Nature 274, 163 - 164 (13 July 1978); doi:10.1038/274163a0

Deletion mapping of the t complex of chromosome 17 of the mouse

ROBERT P. ERICKSON, SUSAN E. LEWIS & KAREN S. SLUSSER

Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan 48109

THE dominant T mutation in the t complex on chromosome 17 of the mouse causes a shortening of the tail in heterozygotes and embryonic lethality in homozygotes¹. Recessive t alleles are defined by their interaction with T to cause tail-lessness in double heterozygotes (T/t) and are often associated with three other properties: (1) homozygous lethality at several different embryonic stages, (2) effects on male reproduction including sterility and transmission ratio distortion, and (3) crossover suppression^2,3. Although the multiplicity of these effects suggests that several genes are involved, crossover suppression has made classical genetic analysis of the region difficult. As T/t animals are viable, the lethal factors associated with recessive t homozygosity cannot be allelic to those associated with T homozygosity. Lyon et al. studied exceptional crossovers and found evidence that the homozygous lethality of t alleles and their property of interacting with T to cause tail-lessness were specified at different genetic loci^4,5. We have studied a presumed deletion, T _orl in crosses with recessive t alleles as well as with alleles at closely linked loci to map further the multiple effects associated with the t complex. We report here that factors associated with t lethality are distal to the T _orl deletion and separable from those responsible for at least one kind ot t allele-associated male sterility apparently included in the deletion.

References

1.	Chesley, P. J. exp. Zool. 70, 429–459 (1935).
2.	Gluecksohn-Waelsch, S. & Erickson, R. P. Curr. Topics devl Biol. 5, 281–316 (1970).
3.	Bennett, D. Cell 6, 441–454 (1975).
4.	Lyon, M. F. & Meredith, R. Heredity 19, 301–312 (1964).
5.	Lyon, M. F. & Meredith, R. Heredity 19, 313–325 (1964).
6.	Moutier, R. Mouse News Lett. 48, 38 (1973); 49, 42 (1973).
7.	Bennett, D. et al. Genet. Res. 26, 95–108 (1975).
8.	Gluecksohn-Schoenheimer, S. J. exp. Zool. 110, 47–76 (1949).
9.	Wroblewska, J. Cryogenetics 10, 199–207 (1971).
10.	Lyon, M. F. & Mason, I. Genet. Res. 29, 255–266 (1977).
11.	Lyon, M. F. & Bechtol, K. B. Genet. Res. 30, 63–76 (1977).
12.	Bennett, W. I., Gall, A. M., Southard, J. L. & Sidman, R. L. Biol. Reprod. 5, 30–58 (1971).
13.	Dooher, G. B. & Bennett, D. J. Embryol. exp. Morph. 32, 749–761 (1974).
14.	Hammerberg, G. & Klein, J. Genet. Res. 26, 203–211 (1975).
15.	Dickie, M. M. Mouse News Lett. 40, 29 (1969).
16.	Bennett, D. & Dunn, L. C. Proc. Symp. Immunogenet. H–2 System, 90–103 (Liblice, Prague, 1970).