Estimation of D segment usage in initial D to JH joinings in a murine immature B cell line. Preferential usage of DFL16.1, the most 5' D segment and DQ52, the most JH-proximal D segment.

We established SPL2-1-2, a murine immature B cell line transformed by tsOS-59, a temperature-sensitive mutant of Abelson murine leukemia virus. SPL2-1-2 has a VHDJH-/G (germ-line) configuration, and can continuously generate D to JH joinings from the germ-line allele during culture. The D to JH joinings are strongly promoted by the shift of the culture temperature from permissive (35 degrees C) to non-permissive temperature (39 degrees C). Using this H chain gene rearrangement system, we succeeded in the estimation of the frequencies of D segment usage in initial D to JH joinings by deletion-mapping analysis. The results demonstrated the preferential utilization of DFL16.1, the most 5' D segment and DQ52, the most JH-proximal D segment in initial D to JH joinings.