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1.
Chinese wild grapes are almost exclusively dioecious and black-fruited, with rare reports of white and hermaphrodite types in V. davidii. To reveal the molecular mechanisms of these phenotypic variations, specific primers were designed to detect the genotypes of mybA-related genes in Vitis species, including the Chinese wild Vitis species, V. riparia, V. rupestris, cultivars of Vitis vinifera and its hybrids. We report here that three mybA-related genes, VvmybA1a, VvmybA2 and VvmybA3, were only detected in cultivars of V. vinifera and its hybrids, but not in V. riparia, V. rupestris or Chinese wild Vitis species, indicating that these genes could be used to test the genetic relationship to V. vinifera. On the other hand, the genes were not detected in the dioecious varieties of V. davidii, but were in the hermaphrodites. In particular, the white-fruited varieties were homozygous for VvmybA1a and showed a low expression of mybA-related genes and UFGT during the entire maturation period. Simple sequence repeat analysis showed that the hermaphrodite varieties of V. davidii, including the white-fruited varieties, were more closely related to V. vinifera cv. Pinot Noir and V. labruscana cv. Kyoho. These results suggested that the white-fruited and hermaphrodite varieties of V. davidii could be the result of its crossing with V. vinifera. It provides a new approach to identify truly Chinese wild varieties and to search for possible hybridization events.  相似文献   

2.
Raman spectra of low (13°C) and high (16°C) m.p. crystals of oleic acid were recorded and the spectral differences were ascribed to different conformations around a pair of sp2, CC axes, i.e. (skew, skew′) and (skew, skew). Crystalline modifications (m.p. 29°C and 29.5°C) of petroselinic acid were found for the first time; after spectral comparison with oleic acid conformations in those crystals were predicted to be (skew, skew′) and (skew, skew). Raman spectra of dioleoyl- and dipetroselinoyl-l-α-phosphatidylcholines were measured for different crystalline phases and the conformation was examined.The skeletal vibration bands of the polymethylene chains of cis- and trans-unsaturated fatty-acids were analysed by using the frequency-phase difference relationships of saturated fatty-acids. The ν4 (stretching) vibrations were localised within each polymethylene chain and the bands of an acid CH3(CH2)m?2CHCH(CH2)n?2COOH were explained in terms of the set of phase differences δ = /m and /n (k = 1, 2,..). A unique ν4 vibration with δ = π/2m was also found. The ν5 (bending) vibrations sometimes couple strongly with each other to form overall vibrations characterised by δ = /(m + n).Implications of the cis-olefin group for the physical properties of phospholipid bilayers and the applicability of Raman spectroscopy in probing chain conformations were discussed.  相似文献   

3.
4.
Elimination and metabolic profiles of the O-glucuronide conjugated products of pyrilamine and their nonconjugated O-dealkylated and N-desmethyl pyrilamine products were determined after the oral administration of (14C)-pyrilamine maleate to Fischer 344 rats, B6C3F1 mice and female rhesus monkeys by stomach tube or i.v. The total cumulative urinary and fecal pyrilamine products were determined. The conjugated pyrilamine metabolites, isolated and identified were the glucuronide products of O-dealkylated pyrilamine and ring-hydroxylated pyrilamine, and the nonconjugated metabolites were predominately the N-desmethylpyrilamine and O-dealkylated pyrilamine and their ring-hydroxylated products. Statistically significant differences were observed in the percentages of the conjugated and nonconjugated metabolites of pyrilamine excreted by the three species studied.  相似文献   

5.
The growth rate and percentage of fertile individuals were studied in the lichens Cladonia rangiferina and C. mitis growing on various substrates in a heath-lichen pine forest and a bilberry-cowberry pine forest with Pleurozium and other mosses, both on the White Sea coast. The substrates were soil, rocks, and pine wood. The proportion of different forms of C. rangiferina growing on the same substrate was compared between the two forest types. C. rangiferina f. rangiferina was more abundant on soil, while C. rangiferina f. crispata dominated on wood. The effect of the substrate on the development of different lichen forms is discussed. The maximum growth rate and the maximum percentage of fertile individuals were recorded in the lichens growing on soil; these parameters were minimal in the lichens growing on wood. These differences were more pronounced in C. rangiferina than in C. mitis. The effects of the nutritive quality and the humidity of the substrate on the growth rate and apothecia formation in lichens are discussed.  相似文献   

6.

Aim

To evaluate the association between the EPHX1 Tyr113His and His139Arg polymorphisms in the EPHX1 gene and the risk of head and neck cancer.

Materials and Methods

Studies on the association of EPHX1 Tyr113His and His139Arg polymorphisms with HNC performed up until June 1st, 2014, were identified using a predefined search strategy. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the strength of these associations.

