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1.
Egbert KO Kruithof Nathalie Satta Jia Wei Liu Sylvie Dunoyer-Geindre Richard J Fish 《BMC evolutionary biology》2007,7(1):148
Background
Toll-like receptors (TLR) recognize pathogen-associated molecular patterns and are important mediators of the innate immune system. TLR1 and TLR6 are paralogs and located in tandem on the same chromosome in mammals. They form heterodimers with TLR2 and bind lipopeptide components of gram-positive and gram-negative bacterial cell walls. To identify conserved stretches in TLR1 and TLR6, that may be important for their function, we compared their protein sequences in nine mammalian species(Homo sapiens, Pan troglodytes, Macaca mulatta, Mus musculus, Rattus norvegicus; Erinaceus europaeus, Bos Taurus, Sus scrofa and Canis familiaris). 相似文献2.
Genes of the immunoglobulin superfamily (IgSF) have a wide variety of cellular activities. In this study, we investigated
molecular evolution of IgSF genes in primates by comparing orthologous sequences of 249 IgSF genes among human, chimpanzee,
orangutan, rhesus macaque, and common marmoset. To evaluate the non-synonymous/synonymous substitution ratio (ω), we applied
Bn-Bs program and PAML program. IgSF genes were classified into 11 functional categories based on the Gene Ontology (GO) database.
Among them, IgSF genes in three functional categories, immune system process (GO:0002376), defense response (GO:0006952),
and multi-organism process (GO:0051704), which are tightly linked to the regulation of immune system had much higher values
of ω than genes in the other GO categories. In addition, we estimated the average values of ω for each primate lineage. Although
each primate lineage had comparable average values of ω, the human lineage showed the lowest ω value for the immune-related
genes. Furthermore, 11 IgSF genes, SIGLEC5, SLAMF6, CD33, CD3E, CEACAM8, CD3G, FCER1A, CD48, CD4, TIM4, and FCGR2A, were implied to have been under positive selective pressure during the course of primate evolution. Further sequence analyses
of CD3E and CD3G from 23 primate species suggested that the Ig domains of CD3E and CD3G underwent the positive Darwinian selection. 相似文献
3.
Background
Protein-coding change is one possible genetic mechanism underlying the evolution of adaptive wing colour pattern variation in Heliconius butterflies. Here we determine whether 38 putative genes within two major Heliconius patterning loci, HmYb and HmB, show evidence of positive selection. Ratios of nonsynonymous to synonymous nucleotide changes (ω) were used to test for selection, as a means of identifying candidate genes within each locus that control wing pattern. 相似文献4.
Olin D. Anderson Yong Q. Gu Xiuying Kong Gerard R. Lazo Jiajie Wu 《Functional & integrative genomics》2009,9(3):397-410
A survey and analysis is made of all available ω-gliadin DNA sequences including ω-gliadin genes within a large genomic clone,
previously reported gene sequences, and ESTs identified from the large wheat EST collection. A contiguous portion of the Gli-B3 locus is shown to contain two apparently active ω-gliadin genes, two pseudogenes, and four fragments of the 3′ portion of
ω-gliadin sequences. Comparison of ω-gliadin sequences allows a phylogenetic picture of their relationships and genomes of
origin. Results show three groupings of ω-gliadin active gene sequences assigned to each of the three hexaploid wheat genomes,
and a fourth group thus far consisting of pseudogenes assigned to the A-genome. Analysis of ω-gliadin ESTs allows reconstruction
of two full-length model sequences encoding the AREL- and ARQL-type proteins from the Gli-A3 and Gli-D3 loci, respectively. There is no DNA evidence of multiple active genes from these two loci. In contrast, ESTs allow identification
of at least three to four distinct active genes at the Gli-B3 locus of some cultivars. Additional results include more information on the position of cysteines in some ω-gliadin genes
and discussion of problems in studying the ω-gliadin gene family.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
5.
6.
Giovanna Jaramillo-Gutierrez Janneth Rodrigues Georges Ndikuyeze Michael Povelones Alvaro Molina-Cruz Carolina Barillas-Mury 《BMC microbiology》2009,9(1):154
Background
Functional screens based on dsRNA-mediated gene silencing identified several Anopheles gambiae genes that limit Plasmodium berghei infection. However, some of the genes identified in these screens have no effect on the human malaria parasite Plasmodium falciparum; raising the question of whether different mosquito effector genes mediate anti-parasitic responses to different Plasmodium species. 相似文献7.
Olivier Jaen Elisabeth Petit-Teixeira Holger Kirsten Peter Ahnert Luca Semerano Céline Pierlot Francois Cornelis Marie-Christophe Boissier Geraldine Falgarone 《Arthritis research & therapy》2009,11(1):R5-10
Introduction
The objective was to study the potential genetic contribution of Toll-like receptor (TLR) genes in rheumatoid arthritis (RA). TLRs bind to pathogen-associated molecular patterns, and TLR genes influence both proinflammatory cytokine production and autoimmune responses. Host–pathogen interactions are involved in RA physiopathology. 相似文献8.
