共查询到20条相似文献,搜索用时 15 毫秒
1.
Background
Hormones frequently guide animal development via the induction of cascades of gene activities, whose products further amplify an initial hormonal stimulus. In Drosophila the transformation of the larva into the pupa and the subsequent metamorphosis to the adult stage is triggered by changes in the titer of the steroid hormone 20-hydroxyecdysone. singed wings (swi) is the only gene known in Drosophila melanogaster for which mutations specifically interrupt the transmission of the regulatory signal from early to late ecdysone inducible genes. 相似文献2.
Donald A Yergeau Clair M Kelley Emin Kuliyev Haiqing Zhu Amy K Sater Dan E Wells Paul E Mead 《BMC developmental biology》2010,10(1):11
Background
The Class II DNA transposons are mobile genetic elements that move DNA sequence from one position in the genome to another. We have previously demonstrated that the naturally occurring Tol2 element from Oryzias latipes efficiently integrates its corresponding non-autonomous transposable element into the genome of the diploid frog, Xenopus tropicalis. Tol2 transposons are stable in the frog genome and are transmitted to the offspring at the expected Mendelian frequency. 相似文献3.
4.
Background
The induction of metalloprotease encoded by empA in Vibrio anguillarum occurs at high cell density in salmon intestinal mucus. Previously we have shown that there are significant differences in empA expression in two strains of V. anguillarum, M93Sm and NB10. It is hypothesized that differences in empA regulation are due to differences in binding of regulatory elements. 相似文献5.
6.
Background
Campylobacter jejuni has been divided into two subspecies: C. jejuni subsp. jejuni (Cjj) and C. jejuni subsp. doylei (Cjd). Nearly all of the C. jejuni strains isolated are Cjj; nevertheless, although Cjd strains are isolated infrequently, they differ from Cjj in two key aspects: they are obtained primarily from human clinical samples and are associated often with bacteremia, in addition to gastroenteritis. In this study, we utilized multilocus sequence typing (MLST) and a DNA microarray-based comparative genomic indexing (CGI) approach to examine the genomic diversity and gene content of Cjd strains. 相似文献7.
Ying Huang Xin Wang Zhigang Cui Yuhuan Yang Yuchun Xiao Liuying Tang Biao Kan Jianguo Xu Huaiqi Jing 《BMC microbiology》2010,10(1):211
Background
Yersinia enterocolitica is an enteric pathogen that invades the intestinal mucosa and proliferates within the lymphoid follicles (Peyer's patches). The attachment invasion locus (ail) mediates invasion by Y. enterocolitica and confers an invasive phenotype upon non-invasive E. coli; ail is the primary virulence factor of Y. enterocolitica. The ferrioxamine receptor (foxA) located on the Y. enterocolitica chromosome, together with its transport protein, transports a siderophore specific for ferric ion. Currently, ail is the primary target gene for nucleic acid detection of pathogenic Y. enterocolitica. 相似文献8.
Background
Salmonella enterica serovar Typhi and Typhimurium are closely related serovars as indicated by >96% DNA sequence identity between shared genes. Nevertheless, S. Typhi is a strictly human-specific pathogen causing a systemic disease, typhoid fever. In contrast, S. Typhimurium is a broad host range pathogen causing only a self-limited gastroenteritis in immunocompetent humans. We hypothesize that these differences have arisen because some genes are unique to each serovar either gained by horizontal gene transfer or by the loss of gene activity due to mutation, such as pseudogenes. S. Typhi has 5% of genes as pseudogenes, much more than S. Typhimurium which contains 1%. As a consequence, S. Typhi lacks several protein effectors implicated in invasion, proliferation and/or translocation by the type III secretion system that are fully functional proteins in S. Typhimurium. SseJ, one of these effectors, corresponds to an acyltransferase/lipase that participates in SCV biogenesis in human epithelial cell lines and is needed for full virulence of S. Typhimurium. In S. Typhi, sseJ is a pseudogene. Therefore, we suggest that sseJ inactivation in S. Typhi has an important role in the development of the systemic infection. 相似文献9.
Kalliopi Georgiades Vicky Merhej Khalid El Karkouri Didier Raoult Pierre Pontarotti 《Biology direct》2011,6(1):6
Background
Genome degradation is an ongoing process in all members of the Rickettsiales order, which makes these bacterial species an excellent model for studying reductive evolution through interspecies variation in genome size and gene content. In this study, we evaluated the degree to which gene loss shaped the content of some Rickettsiales genomes. We shed light on the role played by horizontal gene transfers in the genome evolution of Rickettsiales. 相似文献10.
Background
Aeromonas spp. have been regarded as "emerging pathogens". Aeromonads possess multifactorial virulence and the production of many of these virulence determinants is associated with high cell density, a phenomenon that might be regulated by quorum sensing. However, only two species of the genus are reported to possess the luxRI quorum sensing gene homologs. The purpose of this study was to investigate if the luxRI homologs are universally present in the Aeromonas strains collected from various culture collections, clinical laboratories and field studies. 相似文献11.
