Analysis of recombination in the centromere region of mouse chromosome 7 using ovarian teratoma and backcross methods.
Recombination near the centromere of mouse chromosome 7 was studied using data obtained from ovarian teratomas and backcrosses. The recombination percentage for the centromere-Gpi-1 (glucose phosphate isomerase-1) interval was 13.4 +/- 2.6 using the ovarian teratoma mapping method. In a backcross using the Robertsonian translocation Rb(7.18)9Lub (Rb9) as the centromeric marker, the centromere-Gpi-1 recombination percentage was 4.5 +/- 1.3, demonstrating that Rb9 suppresses recombination near the centromere of chromosome 7. The recombination percentage for the Gpi-1-Ldh-1 (lactate dehydrogenase-1) interval was estimated on the LT/Sv mouse genetic background to be 19.0 +/- 2.9 using the ovarian teratoma mapping method, a value comparable to the 15.5 +/- 4.8 reported earlier. On the same genetic background in a backcross segregating for Rb9, the Gpi-1-Ldh-1 recombination percentage was 7.1 +/- 1.6. Another backcross, without the Rb9 translocation but utilizing a different genetic background, produced a recombination percentage for the Gpi-1-Ldh-1 interval of 10.7 +/- 1.5, a value similar to that obtained in the Rb-containing cross. These results suggest that either the recombination suppression in the centromere area caused by Rb9 does not extend to the Gpi-1-Ldh-1 genetic region or, if it does, that the differing genetic backgrounds of these two crosses influence recombination. No recombinants were detected among 410 offspring produced from a backcross mating segregating for Ldh-1 and ru-2 (ruby-eye-2). Thus, the gene order of Ldh-1 and ru-2 on chromosome 7 remains uncertain.
Eppig
J T
JT
Jackson Laboratory, Bar Harbor, ME 04609.
Eicher
E M
EM
D000818:Animals; D002503:Centromere; D002874:Chromosome Mapping; D002875:Chromosomes; D003433:Crosses, Genetic; D005260:Female; D005819:Genetic Markers; D008297:Male; D051379:Mice; D010051:Ovarian Neoplasms / Q000235:genetics; D011995:Recombination, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D013724:Teratoma / Q000235:genetics; D014407:Tumor Cells, Cultured
D005819:Genetic Markers