共查询到20条相似文献,搜索用时 31 毫秒
1.
Sharma TR Madhav MS Singh BK Shanker P Jana TK Dalal V Pandit A Singh A Gaikwad K Upreti HC Singh NK 《Molecular genetics and genomics : MGG》2005,274(6):569-578
In order to understand the molecular mechanisms involved in the gene-for-gene type of pathogen resistance, high-resolution
genetic and physical mapping of resistance loci is required to facilitate map-based cloning of resistance genes. Here, we
report the molecular mapping and cloning of a dominant gene (Pi-k
h
) present in the rice line Tetep, which is associated with resistance to rice blast disease caused by Magnaporthe grisea. This gene is effective against M. grisea populations prevalent in the Northwestern Himalayan region of India. Using 178 sequence tagged microsatellite, sequence-tagged
site, expressed sequence tag and simple sequence repeat (SSR) markers to genotype a population of 208 F2 individuals, we mapped the Pi-k
h
gene between two SSR markers (TRS26 and TRS33) which are 0.7 and 0.5 cM away, respectively, and can be used in marker-assisted-selection
for blast-resistant rice cultivars. We used the markers to identify the homologous region in the genomic sequence of Oryza sativa cv. Nipponbare, and a physical map consisting of two overlapping bacterial artificial chromosome and P1 artificial chromosome
clones was assembled, spanning a region of 143,537 bp on the long arm of chromosome 11. Using bioinformatic analyses, we then
identified a candidate blast-resistance gene in the region, and cloned the homologous sequence from Tetep. The putative Pi-k
h
gene cloned from Tetep is 1.5 kbp long with a single ORF, and belongs to the nucleotide binding site-leucine rich repeat
class of disease resistance genes. Structural and expression analysis of the Pi-k
h
gene revealed that its expression is pathogen inducible. 相似文献
2.
Qiaojun Jia Jingjuan Zhang Sharon Westcott Xiao-Qi Zhang Mathew Bellgard Reg Lance Chengdao Li 《Functional & integrative genomics》2009,9(2):255-262
The barley sdw1/denso gene not only controls plant height but also yield and quality. The sdw1/denso gene was mapped to the long arm of chromosome 3H. Comparative genomic analysis revealed that the sdw1/denso gene was located in the syntenic region of the rice semidwarf gene sd1 on chromosome 1. The sd1 gene encodes a gibberellic acid (GA)-20 oxidase enzyme. The gene ortholog of rice sd1 was isolated from barley using polymerase chain reaction. The barley and rice genes showed a similar gene structure consisting
of three exons and two introns. Both genes share 88.3% genomic sequence similarity and 89% amino acid sequence identity. A
single nucleotide polymorphism was identified in intron 2 between barley varieties Baudin and AC Metcalfe with Baudin known
to contain the denso semidwarf gene. The single nucleotide polymorphism (SNP) marker was mapped to chromosome 3H in a doubled haploid population
of Baudin × AC Metcalfe with 178 DH lines. Quantitative trait locus analysis revealed that plant height cosegregated with
the SNP. The sdw1/denso gene in barley is the most likely ortholog of the sd1 in rice. The result will facilitate understanding of the molecular mechanism controlling semidwarf phenotype and provide
a diagnostic marker for selection of semidwarf gene in barley.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
3.
