Map construction will primarily be achieved by fingerprint analysis of cosmids to expand the already existing cosmid contig map (9,500 cosmids). Saturation of this map will be achieved by generation of a cosmid pocket map using complex probes generated by interspersed repetitive sequence PCR of selected llp YAC clones. Individual laboratories will focus on specific regions of llp by mapping and generating clones for these regions with fingerprint, cytogenetic, YAC and FISH techniques. The ultimate goal is a complete sequence ready map of llp. The strength of this map will be that it consists of many layers (somatic cell hybrids, YACs, cosmid contigs, FISH) and thus ensures that any errors or ambiguities that arise from cosmid fingerprinting contig assembly are seen. This makes our map very rigorous, an important asset for sequence ready cosmid contigs.
Biological studies will be performed on chromosome regions llpl3pl5. These studies will deal with the cloning of genes involved in important human genetic disorders that have already been accurately placed on the map such as lung cancer or childhood tumours at llpl3 or llpl5 respectively. Human-rodent synteny will be studied. Chromosome structure in relation to gene expression will be studied in region llpl3-pl4, a boundary of gene rich and gene-poor chromosome regions. Aniridia will be used to study the phenomenon of a position effect or a chromatin context effect (nearby translocations) on gene regulation (PAX6) as a first example in humans.
Finally, the imprinting phenomenon will be studied by isolation of genes from the imprinted region llpl5.3-pter and subsequent screening for mono-allelic expression dependent on the parental origin. Their role in diseases subject to imprinting will be analyzed. Repair studies employing human cells derived from xeroderma pigmentosum group C cells (XP-C), will be performed on these genes to test whether imprinted alleles are more sensitive to DNA damage and mutations. The repair assay will also be used to screen llpl5.3-pter for transcription activity.
Funding SchemeCSC - Cost-sharing contracts
SW7 2AY London
EH4 2XU Edinburgh
2300 RA Leiden