Hecht RM et al. (1980) Worm Breeder's Gazette "DNA and nuclear terminal phenotypes of the embryonic lethals of C elegans."

Bartel AH, Schomer DF, Hecht RM, Hungerford III EV, Fairlie S, Oro JA, Schratweiser J

[Worm Breeder's Gazette, 1980]

We have now completed the DNA terminal phenotypes for the B set of embryonic lethals of C. elegans. Flow cytometry was used to measure the total DNA content of 18 embryonic lethals maintained at restrictive temperature (25 C) for 20 hours. The enclosed Table provides these DNA terminal phenotypes as well as three (63'0', 44T, 11Y) from our Houston set of conditional embryonic lethals. The number of independent separate determinations is shown in parenthesis and the total number of embryos analyzed per sample ranged from 3,000 to 270,000 (the average is about 20K to 100K). Cell stages (or nuclear DNA equivalents) that contain more than 8% of the total number of embryos are blocked out in this Table. The above DNA terminal phenotypes are now being complemented by the direct embryonic squash technique. The results that we have obtained are: (1) the average DNA content observed by flow cytometry is reflected by a similar average number of nuclei for several mutants; ( 2) several embryonic lethals give rise to abnormally enlarged ( polyploid) nuclei, and (3) several mutants demonstrate that cleavage is independent of nuclear division. They exhibit blastomeres that do not contain nuclei. [See Figure 1]

Lakowski B et al. (1997) Worm Breeder's Gazette "Psst! Wanna buy a Clock?"

Lakowski B, Hekimi S

[Worm Breeder's Gazette, 1997]

In a recent paper we reported work on the genetic analysis of life span in Clock mutants and numerous double mutants ( Lakowski and Hekimi (1996). Science 272, 1010-1013 ). This work has generated many strain requests, so we have sent the following strains to the CGC: CB4876 clk-1(e2519) III MQ130 clk-1(qm30) III MQ125 clk-2(qm37) III MQ131 clk-3(qm38) II MQ124 clk-3(qm38) II; clk-1(e2519) III MQ225 clk-3(qm38) II; clk-2(qm37) III MQ141 clk-1(e2519) clk-2(qm37)/dpy-17(e164) III MQ223 clk-3(qm38) II; gro-1(e2400)/dpy-17(e164) III MQ224 clk-3(qm38) II; clk-1(qm30)/dpy-17(e164) III MQ524 gro-1(e2400) clk-2(qm37)/ dpy-17(e164) III MQ513 daf-2(e1370) clk-1(e2519) III MQ415 age-1(hx546) fer-15(b26) II; gro-1(e2400) III Notes on using these strains 1) All Clock mutations are maternally and zygotically rescued even in the double mutant strains. 2) Strains homozygous for clk-2(qm37) and gro-1(e2400) are not viable at 25C. They can be studied at 25C if they are allowed to complete embryogenesis at 20C or below and then shifted to 25C. MQ130 clk-1 (qm30) also has difficulty at 25C, segregating many dead eggs, but can be maintained at this temperature. 3) MQ124 clk-3(qm38) II; clk-1(e2519) III is a strain which is just barely viable and can not be maintained at 25C. This strain produces a lot of dead eggs and sporadically becomes sterile during culture. 4) The strains MQ141, 223, 224 and 524 have LGIII Clock mutations balanced over dpy-17(e164) because these Clock double mutant combinations are not viable as homozygotes, dying out over a few generations. dpy-17 was chosen because it lies about 0.2 cM to the left of clk-1 and gro-1 and only about 1 cM to the left of clk-2. dpy-17 is also convenient because it has a strong phenotype as an L1 larva. Homozygous double mutants should be identifiable because their progeny take so long to hatch and to develop.

Rosenbluth RE et al. (1980) Worm Breeder's Gazette "unc-72 (e873) is associated with a crossover suppressor for LG III and LG V and is allelic to unc-36(III)."