Results

In this meta-analysis, 10 case-control studies, which included 9 studies of Tyr113His (1890 cases and 1894 controls) and 10 studies of His139Arg polymorphisms (1982 cases and 2024 controls), were considered eligible for inclusion. Overall, the pooled results indicated that the EPHX1 Tyr113His polymorphism was significantly associated with increased HNC risk (Tyr/His vs. Tyr/Tyr, OR = 1.26, 95%1.02–1.57;His/His+ Tyr/His vs. Tyr/Tyr, OR = 1.29, 95% I = 1.03–1.61). However, no significant association was found between the His139Arg polymorphism and HNC risk. In the subgroup analysis, a statistically significant association between the EPHX1 Tyr113His polymorphism and HNC was observed in population-based case-control studies (PCC), which involved less than 500 participants and genotype frequencies in HWE. This association showed minimal heterogeneity after excluding studies that were determined to contribute to heterogeneity. After categorizing the studies by publication time, a sensitivity analysis and cumulative meta-analysis of the two associations were conducted, and the results of the two analyses were consistent.

Conclusion

Our meta-analysis suggests that EPHX1 Tyr113His polymorphism may be a risk factor for HNC, while the EPHX1 His139Arg polymorphism has no association with HNC risk.  相似文献   

7.
8.
Bradyrhizobium comprises most tropical symbiotic nitrogen-fixing strains, but the correlation between symbiotic and core genes with host specificity is still unclear. In this study, the phylogenies of the nodY/K and nifH genes of 45 Bradyrhizobium strains isolated from legumes of economic and environmental importance in Brazil (Arachis hypogaea, Acacia auriculiformis, Glycine max, Lespedeza striata, Lupinus albus, Stylosanthes sp. and Vigna unguiculata) were compared to 16S rRNA gene phylogeny and genetic diversity by rep-PCR. In the 16S rRNA tree, strains were distributed into two superclades—B. japonicum and B. elkanii—with several strains being very similar within each clade. The rep-PCR analysis also revealed high intra-species diversity. Clustering of strains in the nodY/K and nifH trees was identical: 39 strains isolated from soybean grouped with Bradyrhizobium type species symbionts of soybean, whereas five others occupied isolated positions. Only one strain isolated from Stylosanthes sp. showed similar nodY/K and nifH sequences to soybean strains, and it also nodulated soybean. Twenty-one representative strains of the 16S rRNA phylogram were selected and taxonomically classified using a concatenated glnII-recA phylogeny; nodC sequences were also compared and revealed the same clusters as observed in the nodY/K and nifH phylograms. The analyses of symbiotic genes indicated that a large group of strains from the B. elkanii superclade comprised the novel symbiovar sojae, whereas for another group, including B. pachyrhizi, the symbiovar pachyrhizi could be proposed. Other potential new symbiovars were also detected. The co-evolution hypotheses is discussed and it is suggested that nodY/K analysis would be useful for investigating the symbiotic diversity of the genus Bradyrhizobium.  相似文献   

9.
An efficient and largely genotype-independent transformation method for Brassica napus and Brassica oleracea was established based on neo or bar as selectable marker genes. Hypocotyl explants of Brassica napus and Brassica oleracea cultivars were infected with Agrobacterium strains containing chimeric neo and bar genes. The use of AgNO3 was a prerequisite for efficient shoot regeneration under selective conditions. Vitrification was avoided by decreasing the water potential of the medium, by decreasing the relative humidity in the tissue culture vessel, and by lowering the cytokinin concentration. In this way, rooted transformed shoots were obtained with a 30% efficiency in 9 to 12 weeks. Southern blottings and genetic analysis of S1-progeny showed that the transformants contained on average between one and three copies of the chimeric genes. A wide range of expression levels of the chimeric genes was observed among independent transformants. Up to 25% of the transformants showed no detectable phosphinotricin acetyltransferase or neomycin phosphotransferase II enzyme activities although Southern blottings demonstrated that these plants were indeed transformed.  相似文献   

10.
11.
Five flavonols, four flavones and one C-glycosylflavone were isolated from the leaves of Cathcartia villosa which is growing in the Himalayan Mountains. They were characterized as quercetin 3-O-vicianoside (1), quercetin 7,4′-di-O-glucoside (3), quercetin 3-O-rutinoside (4), quercetin 3-O-glucoside (5), quercetin 3-O-arabinosylarabinosylglucoside (6) (flavonols), luteolin (7), luteolin 7-O-glucoside (8), apigenin (9), chrysoeriol (10) (flavones), and vicenin-2 (11) (C-glycosylflavone) by UV, LC-MS, acid hydrolysis, NMR and/or HPLC and TLC comparisons with authentic samples. On the other hand, two flavonols 1 and kaempferol 3-O-vicianoside (2) were isolated and identified from the flowers of the species. Flavonoids were reported from the genus Cathcartia in this survey for the first time. Their chemical characters were chemotaxonomically compared with those of related Papaveraceous genera, Meconopsis and Papaver.  相似文献   

