ABSTRACT
Human mitochondrial DNA from 50 trios consisting of mother (M), child (C) and father (F) was PCR amplified with primers flanking the hyper-variable regions, HVR1 and HVR2. The amplified products were then fractionated under non-denaturing conditions, silver-stained and compared by single-stranded conformational polymorphism (SSCP). In all but one case, mother and child displayed identical patterns, which could be promptly distinguished from that of the father. For the remaining cases, either set of primers was sufficient to resolve the familial ties. In no instance, M displayed alleles different from those of C within each trio, demonstrating that no false exclusions occurred. The SSCP approach proved to be a robust technique suitable as a preliminary screening in cases requiring identification of multiple samples.
Subject(s)
DNA, Mitochondrial/analysis , Paternity , Polymorphism, Single-Stranded Conformational , Silver Staining , Child , DNA Fingerprinting/methods , Female , Humans , Male , Pedigree , Polymerase Chain ReactionABSTRACT
Eleven samples of wheat (Triticum aestivum) from different Brazilian cultivars and six American varieties were compared for polymorphism, using primers for nine different STR loci. STR analysis of DNA from single grains of the Brazilian varieties showed that for most loci there was very little intra-cultivar polymorphism. The polymorphic variation observed for Brazilian cultivars was similar to that seen in the American varieties. For the Brazilian cultivars PCR analysis could be performed on only one half of a grain. The American samples required more seeds for analysis. The nucleotide sequences of five amplified microsatellites selected at random from the Brazilian samples were also determined and compared to those of the Chinese Spring variety. Although generally the dinucleotide sequence repeat was preserved for most loci, there were significant differences in sequences interspersed within the repeat domain. This result suggested that it may be possible to unequivocally identify the geographical origin of the cultivar by inspection of the DNA sequences of the repeat region
