共查询到20条相似文献,搜索用时 31 毫秒
1.
Two new erythrocyte antigens have been detected by isoimmune antibodies obtained from Gottingen Miniature pigs. By family studies they proved to belong to the E system. The factor designated En is genetically controlled by alleles E 2 = E edghkmn , E 3 = E aegln , E 4 = E edfhkmn , E 6 = E aefln , E 9 = E edghjmn , E 12 = E aegmno and E edgkln , and the factor designated Eo by the allele E 12 = E aegmno .
The En blood factor occurs in all the breeds studied and in frequency it comes close to a related Ee factor. It stands in opposition not only to Eb but also to Ei factor. The Eo factor can be characterized as a rarely occurring Ea subgroup. Besides being antithetic to Ed it is also antithetic to El and Ei factors. For the present, it was found only in Miniature pigs. 相似文献
The En blood factor occurs in all the breeds studied and in frequency it comes close to a related Ee factor. It stands in opposition not only to Eb but also to Ei factor. The Eo factor can be characterized as a rarely occurring Ea subgroup. Besides being antithetic to Ed it is also antithetic to El and Ei factors. For the present, it was found only in Miniature pigs. 相似文献
2.
MASOUD NADERPOUR OLE SØGAARD LUND RICHARD LARSEN ELISABETH JOHANSEN 《Molecular Plant Pathology》2010,11(2):255-263
Eukaryotic translation initiation factors (eIFs) play a central role in potyviral infection. Accordingly, mutations in the gene encoding eIF4E have been identified as a source of recessive resistance in several plant species. In common bean, Phaseolus vulgaris , four recessive genes, bc-1 , bc-2 , bc-3 and bc-u , have been proposed to control resistance to the potyviruses Bean common mosaic virus (BCMV) and Bean common mosaic necrosis virus . In order to identify molecular entities for these genes, we cloned and sequenced P. vulgaris homologues of genes encoding the eIF proteins eIF4E, eIF(iso)4E and nCBP. Bean genotypes reported to carry bc-3 resistance were found specifically to carry non-silent mutations at codons 53, 65, 76 and 111 in eIF4E . This set of mutations closely resembled a pattern of eIF4E mutations determining potyvirus resistance in other plant species. The segregation of BCMV resistance and eIF4E genotype was subsequently analysed in an F2 population derived from the P. vulgaris all-susceptible genotype and a genotype carrying bc-3 . F2 plants homozygous for the eIF4E mutant allele were found to display at least the same level of resistance to BCMV as the parental resistant genotype. At 6 weeks after inoculation, all F2 plants found to be BCMV negative by enzyme-linked immunosorbent assay were found to be homozygous for the mutant eIF4E allele. In F3 plants homozygous for the mutated allele, virus resistance was subsequently found to be stably maintained. In conclusion, allelic eIF4E appears to be associated with a major component of potyvirus resistance present in bc-3 genotypes of bean. 相似文献
3.
Cosenza G Pauciullo A Colimoro L Mancusi A Rando A Di Berardino D Ramunno L 《Animal genetics》2007,38(6):655-658
So far, at least eight alleles in the goat CSN2 locus have been associated with the level of β -casein expression in milk. Alleles CSN2 A , CSN2 A 1 , CSN2 B , CSN2 C , CSN2 D and CSN2 E have been associated with normal content (allele effects of about 5 g of β -casein per litre), whereas the CSN2 0 and CSN2 01 alleles have been associated with non-detectable levels of β -casein. Most of these alleles have been characterized genetically. Herein, we report the identification of a previously unreported SNP in the goat CSN2 promoter region ( AJ011018 :g.1311T>C), which is associated with the absence of β -casein in the milk. Furthermore, we developed a PCR-based method that allows detection of this mutation. 相似文献
4.
A method for genotyping K-casein ( A, B, E ), β-casein ( A 1 , A 2 , A 3 , A5 , B ) and β-lactoglobulin ( A, B ) simultaneously by the use of allele discrimination by primer length combined with automated detection of fragments with a sequencing instrument is described. Seven different mutations within the milk protein genes were analysed in order to distinguish between the alleles examined. The samples were amplified in two separate multiplex polymerase chain reactions (PCRs), which were then pooled and separated according to size in a single lane on the gel. By using stringent PCR conditions, we have been able to achieve allele-specific amplifications and minimize amplification of mismatched primer for all seven mutations. 相似文献
5.