Satnam S. Banga Akihiko H. Yamamoto James M. Mason James B. Boyd 《Molecular & general genetics : MGG》1995,246(2):148-155
The mei-41 gene of Drosophila melanogaster plays an essential role in meiosis, in the maintenance of somatic chromosome stability, in postreplication repair and in DNA double-strand break repair. This gene has been cytogenetically localized to polytene chromosome bands 14C4-6 using available chromosomal aberrations. About 60 kb of DNA sequence has been isolated following a bidirectional chromosomal walk that extends over the cytogenetic interval 14C1-6. The breakpoints of chromosomal aberrations identified within that walk establish that the entire mei-41 gene has been cloned. Two independently derived mei-41 mutants have been shown to carry P insertions within a single 2.2 kb fragment of the walk. Since revertants of those mutants have lost the P element sequences, an essential region of the mei-41 gene is present in that fragment. A 10.5 kb genomic fragment that spans the P insertion sites has been found to restore methyl methanesulfonate resistance and female fertility of the mei-41
D3 mutants. The results demonstrate that all the sequences required for the proper expression of the mei-41 gene are present on this genomic fragment. This study provides the foundation for molecular analysis of a function that is essential for chromosome stability in both the germline and somatic cells.This Paper is dedicated to the memory of Professor James B. Boyd 相似文献
4.
Park JY Koo DH Hong CP Lee SJ Jeon JW Lee SH Yun PY Park BS Kim HR Bang JW Plaha P Bancroft I Lim YP 《Molecular genetics and genomics : MGG》2005,274(6):579-588
We constructed a bacterial artificial chromosome (BAC) library, designated as KBrH, from high molecular weight genomic DNA
of Brassica rapa ssp. pekinensis (Chinese cabbage). This library, which was constructed using HindIII-cleaved genomic DNA, consists of 56,592 clones with average insert size of 115 kbp. Using a partially duplicated DNA
sequence of Arabidopsis, represented by 19 and 9 predicted genes on chromosome 4 and 5, respectively, and BAC clones from the KBrH library, we studied
conservation and microsynteny corresponding to the Arabidopsis regions in B. rapa ssp. pekinensis. The BAC contigs assembled according to the Arabidopsis homoeologues revealed triplication and rearrangements in the Chinese cabbage. In general, collinearity of genes in the paralogous
segments was maintained, but gene contents were highly variable with interstitial losses. We also used representative BAC
clones, from the assembled contigs, as probes and hybridized them on mitotic (metaphase) and/or meiotic (leptotene/pachytene/metaphase
I) chromosomes of Chinese cabbage using bicolor fluorescence in situ hybridization. The hybridization pattern physically identified
the paralogous segments of the Arabidopsis homoeologues on B. rapa ssp. pekinensis chromosomes. The homoeologous segments corresponding to chromosome 4 of Arabidopsis were located on chromosomes 2, 8 and 7, whereas those of chromosome 5 were present on chromosomes 6, 1 and 4 of B. rapa ssp. pekinensis. 相似文献
5.
M. Rossi D. Lijavetzky H. E. Hopp N. Iusem D. Bernacchi M. Rossi H. E. Hopp N. Iusem 《Molecular & general genetics : MGG》1996,252(4):489-492
Asr1, Asr2 andAsr3 are three homologous clones isolated from tomato whose expression is believed to be regulated by abscisic acid (ABA); the corresponding genes thus participate in physiological and developmental processes such as responses of leaf and root to water stress, and fruit ripening. In this report, results obtained with Near Isogenic Lines reveal thatAsr1, Asr2 andAsr3 represent three different loci. In addition, we map these genes on the restriction fragment length polymorphism (RFLP) map of the tomato genome by using an F2 population derived from an interspecific hybrid crossL. esculentum × L. penelli. RFLP data allow us to map these genes on chromosome 4, suggesting that they belong to a gene family. The elucidation of the genomic organization of theAsr gene family may help in understanding the role of its members in the response to osmotic stress, as well as in fruit ripening, at the molecular level. 相似文献
6.
