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1.
Castro-Prado MA Querol CB Sant'Anna JR Miyamoto CT Franco CC Mangolin CA Machado MF 《Genetics and molecular research : GMR》2007,6(3):634-642
The heterokaryotic and vegetative diploid phases of Colletotrichum lindemuthianum are described using nutritional and biochemical markers. Nitrate non-utilizing mutants (nit), derived from R2047, R89, R73, R65, and R23 isolates, were paired in all possible combinations to obtain heterokaryons. Although pairings R2047/R89, R2047/R73, R65/R73, and R73/R23 showed complete vegetative incompatibility, prototrophic heterokaryons were obtained from pairings R2047/R65, R2047/R23, R65/R89, R65/R23, R73/R89, R89/R23, R2047/R2047, R65/R65, R89/R89, R73/R73, and R23/R23. Heterokaryons gave rise to spontaneous mitotic segregants which carried markers corresponding to one or the other of the parental strains. Heterokaryons spontaneously produced prototrophic fast-growing sectors too, characterized as diploid segregants. Diploids would be expected to yield auxotrophic segregants following haploidization in basal medium or in the presence of benomyl. Parental haploid segregants were in fact recovered from diploid colonies growing in basal medium and basal medium containing the haploidizing agent. Although barriers to the formation of heterokaryons in some crosses were detected, the results demonstrate the occurrence of parasexuality among vegetative compatible mutants of C. lindemuthianum. 相似文献
2.
Yoshikane Iwatsubo Naohiro Naruhashi Heinrich E. Weber 《Plant Systematics and Evolution》1995,198(1-2):143-149
Chromosome numbers are presented for 32 collections of 29 European blackberry species (Rubus subg.Rubus) from Germany. One species is triploid (2n = 21), 27 species are tetraploid, (2n = 28), and one species is pentaploid (2n = 35). Chromosome numbers are reported for the first time ofR. adspersus, R. amisiensis, R. calvus, R. conothyrsoides, R. contractipes, R. demissus, R. elegantispinosus, R. ferocior, R. foliosus, R. hypomalacus, R. leucandrus, R. nemorosus, R. platyacanthus, R. praecox, R. rhombifolius, andR. rhytidophyllus. Chromosome numbers forR. dasyphyllus, R. gelertii, R. glandithyrsos, R. lamprocaulos, R. lindebergii, R. macrophyllus, R. montanus, R. muenteri, R. pedemontanus, R. polyanthemus, R. senticosus, R. silvaticus, andR. vigorosus are confirmed. 相似文献
3.
The taxonomy, ecology and distribution of Rinodina deflectens, R. interjecta, R. rinodinoides, R. tephraspis and R. trachytica are treated. New combinations are made for R. interjecta and R. rinodinoides. R. melanocarpa and R. serpentini are synonyms of R. rinodinoides. R. badiella and R. kentuckyensis are synonyms of R. tephraspis , and R. iberica of R. trachytica. 相似文献
4.
5.
P G Farlie R Kerr P Thomas T Symes J Minichiello C J Hearn D Newgreen 《Developmental biology》1999,213(1):70-84
Cranial neural crest cell migration is patterned, with neural crest cell-free zones adjacent to rhombomere (R) 3 and R5. These zones have been suggested to result from death of premigratory neural crest cells via upregulation of BMP-4 and Msx-2 in R3 and R5, consequent to R2-, R4-, and R6-derived signals. We reinvestigated this model and found that cell death detected by acridine orange staining in avian embryos varied widely numerically and in pattern, but with a tendency for an elevated zone centered at the R2/3 boundary. In situ hybridization of BMP-4 mRNA resolved to centers at R3 and R5 but Msx-2 resolved to the R2/3 border with only a faint smear from R5 to R6. Outgrowth of neural crest cells was less in isolated R3 cultures than in R1+2, R2, and R4 cultures, but R3 showed neither a decrease in outgrowth of neural crest cells nor an increase in cell death when cocultured with R1+2, R2, or R4. In addition, in serum-free culture, exogenous BMP-4 strikingly reduced neural crest cell outgrowth from R1+2 and R4 as well as R3. Thus we cannot confirm the role of intraneural cell death in patterning rhombomeric neural crest outgrowth. However, grafting quail R2 or R4 adjacent to the chick hindbrain demonstrated a neural crest cell exclusion zone next to R3 and R5. We suggest that one important pattern determinant for rhombomeric neural crest cell migration involves the microenvironment next to the neural tube. 相似文献
6.
