Linkage of DNA probe B79a (D7S13) to cystic fibrosis

We have conducted, in 64 affected families, a study of linkage between the anonymous DNA segment pB79a (D7S13) and the locus for cystic fibrosis (CF) on chromosome 7q. The maximum lod score was 12.60 at theta = .08 (confidence bounds .045-.135). Although D7S13 is not sufficiently close to CF for routine use in DNA-based prenatal diagnosis, it will be helpful in certain families when other nearby markers are uninformative. D7S13 will also be useful for refining the linkage map of the CF region.     

Localization of the coagulation factor XIII B subunit gene (F13B) to chromosome bands 1q31–32.1 and restriction fragment length polymorphism at the locus

Summary In situ hybridization of tritiated cDNA probes for the gene for the B subunit of coagulation factor XIII localized the F13B locus to bands q31–q32.1 on human chromosome 1 and perhaps more precisely to sub-bands 1q31.2 or 1q31.3. Restriction fragment length polymorphisms (RFLPs) were detected with BglII, EcoRI and XbaI. Because the RFLPs detected with each of the three enzymes were concordant in every individual studied and since each showed a similar size difference, it was concluded that the RFLPs probably result from an insertion or deletion of length approximately 0.37–0.4 kb.     

Terminal restriction fragment length polymorphism (T-RFLP) analysis: Characterizing the unseen

The golden era of microbiology during early 1900s was based on the isolation and characterization of purified single cultures. However, since the understanding of limitations of culturing methods to decipher the majority of the microbial diversity, microbiologists have been keen to assess the abundance and distribution of microbial diversity by alternative methods¹. The quest has been further fueled by the idea of relating such information about the community structure to the ecosystem function. Therefore, the goal of new cohort of modern day microbiologists is to understand microbial community structure and dynamics within their natural habitats. Consequently, a wide variety of culture independent approaches and methods for microbial community structure determination have been developed and applied to varied ecosystems. By far the majority of such methods use direct isolation of genetic content from the environmental samples and PCR amplification of genes of interest for bypassing the culturing biases. Existing methods include Amplified Ribosomal DNA Restriction Analysis (ARDRA), Single Stranded Conformation Polymorphism (SSCP), Thermal and Denaturing Gradient Gel Electrophoresis (TGGE and DGGE), Amplified Length Heterogeneity (ALH) analysis and Terminal Restriction Fragment Length Polymorphism (T-RFLP) analysis².     

The restriction fragment length polymorphism of the DNA loci of human chromosome 7]

The results of comparative RFLP analysis in some DNA loci of chromosome 7 in the populations of different Ukrainian regions are presented. Significant differences in RFLP-genotype distributions among regional populations are found. The role of different genetical processes which take place in the populations of different regions of the Ukraine is under discussion.