Molecular characterization of major histocompatibility complex (B) haplotypes in broiler chickens 总被引:2,自引:0,他引:2
In Leghorn (laying) chickens, susceptibility to a number of infectious diseases is strongly associated with the major histocompatibility ( B ) complex. Nucleotide sequence data have been published for six class I ( B-F ) alleles and for class II ( B-Lβ ) alleles or isotypes from 17 Leghorn haplotypes. It is not known if classical B-L or B-F alleles in broilers are identical, at the sequence level, to any Leghorn alleles. This report describes molecular and immunogenetic characterization of two haplotypes from commercial broiler breeder chickens that were originally identified by serology as a single haplotype, but were differentiated serologically in the present work. The two haplotypes, designated B A4 and B A4variant , shared identical B-G restriction fragment length polymorphism patterns, but differed in one B-Lβ fragment that cosegregated with the serological B haplotype. Furthermore, the nucleotide sequences of the highly variable exons of an expressed B-LβII family gene and B-F gene from the two haplotypes were markedly different from each other. Both the B-LβII family and B-F gene sequences from the B A4 haplotype were identical to the sequences obtained from the reference B 21 haplotype in Leghorns; however, in the B A4 haplotype the B-Lβ 21 and B-F 21 alleles were in linkage with B-G alleles that were not G 21 . The nucleotide sequences from B A4variant were unique among the reported chicken B-LβII family and B-F alleles. 相似文献
6.
Esterase amplification is the major organophosphorus (OP) insecticide resistance mechanism in Culex mosquitoes. The amplified Estα2 1\ Estβ2 1 esterases are found in > 90% of resistant populations worldwide, whereas amplified DNAs (amplicons) containing Estβ1s are much rarer. Individuals with the Estβ1 amplicons appear to be at a selective disadvantage in competition with those carrying the Estα2 1 \ Estβ2 1 amplicons. To test the hypothesis that this is because Estβ1 is less able to bind insecticide than the common amplified esterases, Estβ12 was purified from the multi-resistant Habana strain of Culex quinquefasciatus , from Cuba. In its native form Estβ1 is a monomeric enzyme of 66 kDa, with a pI of 4.8. The bimolecular rate constants for interaction of Estβ12 with several OP insecticides were similar to those for the commonly elevated esterases Estα21 and Estβ21 , and much higher than for the electrophoretically identical non-elevated Estβ13 and Estα3. Hence the apparent selective advantage of the Estα2 1 \ Estβ2 1 amplicon is not due to its greater efficiency of insecticide binding, as OP insecticides are significantly better inhibitors of all the amplified esterases than of their non-amplified counterparts and therefore should be equally effective at conferring resistance. 相似文献
7.
Determination of pig apolipoprotein B genotype by gene amplification and restriction fragment length polymorphism analysis 总被引:1,自引:0,他引:1
Summary
Sequence differences within the pig apoB gene can be used to identify rapidly four of eight known pig apoB alleles, designated LPB1 - LPB 8 . We describe the use of gene amplification, followed by endonuclease digestion and agarose gel electrophoresis, to discern size and restriction site differences. LPB 5 , a common allele associated with reduced low density lipoprotein clearance and hypercholesterolaemia in pigs, is identified by a 283-bp insertion in intron 28. LPB 3 and LPB 7 are distinguished by a unique Hind III site; LPB 8 shares a unique Hinc II site with LPB 5 . This method facilitates identification of the apoB genotype of pigs used in lipoprotein research and allows for further investigation into the association of particular apoB alleles with lipoprotein metabolism abnormalities. 相似文献
Sequence differences within the pig apoB gene can be used to identify rapidly four of eight known pig apoB alleles, designated LPB
8.
Mutational analysis of plant cap-binding protein eIF4E reveals key amino acids involved in biochemical functions and potyvirus infection 总被引:2,自引:0,他引:2
German-Retana S Walter J Doublet B Roudet-Tavert G Nicaise V Lecampion C Houvenaghel MC Robaglia C Michon T Le Gall O 《Journal of virology》2008,82(15):7601-7612
The eukaryotic translation initiation factor 4E (eIF4E) (the cap-binding protein) is involved in natural resistance against several potyviruses in plants. In lettuce, the recessive resistance genes mo11 and mo12 against Lettuce mosaic virus (LMV) are alleles coding for forms of eIF4E unable, or less effective, to support virus accumulation. A recombinant LMV expressing the eIF4E of a susceptible lettuce variety from its genome was able to produce symptoms in mo11 or mo12 varieties. In order to identify the eIF4E amino acid residues necessary for viral infection, we constructed recombinant LMV expressing eIF4E with point mutations affecting various amino acids and compared the abilities of these eIF4E mutants to complement LMV infection in resistant plants. Three types of mutations were produced in order to affect different biochemical functions of eIF4E: cap binding, eIF4G binding, and putative interaction with other virus or host proteins. Several mutations severely reduced the ability of eIF4E to complement LMV accumulation in a resistant host and impeded essential eIF4E functions in yeast. However, the ability of eIF4E to bind a cap analogue or to fully interact with eIF4G appeared unlinked to LMV infection. In addition to providing a functional mutational map of a plant eIF4E, this suggests that the role of eIF4E in the LMV cycle might be distinct from its physiological function in cellular mRNA translation. 相似文献
9.
