Ly5 Gene Nomenclature, C57BL/6J and SJL/J - A History of Change
JAX® NOTES Issue 458, Summer 1994
Larry E. Mobraaten, PhD., Staff Scientist
There has been considerable confusion concerning the correct nomenclature for alleles at the protein-tyrosine phosphatase, receptor type c locus (Ptprc) (formerly Ly5). This has been caused to a greater degree by a change in allele designations for certain inbred strains and by a lesser degree by changes in the locus symbol itself as new information has been forthcoming.
In 1975 K. Komura, K. Itakura, E. A. Boyse, and M. John (1) described an antigen found on T-lymphocytes. The antigenic specificity found on C57BL/6 cells was named Ly5.1 and the specificity on SJL/J cells Ly5.2. Gene naming convention for alleles has been to assign a superscript "a" to the locus symbol for a gene that determines the ".1" specificity and superscript "b" for the ".2" specificity. Consequently, the C57BL/6 allele became Ly5 and the SJL/J allele became Ly5.
E. A. Boyse and colleagues (2) later in 1977 suggested a revised nomenclature for lymphocyte antigens that would distinguish B-cell from T-cell antigens. Under this recommendation Ly5 would have become Lyt4. This apparently was not universally accepted as "Ly5" continued to appear in the literature.
In 1987 H. C. Morse III, F-W . Shen, and U. Hämmerling (3) presented a revised version of nomenclature rules governing mouse lymphocyte antigens. They recommended following the practice of designating C57BL/6 alleles with the superscript "b". The allele and antigen designations of the Ly5 alleles for C57BL/6 and SJL/J, then, were just reversed, the C57BL/6 allele became Ly5 (antigenic specificity Ly5.2) and SJL/J became Ly5 (antigenic specificity Ly5.1).
In 1992 H. C. Morse III (4) presented a further revision of nomenclature governing cell surface antigens whereby Ly5 became Cd45. The nomenclature recommendations authored by Morse and colleagues were approved by the International Committee on Standardized Genetic Nomenclature for Mice.
The current use of the Ptprc designation for Cd45 was based on work in humans following the report of Charbonneau and colleagues (5) who first showed that a protein-tyrosine phosphatase (human placental protein-tyrosine phosphatase 1B) was homologous to the CD45 protein. Ptprc is one of a family of protein-tyrosine phosphatase genes involved in the regulation of cell growth.
Because most of the present confusion centers on the reversal of allele symbols and antigen specificities associated with certain inbred strains for this locus, it would be helpful if authors would specify whether referring to old nomenclature or revised nomenclature when discussing Ly5 (or now Ptprc ) alleles and specificities.
* Because of the confusion concerning the designation of alleles and specificities, this strain will appear incorrectly in the 1994 Jax Price List, which has already been printed, as B6.SJL-Cd45. The correct nomenclature for this strain is now B6.SJL-Ptprc.
1. Komura, K., K. Itakura, E. A. Boyse, and M. John. 1975. Ly-5: a new lymphocyte antigen system. Immunogenetics 1:452-456.
2. Boyse, E.A., H. Cantor, F-W. Shen, and I.F.C. McKenzie. 1977. Nomenclature for antigens demonstrable on lymphocytes. Immunogenetics 5:189.
3. Morse H.C. III, F-W. Shen, and U. Hämmerling. 1987. Genetic nomenclature for loci controlling mouse lymphocyte antigens. Immunogenetics 25:71-78.
4. Morse H.C. III. 1992. Genetic nomenclature for loci controlling surface antigens of mouse hemopoietic cells. J. Immunol. 149:3129-3134.
5. Charbonneau, H., N.K. Tonks, K.A. Walsh, and E.H. Fischer. 1988. The leukocyte common antigen (CD45): a putative receptor-linked protein tyrosine phosphatase. Proc. Nat. Acad. Sci. 85:7182-7186.