Long-Range Chromosomal Mapping of the Carcinoembryonic Antigen (CEA) Gene Family Cluster

A long-range physical map of the carcinoembryonic antigen (CEA)
gene family cluster, which is located on the long arm of chromosome
19, has been constructed. This was achieved by hybridization
analysis of large DNA fragments separated by pulse-field gel
electrophoresis and of DNA from human/rodent somatic cell hybrids,
as well as the assembly of ordered sets of cosmids for this gene
region into contigs. The different approaches yielded very similar
results and indicate that the entire gene family is contained
within a region located at position 19q13.1–q13.2 between the CYP2A
and the D19S15/D19S8 markers. The physical linkage of nine genes
belonging to the CEA subgroup and their location with respect to
the pregnancy-specific glycoprotein (PSG) subgroup genes have been
determined, and the latter are located closer to the telomere. From
large groups of ordered cosmid clones, the identity of all known
CEA subgroup genes has been confirmed either by hybridization using
gene-specific probes or by DNA sequencing. These studies have
identified a new member of the CEA subgroup (CGM8), which probably
represents a pseudogene due to the existence of two stop codons,
one in the leader and one in the N-terminal domain exons. The gene
order and orientation, which were determined by hybridization with
probes from the 5′ and 3′ regions of the genes, are as follows:
cen/3′-CGM7-5′/3′-CGM2-5′/5′-CEA-3′/5′-NCA-3′/5′-
CGM1-3′/3′-BGP-5′/3′-CGM9-5′/3′-CGM6-5′/5′-CGM8-3′/PSGcluster/qter.