Insecticide resistance in Chinese populations of the Culex pipiens complex through esterase overproduction 总被引:1,自引:0,他引:1
F. Cui L.-F. Lin C.-L. Qiao Y. Xu M. Marquine M. Weill & M. Raymond 《Entomologia Experimentalis et Applicata》2006,120(3):211-220
In most parts of China, mosquitoes have been subjected to organophosphate (OP) insecticide treatments since the mid-1960s, and resistance gene monitoring in the Culex pipiens complex (Diptera: Culicidae) started in only a few locations from the end of the 1980s. Many resistant alleles at the Ester locus have been found in field populations, including those commonly found around the world ( Ester B1 and Ester 2 ), and those endemic to China ( Ester B6 , Ester B7 , Ester 8 , and Ester 9 ). This situation is atypical, and may represent a complex situation for the evolution of insecticide resistance genes in China. To increase our understanding of the Chinese situation and our ability to manage resistance in the C. pipiens complex, a large study was performed. Twenty field populations were sampled from Beijing to Guangzhou. Bioassays with five insecticides (dichlorvos, parathion, chlorpyrifos, 2-sec-butylphenyl methyl carbamate, and propoxur) disclosed resistance levels variable according to the geographic origin, and up to 85-fold for dichlorvos. Six overproduced esterases were identified, including two that have not been previously described. Most of them were found in all samples, although at variable frequencies, suggesting variable selection or a transient situation, e.g., each one was recently restricted to a particular geographic area. The results are discussed in the context of recent alterations to insecticide campaigns, and of the evolution of resistance genes in Chinese C. pipiens populations. 相似文献
10.
The virucidal properties of iodophor, chlorine (sodium hypochlorite), formalin, thimerosal (organic mercurial compound), malachite green, and acriflavine were tested on infectious pancreatic necrosis virus (IPNV). Iodine and chlorine showed good activity, but efficacy depended on the concentration of virus, the presence of organic matter (calf serum), and water p H. Water hardness (0-300 mg 1−1 as CaCO3 ) did not affect virucidal activity. In a 5 min exposure, 4 mg 1−1 available iodine inactivated 103.9 TCID50 m1−1 IPNV but 16 mg 1−1 iodine were needed for inactivation of 106.3 TCID50 m1−1 . The addition of 0-5% calf serum significantly reduced the iodine concentration and the virucidal activity. In comparison, 4 mg 1−1 chlorine were needed to inactivate 1046 TCID50 m1−1 IPNV in 5 min. However, the addition of 0-07 % serum greatly reduced the chlorine concentration and extended the virucidal contact time to 30 min or more. IPNV at 106.3 TCID60 m1−1 was not inactivated by exposures for 60 min to 0-2% formalin, 10 min to 0-2% thimerosal, 60 min to 5 mg 1−1 malachite green, or 20 min to 500 mg 1−1 acriflavine. However, acriflavine at 0-5 mg 1−1 in cell culture media prevented the development of cytopathology caused by IPNV and may be useful in the treatment of the disease. 相似文献
11.
12.
The effects of physical and chemical factors on the production of H2 O2 from Escherichia coli cells were studied. When 20 mmol 1-1 Tris-HCl buffer was used for this purpose the electron transport system (ETS) showed the highest activity at pH 7.6-8.2. KCN promoted the production of H2 O2 from E. coli cells, and the optimum concentration was changed in different reaction times and pH values. Glucose, 5 mg ml-1 , increased the ETS activity about twofold. The other substrates and surfactants did not increase the chemiluminescence intensity. NaNO2 and Na2 SO4 in inorganic salts significantly reduced the ETS activity above 70%. In addition, the optimum temperature for the production of H2 O2 was 30°C in this study. When glucose (5 mg ml-1 ) and KCN (0.2 mmol 1-1 ) were added to the reaction buffer containing 0.5 mmol 1-1 menadione, the detectable minimum cell densities (averages of triplicate assay) of E. coli, Enterobacter cloacae and Serratia marcescens were 5 times 103 cells ml-1 , 104 cells ml-1 and 104 cells ml-1 respectively. 相似文献
13.