T E Lobanok 《Genetika》1975,11(5):119-126
The compatibility of four wild type fi+R factors to R1 factor, a representative of the FII compatibility group of F-like class of the plasmids was studied. Two of them (R448 and R459) were incompatible to the R1 factor at selective for R448 and R459 donors conditions. The recipient R1 factor elimination apparently takes place at the first generations of conjugants. The compatibility of these R plasmids to R1 is possible at selective for donor and recipient plasmids conditions. R459 and R1 factors were transfered to Escherichia coli W945 simultaneously and recombination between them was suggested. B211 and R215 factors are compatible to R1 factor and their coexistence with the last is stable despite whether conjugants were selected on one or two R plasmids principle. Further conjugants transfer R211 and R215 only, but not R1. It is concluded that R factors No 448 and No 459 are of FII group compatibility. R211 and R215 factors group compatibility is still unknown. 相似文献
7.
发根农杆菌菌株的综合鉴定及活力比较 总被引:2,自引:0,他引:2
利用3-酮乳糖产物法、差异酸生成实验和游动性实验鉴定发根农杆菌菌株A4、R1205、R1000、R1601、R1022和15834的菌株类型和活力。结果表明,R1205、R1601、R1000、A4为Ⅱ型农杆菌,其活力从大到小依次是R1000、R1205、A4、R1601。利用PCR方法鉴定表明,A4、R1205、R1000和R1601为发根农杆菌,而R1022和15834未出现阳性结果。黄瓜遗传转化力鉴定结果表明,R1000的遗传转化力最大,达到79.16%,其它菌株依次是R1205、R1601、A4。根据上述三方面综合鉴定,R1000菌株活力最大。 相似文献
8.
Pediatric cataract of the congenital type is the most common form of childhood blindness and it is clinically and genetically heterogeneous. Mutations in 22 different genes have been identified to be associated with congenital cataracts, and among them, eight mutants belong to αA-crystallin. To explain how mutations in αA-crystallin lead to the development of cataract, quaternary structural parameters, and chaperone function have been investigated in αA-wt and in the following mutants: R12C, R21L, R21W, R49C, R54C, R116C, and R116H. Average molar mass, mass at the RI peak, mass across the peak, hydrodynamic radius (R(h)), and polydispersity index (PDI) were determined by dynamic light-scattering measurements. The average molar mass and mass across the peak showed major increase in R116C and R116H, moderate increase in R12C, R21W, and R54C, and no increase in R21L and R49C as compared to αA-wt. PDI and R(h) values were significantly increased only in R116C and R116H. Significant secondary structural changes, as determined by CD measurements, were seen in R21W, R21L, R116C, and R116H, and tertiary structural changes were evident in R21W, R54C, R116C, and R116H. Non-reducing SDS-PAGE has shown the presence of dimers presumably formed by inter-polypeptide disulfide bonds. Chaperone activity, as measured with ADH as the target protein, appeared normal in R49C and R54C, while R12C, R21L, and R21W showed moderate loss and R116C and R116H showed significant loss. Although a specific change in the αA-crystallin behavior that is common to all the mutants was not evident, each mutant showed one or more perturbation as the end effect that leads to cataract. 相似文献
9.
