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A linkage map of three anonymous human DNA fragments and SOD‐1 on chromosome 21.
Author(s) -
Kittur S.D.,
Antonarakis S.E.,
Tanzi R.E.,
Meyers D.A.,
Chakravarti A.,
Groner Y.,
Phillips J.A.,
Watkins P.C.,
Gusella J.F.,
Kazazian H.H.
Publication year - 1985
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1985.tb03923.x
Subject(s) - biology , genetics , dna , linkage (software) , chromosome , microbiology and biotechnology , gene
Using DNA polymorphisms adjacent to single‐copy genomic fragments derived from human chromosome 21, we initiated the construction of a linkage map of human chromosome 21. The probes were genomic EcoRI fragments pW228C, pW236B, pW231C and a portion of the superoxide dismutase gene (SOD‐1). DNA polymorphisms adjacent to each of the probes were used as markers in informative families to perform classical linkage analysis. No crossing‐over was observed between the polymorphic sites adjacent to genomic fragments pW228C and pW236B in 31 chances for recombination. Therefore, these fragments are closely linked to one another (theta = 0.00, lod score = 6.91, 95% confidence limits = 0‐10 cM) and can be treated as one ‘locus’ with four high‐frequency markers. There is a high degree of non‐random association of markers adjacent to each of these two probes which suggests that they are physically very close to one another in the genome. The pW228C ‐ pW236B ‘locus’ was also linked to the SOD‐1 gene (theta = 0.07, lod score = 4.33, 95% confidence limits = 1‐20 cM). On the other hand, no evidence for linkage was found between the pW228C‐pW236B ‘locus’ and the genomic fragment pW231C (theta = 0.5, lod score = 0.00). Based on the fact that pW231C maps to 21q22.3 and SOD‐1 to 21q22.1, we suggest that the pW228C‐pW236B ‘locus’ lies in the proximal long arm of chromosome 21. These data provide the outline of a linkage map for the long arm of chromosome 21, and indicate that the pW228C‐pW236B ‘locus’ is a useful marker system to differentiate various chromosome 21s in a population.