Two cell-surface markers for human chromosome 1 in interspecies hybrids

Area of Science:

• Immunology
• Human Genetics
• Cell Biology

Background:

• Monoclonal antibodies AbAJ9 and AbT87 recognize distinct human cell-surface antigen systems.
• These antigens are glycoproteins with molecular weights of 140,000 and 60,000, respectively.
• Antigen expression is observed in various human cell types but not in rodent cell lines.

Purpose of the Study:

• To investigate the genetic control of human cell-surface antigen expression.
• To map the genes responsible for the AJ9 and T87 antigens.
• To utilize rodent-human somatic cell hybrids for genetic analysis.

Main Methods:

• Serological analysis using an immune rosetting assay.
• Construction and analysis of rodent-human somatic cell hybrids.
• Hybrid selection to isolate cells containing specific human chromosome fragments.

Main Results:

• The expression of both AJ9 and T87 antigens in hybrid cells requires the presence of human chromosome 1.
• Two independent gene loci on chromosome 1, MSK-1 (for AJ9) and MSK-2 (for T87), control antigen expression.
• MSK-1 was mapped to the 1 cen-p22 region and MSK-2 to the 1q32-qter region.

Conclusions:

• Human chromosome 1 harbors the genes for the AJ9 and T87 cell-surface antigens.
• The identified gene loci, MSK-1 and MSK-2, are crucial for the expression of these distinct antigens.
• Precise mapping of these loci provides valuable information for further genetic studies.