Isolation, characterization, and chromosome assignment of mouse N-ras gene from carcinogen-induced thymic lymphoma
Abstract:
Treatment of mice with the carcinogen N-methylnitrosourea results in the development of thymic lymphomas with frequent involvement of the N-ras oncogene. The activated mouse N-ras gene was isolated from one of these lymphomas and, by transformation in concert with restriction digestion, a map of the gene was prepared and its approximate boundaries were determined. By means of somatic cell hybrids the normal N-ras gene was found to be unlinked to other members of the ras gene family.
Insights
Mice treated with N-methylnitrosourea developed thymic lymphomas. Researchers mapped the activated N-ras oncogene and found the normal N-ras gene is unlinked to other ras family members.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- N-methylnitrosourea is a carcinogen that induces thymic lymphomas in mice.
- The N-ras oncogene is frequently involved in these chemically induced lymphomas.
Purpose of the Study:
- To isolate and characterize the activated mouse N-ras gene from N-methylnitrosourea-induced thymic lymphomas.
- To determine the physical map and boundaries of the activated N-ras gene.
- To investigate the genetic linkage of the normal N-ras gene to other ras family genes.
Main Methods:
- Induction of thymic lymphomas in mice using N-methylnitrosourea.
- Isolation and transformation of the activated mouse N-ras gene.
- Restriction digestion to create a gene map.
- Somatic cell hybridization to analyze gene linkage.
Main Results:
- The activated N-ras oncogene was successfully isolated from lymphoma cells.
- A physical map of the N-ras gene was constructed, defining its approximate boundaries.
- Somatic cell hybrid analysis revealed that the normal N-ras gene is not linked to other known ras family genes.
Conclusions:
- The N-ras oncogene plays a significant role in N-methylnitrosourea-induced thymic lymphomagenesis.
- The characterization of the N-ras gene provides insights into its structure and function in cancer development.
- The unlinked nature of N-ras suggests independent regulation or evolutionary origins compared to other ras family members.