Background
Fine tuning expression of genes is a prerequisite for the strictly human pathogen Neisseria meningitidis to survive hostile growth conditions and establish disease. Many bacterial species respond to stress by using alternative σ factors which, in complex with RNA polymerase holoenzyme, recognize specific promoter determinants. σE, encoded by rpoE (NMB2144) in meningococci, is known to be essential in mounting responses to environmental challenges in many pathogens. Here we identified genes belonging to the σE regulon of meningococci. 相似文献9.
Tatjana Sjakste Kristina Bielskiene Marion Röder Olga Sugoka Danute Labeikyte Lida Bagdoniene Benediktas Juodka Yegor Vassetzky Nikolajs Sjakste 《BMC plant biology》2009,9(1):56-16
Background
The tightly bound to DNA proteins (TBPs) is a protein group that remains attached to DNA with covalent or non-covalent bonds after its deproteinisation. The functional role of this group is as yet not completely understood. The main goal of this study was to evaluate tissue specific changes in the TBP distribution in barley genes and chromosomes in different phases of shoot and seed development. We have: 1. investigated the TBP distribution along Amy32b and Bmy1 genes encoding low pI α-amylase A and endosperm specific β-amylase correspondingly using oligonucleotide DNA arrays; 2. characterized the polypeptide spectrum of TBP and proteins with affinity to TBP-associated DNA; 3. localized the distribution of DNA complexes with TBP (TBP-DNA) on barley 1H and 7H chromosomes using mapped markers; 4. compared the chromosomal distribution of TBP-DNA complexes to the distribution of the nuclear matrix attachment sites. 相似文献10.
Bacterial α2-macroglobulins: colonization factors acquired by horizontal gene transfer from the metazoan genome?
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Background
Invasive bacteria are known to have captured and adapted eukaryotic host genes. They also readily acquire colonizing genes from other bacteria by horizontal gene transfer. Closely related species such as Helicobacter pylori and Helicobacter hepaticus, which exploit different host tissues, share almost none of their colonization genes. The protease inhibitor α2-macroglobulin provides a major metazoan defense against invasive bacteria, trapping attacking proteases required by parasites for successful invasion. 相似文献11.
12.
Toll-like receptors (TLRs) mediate immune response via recognition of pathogen-associated molecular patterns (PAMPs), thus
play important roles in host defense. Polymorphisms of TLR5 may affect their recognition of bacterial flagellin, leading to
varied host resistance to pathogenic infections. Here, we cloned TLR5 genes from Common Pheasant, Guinea fowl and 9 Chicken
breeds and analyzed their sequences. The open reading frames of TLR5 were sequenced. Amino acid analysis indicated that TLR5
from Chicken breeds shared 99.4–99.9% homology. The amino acid homology of TLR5 ranged from 92.1 to 92.5% between Chickens
and Guinea fowl, 95.7–96.1% between Chickens and Turkey, 94.3–94.7% between Chickens and Common Pheasant, and 79.9–80.1% between
Chickens and Zebra-finch. Different genetic patterns were determined among Chickens, Common Pheasant, Guinea fowl, Turkey
and Zebra-finch. It was found that there were 92 amino acid polymorphic sites, among which 5 sites in chicken TLR5, 63 sites
in Guinea fowl TLR5 and 44 sites in Common Pheasant TLR5. Our data indicate that the positive Darwinian selection occurred
in avian TLR5 genes since frequency of non-synonymous (d
N
) > frequency of synonymous (d
S
). These results also demonstrate that avian TLR5 genes are polymorphic among avian breeds, suggesting a varied resistance
among breeds of avian. This information might be of help to improve the health of avian by breeding and vaccination. 相似文献
13.
Mayken W Wadman Ronald P de Vries Stefanie IC Kalkhove Gerrit A Veldink Johannes FG Vliegenthart 《BMC microbiology》2009,9(1):59
Background
Aspergillus niger is an ascomycetous fungus that is known to reproduce through asexual spores, only. Interestingly, recent genome analysis of A. niger has revealed the presence of a full complement of functional genes related to sexual reproduction [1]. An example of such genes are the dioxygenase genes which in Aspergillus nidulans, have been shown to be connected to oxylipin production and regulation of both sexual and asexual sporulation [2–4]. Nevertheless, the presence of sex related genes alone does not confirm sexual sporulation in A. niger. 相似文献14.
15.
