The pericentromeric 21 DNA marker pGSM21 (D21S13) contains an expressed HTF island.
The DNA marker locus D21S13, localized in the 21q11.1-q21 region, has been closely linked to familial Alzheimer's disease. We constructed a physical map of 1.7 Mb around D21S13 using probes pGSM21 and pGSE9. The results indicated that pGSM21 contains recognition sites for at least three rare-cutting restriction enzymes. The clustering of rare-cutting restriction sites is indicative of the presence of an HTF (HpaII tiny fragment) island. Restriction site mapping and methylation analysis proved that pGSM21 contains a methylation-free HTF island. Furthermore, a cDNA correlate has been isolated confirming that pGSM21 is part of an expressed sequence. Today, the gene associated with pGSM21 is the gene closest to the centromere on the 21q arm.
Department of Biochemistry, University of Antwerp, Belgium.
P
P
Stinissen
W
W
Van Hul
G
G
Van Camp
H
H
Backhovens
A
A
Wehnert
A
A
Vandenberghe
C
C
Van Broeckhoven
D002891:Chromosomes, Human, Pair 21; D004247:DNA / Q000235:genetics / Q000378:metabolism; D019003:Deoxyribonuclease HpaII; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism*; D005796:Genes; D005819:Genetic Markers; D006801:Humans; D008297:Male; D008745:Methylation; D015183:Restriction Mapping
D005819:Genetic Markers; D004247:DNA; D019003:Deoxyribonuclease HpaII; D015252:Deoxyribonucleases, Type II Site-Specific