12.
Although Trypanosoma rotatorium undergoes transformation and prolific multiplication in the mid and hindgut of Culex territans, several attempts to experimentally infect laboratory-reared, Rana pipiens by different routes were unsuccessful. Trypanosoma avium undergoes a similar pattern of development in the gut of Simulium rugglesi. Experimental infections of T. avium in ducklings indicates that S. rugglesi serves as an intermediate host and probably as an active and passive vector of the parasite in nature.  相似文献   

13.
The association between polymorphism at the mc1r locus and colour variation was studied in two wall lizard species (Podarcis lilfordi and P. pityusensis) from the Balearic archipelago. Podarcis lilfordi comprises several deep mitochondrial lineages, the oldest of which originated in the Pliocene, while much shallower mitochondrial lineages are found in P. pityusensis. Here, we examined whether specific substitutions were associated with the melanic colouration found in islet populations of these species. Homologous nuclear sequences covering most of the mc1r gene were obtained from 73 individuals from melanic and non-melanic Podarcis from different populations (the entire gene was also sequenced in six selected individuals). MtDNA gene trees were also constructed and used as a framework to assess mc1r diversity. Mc1r showed greater polymorphism in P. lilfordi than in P. pityusensis. However, we observed no substitutions that were common to all melanic individuals across the two species. Only one significant association was detected in the mc1r partial sequence, but this was a synonymous A/G mutation with A alleles being more abundant in melanic populations. In addition, there were no associations between the main dominant phenotypes (green and brown, blue and yellow spots and ventral colour) and synonymous or non-synonymous substitutions in the mc1r gene. There was no statistical evidence of selection on mc1r. This study suggests no relationship between mc1r polymorphism and colour variation in Balearic Podarcis.  相似文献   

14.
15.
The structure of microbial communities of brown algae, red algae, and of the red alga Gracilaria verrucosa, healthy and affected with thallus rot, were comparatively investigated; 61 strains of heterotrophic bacteria were isolated and characterized. Most of them were identified to the genus level, some Vibrio spp., to the species level according to their phenotypic properties and the fatty acid composition of cellular lipids. The composition of the microflora of two species of brown algae was different. In Chordaria flagelliphormis, Pseudomonas spp. prevailed, and in Desmarestia viridis, Bacillus spp. The composition of the microflora of two red algae, G. verrucosa and Camphylaephora hyphaeoides, differed mainly in the ratio of prevailing groups of bacteria. The most abundant were bacteria of the CFB cluster and pseudoalteromonads. In addition, the following bacteria were found on the surface of the algae: Sulfitobacter spp., Halomonas spp., Acinetobacter sp., Planococcus sp., Arthrobacter sp., and Agromyces sp. From tissues of the affected G. verrucosa, only vibrios were isolated, both agarolytic and nonagarolytic. The existence of specific bacterial communities characteristic of different species of algae is suggested and the relation of Vibrio sp. to the pathological process in the tissues of G. verrucosa is supposed.  相似文献   

16.
To determine mechanisms for age-related decrease of GHS-R1a expression in the chicken proventriculus, changes in mRNA expression of ghrelin and ghrelin-O-acetyltransferase (GOAT) as well as ghrelin concentrations in the proventriculus and plasma were examined in growing chickens. Changes in expression levels of ghrelin, GOAT and GHS-R1a mRNAs were also examined in different brain regions (pituitary, hypothalamus, thalamus, cerebellum, cerebral cortex, olfactory bulb, midbrain and medulla oblongata). Ghrelin concentrations in the proventriculus and plasma increased with aging and reached plateaus at 30–50 days after hatching. High level of ghrelin mRNA decreased at 3 days after hatching, and it became stable at half of the initial level. Expression levels of GHS-R1a and GOAT decreased 3 or 5 days after hatching and became stable at low levels. Significant negative correlations were found between plasma ghrelin and mRNA levels of GOAT and GHS-R1a. Expression levels of ghrelin mRNA were different in the brain regions, but a significant change was not seen with aging. GHS-R1a expression was detected in all brain regions, and age-dependent changes were observed in the pituitary and cerebellum. Different from the proventriculus, the expression of GOAT in the brain increased or did not change with aging. These results suggest that decreased GHS-R1a and GOAT mRNA expression in the proventriculus is due to endogenous ghrelin-induced down-regulation. Expression levels of ghrelin, GOAT and GHS-R1a in the brain were independently regulated from that in the proventriculus, and age-related and region-dependent regulation pattern suggests a local effect of ghrelin system in chicken brain.  相似文献   

