Autoradiographs of MVR-PCR at the insulin minisatellite

MVR-PCR of class I alleles

MVR-PCR maps of 6 class I alleles are presented. Codes are read from bottom (5' end of the minisatellite) to top (3' end of the minisatellite, next to the insulin gene). All alleles were MVR mapped with primers INS-MA, INS-MB, INS-MC, INS-MD, INS-ME, and INS-MH (loaded from left to right).

INS-MC detects both B- and C-type repeats. INS-MB discriminates between these two variants. Similarly, INS-MD should detect both D- and F-type repeats. However, further analysis of a selection of alleles with primer INS-MF which detects only F-type repeats indicated that all repeats detected by INS-MD were F-type repeats. No E- or H-type repeats were detected in class I alleles.

The first few repeats were often not detectable after short (14 hr at room temperature) exposure of the autoradiograph. Autoradiographs of each radiolabelled Southern blot were therefore also produced after 36 hr exposure at -80ûC with intensifier screen. A subdivision of class I alleles is apparent from the autoradiograph presented, most readily defined by the presence or absence of F-type repeats located at the centre and top of alleles, which corresponds to the division of alleles into lineages ID and IC respectively.

MVR-PCR of class III alleles

MVR-PCR maps of 2 class III alleles (IIIA152.2 and IIIB145.1) are presented. The system of MVR-PCR could only accurately type the first ~100 repeats of the repeat array. The remainder of the allele was therefore mapped by creating deletion amplicons covering the 3' end of the array. For both alleles shown above, maps are presented for the full allele, and for two deletion amplicons.

This last autoradiograph is included as I think it looks really nice.

These pages provide supplementary information for the following publications:

Global haplotype diversity in the human insulin gene region. Stead, J.D.H., Hurles, M.E. and Jeffreys, A.J. Genome Res. 13, 2101-11 (2003)

Structural analysis of insulin minisatellite alleles reveals unusually large differences in diversity between Africans and non-Africans. Stead, J.D.H. and Jeffreys, A.J. Am. J. Hum. Genet. 71, 1273-84 (2002)

Influence of allele lineage on the role of the insulin minisatellite in susceptibility to type 1 diabetes. Stead, J.D.H., Buard, J., Todd, J.A. and Jeffreys, A.J. Hum. Mol. Genet., 9, 2929-2935 (2000).

Allele diversity and germline mutation at the insulin minisatellite. Stead, J.D.H. and Jeffreys, A.J. Hum. Mol. Genet., 9, 713-723 (2000).