Mutation detection by denaturing gradient gel electrophoresis (DGGE)

The molecular analysis of genetic diseases relies on several technical approaches which allow genetic and physical mapping, characterization of the gene structure, expression studies, and identification of disease-causing mutations. Denaturing gradient gel electrophoresis (DGGE) allows the rapid screening for single base changes in enzymatically amplified DNA. The technique is based on the migration of double-stranded DNA molecules through polyacrylamide gels containing linearly increasing concentrations of a denaturing agent. In this review DGGE and the several modifications of the original protocol are presented. Moreover, its applications in human molecular genetics are summarized together with a preliminary comparison with other mutation detection technologies such as chemical cleavage, RNase protection, and single-strand conformation polymorphism.

Nuclear DNA polymorphisms in a wild population of yellow baboons (Papio hamadryas cynocephalus) from Mikumi National Park, Tanzania

Yellow baboons (Papio hamadryas cynocephalus) from Mikumi National Park, Tanzania were studied for polymorphisms in nuclear DNA. The study population consists of four social groups that inhabit overlapping home ranges and exchange males. As a result, these groups are considered to be members of a single interbreeding population. Human DNA clones were used as probes to screen five loci (AT3, REN, HEXB, VIM, and APOB) for restriction fragment length polymorphisms (RFLP). A total of 14 polymorphisms, at least one at each locus, was detected in a panel of 27 baboons tested using six restriction enzymes for each locus. Eleven of these RFLP systems have average heterozygosity values greater than 0.40. This initial screening demonstrates that human DNA clones can be used to detect significant numbers of informative DNA polymorphisms in single-copy nuclear genes of this species and suggests that the average proportion of nucleotides polymorphic across nuclear loci in this population may be between 1.0% and 1.3%.