Assignment of the structural gene coding for albumin to human chromosome 4

Area of Science:

• Human Genetics
• Molecular Biology
• Genomics

Background:

• Albumin, a developmentally regulated serum protein, is synthesized in the liver.
• Previous family studies suggested autosomal linkage between albumin and the group-specific component (GC) protein.
• The GC protein was previously assigned to human chromosome 4, indirectly suggesting albumin's location.

Purpose of the Study:

• To directly assign the human albumin gene to a specific chromosome using molecular techniques.
• To confirm the chromosomal location of the albumin gene in the human genome.

Main Methods:

• Isolation and characterization of a human albumin complementary DNA (cDNA) probe.
• Hybridization of the cDNA probe to human and Chinese hamster (CHO-K1) DNA digested with restriction enzymes (HindIII and EcoR1).
• Analysis of human/CHO-K1 cell hybrids to determine the presence of human albumin gene sequences.

Main Results:

• Hybridization revealed distinct DNA fragment patterns for human and Chinese hamster DNA.
• Human albumin gene sequences were detected in cell hybrids containing specific human chromosomes.
• Analysis of 22 primary cell hybrids definitively assigned the albumin gene to human chromosome 4.

Conclusions:

• The structural gene for human albumin is directly assigned to human chromosome 4.
• This study provides direct molecular evidence for the chromosomal localization of the albumin gene.