Baillie DL, Rosenbluth RE

[Worm Breeder's Gazette, 1980]

As previously reported (Cold Spring Harbor, 1979), we found that unc- 72 (e873), which had originally been positioned close to dpy-11 ( BRENNER 1974), is a dominant crossover suppressor. We now report that the regions suppressed are to the right of unc-32(III), at least upto unc-64(III), and to the left of dpy-11(V), at least upto unc-60(V). We also found that unc-67 showed no linkage to dpy-18(III) but appeared to be linked to dpy-5(I). The above crossover suppression, therefore, covers the right and left respective arms of LG III and LG V upto the most distal known markers, in each case. Segregation patterns and egg survival data from e873 heterozygotes are consistent with e873 being a translocation. The translocation has been named eT1(III;V). The recessive Unc-72 phenotype exhibited by e873 is not complemented by e251, a mutation in the unc-36(III) gene. Consistent with this, Unc-72 and Unc-36 phenotype are very similar. Thus eT1(III;V) carries a defect in unc-36. The possibility that this defect may be due to one of the breaks, makes unc-36 the putative site of an LG III breakpoint. In view of the fact that e873 is a chromosomal aberration, it is of interest to note that it was isolated after P-decay (BRENNER 1974). We hope that the identification of the crossover suppression properties, and the unc-36 allelism of e873 will make it a useful tool for the future genetic analysis of C. elegans.

Kari CK et al. (1985) Worm Breeder's Gazette "some chromosome rearrangements."

Winter M, Herman RK, Kari CK

[Worm Breeder's Gazette, 1985]

A new X chromosome-duplication, called mnDp57(X;I), carries the wild- type alleles of unc-2, unc-20, not carry the wild-type alleles of dpy-3 or dpy-8, which flank this region. The duplication is situated less than one map unit from unc-54 I; it does not have much effect on crossing over on linkage group (LG) I, and it is homozygous viable. Duplication-bearing males mate well. The autosomal duplication mnDp37(III;f) is very large, extending from the left of dpy-1 (but not including unc-45), to the right of unc- 25 (but not including unc-64). Because of the way in which it was made, it carries the mutation unc-32(e189). It occasionally recombines with the normal chromosome III. We have also obtained variants of mnDp37, some spontaneous and some apparently induced by gamma rays. One spontaneous variant is called mnDp40(III;f); it carries the wild-type alleles of dpy-1, s several markers farther to the right, such as lon-1, unc-36 and unc-50. Hermaphrodites carrying mnDp40 give more nullo-duplication self- progeny than do hermaphrodites carrying mnDp37.The X-ray-induced translocation mnT4(III;IV) was identified by virtue of its property of reducing the apparent recombination between dpy-1 and unc-32 to less than 1%. Recombination on LGIV is not greatly affected. There is strong pseudolinkage between dpy-1 III and unc-8 IV (about 1% recombination), suggesting that the latter is in the neighborhood of a breakpoint. We have evidence for significant nondisjunction between mnT4 and the normal chromosome III, leading to animals that are mnT4/III/III.

Manser J et al. (1985) Worm Breeder's Gazette "Autosomal Extragenic Suppressors Of her-1(n695) V"

Wood WB, Manser J, Trent C

[Worm Breeder's Gazette, 1985]

We are studying five extragenic mutations that suppress the Tra phenotype of her-1(n695) V (see preceding abstract): ct27 III (gamma- ray induced), n1091 III and ct49 III (allelic, EMS-induced; ct49 was isolated by Sean Burgess), and n1092 V and n1102 V (allelic, EMS- induced). ct27 III has a semi-dominant dpy phenotype in XX animals; XO animals are less severely Dpy and are abnormal males. Both ct27; n695 and ct27/+;n695 XX animals exhibit strong suppression of the n695 Tra phenotype. Because ct27 results in a phenotype somewhat similar to that caused by mutations in the chauvinist dpy genes (dpy's 21, 26, 27, 28) it may suppress n695 with an effect on X-chromosome expression. n1091 III has no apparent effect on XX or XO animals by itself, while ct49 III XX and XO animals are Dpy h we have not eliminated the possibility that this phenotype results from a second closely linked mutation). n1091;n695 XX animals are well suppressed; n1091/+;n695 XX animals are not. n1092 V and n1102 V map near unc-76 (about 5% from her-1). Neither appears to have any effect on XX or XO animals by itself. For n1092 and n1102, both n695 sup and n695 sup/n695 + XX animals show strong suppression. n695n1O91 XO, n695n1O92 XO, and n695n11O2 XO animals are all normal males (that is, they are apparently identical to n695 XO animals). This suggests that the EMS-induced suppressor mutations on III and V affect a process that is active in XX, but not XO, animals. For example, the genes identified by these mutations could be involved in turning off her-1 expression in XX animals.

