This t-haplotype allele arose by homologous recombination between DNA markers T119I and T66E in wild-type and t6 haplotype chromatin. th45 carries t DNA that extends over Tcp-1 and includes the t-specific form of RP17. This represents recombination between wild-type and t haplotype chromosomes across the proximal inversion. (J:8163, J:20080)