14.
Abstract: The present study reports the ion dependency of 2β-carbomethoxy-3β-(4-fluorophenyl)[3 H]tropane ([3 H]- CFT) binding to the dopamine transporter in the rat striaturn. The results indicate that [3 H]CFT binding to synaptosomal P2 membranes requires low concentrations of Na+ (peak binding between 20 and 50 m M Na+ ), is stimulated by phosphate anion or l- , but is unaffected or only slightly affected by F- , Cl- , Br- , NO3 - , or SO4 2- , Concentrations of Na+ of >50 m M become inhibitory except in the presence of l- , which shifts peak binding levels toward higher Na+ concentrations and also elevates the peak binding level. K+ strongly decreased [3 H]CFT binding with a shallow inhibition curve, and Na+ could not overcome this effect. Saturation analysis of [3 H]CFT binding revealed a single binding site changing its affinity for CFT depending on the concentration of sodium phosphate buffer (6, 10, 30, 50, 130, or 200 m M ; 1 mM plus 49 mM NaCIversus 10 m M plus 40 m M NaCI; or 1 mM plus 129 m M Nal versus 10 m M plus 120 m M Nal). No differences were observed in the density of CFT binding sites between any of the conditions examined. 相似文献
15.
Abstract The Escherichia coli ptsI and ptsH genes code for the synthesis of two proteins of the phosphoenolpyruvate-dependent phosphotransferase system (PTS), namely enzyme I and protein HPr. A number of ptsI + ptsH + /F' ptsI + ptsH merodiploids was obtained. It was shown in experiments in vivo that ptsH mutations in the transposition are dominant. Bacterial extracts from these merodiploids supported [14 C]methyl glucoside (MG) phosphorylation at the expense of phosphoenolpyruvate only half as much as extracts from the pts + cells. ptsI + ptsH /F' ptsI + ptsH + merodiploids appeared to be non-viable; the reason for this lack of viability is discussed. 相似文献
16.
The eukaryotic translation initiation factor 4E controls lettuce susceptibility to the Potyvirus Lettuce mosaic virus 总被引:18,自引:0,他引:18
下载免费PDF全文
![点击此处可从《Plant physiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Nicaise V German-Retana S Sanjuán R Dubrana MP Mazier M Maisonneuve B Candresse T Caranta C LeGall O 《Plant physiology》2003,132(3):1272-1282
The eIF4E and eIF(iso)4E cDNAs from several genotypes of lettuce (Lactuca sativa) that are susceptible, tolerant, or resistant to infection by Lettuce mosaic virus (LMV; genus Potyvirus) were cloned and sequenced. Although Ls-eIF(iso)4E was monomorphic in sequence, three types of Ls-eIF4E differed by point sequence variations, and a short in-frame deletion in one of them. The amino acid variations specific to Ls-eIF4E(1) and Ls-eIF4E(2) were predicted to be located near the cap recognition pocket in a homology-based tridimensional protein model. In 19 lettuce genotypes, including two near-isogenic pairs, there was a strict correlation between these three allelic types and the presence or absence of the recessive LMV resistance genes mo1(1) and mo1(2). Ls-eIF4E(1) and mo1(1) cosegregated in the progeny of two separate crosses between susceptible genotypes and an mo1(1) genotype. Finally, transient ectopic expression of Ls-eIF4E restored systemic accumulation of a green fluorescent protein-tagged LMV in LMV-resistant mo1(2) plants and a recombinant LMV expressing Ls-eIF4E degrees from its genome, but not Ls-eIF4E(1) or Ls-eIF(iso)4E, accumulated and produced symptoms in mo1(1) or mo1(2) genotypes. Therefore, sequence correlation, tight genetic linkage, and functional complementation strongly suggest that eIF4E plays a role in the LMV cycle in lettuce and that mo1(1) and mo1(2) are alleles coding for forms of eIF4E unable or less effective to fulfill this role. More generally, the isoforms of eIF4E appear to be host factors involved in the cycle of potyviruses in plants, probably through a general mechanism yet to be clarified. 相似文献
17.