The detection threshold (DeltaR(50)) of resistive (R) loads is a function of the total background resistance (R(0)). Increased R(0) increases the DeltaR(50), but the ratio DeltaR(50)/R(0) remains constant. The respiratory-related evoked potential (RREP) is elicited only by R loads greater than the cognitive detection threshold, DeltaR(50). We hypothesized that the RREP Nf, P1, and N1 peaks will be elicited only when the added load DeltaR/R(0) is greater than the normal detection threshold, DeltaR(50)/R(0) = 0.30. We also hypothesized that when the R(0) is increased by adding extrinsic R, the RREP will not be elicited if the DeltaR/R(0) is less than the 0.30 ratio. RREPs were recorded with healthy volunteers (n = 20) respiring through a non-rebreathing valve. Three inspiratory R loads that spanned the DeltaR(50)/R(0) = 0.30 detection threshold were presented in two conditions: 1) no added R(0) (R1 < 0.30, R2 > 0.30, R3 > 0.30); and 2) increased R(0) = 13.3 cmH(2)O.l(-1).s (R1 < 0.30, R2 < 0.30, R3 > 0.30). For the control R(0), P1, Nf, and N1 peaks of the RREP were elicited by both R2 and R3, and not present with R1. The increased R(0) decreased R2/R(0) > 1.5 to R2/R(0) < 0.15. With increased R(0), the R1 and R2 loads did not elicit the RREP, but the Nf, P1, and N1 peaks were present for R3. These results demonstrate that the RREP is present if the DeltaR is above the cognitive detection threshold, and the RREP is absent if the load is below the detection threshold. When the R(0) is increased to make the DeltaR/R(0) less than the detection threshold, the DeltaR no longer elicits the RREP. 相似文献
10.
Recent evidence suggests that stochasticism is important for generating cell type diversity. We have identified a novel stochastic fate choice as part of the mechanism by which Delta/Notch (Dl/N) signaling specifies R7 fate in the Drosophila eye. The equivalence of R1/R6/R7 precursors is normally broken by the activation of N, which specifies the R7 fate. The orphan nuclear hormone receptor Seven-up (Svp) is necessary and sufficient to direct R1/R6/R7 precursors to adopt the R1/R6 fate. A simple model, therefore, is that N represses Svp, which otherwise prevents adoption of the R7 fate. However, we have found that R1/R6s lacking svp stochastically adopt either the R7 or the R8 fate with equal likelihood. We show that N specifies the R7 fate by a novel branched pathway: N represses Svp expression, thereby exposing an underlying stochastic choice between the R7 and R8 fates, and then tips this choice towards the R7 fate. 相似文献
11.
Carotenoid pigments of genus Rhodococcus 总被引:1,自引:0,他引:1
A study of carotenoid pigments of the genus Rhodococcus was carried out. According to carotenes contained, Rhodococcus species were divided into three groups: the first group of Rhodococcus luteus, R. coprophilus, R. lentifragmentus, and R. maris, which formed beta-carotene; the second group of R. equi, R. rubropertinctus, R. aichiensis, R. sputi, R. chubuensis, R. obuensis, R. bronchialis, R. roseus, R. rhodochrous, R. rhodnii, and R. terrae, which formed gamma-carotene-like substance; and the third group of R. aurantiacus, which formed neither carotene. Other carotenoid pigments were different according to the species. 相似文献
12.
Dou QW Tanaka H Nakata N Tsujimoto H 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,114(1):41-47
Genome characterization of 14 hexaploid lines that spontaneously appeared in octoploid Triticales was carried out by sequential genomic in situ hybridization and fluorescence in situ hybridization, high molecular weight glutenin subunits and SSR marker analyses. All of the lines showed a chromosome constitution of complete A and B genomes, and a composite genome consisting of the chromosomes of D and R genomes. The composite genome of the 11 lines consisted of chromosomes 1R, 2D, 3R, 4R, 5R, 6R and 7R, that of the two lines were 1D, 2D, 3R, 4R, 5R, 6R and 7R, and that of one line was 1R, 2D, 3R, 4R, 5R, 6D and 7R. The incompatibility of the D and R genomes in common wheat genetic background, preferential retention of chromosome 2D and importance of these lines for the development of hexaploid Triticale are discussed in this report. 相似文献
13.
