Molecular Mapping of Chromosomes 17 and X 



David F. Barker, Hunlington F. Willard. Pamela R. Fain, Arnold R. Oliphant, 



and David E. Goldgar 



Deparlment of Genetic Epidemiology, University of Utah Research Park, 



Salt Lake City. UT 84108 



(801)581-5070 



The focus of this project is the construction of high-density genetic maps of 

 chromosomes 17 and X and the correlation of these maps with a set of overlapping 

 cloned DNA segments. We have isolated over 70 new restriction fragment length 

 polymorphisms (RFLPs) for chromosome 17 and over 75 for X. The set of available 

 chromosome- 17 probes is sufficient to construct a genetic map with an average density 

 of 1 to 2 cM and utilizes the CEPH (Centre d'Etude du Polymorphisme Humain) set of 

 reference linkage families. The set of X markers will permit the construction of a 2- to 

 4-cM map. Physical mapping of the chromosomes utilizes both naturally occurring 

 translocation break points and a series of selectively isolated "push-pull" hybrids that 

 provide a potentially unlimited series of physical break points from proximal Xp to 

 distal Xq. Physical localization of probes is also facilitated on the X chromosome by 

 studies of males with a variety of disease-associated small deletions, and on chromo- 

 some 17 by the existence of deletions associated with partial loss of 17p in some tumor 

 tissues and in the Miller-Dieker syndrome. With the combined application of the above 

 genetic and physical mapping methods, an initial ordering of clusters of DNA probes 

 along each chromosome will be established. The techniques of pulsed-field gel 

 fragment mapping and the isolation of overlapping clones in yeast artificial 

 chromosomes will then be applied to establish an ordered map of all probes and 

 fragments. 



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