Dominant expression of the T cell receptor BALB invariant delta (BID) chain in resident pulmonary lymphocytes is due to selection.

During ontogeny, the T cell receptor BALB invariant delta (BID) chain (Sim, G. -K. and Augustin, A., Cell 1990. 61:397) is generated in C57BL/6 fetal thymocytes at levels similar to those detected in BALB/c mice. Hence, the dominance of BID observed among resident pulmonary lymphocytes of BALB/c and of (BALB/c x C57BL/6) F1 and its absence in C57BL/6 mice is due to positive selection and peripheral expansion rather than to the inability of C57BL/6 mice to generate this particular rearrangement.