Yu Q Hou S Hobza R Feltus FA Wang X Jin W Skelton RL Blas A Lemke C Saw JH Moore PH Alam M Jiang J Paterson AH Vyskot B Ming R 《Molecular genetics and genomics : MGG》2007,278(2):177-185
Sex chromosomes in flowering plants evolved recently and many of them remain homomorphic, including those in papaya. We investigated
the chromosomal location of papaya’s small male specific region of the hermaphrodite Y (Yh) chromosome (MSY) and its genomic features. We conducted chromosome fluorescence in situ hybridization mapping of Yh-specific bacterial artificial chromosomes (BACs) and placed the MSY near the centromere of the papaya Y chromosome. Then
we sequenced five MSY BACs to examine the genomic features of this specialized region, which resulted in the largest collection
of contiguous genomic DNA sequences of a Y chromosome in flowering plants. Extreme gene paucity was observed in the papaya
MSY with no functional gene identified in 715 kb MSY sequences. A high density of retroelements and local sequence duplications
were detected in the MSY that is suppressed for recombination. Location of the papaya MSY near the centromere might have provided
recombination suppression and fostered paucity of genes in the male specific region of the Y chromosome. Our findings provide
critical information for deciphering the sex chromosomes in papaya and reference information for comparative studies of other
sex chromosomes in animals and plants.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
7.
Cunningham C Hikima J Jenny MJ Chapman RW Fang GC Saski C Lundqvist ML Wing RA Cupit PM Gross PS Warr GW Tomkins JP 《Marine biotechnology (New York, N.Y.)》2006,8(5):521-533
Large-insert genomic bacterial artificial chromosome (BAC) libraries of two culturally and economically important oyster species,
Crassostrea virginica and C. gigas, have been developed as part of an international effort to develop tools and reagents that will advance our ability to conduct
genetic and genomic research. A total of 73,728 C. gigas clones with an average insert size of 152 kb were picked and arrayed representing an 11.8-fold genome coverage. A total of
55,296 clones with an average insert size of 150 kb were picked and arrayed for C. virginica, also representing an 11.8-fold genome coverage. The C. gigas and C. virginica libraries were screened with probes derived from selected oyster genes using high-density BAC colony filter arrays. The probes
identified 4 to 25 clones per gene for C. virginica and 5 to 50 clones per gene for C. gigas. We conducted a preliminary analysis of genetic polymorphism represented in the C. gigas library. The results suggest that the degree of divergence among similar sequences is highly variable and concentrated in
intronic regions. Evidence supporting allelic polymorphism is reported for two genes and allelic and/or locus specific polymorphism
for several others. Classical inheritance studies are needed to confirm the nature of these polymorphisms. The oyster BAC
libraries are publicly available to the research community on a cost-recovery basis at 相似文献
8.
Yasukochi Y Ashakumary LA Wu C Yoshido A Nohata J Mita K Sahara K 《Development genes and evolution》2004,214(12):606-614
A bacterial artificial chromosome (BAC) contig was constructed by chromosome walking, starting from the Hox genes of the silkworm, Bombyx mori. Bombyx orthologues of the labial (lab) and zerknült (zen) genes were newly identified. The size of the BAC contig containing the Hox gene cluster—except the lab and Hox 2 genes—was estimated to be more than 2 Mb. The Bombyx Hox cluster was mapped to linkage group (LG) 6. The lab gene was mapped on the same LG, but far apart from the cluster. Fluorescence in situ hybridization analysis confirmed that the major Hox gene cluster and lab were at different locations on the same chromosome in B. mori.Edited by M. Akam 相似文献
9.
Harry J. Klee Maria B. Hayford Stephen G. Rogers 《Molecular & general genetics : MGG》1987,210(2):282-287
Summary Cloning of genes by transformation with genomic banks and rescue of a phenotype has been extensively used in bacterial systems. This approach has not been possible in plant systems because of the large genome sizes and poor transformation frequencies of most plant species. Recent advances in plant transformation permit the generation of large numbers of transformants in petunia. We have used this system to rescue a model gene encoding resistance to kanamycin by shotgun cloning. The gene encoding neomycin phosphotransferase (NPTII) was introduced into the genome of Arabidopsis thaliana by Agrobacterium tumefaciens-mediated transformation. A genomic bank of DNA from this tissue was constructed in a cosmid vector containing features which would allow its use in plant transformation. The unselected genomic bank was mobilized from Escherichia coli to A. tumefaciens and used to retransform petunia leaf discs. The rescued gene was identified by its ability to confer a kanamycin-resistant phenotype in petunia tissue. The presence of the NPTII gene was confirmed by nopaline assay and Southern blot analysis. This experiment demonstrates the feasibility of gene rescue, in certain circumstances, in plants. 相似文献
10.
