Table 1.

GFP-marked balancers in C. elegans^a

Name of Balancer	Homo. Lethal?	Region Balanced	Type of Balancer	GFP Marker
nT1b[qIs51]	yes	right end of chromosome IV through unc-17, left end chromosome V through unc-76	reciprocal translocationc	myo2::GFP, pes-10::GFP, F2B7.9::GFP
hT2d,e[qIs48]	yes	chromosome I from left end through unc-101, chromosome III from right end through dpy- 17	reciprocal translocationc	myo2::GFP, pes-10::GFP, ges-1::GFP
mIn1f[mIs14]	no	chromosome II between lin-31 and rol-1	inversion	myo2::GFP, pes-10::GFP, F2B7.9::GFP
qC1 [qIs26]g	yes	left portion chromosome III between tra-1 and dpy-1	unknown	lag-2::GFP
eT1[nIs267]	no	chromosome V left end through unc-23, chromosome III right end through unc-36	reciprocal translocationc	myo-2::GFP
mIs10h	no	chromosome V between unc- 60 and dpy-11.	insertion	myo2::GFP, pes-10::GFP, F2B7.9::GFP
mIs11	no	chromosome IV, unknown interval near dpy-20. This has been used successfully to balance deletions in cyb-1, syn- 4 tag-316, htp-1, mep-1, and tag-137.	insertion	myo2::GFP, pes-10::GFP, F2B7.9::GFP
mIs12	no	chromosome II ,unknown interval near unc-4.	insertion	myo2::GFP, pes-10::GFP, F2B7.9::GFP
mIs13	no	chromosome I, unknown interval near unc-54. This has been used successfully to balance deletions in tag-115, kin-1, npp-4, ero-1 and bbs-1.	insertion	myo2::GFP, pes-10::GFP, F2B7.9::GFP
okIs57	no	chromosome X, unknown interval near unc-3.	insertion	myo2::GFP, pes-10::GFP, F2B7.9::GFP
okIs59	no	chromosome I, unknown interval between dpy-5 and unc-13. This has been used to balance deletions in air-2, dao- 5, npp-7, chn-1, tag-83 and gly- 2.	insertion	myo2::GFP, pes-10::GFP, F2B7.9::GFP

^aInformation on balancers comes from WS228,^19,20, and author observations

^bnT1[qIs51] carries an uncharacterized lesion in daf-15. Some mutations lying within the balanced extents of nT1 are unstable over nT1[qIs51].

^cReciprocal translocation balancers produce aneuploid inviable progeny²⁰, and this reduces the expected yield of viable homozygotes.

^dThe qIs48 element is sometimes lost by apparent rare recombination, leaving behind viable hT2 homozygotes marked with the original bli-4 mutation.

^eSome mutations lying within the balanced extents of hT2 are unstable over hT2[qIs48].

^fSome lethal alleles balanced by the original non-GFP mIn1[dpy-10] and lying near the left breakpoint are not balanced by mIn1[mIs14 dpy-10].

^gqIs26 also carries dominant rol-6 allele su1006.

^hBalancing activity of mIs10 should be confirmed.