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Mendelian Segregation (mendelian + segregation)
Selected AbstractsLinear allele-specific long-range amplification: a novel method of long-range molecular haplotyping,,HUMAN MUTATION, Issue 4 2005Wei-Ming Wu Abstract Haplotypes have been repeatedly shown to be more powerful than collections of single-locus markers in gene-mapping studies. Various haplotyping methods including statistical estimation are employed but molecular haplotyping, the acquisition of information directly on physical DNA sequences, has been in demand for its accuracy and independence from family pedigrees. We investigated the allelic specificity of long-range PCR, which was successful for long-range haplotyping in recent reports, and found problems of initial mispriming and crossover amplification significantly confounded its application. Based on these observations, we designed a novel method based on linear amplification of a hemizygous DNA segment with a single phosphorothioate-modified oligonucleotide. Our results revealed, with a single nucleotide polymorphism as the discriminative marker, downstream haplotypes of 14,15 kb DNA segment could be confidently scored. With two rounds of the method and five single nucleotide polymorphisms, molecular haplotypes of 29.3 kb spanning the HCR and CDSN genes, two genes associated with the susceptibility of psoriasis, of 11 members, belonging to a CEPH family, were revealed. Clear Mendelian segregation of 35 highly heterozygous SNPs confirmed the accuracy of the method. Problems of low specificity associated with long-range PCR were not observed. The simplicity, along with long-sequence accessibility and feasibility of a single nucleotide difference as the discriminative marker indicated our method holds promise for future gene-mapping studies. © 2005 Wiley-Liss, Inc. [source] Characterization of 28 microsatellite loci for the butterfly Bicyclus anynanaMOLECULAR ECOLOGY RESOURCES, Issue 1 2005A. E. VAN'T HOF Abstract We present 28 polymorphic microsatellite loci, including a sex-linked W-chromosome marker, for the Afrotropical butterfly, Bicyclus anynana. Our primary motivation to develop these markers was to apply them in quantitative trait loci (QTL) mapping studies. A technique is also proposed that may be useful in avoiding redundant sequences which are common in lepidopteran-enriched libraries. Pedigree analysis was performed to test Mendelian segregation of the markers and to address the issue of null alleles. [source] Genomic and cDNA microsatellites from apricot (Prunus armeniaca L.)MOLECULAR ECOLOGY RESOURCES, Issue 4 2004L. S. HAGEN Abstract We developed primers for the amplification of 24 polymorphic nuclear microsatellites in apricot (Prunus armeniaca L.). Thirteen loci originated from three genomic libraries enriched for TC, TG and AAG motifs. Eight loci were developed from three fruit EST (Expressed-Sequence-Tag) libraries and three from a leaf cDNA microsatellite-enriched library. There were up to nine alleles per polymorphic locus in 12 different cultivars. No difference in allele numbers were shown between cDNA and genomic-source loci. Mean expected heterozygosity was 0.65 (range: 0.15,0.87). Mendelian segregation was confirmed for all loci. These markers should be helpful for diversity studies, genome mapping and cultivar identification in apricot and related species. [source] Magnaporthe grisea interactions with the model grass Brachypodium distachyon closely resemble those with rice (Oryza sativa)MOLECULAR PLANT PATHOLOGY, Issue 4 2004ANDREW P. M. ROUTLEDGE SUMMARY Germplasm of Brachypodium distachyon was inoculated with Magnaporthe grisea using either rice- (Guy11) or grass-adapted (FAG1.1.1, PA19w-06, PA31v-01) host-limited forms of the fungus, and interactions with varying degrees of susceptibility and resistance were identified. Ecotype ABR5 was resistant to each M. grisea strain whereas ABR1 was susceptible to all but P31vi-01. Mendelian segregation in ABR1 × ABR5 crosses suggested that a single dominant resistance gene conferred resistance to Guy11. Microscopic analyses revealed that the aetiology of Guy11 fungal development and disease progression in ABR1 closely resembled that of rice infections. In ABR5, Guy11 pathogenesis was first suppressed at 48 h post-inoculation, at the secondary hyphal formation stage and was coincident with cytoplasmic granulation. Resistance to strains PA31v-01 and FAG1.1.1 was associated with a localized cell death with little callose deposition. 3,3-Diaminobenzidine staining indicated the elicitation of cell death in B. distachyon was preceded by oxidative stress in the interacting epidermal cells and the underlying mesophyll cells. Northern blot hybridization using probes for barley genes (PR1, PR5 and PAL) indicated that each was more rapidly expressed in ABR5 challenged with Guy11 although the B. distachyon defence genes BD1 and BD8 were more quickly induced in ABR1. Such data show that B. distachyon is an appropriate host for functional genomic investigations into M. grisea pathology and plant responses. [source] | ||||||||||