Abstract
The Caenorhabditis elegans mutation e873, which results in a recessive uncoordinated phenotype (formerly named Unc-72) and which had been isolated after 32P treatment (Brenner 1974), has now been found to act as a crossover suppressor and to be associated with a translocation between linkage groups (LG's) III and V. The translocation has been named, eT1(III; V); eT1 acts as a dominant crossover suppressor for both the right half of LGIII and the left half of LGV, providing a balancer for a total of 39 map units. The uncoordinated e873 phenotype has been shown to be a consequence of an inactive unc-36III gene. It was possible to demonstrate that, in translocation heterozygotes, eT1 chromosomes marked with either sma-3 or dpy-11 segregate from normal LGIII, while those marked with bli-5, sma-2 or unc-42 segregate from normal LGV. Since bli-5 and sma-2 are normally on LGIII, and dpy-11 is normally on LGV, it is concluded that: (a) eT1 is a reciprocal translocation; (b) there is a breakpoint between sma-3 and sma-2 in LGIII (the region containing unc-36) and one between dpy-11 and unc-42 in LGV; (c) there is no dominant centromere between sma-2 and bli-5 on LGIII, since in eT1 these genes are not linked to a LGIII centromere. Similarly, it is highly unlikely that there is a centromere to the left of dpy-11 on LGV. The new gene order in eT1 was determined by measuring recombination rates between markers in eT1 homozygotes. It is concluded that the new order is: dpy-1 sma-3 (break) dpy-11 unc-60, and bli-5 sma-2 (break) unc-42 unc-51.—This is the first analysis of a C. elegans translocation with respect to reciprocity, breakpoints and new gene order.
Full Text
The Full Text of this article is available as a PDF (1.0 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Horvitz H. R., Brenner S., Hodgkin J., Herman R. K. A uniform genetic nomenclature for the nematode Caenorhabditis elegans. Mol Gen Genet. 1979 Sep;175(2):129–133. doi: 10.1007/BF00425528. [DOI] [PubMed] [Google Scholar]
- Meneely P. M., Herman R. K. Lethals, steriles and deficiencies in a region of the X chromosome of Caenorhabditis elegans. Genetics. 1979 May;92(1):99–115. doi: 10.1093/genetics/92.1.99. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Roberts P. A. Screening for x-ray-induced crossover suppressors in Drosophila melanogaster: prevalence and effectiveness of translocations. Genetics. 1970 Jul;65(3):429–448. doi: 10.1093/genetics/65.3.429. [DOI] [PMC free article] [PubMed] [Google Scholar]