Genetic and Physical Mapping of the RPP13 Locus, in Arabidopsis, Responsible for Specific Recognition of Several Peronospora parasitica (Downy Mildew) Isolates

Fifteen isolates of the biotrophic oomycete Peronospora parasitica (downy mildew) were obtained from a population of Arabidopsis thaliana plants that established naturally in a garden the previous year. They exhibited phenotypic variation in a set of 12 Arabidopsis accessions that suggested that the parasite population consisted of at least six pathotypes. One isolate, Maks9, elicited an interaction phenotype of flecking necrosis and no sporulation (FN) in the Arabidopsis accession Nd-1, and more extensive pitting necrosis with no sporulation (PN) in the accession Ws-2. RPP13 was designated as the locus for a single dominant resistance gene associated with the resistance in Nd-1 and mapped to an interval of approximately 60 kb on a bacterial artificial chromosome (BAC) contig on the lower arm of chromosome 3. This locus is approximately 6 cM telomeric to RPP1, which was previously described as the locus for the PN interaction with five Peronospora isolates, including resistance to Maks9 in Ws-2. New Peronospora isolates were obtained from four other geographically distinct populations of P. parasitica. Four isolates were characterized that elicited an FN phenotype in Nd-1 and mapped resistance to the RPP13 locus. This suggests that the RPP13 locus contains either a single gene capable of multiple isolate recognition or a group of tightly linked genes. Further analysis suggests that the RPP11 gene in the accession Rld-0 may be allelic to RPP13 but results in a different recognition capability.

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Comparative physical mapping reveals features of microsynteny between Glycine max, Medicago truncatula, and Arabidopsis thaliana

Genome ◽

10.1139/g03-106 ◽

2004 ◽

Vol 47 (1) ◽

pp. 141-155 ◽

Cited By ~ 38

Author(s):

H H Yan ◽

J Mudge ◽

D-J Kim ◽

R C Shoemaker ◽

D R Cook ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Glycine Max ◽

Medicago Truncatula ◽

Physical Mapping ◽

Large Scale ◽

Sequence Similarity ◽

Artificial Chromosome ◽

Bac Contig ◽

Cross Hybridization ◽

Bac Contigs

To gain insight into genomic relationships between soybean (Glycine max) and Medicago truncatula, eight groups of bacterial artificial chromosome (BAC) contigs, together spanning 2.60 million base pairs (Mb) in G. max and 1.56 Mb in M. truncatula, were compared through high-resolution physical mapping combined with sequence and hybridization analysis of low-copy BAC ends. Cross-hybridization among G. max and M. truncatula contigs uncovered microsynteny in six of the contig groups and extensive microsynteny in three. Between G. max homoeologous (within genome duplicate) contigs, 85% of coding and 75% of noncoding sequences were conserved at the level of cross-hybridization. By contrast, only 29% of sequences were conserved between G. max and M. truncatula, and some kilobase-scale rearrangements were also observed. Detailed restriction maps were constructed for 11 contigs from the three highly microsyntenic groups, and these maps suggested that sequence order was highly conserved between G. max duplicates and generally conserved between G. max and M. truncatula. One instance of homoeologous BAC contigs in M. truncatula was also observed and examined in detail. A sequence similarity search against the Arabidopsis thaliana genome sequence identified up to three microsyntenic regions in A. thaliana for each of two of the legume BAC contig groups. Together, these results confirm previous predictions of one recent genome-wide duplication in G. max and suggest that M. truncatula also experienced ancient large-scale genome duplications.Key words: Glycine max, Medicago truncatula, Arabidopsis thaliana, conserved microsynteny, genome duplication.

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Construction of bacterial artificial chromosome libraries from the parasitic nematode Brugia malayi and physical mapping of the genome of its Wolbachia endosymbiont

International Journal for Parasitology ◽

10.1016/j.ijpara.2004.02.001 ◽

2004 ◽

Vol 34 (6) ◽

pp. 733-746 ◽

Cited By ~ 14

Author(s):

Jeremy M Foster ◽

Sanjay Kumar ◽

Mehul B Ganatra ◽

Ibrahim H Kamal ◽

Jennifer Ware ◽

...

Keyword(s):

Bacterial Artificial Chromosome ◽

Physical Mapping ◽

Parasitic Nematode ◽

Brugia Malayi ◽

Artificial Chromosome ◽

Wolbachia Endosymbiont

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A Comparison of Peronospora parasitica (Downy Mildew) Isolates from Arabidopsis thaliana and Brassica oleracea Using Amplified Fragment Length Polymorphism and Internal Transcribed Spacer 1 Sequence Analyses

Fungal Genetics and Biology ◽

10.1006/fgbi.2000.1216 ◽

2000 ◽

Vol 30 (2) ◽

pp. 95-103 ◽

Cited By ~ 35

Author(s):

Anne P. Rehmany ◽

James R. Lynn ◽

Mahmut Tör ◽

Eric B. Holub ◽

Jim L. Beynon

Keyword(s):

Arabidopsis Thaliana ◽

Brassica Oleracea ◽

Downy Mildew ◽

Length Polymorphism ◽

Fragment Length ◽

Internal Transcribed Spacer ◽

Fragment Length Polymorphism ◽

Amplified Fragment Length Polymorphism ◽

Peronospora Parasitica ◽

Sequence Analyses

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An integrated physical, genetic and cytogenetic map around the sunn locus of Medicago truncatula

Genome ◽

10.1139/g03-019 ◽

2003 ◽

Vol 46 (4) ◽

pp. 665-672 ◽

Cited By ~ 19

Author(s):

E Schnabel ◽

O Kulikova ◽

R V Penmetsa ◽

T Bisseling ◽

D R Cook ◽

...

Keyword(s):

Genetic Distance ◽

Medicago Truncatula ◽

Genetic Map ◽

Sinorhizobium Meliloti ◽

Chromosome Region ◽

Single Gene ◽

Artificial Chromosome ◽

Cytogenetic Map ◽

Bac Contig ◽

Group 4

The sunn mutation of Medicago truncatula is a single-gene mutation that confers a novel supernodulation phenotype in response to inoculation with Sinorhizobium meliloti. We took advantage of the publicly available codominant PCR markers, the high-density genetic map, and a linked cytogenetic map to define the physical and genetic region containing sunn. We determined that sunn is located at the bottom of linkage group 4, where a fine-structure genetic map was used to place the locus within a ~400-kb contig of bacterial artificial chromosome (BAC) clones. Genetic analyses of the sunn contig, as well as of a second, closely linked BAC contig designated NUM1, indicate that the physical to genetic distance within this chromosome region is in the range of 1000 1100 kb·cM1. The ratio of genetic to cytogenetic distance determined across the entire region is 0.3 cM·μm1. These estimates are in good agreement with the empirically determined value of ~300 kb·μm1 measured for the NUM1 contig. The assignment of sunn to a defined physical interval should provide a basis for sequencing and ultimately cloning the responsible gene.Key words: FISH, physical to genetic distance, Medicago truncatula, map-based cloning.

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