11.
Rolf Stucka Sylvie Dequin Jean-Michel Salmon Carlos Gancedo 《Molecular & general genetics : MGG》1991,229(2):307-315
Summary A gene encoding pyruvate carboxylase has previously been isolated from Saccharomyces cerevisiae. We have isolated a second gene, PYC2, from the same organism also encoding a pyruvate carboxylase. The gene PYC2 is situated on the right arm of chromosome II between the DUR 1, 2 markers and the telomere. We localized the previously isolated gene, which we designate PYC1, to chromosome VII. Disruption of either of the genes did not produce marked changes in the phenotype. However, simultaneous disruption of both genes resulted in inability to grow on glucose as sole carbon source, unless aspartate was added to the medium. This indicates that in wild-type yeast there is no bypass for the reaction catalysed by pyruvate carboxylase. The coding regions of both genes exhibit a homology of 90% at the amino acid level and 85% at the nucleotide level. No appreciable homology was found in the corresponding flanking regions. No differences in the K
m values for ATP or pyruvate were observed between the enzymes obtained from strains carrying inactive, disrupted versions of one or other of the genes.A preliminary report of this work was presented at the 15th International Conference on Yeast Genetics and Molecular Biology, The Hague, Netherlands. Abstract appeared in Yeast
6, S-240 (1990) 相似文献
12.
Detlef Weigel Elisabeth Knust José A. Campos-Ortega 《Molecular & general genetics : MGG》1987,207(2-3):374-384
Summary The gene master mind (mam) is located in bands 50C23-D1 of the second chromosome of Drosophila melanogaster. mam is one of the neurogenic genes, whose function is necessary for a normal segregation of neural and epidermal lineages during embryonic development. Loss of function of any of the neurogenic genes results in a mis-routeing into neurogenesis of cells that normally would have given rise to epidermis. We describe here the molecular cloning of 198 kb of genomic DNA containing the mam gene. Ten different mam mutations (point mutants and chromosomal aberrations) have been mapped within 45 kb of the genomic walk. One of the mutations, an insertion of a P-element, was originally recovered from a dysgenic cross. Four different wild-type revertants of this mutation were characterized at the molecular level and, although modifications of the insertions were found, in no case was the transposon completely excised. An unusually high number of the repetitive opa sequence, and of an additional previously unknown element, which we have called N repeat, are scattered throughout the 45 kb where the mam mutations map. The functional significance of these repeats is unknown. 相似文献
13.
Canto-Canché B Guillén-Maldonado DK Peraza-Echeverría L Conde-Ferráez L James-Kay A 《Molecular biotechnology》2007,36(1):64-70
A bacterial artificial chromosome library of the causal agent of the Black Sigatoka leaf spot disease of banana and plantain,
Mycosphaerella fijiensis, has been constructed using a non-sphaeroplasting technique and characterized using both homologous and heterologous probes.
After first and a second size selection of PFGE-fractionated DNA, a ligation was obtained using a 1:4 molar ratio (insert:vector).
One hundred random clones were analyzed, and the mean insert size was estimated to be 90 kb. The range of the insert sizes
was between 40 and 160 kb. The highest percentage of inserts belonged to the range between 80 and 100 kb; 32% of the inserts
had 2 or 3 internal NotI sites. This library consists of 1920 clones, if the genomic size is at least 35 Mb, then this represents 4.9× genome equivalents,
which was supported by hybridization results with homologous and heterologous probes.
