An Amplified Fragment Length Polymorphism Map of the Silkworm

Abstract The silkworm (Bombyx mori L.) is a lepidopteran insect with a long history of significant agricultural value. We have constructed the first amplified fragment length polymorphism (AFLP) genetic linkage map of the silkworm B. mori at a LOD score of 2.5. The mapping AFLP markers were genotyped in 47 progeny from a backcross population of the cross no. 782 × od100. A total of 1248 (60.7%) polymorphic AFLP markers were detected with 35 PstI/TaqI primer combinations. Each of the primer combinations generated an average of 35.7 polymorphic AFLP markers. A total of 545 (44%) polymorphic markers are consistent with the expected segregation ratio of 1:1 at the significance level of P = 0.05. Of the 545 polymorphic markers, 356 were assigned to 30 linkage groups. The number of markers on linkage groups ranged from 4 to 36. There were 21 major linkage groups with 7-36 markers and 9 relatively small linkage groups with 4-6 markers. The 30 linkage groups varied in length from 37.4 to 691.0 cM. The total length of this AFLP linkage map was 6512 cM. Genetic distances between two neighboring markers on the same linkage group ranged from 0.2 to 47 cM with an average of 18.2 cM. The sex-linked gene od was located between the markers P1T3B40 and P3T3B27 at the end of group 3, indicating that AFLP linkage group 3 was the Z (sex) chromosome. This work provides an essential basic map for constructing a denser linkage map and for mapping genes underlying agronomically important traits in the silkworm B. mori L.

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A Genetic Linkage Map of the Model Legume Lotus japonicus and Strategies for Fast Mapping of New Loci

Genetics ◽

10.1093/genetics/161.4.1673 ◽

2002 ◽

Vol 161 (4) ◽

pp. 1673-1683 ◽

Cited By ~ 3

Author(s):

Niels Sandal ◽

Lene Krusell ◽

Simona Radutoiu ◽

Magdalena Olbryt ◽

Andrea Pedrosa ◽

...

Keyword(s):

Linkage Map ◽

Genetic Map ◽

Length Polymorphism ◽

Fragment Length ◽

Fragment Length Polymorphism ◽

Lotus Japonicus ◽

Aflp Markers ◽

Linkage Groups ◽

Model Legume ◽

Group I

Abstract A genetic map for the model legume Lotus japonicus has been developed. The F2 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.

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An integrated restriction fragment length polymorphism - amplified fragment length polymorphism linkage map for cultivated sunflower

Genome ◽

10.1139/g00-111 ◽

2001 ◽

Vol 44 (2) ◽

pp. 213-221 ◽

Cited By ~ 44

Author(s):

Melaku Ayele Gedil ◽

Crispin Wye ◽

Simon Berry ◽

Bart Segers ◽

Johan Peleman ◽

...

Keyword(s):

Restriction Fragment Length Polymorphism ◽

Restriction Fragment ◽

Length Polymorphism ◽

Fragment Length ◽

Fragment Length Polymorphism ◽

Amplified Fragment Length Polymorphism ◽

Aflp Markers ◽

Rflp Markers ◽

Linkage Groups ◽

Restriction Fragment Length

Restriction fragment length polymorphism (RFLP) maps have been constructed for cultivated sunflower (Helianthus annuus L.) using three independent sets of RFLP probes. The aim of this research was to integrate RFLP markers from two sets with RFLP markers for resistance gene candidate (RGC) and amplified fragment length polymorphism (AFLP) markers. Genomic DNA samples of HA370 and HA372, the parents of the F2 population used to build the map, were screened for AFLPs using 42 primer combinations and RFLPs using 136 cDNA probes (RFLP analyses were performed on DNA digested with EcoRI, HindIII, EcoRV, or DraI). The AFLP primers produced 446 polymorphic and 1101 monomorphic bands between HA370 and HA372. The integrated map was built by genotyping 296 AFLP and 104 RFLP markers on 180 HA370 × HA372 F2 progeny (the AFLP marker assays were performed using 18 primer combinations). The HA370 × HA372 map comprised 17 linkage groups, presumably corresponding to the 17 haploid chromosomes of sunflower, had a mean density of 3.3 cM, and was 1326 cM long. Six RGC RFLP loci were polymorphic and mapped to three linkage groups (LG8, LG13, and LG15). AFLP markers were densely clustered on several linkage groups, and presumably reside in centromeric regions where recombination is reduced and the ratio of genetic to physical distance is low. Strategies for targeting markers to euchromatic DNA need to be tested in sunflower. The HA370 × HA372 map integrated 14 of 17 linkage groups from two independent RFLP maps. Three linkage groups were devoid of RFLP markers from one of the two maps.Key words: amplified fragment length polymorphism (AFLP), restriction fragment length polymorphism (RFLP), Helianthus, sunflower, genetic map.

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