A genetic linkage map of the model legume Lotus japonicus and strategies for fast mapping of new loci.
A genetic map for the model legume Lotus japonicus has been developed. The F(2) mapping population was established from an interspecific cross between L. japonicus and L. filicaulis. A high level of DNA polymorphism between these parents was the source of markers for linkage analysis and the map is based on a framework of amplified fragment length polymorphism (AFLP) markers. Additional markers were generated by restriction fragment length polymorphism (RFLP) and sequence-specific PCR. A total of 524 AFLP markers, 3 RAPD markers, 39 gene-specific markers, 33 microsatellite markers, and six recessive symbiotic mutant loci were mapped. This genetic map consists of six linkage groups corresponding to the six chromosomes in L. japonicus. Fluorescent in situ hybridization (FISH) with selected markers aligned the linkage groups to chromosomes as described in the accompanying article by Pedrosa et al. 2002(this issue). The length of the linkage map is 367 cM and the average marker distance is 0.6 cM. Distorted segregation of markers was found in certain sections of the map and linkage group I could be assembled only by combining colormapping and cytogenetics (FISH). A fast method to position genetic loci employing three AFLP primer combinations yielding 89 markers was developed and evaluated by mapping three symbiotic loci, Ljsym1, Ljsym5, and Ljhar1-3.
Laboratory of Gene Expression, Department of Molecular and Structural Biology, University of Aarhus, DK-8000 Aarhus C, Denmark. sandal@biobase.dk
Niels
N
Sandal
Lene
L
Krusell
Simona
S
Radutoiu
Magdalena
M
Olbryt
Andrea
A
Pedrosa
Silke
S
Stracke
Shusei
S
Sato
Tomohiko
T
Kato
Satoshi
S
Tabata
Martin
M
Parniske
Andreas
A
Bachmair
Tina
T
Ketelsen
Jens
J
Stougaard
D002874:Chromosome Mapping / Q000379:methods*; D005819:Genetic Markers; D006824:Hybridization, Genetic; D000070116:Lotus / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D017422:Sequence Analysis, DNA; D013559:Symbiosis / Q000235:genetics
D005819:Genetic Markers