Quantification of pathogenic micro-organisms in the sludge from treated hospital wastewater 总被引:1,自引:1,他引:0
The sludge from hospital waste treatment facilities is a potential source of infectious organisms. The average numbers of micro-organisms in the sludge of hospital wastewater in Taiwan were as follows: total count 8·1 × 107 cfu g−1 (dry weight of sludge), and 1·4 × 106 , 3·6 × 105 , 1·6 × 105 , 2·2 × 105 and 5·5 × 104 cfu g−1 (dry weight of sludge) for total coliforms, faecal coliforms, faecal streptococci, Pseudomonas aeruginosa and Salmonella spp., respectively . Salmonella spp. were detected in 37% (10 of 27) of the sludges from hospital wastewaters. Therefore, the treatment of such sludge to reduce pathogenic micro-organisms should be considered. 相似文献
18.
Abstract: The feeding of the marine ciliate Euplotes mutabilis was studied using bacteria ( Vibrio natriegens ) doubly labelled with 3 H-thymidine and 14 C-leucine. In the presence of abundant bacteria (30 × 106 bacteria ml−1 ), an average Euplotes cell (initially without food vacuoles) with a protein content of 12 ng consumed 16 × 103 bacteria in the first hour and 27 × 103 bacteria over four hours, accumulating about 60% of the bacterial protein into ciliate macromolecules. Euplotes which had been starved or under-fed to reduce cell protein biomass to 7 or 9 ng consumed significantly fewer bacteria, but the gross growth efficiency for protein did not change. The rate of consumption of bacteria by large Euplotes of protein content 15 ng was initially less than that of 12 ng cells, and it decreased markedly before the end of a 4-hour experiment. Recently divided cells ingested bacteria rapidly, but showed a reduced gross growth efficiency of about 40%. At low bacterial concentrations (6 × 106 bacteria ml−1 ) the rates of ingestion were markedly reduced to between and of maximal levels; the smallest cells could not sustain feeding activity at the low prey concentration and gross growth efficiency fell from 43 to 20% during a 4-hour experiment. The strategy adopted by Euplotes in response to local fluctuations in food supply involves rapid consumption with high growth efficiency in times of plenty, but slow shrinkage without cell division to survive in times of shortage. 相似文献
19.
SYNOPSIS. Euplotes vannus , a hypotrich ciliate. grows well over broad ranges of temperature and salinity. It requires higher densities of food (> 1 × 104 cells/ml) for rapid reproduction than do the other herbivores, the foraminiferan Al-logromia laticollaris (> 1 × 102 cells/ml), and the nematode Chromadorina germanica (∼ 1 × 103 cells/ml), to which it was compared. If food levels were initially very high (∼ 1 × 108 cells/ml) the ciliates reproduced rapidly and consumed the algae faster than it could reproduce. Some balance between the algae and the ciliates was achieved at initial algal concentrations of ∼ 1 × 105 cells/ml. In microcosm experiments at 25 C with equal numbers of C. germanica and A. laticollaris. E. vannus proved to be a very poor competitor; reaching only 20% of control levels when grow with C. germanica and only 13% when cultured with A. laticollaris . It was a better competitor in 2-species microcosms, at lower temperatures, and when its ratio to the other species was initially higher.
The experimental evidence suggests that E. vannus is best adapted to being a migrating initial colonizer of fresh algal blooms. 相似文献
The experimental evidence suggests that E. vannus is best adapted to being a migrating initial colonizer of fresh algal blooms. 相似文献
20.
van den Berg MP Huizink AC van Baal GC Tieman W van der Ende J Verhulst FC 《Genes, Brain & Behavior》2008,7(1):88-95
The aim of the present study was to estimate the genetic, shared and nonshared environmental contributions to self-reported and parent-reported internalizing and externalizing problems in a follow-up study of intercountry adopted young adults. Young Adult Self-Report ratings were obtained from 1475 adoptees aged 22–32 years and Young Adult Behavior Checklist ratings from 1115 adoptive parents. For the genetic analyses, a subset of 143 adopted biologically related and 295 unrelated siblings was used. The data were subjected to model fitting decomposing three sources of variance: genetic factors (A) shared environment (C) and nonshared environment (E). Genetic factors were of more importance in both self-reported ( A 2 = 54%, C 2 = 0, and E 2 = 46%) and parent-reported ( A 2 = 76%, C 2 = 15% and E 2 = 9%) internalizing problems. Environmental factors were of more importance in both self-reported ( A 2 = 33%, C 2 = 17% and E 2 = 50%) and parent-reported ( A 2 = 28%, C 2 = 27% and E 2 = 45%) externalizing problems. This was in contrast with findings from the first and second assessments in the same sample during adolescence when genetic factors were more important in explaining externalizing problems compared with internalizing problems. Our results suggest a developmental reversal in genetic and environmental influences on behavior problems from early adolescence into adulthood, which could be related to different underlying developmental trajectories. 相似文献