17.
Considerably fewer spores of Bacillus stearothermophilus, B. megaterium, and Clostridium sporogenes were recovered than were spores of B. subtilis var. niger and Aspergillus niger after 4 to 5 days at 53 and 60 C in ultrahigh vacuum. There were no significant differences in the recoveries of these five organisms at 25 C and atmospheric pressure, and after exposure to 25 and -190 C in vacuum. At 60 C, a far greater decrease in viability was demonstrated for B. stearothermophilus, B. megaterium, and C. sporogenes in ultrahigh vacuum than at atmospheric pressure. Viable B. subtilis var. niger spores were not detected in an initial 107 spores after retention at 90 C and ultrahigh vacuum, and 104 spores were viable after 5 days at 90 C and atmospheric pressure from an initial 106 spores. Molds and actinomycetes in soil were particularly resistant up to 69 C in vacuum. Actinomycetes were the only soil organisms recovered so far at 120 C.  相似文献   

18.
DNA sequence data was collected for the C and D introns in the duplicate growth hormone loci (GH1 and GH2) from Brachmystax lenok, two subspecies of Hucho hucho, Hucho (Parahucho) perryi, Salmo salar, Salmo trutta, Acantholingua ohridana (Salmothymus), six species of Salvelinus, eight species of Oncorhynchus including O. masou, and three outgroups including Thymallus thymallus, Coregonus artedi, and Coregonus clupeaformis. Phylogenetic analyses were performed using maximum parsimony and maximum likelihood (PAUP, version 4.08beta) with gaps as missing data and as a fifth base. B. lenok was basal in all of the trees and all of the other genera were monophyletic with the exception that A. ohridana always placed within Salmo, and H. hucho sp. often placed with B. lenok. The GH1 introns supported a sister relationship between Oncorhynchus and Salvelinus, while the combined GH2 introns were ambiguous at this node. This result contrasts with trees based on morphology and the ribosomal ITS1 sequences that support a sister relationship between Salmo and Oncorhynchus. The only estrogen response element (ERE) in the gene is found in the C intron and has mutated in GH2 in all of the species except B. lenok. The ERE element in GH1 has undergone another mutation in all of the species except for B. lenok, and members of the two genera Salvelinus and Oncorhynchus. Thus these latter two genera are the only ones with a difference in expression of GH1 and GH2 in the presence of estrogen. Differences in selective pressure on the introns in the duplicate genes in different taxa could account for the conflicting results obtained in the phylogenetic analysis.  相似文献   

19.
To infer the phylogenetic relationships of Xylaria species associated with termite nests within the genus Xylaria and among genera of the subfamily Xylarioideae, β-tubulin, RPB2, and α-actin sequences of 131 cultures of 114 species from Xylaria and 11 other genera of the subfamily were analyzed. These 11 genera included Astrocystis, Amphirosellinia, Discoxylaria, Entoleuca, Euepixylon, Kretzschmaria, Nemania, Podosordaria, Poronia, Rosellinia, and Stilbohypoxylon. We showed that Xylaria species were distributed among three major clades, TE, HY, and PO, with clade TE—an equivalent of the subgenus Pseudoxylaria—encompassing exclusively those species associated with termite nests and the other two clades containing those associated with substrates other than termite nests. Xylaria appears to be a paraphyletic genus, with most of the 11 genera submerged within it. Podosordaria and Poronia, which formed a distinct clade, apparently diverged from Xylaria and the other genera early. Species of Entoleuca, Euepixylon, Nemania, and Rosellinia constituted clade NR, a major clade sister to clade PO, while those of Kretzschmaria were inserted within clade HY and those of Astrocystis, Amphirosellinia, Discoxylaria, and Stilbohypoxylon were within clade PO.  相似文献   

20.
In this study, we characterized the genetic background of various nleA variants in 106 Shiga toxin-producing Escherichia coli (STEC) and enteropathogenic Escherichia coli (EPEC) strains. The flanking regions of eight nleA variants were analyzed by DNA sequencing and compared with the corresponding regions of five previously described NleA-encoding prophages. The analyzed nleA variants were all located downstream of the DNA region responsible for phage morphogenesis. In particular, the type III effector genes avrA, ospB, nleH, and nleG and IS elements were detected in the neighborhood of nleA. The structure of the eight analyzed regions flanking nleA primarily resembled the corresponding region of the NleA4795-encoding prophage BP-4795. Using PCR, the gene order flanking 13 nleA variants in strains of different serogroups was compared to the respective regions in reference strains. The analyses showed that strains which harbor prophages with conserved flanking regions of a particular nleA variant predominantly occurred, and IS elements were additionally detected in these regions. We were able to mobilize nleA by transduction in 20% of strains determined, which comprised in particular EPEC strains harboring an nleA variant, the gene encoding the protein known as “EspI-like.” Plaque hybridization was used to identify phages that harbor the genes stx and nleA. However, only two strains harbored variant nleA4795 in the genome of an Stx1 prophage.  相似文献   

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