Greenwald IS et al. (1983) Worm Breeder's Gazette "Tc1 polymorphisms on the right arm of LGIII."

Greenwald IS, Hodgkin JA

[Worm Breeder's Gazette, 1983]

As starting points for the molecular cloning of lin-12 III and tra-1 III, we have identified several Tc1 polymorphisms linked to these genes. Genomic DNA was prepared from appropriate Bristol/Bergerac hybrid strains, cut with EcoRI, and probed with Tc1 (kindly provided by Scott Emmons). Our data are summarized in the maps below, which give the approximate map locations and EcoRI fragment sizes of the Bergerac-specific Tc1's. [See Figure 1]

McKim KS et al. (1986) Worm Breeder's Gazette "unc-60 on eT1."

Rosenbluth RE, Baillie DL, McKim KS

[Worm Breeder's Gazette, 1986]

We are interested in the physical limits of the eT1 translocation. Previous work (Rosenbluth and Baillie 1981) showed that eT1(III,V) was the product of two breaks; one on LGIII (between sma-3 and sma-2) and one on LGV (between dpy-11 and unc-42). While it was shown that eT1(V) carried the whole of the right arm of LGIII, it was only assumed that eT1(III) carried the whole left arm of LGV. The possibility remained that eT1 was the product of more than two breaks and only the medial portion was translocated. The following two tests show the translocated portion of LGV (segregating from LGIII on eT1(III)) extends to at least unc-60. This demonstration was made possible as a result of having an unc-60 allele, s1310, induced on the eT1 chromosome. The outcross progeny from the cross +;unc-60(m35)/ unc-60(s1310) eT1 X +;unc-60(m35) dpy-11(e224)/eT1 will be Unc-60's, ozygotes) and Wild types. The ratio of F1 wildtypes giving DpyUnc to those giving just Unc worms depends on which chromosome s1310 segregates with. If a 1:1 ratio is observed, s1310 is on eT1(III), if a 1:0 ratio for Unc's is observed, than s1310 is on eT1(V). In fact the data indicated eT1(III) was the answer (8 DpyUnc to 4 Unc).In confirmation, +/eT1 unc-60(s1310);unc-60(e890) crossed to +/eT1 gave Unc-60 male progeny in the F1; again indicating eT1(III) is the position of s1310 since the two unc-60 alleles segregated into the same oocyte. Genetic evidence now shows the translocated portion of LGV on eT1( III) covers the the region between unc-60 and a point between dpy-11 and unc-42.Supported by NSERC and MDA of Canada grants to D.L.B.

Manser J et al. (1986) Worm Breeder's Gazette "update on mutants defective in embryonic cell migrations."

Manser J, Wood WB

[Worm Breeder's Gazette, 1986]

We have continued our study of mutations affecting the long range embryonic migrations of the neurons CAN, HSN and ALM (see 1985 C. elegans Meeting Abstracts, p. 18). To date we have studied six mutations that define five loci and can be divided into two phenotypic classes (see table below). In Class-1 mutants [mig(ct41) III and mig- 2(rh17) X], the CAN, HSN, and ALM migrations are all partially defective with high penetrance. In Class-2 mutants [vab-8(e1017 and ct33) V, mig(ct73) V, and mig(7a) III], CAN migration is defective with high penetrance whereas defects in HSN and ALM migrations with much lower penetrance vary among the mutants as shown in the table. mig(ct73) V and mig(7a) III are recently acquired mutants. mig(ct73) V was isolated by us as a spontaneous mutant that appeared on an N2 stock plate. mig(7a) III was isolated by Eve Wolinsky (MIT). Both mutants were recognized by their skinny tails, a phenotype attributed to CAN misplacement in vab-8 animals (Sulston and Hodgkin, WBG vol. 5. , No. 1, p.19). mig(ct73) V complements vab-8(e1017) V, and mig(7a) III complements mig(ct41) III. CAN migration is less severely affected in mig(ct73) V and mig(7a) III than it is in vab-8 V. In most vab-8 animals, CAN migration is apparently completely abolished: the CAN nucleus is found over the nerve ring in the head (Sulston and Hodgkin, loc. cit.; B. Stern, 1985 C. elegans Meeting Abstracts). In most mig(ct73) V and mig(7a) III L1's, CAN is seen partway between its position of birth and its normal postembryonic position (Nomarski optics). Three double mutants have been constructed, characterized, and found to show additive effects of the two mutations. Double mutants carrying either of the Class-1 mutations mig(ct41) III or mig- 2(rh17) X and a vab-8 mutation appear to exhibit completely defective CAN migration, while HSN and ALM migrations are partially defective with high penetrance. A double mutant carrying both of the Class-1 mutations, like mutants, exhibits partially defective CAN, HSN, and ALM migrations, but these nuclei tend to remain closer to their positions of birth in the double mutant. [See Figure 1]

