Microsatellite polymorphism at the D9S12 locus

Nucleic Acids Research, Vol. 19, No. 18 5097 A third Taql allele is detected by the probe pTD3-21 (D15S10) in Southern African chromosomes M.-A.Colman, P.Segalo, M.Ramsay and T.Jenkins MRC Human Ecogenetics Research Unit, Department of Human Genetics, School of Pathology, South African Institute for Medical Research and University of the Witwatersrand, Johannesburg, South Africa Source/Description: Probe pTD3 -21 is a human cDNA clone which was isolated from HindIII total-digest libraries of flowsorted inverted duplicated human chromosomes 15 (1) and has been subcloned as a 2.2 kb HindIll fragment in the vector pBR322. It maps to the region absent in Prader-Willi Syndrome patients with deletions (2). Polymorphism: pTD3 -21 was originally reported to detect a twoallele TaqI polymorphism with polymorphic fragment sizes of 9.0 kb and 8.2 kb and a constant band of 0.5 kb, with a PIC value of 0.28 (3). pTD3 -21 has also been found to detect a third, African-specific allele of 3.0 kb. Frequency: Determined in 20 random Caucasoid individuals, 23 random San individuals ('Bushmen') and 64 random Negroid individuals who are the parents of tyrosinase-positive oculocutaneous albino (ty-pos OCA) children. Frequency Allele Size (kb) Negroid San Caucasoid Al 9.0 0.48 0.15 0.90 0.10 A2 8.2 0.40 0.52 A3 3.0 0.12 0.33 PIC 0.59 0.60 0.16 Chromosomal Localisation: Probe pTD3 -21 (DISS 10) maps to the region 15q 1-q12 (1). Mendelian Inheritance: Codominant segregation has been shown in 9 families, two of which are shown below. The black symbols represent children with ty-pos OCA which is inherited as an autosomal recessive. Probe Availability: Probe pTD3 -21 was purchased from ATCC (depositor Marc Lalande). References: 1) Donlon et al. (1986) PNAS USA 83, 4408-4412. 2) Latt et al. (1987) Cytogenet. Cell Genet. 46, 644. 3) Nicholls et al. (1989) Am. J. Med. Genet. 33, 66-77. kb 22 ..3O : 9~~~~~~~~~30 3 21AT2 p3_ 46 4 p3 . 21./TaqI const Microsatellite polymorphism at the D9S12 locus M.A.R.Yuille, M.Leversha, D.R.Goudie, N.A.Affara and M.A.Ferguson-Smith University of Cambridge, Department of Pathology, Tennis Court Road, Cambridge CB3 9JH, UK Source/Description: Cosmid T512 - which we obtained by screening a human genomic library with a HinfI fragment of the probe pTHH22 (Holm et al., 1988) - contains (CA)16, the flanks of which were sequenced as described (Yuille et al., 1991). Alleles were typed using the polymerase chain reaction. Primer Sequences: 5' CCT CCA CAT GGA CTC ACC TG 3' (CA strand); 5' AAG GGG AGG GAA TCA GGT GT 3' (TG strand). Polymorphism: Heterozygosity was estimated at 74% by analysis of 92 chromosomes from unrelated individuals. Allele bp Frequency Bi 194 0.01 B2 0.05 192 B3 190 0.10 B4 188 0.05 B5 186 0.06 0.21 B6 184 0.43 B7 182 ND B8 180 178 0.01 B9 BlO 176 0.08 Chromosomal Localisation: Fluorescence in situ hybridisation localises cosT512 to Chr 9q22.3 1. Mendelian Inheritance: Co-dominant segregation was observed in 9 families of 2, 3 and 4 generations. Comments: Alleles were typed as described (Yuille et al., 1990) except: all NTPs were at 125 pM; 1.0 /Ci of alpha 32P-dCTP was used; samples were heat denatured at 95°C and snap-chilled on ice before gel-loading. EMBL Data Library accession number for sequence data is X60736. Acknowledgements: This work was supported in part by the Imperial Cancer Research Fund. Dr C.A.Sargent kindly provided access to a cosmid library. References: 1) Yuille,M.A.R. et al. (1990) Nucl. Acids Res. 18, 7472. 2) Yuille,M.A.R. et al. (1991)Nucl. Acids Res. 19, 1950. 3) Holm,T. et al. (1988) Nucl. Acids Res. 15, 5216.