Background
Of the major families of long terminal repeat (LTR) retrotransposons, the Pao/BEL family is probably the least well studied. It is becoming apparent that numerous LTR retrotransposons and other mobile genetic elements have colonized the genome of the human blood fluke, Schistosoma mansoni. 相似文献12.
Background
Gonadotropin releasing hormone (GnRH) is responsible for stimulation of gonadotropic hormone (GtH) in the hypothalamus-pituitary-gonadal axis (HPG). The regulatory mechanisms responsible for brain specificity make the promoter attractive for in silico analysis and reporter gene studies in zebrafish (Danio rerio).Results
We have characterized a zebrafish [Trp7, Leu8] or salmon (s) GnRH variant, gnrh 3. The gene includes a 1.6 Kb upstream regulatory region and displays the conserved structure of 4 exons and 3 introns, as seen in other species. An in silico defined enhancer at -976 in the zebrafish promoter, containing adjacent binding sites for Oct-1, CREB and Sp1, was predicted in 2 mammalian and 5 teleost GnRH promoters. Reporter gene studies confirmed the importance of this enhancer for cell specific expression in zebrafish. Interestingly the promoter of human GnRH-I, known as mammalian GnRH (mGnRH), was shown capable of driving cell specific reporter gene expression in transgenic zebrafish.Conclusions
The characterized zebrafish Gnrh3 decapeptide exhibits complete homology to the Atlantic salmon (Salmo salar) GnRH-III variant. In silico analysis of mammalian and teleost GnRH promoters revealed a conserved enhancer possessing binding sites for Oct-1, CREB and Sp1. Transgenic and transient reporter gene expression in zebrafish larvae, confirmed the importance of the in silico defined zebrafish enhancer at -976. The capability of the human GnRH-I promoter of directing cell specific reporter gene expression in zebrafish supports orthology between GnRH-I and GnRH-III.13.
Background
Transposable elements are abundant in eukaryotic genomes and it is believed that they have a significant impact on the evolution of gene and chromosome structure. While there are several completed eukaryotic genome projects, there are only few high quality genome wide annotations of transposable elements. Therefore, there is a considerable demand for computational identification of transposable elements. LTR retrotransposons, an important subclass of transposable elements, are well suited for computational identification, as they contain long terminal repeats (LTRs). 相似文献14.
15.
16.
Radim Cegan Gabriel AB Marais Hana Kubekova Nicolas Blavet Alex Widmer Boris Vyskot Jaroslav Doležel Jan Šafář Roman Hobza 《BMC plant biology》2010,10(1):180
Background
The evolution of sex chromosomes is often accompanied by gene or chromosome rearrangements. Recently, the gene AP3 was characterized in the dioecious plant species Silene latifolia. It was suggested that this gene had been transferred from an autosome to the Y chromosome. 相似文献17.
Svetlana?E?Moskalenko Svetlana?V?Chabelskaya Sergei?G?Inge-Vechtomov Michel?Philippe Galina?A?Zhouravleva
Background
Termination of protein synthesis in eukaryotes involves at least two polypeptide release factors (eRFs) – eRF1 and eRF3. The highly conserved translation termination factor eRF1 in Saccharomyces cerevisiae is encoded by the essential gene SUP45. 相似文献18.
Jiu-Cun Wang Syeling Lai Xinjian Guo Xuefeng Zhang Benoit de Crombrugghe Sonali Sonnylal Frank C Arnett Xiaodong Zhou 《Arthritis research & therapy》2010,12(2):R60
Introduction
SPARC is a matricellular protein, which, along with other extracellular matrix components including collagens, is commonly over-expressed in fibrotic diseases. The purpose of this study was to examine whether inhibition of SPARC can regulate collagen expression in vitro and in vivo, and subsequently attenuate fibrotic stimulation by bleomycin in mouse skin and lungs. 相似文献19.
Guma MK Abdeldaim Kristoffer Strålin Jens Korsgaard Jonas Blomberg Christina Welinder-Olsson Björn Herrmann 《BMC microbiology》2010,10(1):310
Background
Streptococcus pneumoniae and Haemophilus influenzae cause pneumonia and as Neisseria meningitidis they are important agents of meningitis. Although several PCR methods have been described for these bacteria the specificity is an underestimated problem. Here we present a quantitative multiplex real-time PCR (qmPCR) for detection of S. pneumoniae (9802 gene fragment), H. influenzae (omp P6 gene) and N. meningitidis (ctrA gene). The method was evaluated on bronchoalveolar lavage (BAL) samples from 156 adults with lower respiratory tract infection (LRTI) and 31 controls, and on 87 cerebrospinal fluid (CSF) samples from meningitis patients. 相似文献20.
Borbála Tihanyi Tibor Vellai Ágnes Regős Eszter Ari Fritz Müller Krisztina Takács-Vellai 《BMC developmental biology》2010,10(1):78