Howell AM et al. (1992) Worm Breeder's Gazette "Isolation and Characterization of Balancers for LG III"

Stewart HI, Howell AM, Nethery H, Baillie DL

[Worm Breeder's Gazette, 1992]

As part of the genetic toolkit project, we have been isolating and characterizing balancers for LG III. These will be used in screens for recessive lethal mutations and the generation of deficiencies. The translocation eT1 (711,V) balances most of the right half of LG III, so we concentrated our attention on the left half. sDp3 is a free duplication of an approximately 20 map unit interval which includes at least half of the gene cluster of LG III. A strain with the genotype sDp3/dpy-17 unc-32 +/dpy-17 + lin-12 was constructed and used to screen for EMS-induced lethals. Fifty-four lethal mutations induced on the dpy-17 unc-32 chromosome were isolated after screening 2836 mutagenized chromosomes. Mapping of these lethals is in progress. So far, six map to the left of dpy-17 and eleven map to the right of dpy-17 .This is consistent with the position of the gene cluster on LG III. This strain has also been used to isolate lethals induced with 2000R of gamma radiation. In order to balance the left end of LG III, we screened for suppression of crossing over between unc-45 and dpy-1 after treatment with 2000R of gamma radiation. We have recovered two homozygous viable crossover suppressors, sC1 and sC2 .sC1 eliminates recombination in this region. We are currently determining the boundaries of crossover suppression of sC1 and plan to induce markers on it to make it useful for lethal screens. Funded by the NIH National Center for Research Resources.

Landel CP et al. (1982) Worm Breeder's Gazette "is unc-92 actin?"

Hirsh DI, Landel CP, Carr SH, Files JG

[Worm Breeder's Gazette, 1982]

We thought that unc-92, a dominant unc with disorganized muscle and a high reversion frequency, might be an actin gene because of its phenotype and because of its map position (Newsletter 6, 23 (1981)). Using a Bergerac strain/Bristol strain DNA polymorphism adjacent to the cluster of actin genes I, II and III, we were able to locate the actin cluster between unc-23 and sma-1. The arrangement of actin genes I, II and III within a 12 kb stretch of DNA suggested mechanisms for the high unc-92 reversion frequency, including gene conversion between genes and nonhomologous recombination. Nonhomologous recombination should reduce three genes to two which would be easy to detect by Southern blot analysis. We therefore obtained from Bob Waterston six revertants of the St15 allele of unc-92; three revertants arose spontaneously and three were obtained after an EMS mutagenesis. We isolated DNA from each revertant strain and analyzed it by Southern blot analysis. Five of the revertants showed a pattern identical to that of both St15 and N2 when probed for actin sequences, but one revertant, RW2246, which derived from the EMS mutagenesis, showed an anomalous pattern. Further restriction mapping of RW2246 by Southern blot analysis revealed that this revertant contained a 5kb deletion that fused the 5' portion of gene II to the 3' portion of gene III. The fusion could have been the result of recombination between genes II and III, deleting the unc-92 lesion and creating a new hybrid gene. We believe that the revertant phenotype resulted from this fusion. Because most of the differences between actin genes occur at their 5' ends, the fusion leaves the revertant with the equivalent of only genes I and II. Despite the lack of gene III, the revertant appears wild type because genes I and III appear thus far to be identical by restriction endonuclease and sequence analyses. We therefore believe that unc-92 is the actin gene cluster, although final proof awaits comparison of the actin DNA sequences of N2 and St15.