ABSTRACT
The aim of the present study was to examine a single locus variable number tandem repeat for the purpose of DNA genotyping ("fingerprinting"). DNAs of 175 individuals from five ethnic groups (Black, Chinese, Japanese, Caucasian, and Melanesian) were analyzed. Restriction fragment length polymorphic analysis of random individuals revealed individual specific DNA patterns in all but one group. Among 20 Melanesian inhabitants of the Vanuatu islands in the southwest Pacific, three individuals were found to share a common pattern. This island population represents a "genetic isolate" and illustrates the importance of carrying out population studies on individual ethnic groups of interest. The complexity and the genetic stability of the D1Z2 region as revealed by the probe hMF1 make it an excellent candidate for DNA genotyping in paternity testing as 101 Caucasian individuals each had unique patterns for PstI and SinI digests.
Subject(s)
Chromosomes, Human, Pair 1 , DNA Fingerprinting/methods , Paternity , Polymorphism, Restriction Fragment Length , Repetitive Sequences, Nucleic Acid/genetics , Base Sequence , Blotting, Southern , Cloning, Molecular , Female , Genotype , Humans , Male , Molecular Sequence Data , White People/geneticsABSTRACT
DNAs from 122 individuals representing 5 ethnic groups (Black, Chinese, Japanese, Caucasian and Melanesian) were analyzed for restriction fragment length polymorphisms (RFLPs) with a hypervariable repeated sequence located uniquely on chromosome 1 (hMF No.1; is a component of the D1Z2 locus). When human genomic DNA is digested with a variety of enzymes (TaqI, EcoRI, SinI, PstI, HaeIII) the hMF No.1 probe reveals multiple RFLPs. Ethnic group differences were found in the frequencies of specific EcoRI bands. The most striking ethnic group variation was the presence of a unique fragment amongst the Japanese.
Subject(s)
Alleles , Chromosomes, Human, Pair 1/analysis , DNA Probes , Genetic Markers/analysis , Racial Groups , Base Sequence , Humans , Molecular Sequence Data , Polymorphism, Restriction Fragment LengthABSTRACT
The clone designated hMF #1 represents a clustered DNA family, located on chromosome 1, consisting of tandem arrays displaying a monomeric length of 40 bp and a repetition frequency of approximately 7 x 10(3) copies per haploid genome. The sequence hMF #1 reveals multiple restriction fragment length polymorphisms (RFLPs) when human genomic DNA is digested with a variety of 4-6-bp recognition sequence restriction enzymes (i.e., Taq I, Eco RI, Pst I, etc.). When hamster and mouse genomic DNA was digested and analyzed, no cross-species homology could be observed. Further investigation revealed considerable hybridization in the higher primates (chimpanzee, gorilla, and orangutan) as well as some monkey species. The evolutionary relationship of this repetitive DNA sequence, found in humans, to that of other primates was explored using two hybridization methods: DNA dot blot to establish copy number and Southern DNA analysis to examine the complexity of the RFLPs. Homology to the hMF #1 sequence was found throughout the suborder Anthropoidea in 14 ape and New and Old World monkey species. However the sequence was absent in one species of the suborder Prosimii. Several discrepancies between "established" evolutionary relationships and those predicted by hMF #1 exist, which suggests that repetitive elements of this type are not reliable indicators of phylogenetic branching patterns. The phenomenon of marked diversity between sequence homologies and copy numbers of dispersed repetitive DNA of closely related species has been observed in Drosophila, mice, Galago, and higher primates. We report here a similar phenomenon for a clustered repeat that may have originated at an early stage of primate evolution.
