The Human Pregnancy-Specific Glycoprotein Genes are Tightly Linked on the Long Arm of Chromosome 19 and are Coordinately Expressed

The pregnancy-specific glycoprotein (PSG) genes encode a group of
proteins which are found in large amounts in placenta and maternal
serum. In situ hybridization analyses of metaphase chromosomes
reveal that all the human pregnancy-specific glycoprotein (PSG)
genes are located on the long arm of chromosome 19 (19q13.2–13.3),
overlapping the region containing the closely-related
carcinoembryonic antigen (CEA) gene subgroup. Higher resolution
analyses indicate that the PSG genes are closely linked within an
800kb SacII restriction endonuclease fragment. This has been
confirmed through restriction endonuclease mapping and DNA sequence
analyses of isolated genomic clones, which show that at least some
of these genes are located in very close proximity. Further, these
studies have helped to identify a new member of the PSG gene
sub-family (PSG7). DNA/RNA hybridization analyses, using
gene-specific oligonucleotide probes based on published sequences,
showed that five from six PSG genes tested are coordinately
transcribed in the placenta. Due to the close proximity of these
genes and their coordinated expression pattern, common
transcriptional regulatory elements may exist.