地黄属种间亲缘关系研究 总被引:10,自引:1,他引:9
对地黄属6个物种进行了形态解剖学观察、染色体计数、核核糖体内转录间隔区(ITS)序列分析.结果表明,茎的高度、幼叶形态、花萼和花冠形态及颜色、种子千粒重和大小、外种皮网壁厚度、外种皮内侧网纹直径等均是该属内分类的可靠依据.高地黄与裂叶地黄在外部形态及解剖结构的各个方面均极为近似,地黄与茄叶地黄间也存在较大的相似性.茄叶地黄、高地黄、湖北地黄、天目地黄的染色体数目,分别为n=28、14、14、14,确认地黄和茄叶地黄为属内四倍体物种,其余种均为二倍体.ITS测序分析显示,地黄属为单系起源,天目地黄与湖北地黄、高地黄与裂叶地黄、地黄与茄叶地黄构成属内3个分支,与形态学及细胞学研究结果一致.研究认为,天目地黄与湖北地黄有较近的亲缘关系;高地黄和裂叶地黄应为同一物种;地黄与茄叶地黄是属内进化水平最高的类群. 相似文献
14.
Distribution and application of mycobactins for the characterization of species within the genus Rhodococcus 总被引:7,自引:0,他引:7
Representatives of 11 species of Rhodococcus were examined for their ability to synthesize mycobactin, a lipid-soluble siderophore, following iron-limited growth on solidified glycerol/asparagine medium. Rhodococcus bronchialis, R. terrae and R. rubropertinctus formed mycobactins, whereas the remaining species (R. coprophilus, R. equi, R. erythropolis, R. rhodnii, R. rhodochrous, R. ruber, R. maris and R. luteus) failed to synthesize these compounds even under conditions of strictly iron-limited growth. The mycobactins from R. terrae and R. rubropertinctus showed close similarity by thin-layer chromatography and high-performance liquid chromatography and could be easily distinguished from that of R. bronchialis. 相似文献
15.
Reinvestigation of the aerial parts of Matricaria aurea led to the isolation of three new bisabolenes and a new acetylene. The structures of the four compounds, namely (1R*,2R*,3R*,6R*,7R*)1,2,3,6,7- pentahydroxy-bisabol-10(11)-ene, (1R*,2R*,3R*,6R*,7R*)1,2,3,6,7-pentahydroxy-1-acetoxy-bisabol-10(1 1)-ene, (1R*,2R*,3R*,6R*,7R*)1,2,3,6,7-pentahydroxy-2-acetoxy-bisabol-10(1 1)-ene and (3S*,4S*,5R*)-(E)-3,4-dihydroxy-2-(hexa-2,4-diynyliden)-1,6- dioxaspiro-(4,5)decane, were deduced from the high field NMR studies. 相似文献
16.
Very little research has explored regurgitation and reingestion (R/R) in orangutans. We first aimed to determine the prevalence of R/R in the North American zoo population through a survey of accredited institutions. We report the prevalence of R/R in orangutans >4 years of age as 35% with some sex and species differences. Additionally, survey respondents reported fruit and sweet foods as the most common triggers of R/R. We also explored rates of R/R in a single group of Bornean orangutans at Cleveland Metroparks Zoo. We examined the relationship between R/R and feeding schedule and opportunistically observed rates of R/R with and without the presence of browse and sweet foods. We found evidence that R/R is associated with feeding time and that the presence of browse significantly increased the amount of time that animals spent feeding. There was a trend toward decreased R/R when browse was available. We also observed higher rates of R/R when sweet foods were available and we propose that this may have mitigated some of the beneficial effects of browse. We suggest that future studies look further at nutritional influences on R/R behavior. Zoo Biol. 31:609‐620, 2012. © 2012 Wiley Periodicals, Inc. 相似文献
17.
Transfer to wheat (Triticum aestivum) of small chromosome segments from rye (Secale cereale) carrying disease resistance genes 总被引:1,自引:0,他引:1
One hundred wheat lines, derived from monosomic additions of chromosome 1R of rye inbred line R12 (Chinese rye), were detected
by PCR amplification using rye-specific primer pairs. Only 5 wheat lines, 1R296, 1R330, 1R314, 1R725, and 1R734, were determined
to contain rye chromatin. While 1R296 and 1R330 were highly susceptible to stripe rust and powdery mildew, 1R314, 1R725 and
1R734 were highly resistant to both diseases. Acid-polyacrylamide gel electrophoresis showed that the ω-secalin bands were
absent in 1R314, but present in the other 4 wheat lines. Genomicin situ hybridization indicated that 1R296, 1R330, and 1R725 contained translocations involving the whole short arm of chromosome
1R. However, 1R314 and 1R734 contained a pair of wheat chromosomes with small, terminal, rye-derived chromosome segments.
