulated nuclear gene expression is related to male sterility. 相似文献7.
8.
9.
Lingqiang Wang Kai Guo Yu Li Yuanyuan Tu Huizhen Hu Bingrui Wang Xiaocan Cui Liangcai Peng 《BMC plant biology》2010,10(1):282
Background
The cellulose synthase and cellulose synthase-like gene superfamily (CESA/CSL) is proposed to encode enzymes for cellulose and non-cellulosic matrix polysaccharide synthesis in plants. Although the rice (Oryza sativa L.) genome has been sequenced for a few years, the global expression profiling patterns and functions of the OsCESA/CSL superfamily remain largely unknown. 相似文献10.
Kenneth M Noll Pascal Lapierre J Peter Gogarten Dhaval M Nanavati 《BMC evolutionary biology》2008,8(1):7
Background
The mal genes that encode maltose transporters have undergone extensive lateral transfer among ancestors of the archaea Thermococcus litoralis and Pyrococcus furiosus. Bacterial hyperthermophiles of the order Thermotogales live among these archaea and so may have shared in these transfers. The genome sequence of Thermotoga maritima bears evidence of extensive acquisition of archaeal genes, so its ancestors clearly had the capacity to do so. We examined deep phylogenetic relationships among the mal genes of these hyperthermophiles and their close relatives to look for evidence of shared ancestry. 相似文献11.
12.
13.
Laurent X Nouvel Tiago Dos Vultos Eric Kassa-Kelembho Jean Rauzier Brigitte Gicquel 《BMC microbiology》2007,7(1):39
Background
Previous studies have suggested that variations in DNA repair genes of W-Beijing strains may have led to transient mutator phenotypes which in turn may have contributed to host adaptation of this strain family. Single nucleotide polymorphism (SNP) in the DNA repair gene mutT1 was identified in MDR-prone strains from the Central African Republic. A Mycobacteriumtuberculosis H37Rv mutant inactivated in two DNA repair genes, namely ada/alkA and ogt, was shown to display a hypermutator phenotype. We then looked for polymorphisms in these genes in Central African Republic strains (CAR). 相似文献14.
Helena Marešová Zdena Marková Renáta Valešová Jan Sklenář Pavel Kyslík 《BMC biotechnology》2010,10(1):7
Background
Penicillin G acylase of Escherichia coli (PGAEc) is a commercially valuable enzyme for which efficient bacterial expression systems have been developed. The enzyme is used as a catalyst for the hydrolytic production of β-lactam nuclei or for the synthesis of semi-synthetic penicillins such as ampicillin, amoxicillin and cephalexin. To become a mature, periplasmic enzyme, the inactive prepropeptide of PGA has to undergo complex processing that begins in the cytoplasm (autocatalytic cleavage), continues at crossing the cytoplasmic membrane (signal sequence removing), and it is completed in the periplasm. Since there are reports on impressive cytosolic expression of bacterial proteins in Pichia, we have cloned the leader-less gene encoding PGAEc in this host and studied yeast production capacity and enzyme authenticity. 相似文献15.
Shigeyuki Tanaka Akari Ichikawa Kaori Yamada Gento Tsuji Takumi Nishiuchi Masashi Mori Hironori Koga Yoko Nishizawa Richard O'Connell Yasuyuki Kubo 《BMC plant biology》2010,10(1):288
Background
Rice CEBiP recognizes chitin oligosaccharides on the fungal cell surface or released into the plant apoplast, leading to the expression of plant disease resistance against fungal infection. However, it has not yet been reported whether CEBiP is actually required for restricting the growth of fungal pathogens. Here we evaluated the involvement of a putative chitin receptor gene in the basal resistance of barley to the ssd1 mutant of Magnaporthe oryzae, which induces multiple host defense responses. 相似文献16.
Background
Vibrio cholerae is the causative agent of cholera. Extensive studies reveal that complicated regulatory cascades regulate expression of virulence genes, the products of which are required for V. cholerae to colonize and cause disease. In this study, we investigated the expression of the key virulence regulator ToxR under different conditions. 相似文献17.
Background
Interspecific hybrids of frogs of the genus Xenopus result in sterile hybrid males and fertile hybrid females. Previous work has demonstrated a dramatic asymmetrical pattern of misexpression in hybrid males compared to the two parental species with relatively few genes misexpressed in comparisons of hybrids and the maternal species (X. laevis) and dramatically more genes misexpressed in hybrids compared to the paternal species (X. muelleri). In this work, we examine the gene expression pattern in hybrid females of X. laevis × X. muelleri to determine if this asymmetrical pattern of expression also occurs in hybrid females. 相似文献18.
Elena Simionato Pierre Kerner Nicolas Dray Martine Le Gouar Valérie Ledent Detlev Arendt Michel Vervoort 《BMC evolutionary biology》2008,8(1):170
Background
Functional studies in model organisms, such as vertebrates and Drosophila, have shown that basic Helix-loop-Helix (bHLH) proteins have important roles in different steps of neurogenesis, from the acquisition of neural fate to the differentiation into specific neural cell types. However, these studies highlighted many differences in the expression and function of orthologous bHLH proteins during neural development between vertebrates and Drosophila. To understand how the functions of neural bHLH genes have evolved among bilaterians, we have performed a detailed study of bHLH genes during nervous system development in the polychaete annelid, Platynereis dumerilii, an organism which is evolutionary distant from both Drosophila and vertebrates. 相似文献19.
Misa U Austin Wei-Siang Liau Krishnaswamy Balamurugan Balasubramaniem Ashokkumar Hamid M Said Craig W LaMunyon 《BMC developmental biology》2010,10(1):46
Background
The C. elegans gene folt-1 is an ortholog of the human reduced folate carrier gene. The FOLT-1 protein has been shown to transport folate and to be involved in uptake of exogenous folate by worms. A knockout mutation of the gene, folt-1(ok1460), was shown to cause sterility, and here we investigate the source of the sterility and the effect of the folt-1 knockout on somatic function. 相似文献20.