The albino-deletion complex of the mouse: Molecular mapping of deletion breakpoints that define regions necessary for development of the embryonic and extraembryonic ectoderm

Abstract

Previous complementation analyses ith five (c(11DSD), c(5FR60Hg), c(4FR60Hd), c(6H)) of the mouse albino deletions defined at least two genes on chromosome 7, known as eed and exed, which are necessary for development of the embryonic and extraembryonic ectoderm, respectively, of early postimplantation embryos. The region of chromosome 7 containing these two genes has now been accessed at the molecular level by cloning two of the deletion breakpoint-fusion fragments. The c(2YPSj) breakpoints were isolated by cloning an EcoRI fragment containing a copy of an albino region-specific repeat unique to c(2YPSj) DNA. Similarly, the c(11DSD) breakpoints were isolated by cloning a c(11DSD) EcoRI fragment detected by a unique-sequence probe mapping proximal to the albino-coat-color locus. By mapping the cloned breakpoints relative to the remaining three deletions, the c(11DSD) distal breakpoint was found to define the distal limit of the region containing eed, whereas the c(2YPSj) and c(6H) distal breakpoints were found to define the proximal and distal limits, respectively, of the region containing exed.