Molecular cytogenetic resources for chromosome 4 and comparative analysis of phylogenetic chromosome IV in great apes

We have generated a panel of 55 somatic cell hybrids retaining fragments of human chromosome 4. Each hybrid has been characterized cytogenetically by FISH and molecularly by 37 STSs, evenly spaced along the chromosome. The pa nel can be exploited to map subregionally DNA sequences on chromosome 4 and to generate partial chromosome paints useful in the characterization of ch romosomal rearrangements involving this chromosome. Furthermore, a panel of 84 YACs mapping on chromosome 4 has been characterized by FISH. A subset o f this panel is recognized by STSs used in the somatic cell hybrid characte rization. In this way a correlation between the genetic and the physical ma ps can be established. These resources have been used to investigate the co nservation of the phylogenetic chromosome IV in great apes. The results ind icate that all the pericentric inversions that differentiate chromosome TV in these species are distinct and that one of the breakpoints frequently li es very close to the centromere. In 4 instances, the YAC containing the bre akpoint was identified. The breakpoint in IVq of PTR and MMU lies in the sa me YAC, suggesting that this breakpoint has been utilized twice in the evol utionary history of this chromosome. (C) 2000 Academic Press.