The results suggest that the translocation breakpoint of 1RS in 1R314 was located between theSec-1 locus and the disease-resistance loci, while in line 1R734, the breakpoint was located between theSec-1 locus and the centromere. Taking account of the improved disease resistance of 1R725, 1R314 and 1R734, the chromosome arm
1RS of R12 may represent new and valuable disease resistance resources for wheat improvement. 相似文献
18.
In-vivo-modified gonococcal plasmid pJD1. A model system for analysis of restriction enzyme sensitivity to DNA modifications 总被引:4,自引:0,他引:4
The 4207-bp cryptic plasmid (pJD1) of Neisseria gonorrhoeae has 5-methylcytosine bases present at several positions in the DNA sequence. Fortuitously, these modified bases lie in the recognition sequences of many restriction enzymes. This feature makes the cryptic plasmid a model system for assaying the effect of these modified cytosines on the activities of the following restriction endonucleases and their isoschizomers: R X AvaII, R X BamHI, R X BglI, R X Fnu4HI, R X HaeII, R X HaeIII, R X HhaI, R X HpaII, R X KpnI, R X MspI, R X NaeI, R X NarI, R X NciI, R X NgoI, R X NgoII, and R X Sau96I. Of particular interest was the finding that methylation of one of the external cytosines of the palindrome 5'-CCGG-3' prevented its cleavage by R X MspI, but not by R X HpaII as had been suggested by Walder et al. [J. Biol. Chem. (1983) 258, 1235-1241]. 相似文献
19.
Genetic relationships among 10 species of bugs belonging to the tribe Rhodniini (Hemiptera: Reduviidae), including some important vectors of Chagas disease, were inferred from allozyme analysis of 12 enzyme loci (out of 21 enzyme systems examined), using agarose gel electrophoresis. These species formed two clusters: one comprising Rhodnius brethesi, R. ecuadoriensis, R. pallescens and R. pictipes; the other with Psammolestes tertius, Rhodnius domesticus and the Rhodnius prolixus group comprising R. nasutus, R. neglectus, R. prolixus and R. robustus. The resulting tree was [((R. ecuadoriensis, R. pallescens) R. brethesi) R. pictipes], [R. domesticus (P. tertius [(R. nasutus, R. neglectus) (R. prolixus, R. robustus)])]. Rhodnius nasutus and R. neglectus differed by only one locus, whereas no diagnostic loci were detected between R. prolixus and R. robustus (22 loci were analysed for these four species), despite considerable DNA sequence divergence between species in each of these pairs. Allozymes of the R. prolixus group showed greater similarity with Psammolestes tertius than with other Rhodnius spp., indicating that Rhodnius is paraphyletic and might include Psammolestes. 相似文献
20.
Franck N Morales JP Arancibia-Avendaño D de Cortázar VG Perez-Quezada JF Zurita-Silva A Pastenes C 《The New phytologist》2011,192(4):939-951
We studied the seasonal fluctuation of soil respiration (R(S)), and its root-dependent (R(R)) and basal (R(B)) components, in a Vitis vinifera (Chardonnay) vineyard. The R(S) components were estimated through independent field methods (y-intercept and trenching) and modeled on the basis of a Q(10) response to soil temperature, and fine and coarse root respiration coefficients. The effect of assimilate availability on R(R) was assessed through a trunk girdling treatment. The apparent Q(10) for R(R) was twice that of R(B) (3.5 vs 1.6) and increased linearly with increasing vine root biomass. The fastest R(R) of fine roots was during rapid fruit growth and the fastest R(R) of coarse roots was immediately following fruit development. R(S) was estimated at 32.6 kg ha(-1) d(-1) (69% as a result of R(R) ) for the hottest month and at 7.6 kg ha(-1) d(-1) (18% as a result of R(R)) during winter dormancy. Annual R(S) was low compared with other natural and cultivated ecosystems: 5.4 Mg ha(-1) (46% as a result of R(R)). Our estimates of annual vineyard R(S) are the first for any horticultural crop and suggest that the assumption that they are similar to those of annual crops or forest trees might lead to an overestimation. 相似文献