Natsumi Okada Shigeaki Matsuda Junko Matsuyama Kwon-Sam Park Calvin de los Reyes Kazuhiro Kogure Takeshi Honda Tetsuya Iida 《BMC microbiology》2010,10(1):302
Background
Vibrios, which include more than 100 species, are ubiquitous in marine and estuarine environments, and several of them e.g. Vibrio cholerae, V. parahaemolyticus, V. vulnificus and V. mimicus, are pathogens for humans. Pathogenic V. parahaemolyticus strains possess two sets of genes for type III secretion system (T3SS), T3SS1 and T3SS2. The latter are critical for virulence of the organism and be classified into two distinct phylogroups, T3SS2α and T3SS2β, which are reportedly also found in pathogenic V. cholerae non-O1/non-O139 serogroup strains. However, whether T3SS2-related genes are present in other Vibrio species remains unclear. 相似文献16.
Cholesterol‐α‐glucosyltransferase gene is present in most Helicobacter species including gastric non‐Helicobacter pylori helicobacters obtained from Japanese patients
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Masatomo Kawakubo Kazuki Horiuchi Takehisa Matsumoto Jun Nakayama Taiji Akamatsu Tsutomu Katsuyama Hiroyoshi Ota Junji Sagara 《Helicobacter》2018,23(1)
Background
Non‐Helicobacter pylori helicobacters (NHPHs) besides H. pylori infect human stomachs and cause chronic gastritis and mucosa‐associated lymphoid tissue lymphoma. Cholesteryl‐α‐glucosides have been identified as unique glycolipids present in H. pylori and some Helicobacter species. Cholesterol‐α‐glucosyltransferase (αCgT), a key enzyme for the biosynthesis of cholesteryl‐α‐glucosides, plays crucial roles in the pathogenicity of H. pylori. Therefore, it is important to examine αCgTs of NHPHs.Materials and Methods
Six gastric NHPHs were isolated from Japanese patients and maintained in mouse stomachs. The αCgT genes were amplified by PCR and inverse PCR. We retrieved the αCgT genes of other Helicobacter species by BLAST searches in GenBank.Results
αCgT genes were present in most Helicobacter species and in all Japanese isolates examined. However, we could find no candidate gene for αCgT in the whole genome of Helicobacter cinaedi and several enterohepatic species. Phylogenic analysis demonstrated that the αCgT genes of all Japanese isolates show high similarities to that of a zoonotic group of gastric NHPHs including Helicobacter suis, Helicobacter heilmannii, and Helicobacter ailurogastricus. Of 6 Japanese isolates, the αCgT genes of 4 isolates were identical to that of H. suis, and that of another 2 isolates were similar to that of H. heilmannii and H. ailurogastricus.Conclusions
All gastric NHPHs examined showed presence of αCgT genes, indicating that αCgT may be beneficial for these helicobacters to infect human and possibly animal stomachs. Our study indicated that NHPHs could be classified into 2 groups, NHPHs with αCgT genes and NHPHs without αCgT genes. 相似文献17.
18.
Price ER Staples JF Milligan CL Guglielmo CG 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2011,181(4):565-573
Birds primarily fuel migratory flights with fat, and the composition of that fat has the potential to affect overall lipid
oxidation rates. We measured the whole muscle lipid oxidation rates in extensor digitorum communis muscles from white-throated sparrows (Zonotrichia albicollis Gmelin) incubated for 20 min at 20°C with radiolabeled stearate (18:0), oleate (18:1ω9), or linoleate (18:2ω6). Lipid oxidation
rates were ~40% higher with linoleate than oleate (oleate: 36 ± 8.54 μmol CO2 g−1 h−1), and ~75% lower with stearate compared with oleate, indicating that maximal lipid oxidation rates can indeed be affected
by the type of fatty acid supplied to the muscle. Additionally, we investigated the activity of the mitochondrial fatty acid
transport-associated enzyme carnitine palmitoyl transferase (CPT) in pectoralis muscles of 5 bird species (Zonotrichia albicollis, Philomachus pugnax, Sturnus vulgaris, Taeniopygia guttata, Passer domesticus). Activity was measured in homogenized samples using various fatty acyl-CoA substrates (16:0, 16:1, 18:0, 18:1ω9, 18:2ω6,
18:3ω3, 18:3ω6, 20:0, 20:4ω6, 22:6ω3) in a spectrophotometric assay. CPT activity increased with the degree of unsaturation
and decreased with chain length. CPT activity did not differ between ω3 and ω6 isomers of 18:3, nor was the pattern of CPT
substrate preference different between captive white-throated sparrows in a migratory (i.e., displaying Zugunruhe) or non-migratory
state. These findings can explain previously observed differences in peak performance induced by dietary fat composition and
suggest that lipid supply is limiting to maximal exercise performance in birds. 相似文献
19.
Background
Streptomyces coelicolor is the most studied Streptomyces species and an excellent model for studying differentiation and antibiotic production. To date, many genes have been identified to be required for its differentiation (e.g. bld genes for aerial growth and whi genes for sporulation) and antibiotics production (including actII-orf4, redD, cdaR as pathway-specific regulatory genes and afsR, absA1/A2 as pleiotropic regulatory genes). 相似文献20.