V delta repertoire during thymic ontogeny suggests three novel waves of gamma delta TCR expression

Taking advantage of a PCR technique that allows amplification of all variab le region genes with equal efficiency, we defined three novel waves of TCR delta-chain transcription during thymic ontogeny, The canonical DV101-D2-J2 rearrangement was confined to a narrow window from days 14 to 18 of gestat ion, indicating that the postulated two consecutive gamma delta precursor w aves bearing this canonical DV101 rearrangement will coincide on day 16. Ne onatal delta-chain transcripts used a second wave of diverse V alpha gene s egments that are exclusively located in the delta locus-proximal gene clust er of intermingled single members of different V alpha subfamilies. In the adult, only expression of a clan of three homologous subfamilies, ADV7, DV1 04, and ADV17, persists, The members of the ADV7 subfamily are also scatter ed across the a locus, but their usage does not show the position-dependent bias of the other V alpha-to-delta rearrangements.