Blondy Canto-Canché and Diana Karina Guillén-Maldonado contributed equally to this work and should be regarded as co-first
authors. 相似文献
14.
Genetic and physical mapping of <Emphasis Type="Italic">Pi36</Emphasis>(t), a novel rice blast resistance gene located on rice chromosome 8 总被引:12,自引:0,他引:12
Blast resistance in the indica cultivar (cv.) Q61 was inherited as a single dominant gene in two F2 populations, F2-1 and F2-2, derived from crosses between the donor cv. and two susceptible japonica cvs. Aichi Asahi and Lijiangxintuanheigu (LTH), respectively. To rapidly determine the chromosomal location of the resistance
(R) gene detected in Q61, random amplified polymorphic DNA (RAPD) analysis was performed in the F2-1 population using bulked-segregant analysis (BSA) in combination with recessive-class analysis (RCA). One of the three linked
markers identified, BA1126550, was cloned and sequenced. The R gene locus was roughly mapped on rice chromosome 8 by comparison of the BA1126550 sequence with rice sequences in the databases (chromosome landing). To confirm this finding, seven known markers, including
four sequence-tagged-site (STS) markers and three simple-sequence repeat (SSR) markers flanking BA1126550 on chromosome 8, were subjected to linkage analysis in the two F2 populations. The locus was mapped to a 5.8 cM interval bounded by RM5647 and RM8018 on the short arm of chromosome 8. This
novel R gene is therefore tentatively designated as Pi36(t). For fine mapping of the Pi36(t) locus, five additional markers including one STS marker and four candidate resistance gene (CRG) markers were developed
in the target region, based on the genomic sequence of the corresponding region of the reference japonica cv. Nipponbare. The Pi36(t) locus was finally localized to an interval of about 0.6 cM flanked by the markers RM5647 and CRG2, and co-segregated with
the markers CRG3 and CRG4. To physically map this locus, the Pi36(t)-linked markers were mapped by electronic hybridization to bacterial artificial chromosome (BAC) or P1 artificial chromosome
(PAC) clones of Nipponbare, and a contig map was constructed in silico through Pairwise BLAST analysis. The Pi36(t) locus was physically delimited to an interval of about 17.0 kb, based on the genomic sequence of Nipponbare. 相似文献
15.
István Papp László Dorgai Péter Papp Erzsébet Jónás Ferenc Olasz László Orosz 《Molecular & general genetics : MGG》1993,240(2):258-264
Bacteriophage 16-3 inserts its genome into the chromosome of Rhizobium meliloti strain 41 (Rm41) by site-specific recombination. The DNA regions around the bacterial attachment site (attB) and one of the hybrid attachment sites bordering the integrated prophage (attL) were cloned and their nucleotide sequences determined. We demonstrated that the 51 by region, where the phage and bacterial DNA sequences are identical, is active as a target site for phage integration. Furthermore it overlaps the 3 end of a putative proline tRNA gene. This gene shows 79% similartiy to the corresponding proline tRNA-like genomic target sequence of certain integrative plasmids in Actinomycetes. 相似文献
16.
J. Yaghoobi I. Kaloshian Y. Wen V. M. Williamson 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1995,91(3):457-464
Accessions of the wild tomato species L. peruvianum were screened with a root-knot nematode population (557R) which infects tomato plants carrying the nematode resistance gene Mi. Several accessions were found to carry resistance to 557R. A L. peruvianum backcross population segregating for resistance to 557R was produced. The segregation ratio of resistant to susceptible plants suggested that a single, dominant gene was a major factor in the new resistance. This gene, which we have designated Mi-3, confers resistance against nematode strains that can infect plants carrying Mi. Mi-3, or a closely linked gene, also confers resistance to nematodes at 32°C, a temperature at which Mi is not effective. Bulked-segregant analysis with resistant and susceptible DNA pools was employed to identify RAPD markers linked to this gene. Five-hundred-and-twenty oligonucleotide primers were screened and two markers linked to the new resistance gene were identified. One of the linked markers (NR14) was mapped to chromosome 12 of tomato in an L. esculentum/L. pennellii mapping population. Linkage of NR14 and Mi-3 with RFLP markers known to map on the short arm of chromosome 12 was confirmed by Southern analysis in the population segregating for Mi-3. We have positioned Mi-3 near RFLP marker TG180 which maps to the telomeric region of the short arm of chromosome 12 in tomato. 相似文献
17.
