GENETIC AND MOLECULAR ANALYSIS OF NEW REC OMBINANT-T HAPLOTYPE-T(M8) AND HAPLOTYPE-T(M9)

The results of genetic and molecular analysis of new recombinant mouse haplotypes t(M8) and t(M9), derived from t(w12) and t(12), are descri bed. Data on viability and fertility of t(M)/t(M) homozygotes are pres ented, as well as that on t-chromosome transmission ratio distortion ( TRD) in the progeny of heterozygous males. Blot-hybridization analysis was performed using four t-specific probes: Tu48, Tu66, Tu119, and Tu 122. Comparison of data obtained in the study with that on the structu re of the initial haplotypes suggests that both recombinant haplotypes resulted from unequal crossing-over. In the case of t(M9) haplotype, the crossing-over site was probably located in the region of distal t complex inversion, and t(M8) haplotype resulted from two crossing-over events in the medial part of t complex.