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991.
Males of certain species belonging to the Bactrocera
dorsalis complex are strongly attracted to, and readily feed on methyl eugenol (ME), a plant secondary compound that is found in over 480 plant species worldwide. Amongst those species is one of the world’s most severe fruit pests the Oriental fruit fly, Bactrocera
dorsalis
s.s., and the former taxonomic species Bactrocera
invadens, Bactrocera
papayae and Bactrocera
philippinensis. The latter species have been recently synonymised with Bactrocera
dorsalis based on their very similar morphology, mating compatibility, molecular genetics and identical sex pheromones following consumption of ME. Previous studies have shown that male fruit fly responsiveness to lures is a unique phenomenon that is dose species-specific, besides showing a close correlation to sexual maturity attainment. This led us to use ME sensitivity as a behavioural parameter to test if Bactrocera
dorsalis and the three former taxonomic species had similar sensitivity towards odours of ME. Using Probit analysis, we estimated the median dose of ME required to elicit species’ positive response in 50% of each population tested (ED50). ED50 values were compared between Bactrocera
dorsalis and the former species. Our results showed no significant differences between Bactrocera
dorsalis
s.s., and the former Bactrocera
invadens, Bactrocera
papayae and Bactrocera
philippinensis in their response to ME. We consider that the Bactrocera males’ sensitivity to ME may be a useful behavioural parameter for species delimitation and, in addition to other integrative taxonomic tools used, provides further supportive evidence that the four taxa belong to one and the same biological species, Bactrocera
dorsalis. 相似文献
992.
993.
994.
995.
996.
Intellectual disability-associated dBRWD3 regulates gene expression through inhibition of HIRA/YEM-mediated chromatin deposition of histone H3.3
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997.
998.
Canying Liu Huajun Zheng Minjun Yang Zhuofei Xu Xiangru Wang Liuya Wei Biao Tang Feng Liu Yanyan Zhang Yi Ding Xibiao Tang Bin Wu Timothy J. Johnson Huanchun Chen Chen Tan 《BMC genomics》2015,16(1)
Background
Strains of extraintestinal pathogenic Escherichia coli (ExPEC) can invade and colonize extraintestinal sites and cause a wide range of infections. Genomic analysis of ExPEC has mainly focused on isolates of human and avian origins, with porcine ExPEC isolates yet to be sequenced. To better understand the genomic attributes underlying the pathogenicity of porcine ExPEC, we isolated two E. coli strains PCN033 and PCN061 from pigs, assessed their in vivo virulence, and completed and compared their genomes.Results
Animal experiments demonstrated that strain PCN033, but not PCN061, was pathogenic in a pig model. The chromosome of PCN033 was 384 kb larger than that of PCN061. Among the PCN033-specific sequences, genes encoding adhesins, unique lipopolysaccharide, unique capsular polysaccharide, iron acquisition and transport systems, and metabolism were identified. Additionally, a large plasmid PCN033p3 harboring many typical ExPEC virulence factors was identified in PCN033. Based on the genetic variation between PCN033 and PCN061, corresponding phenotypic differences in flagellum-dependent swarming motility and metabolism were verified. Furthermore, the comparative genomic analyses showed that the PCN033 genome shared many similarities with genomic sequences of human ExPEC strains. Additionally, comparison of PCN033 genome with other nine characteristic E. coli genomes revealed 425 PCN033-special coding sequences. Genes of this subset included those encoding type I restriction-modification (R-M) system, type VI secretion system (T6SS) and membrane-associated proteins.Conclusions
The genetic and phenotypic differences between PCN033 and PCN061 could partially explain their differences in virulence, and also provide insight towards the molecular mechanisms of porcine ExPEC infections. Additionally, the similarities between the genomes of PCN033 and human ExPEC strains suggest that some connections between porcine and human ExPEC strains exist. The first completed genomic sequence for porcine ExPEC and the genomic differences identified by comparative analyses provide a baseline understanding of porcine ExPEC genetics and lay the foundation for their further study.Electronic supplementary material
The online version of this article (doi:10.1186/s12864-015-1890-9) contains supplementary material, which is available to authorized users. 相似文献999.
Li H Jin G Qin J Tian M Shi J Yang W Tan X Zhang X Zou L 《Histochemistry and cell biology》2011,136(5):515-526
During the central nervous system (CNS) development, radial glia cells (RGCs) play at least two essential roles, they contribute
to neuronal production and the subsequent guidance of neuronal migration, whereas its precise distribution and contribution
to cerebral cortex remains less understood. In this research, we used Vimentin as an astroglial marker and Sox2 as a neural
progenitor marker to identify and investigate RGCs in rat cerebral cortex at embryonic day (E) 16.5. We found that the Sox2+
progenitor cells localized in the germinal zone (GZ) of E16.5 cerebral cortex, ~95% Sox2+ cells co-localized with Vimentin+
or Nestin+ radial processes which extended to the pial surface across the cortical plate (CP). In vitro, we obtained RG-like
cells from E16.5 cerebral cortex on adherent conditions, these Sox2+ Radial glia (RG)-like cells shared some properties with
RGCs in vivo, and these Sox2+ RG-like cells could differentiate into astrocytes, oligodendrocytes and presented the radial
glia—neuron lineage differentiation ability. Taken together, we identified and investigated some characterizations and properties
of Sox2+ RGCs derived from E16.5 cerebral cortex, we suggested that the embryonic Sox2+ progenitor cells which located in
the cortical GZ were mainly composed of Sox2+ RGCs, and the cortex-derived Sox2+ RG-like cells displayed the radial glia—neuron
lineage differentiation ability as neuronal progenitors in vitro. 相似文献
1000.
Hualin Jiang Fangfang Zhong Lu Sun Weiyue Feng Zhong-Xian Huang Xiangshi Tan 《Amino acids》2011,40(4):1195-1204
The cytochrome P450 (CYP) superfamily plays a key role in the oxidative metabolism of a wide range of drugs and exogenous
chemicals. CYP2C8 is the principal enzyme responsible for the metabolism of the anti-cancer drug paclitaxel in the human liver.
Nearly all previous works about polymorphic variants of CYP2C8 were focused on unpurified proteins, either cells or human
liver microsomes; therefore their structure–function relationships were unclear. In this study, two polymorphic enzymes of
CYP2C8 (CYP2C8.4 (I264M) and CYP2C8 P404A) were expressed in E. coli and purified. Metabolic activities of paclitaxel by the two purified polymorphic enzymes were observed. The activity of CYP2C8.4
was 25% and CYP2C8 P404A was 30% of that of WT CYP2C8, respectively. Their structure–function relationships were systematically
investigated for the first time. Paclitaxel binding ability of CYP2C8.4 increased about two times while CYP2C8 P404A decreased
about two times than that of WT CYP2C8. The two polymorphic mutant sites of I264 and P404, located far from active site and
substrate binding sites, significantly affect heme and/or substrate binding. This study indicated that two important nonsubstrate
recognition site (SRS) residues of CYP2C8 are closely related to heme binding and/or substrate binding. This discovery could
be valuable for explaining clinically individual differences in the metabolism of drugs and provides instructed information
for individualized medication. 相似文献