H. -P. During B. Nelsen-Salz R. Garber E. Tillmann 《Molecular & general genetics : MGG》1989,219(1-2):299-305
Summary The structure of the unstable Ds-induced sh-m5933 allele of the maize sucrose synthase gene was analysed and a double Ds structure found in opposite orientation on both sides of a 30 kb insert interrupting the sucrose synthase gene. The double Ds structures bordering the insert are identical over a distance of approximately 3 kb. These double Ds structures and the DNA segments beyond them are in opposite orientation and identical over a distance of approx. 5.3 kb. A hypothesis for how such a symmetrical structure could be formed is proposed. When one complete Ds element was excised from one of the double Ds structures a half Ds element was left behind. This half Ds element was found in one revertant strain which displayed an altered pattern of chromosome breakage compared to revertant strains which had not undergone Ds excision. Nine new maize strains which showed a similarly altered chromosome breakage pattern were isolated. In all nine cases we observed an indistinguishable deletion in the genomic DNA. These excisions are likely to be the result of similar excision events to that described above. We conclude that double Ds structures are responsible for Ds-induced chromosome breakage. 相似文献
18.
Anne-Marie Estévenon Jan Kooistra Nicole Sicard 《Molecular & general genetics : MGG》1995,246(4):514-518
An Escherichia coli mutant lacking deoxycytidine triphosphate deaminase (Dcd) activity and an unknown function encoded by a gene designated ior exhibits sensitivity to ionizing radiation whereas dcd mutants themselves are not sensitive. A DNA fragment from an E. coli genomic library that restores the wild type level of UV and gamma ray resistance to this mutant has been cloned in the multicopy vector pBR322. Comparison of its restriction map with the physical map of the E. coli chromosome revealed complete identity to the recBD genes. ior affects ATP-dependent exonuclease activity, suggesting that it is an allele of recB. This mutation alone does not confer sensitivity to UV and gamma radiation, indicating that lack of Dcd activity is also required for expression of radiation sensitivity. 相似文献
19.
Electrophoretic variation characterized by the presence (ES-5B+) or absence (ES-5B–) of esterase-5B in the plasma of the house mouse has been observed. It is suggested that the expression of esterase-5B is controlled by an autosomal locus, Esr, linked to Ldr-1 on chromosome 6, in addition to the presumptive structural locus Es-5, which is located on chromosome 8. A gene order of Lyt-3-Esr-Ldr-1 was determined by two crosses.Supported by the Deutsche Forschungsgemeinschaft (SFB 46).This is communication No. 33 of a research program devoted to the investigation of cellular distribution and genetics of nonspecific esterases. 相似文献
20.
A physical and genetic map of the chromosome of Methanobacterium wolfei was constructed by using pulsed-field gel electrophoresis of restriction fragments generated by digestion with NotI and NheI. The chromosome was found to be circular and 1,729 kb in size. Twenty-eight genes were mapped to specific restriction enzyme fragments by performing hybridization experiments with gene probes from various Methanobacterium strains. The genomic map obtained was compared with the updated genomic map of Methanobacterium thermoautotrophicum Marburg. In spite of major restriction pattern dissimilarities, the overall genetic organization seemed to be conserved between the genomes of the two strains. In addition, the two rRNA operons of strain Marburg were precisely mapped on the chromosome, and it was shown that they are transcribed in the same direction. 相似文献