D20S16 is a complex interspersed repeated sequence: genetic and physical analysis of the locus.
Genomics
; 25(2): 394-403, 1995 Jan 20.
Article
em En
| MEDLINE
| ID: mdl-7789973
ABSTRACT
The genomic structure of the D20S16 locus has been evaluated using genetic and physical methods. D20S16, originally detected with the probe CRI-L1214, is a highly informative, complex restriction fragment length polymorphism consisting of two separate allelic systems. The allelic systems have the characteristics of conventional VNTR polymorphisms and are separated by recombination (theta = 0.02, Zmax = 74.82), as demonstrated in family studies. Most of these recombination events are meiotic crossovers and are maternal in origin, but two, including deletion of the locus in a cell line from a CEPH family member, occur without evidence for exchange of flanking markers. DNA sequence analysis suggests that the basis of the polymorphism is variable numbers of a 98-bp sequence tandemly repeated with 87 to 90% sequence similarity between repeats. The 98-bp repeat is a dimer of 49 bp sequence with 45 to 98% identity between the elements. In addition, nonpolymorphic genomic sequences adjacent to the polymorphic 98-bp repeat tracts are also repeated but are not polymorphic, i.e., show no individual to individual variation. Restriction enzyme mapping of cosmids containing the CRI-L1214 sequence suggests that there are multiple interspersed repeats of the CRI-L1214 sequence on chromosome 20. The results of dual-color fluorescence in situ hybridization experiments with interphase nuclei are also consistent with multiple repeats of an interspersed sequence on chromosome 20.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Marcadores Genéticos
/
Repetições Minissatélites
Limite:
Female
/
Humans
/
Male
Idioma:
En
Ano de publicação:
1995
Tipo de documento:
Article