Unspecified substitution in exon 3.
restriction map normal; Mitcheson, Simonelig, Williams and O'Hare (1993)
imaginal disc & metaphase & condensed nuclear chromosome | conditional ts
imaginal disc & mitotic metaphase | conditional ts
imaginal disc & spindle | conditional ts
mitotic cell cycle & larval brain | conditional ts
nuclear chromosome & larval brain | conditional ts
Homozygous females raised at 25[o]C and shifted for 5 days to 29[o]C have a greatly reduced number of follicle cells in the ovaries. These follicle cells are in clusters. Their number is insufficient to surround every growing egg chamber, and follicular stalks between egg chambers are also absent. Homozygous pupae shifted to 29[o]C eclose to give viable adults, but mitotically active tissues show progressively stronger defects with increasing time spent at 29[o]C. Females shifted to 29[o]C one day before eclosion and then maintained at 29[o]C for four days have a reduced number of follicle cells. Females shifted to 29[o]C two days before eclosion and then maintained at 29[o]C have cysts with fewer than the normal number of 16 germ cells five days after eclosion. The more strongly affected ovarioles have long egg chambers which contain a succession of polyploid nuclei. Polyploidisation of the germ cells occurs prematurely in the germarium. Homozygous embryos shifted to 29[o]C develop into third instar larvae and then die. The imaginal discs are very reduced in size compared to wild type and the brain is atrophied, both in the optic lobes and in the ventral ganglion. Histoblasts are unaffected. Chromosomes are highly overcondensed in the brains of third instar larvae that have been shifted to 29[o]C for 4 to 48 hours. The number of metaphase mitotic figures in homozygous brains increases over the first 14 hours at 29[o]C and then plateaus between 14 to 22 hours at 29[o]C, where the number of that of wild type. This accumulation of metaphases is accompanied by a decrease in the number of anaphases. The ratio of metaphases to anaphases is 10 in mutant larvae compared to 3.5 in wild type. A decrease in the number of metaphases is seen after 22 hours at 29[o]C in mutant larvae. Two types of abnormal metaphases are seen in the imaginal discs of second instar larvae shifted to 29[o]C for 24 hours or 3 days. In the first type, the mitotic spindle is bipolar but is asymmetric. The microtubules form distorted spindles around the chromosomes and some of those that radiate out from the poles show an incorrect orientation. In the second type, the mitotic spindle is very reduced in size or is absent. In both cases the metaphase plate is disorganised and the chromosomes show a high degree of condensation. The centrosomes appear to be normally located at the poles of the spindle in both cases, however, because of the altered spindle structure, the centrosomes are abnormally close to the condensed DNA. The number of spindles that are reduced in size increases at the expense of asymmetric spindles with increasing time spent at 29[o]C. Mitotic cells accumulate immediately anterior to the morphogenetic furrow (MF) in homozygous larvae shifted for 3 days at 29[o]C, as occurs in wild-type larvae, but no mitotic cells are seen posterior to the MF, in contrast to wild type. Eye-antennal discs show extensive cell death after a 3 day shift to 29[o]C, mostly anterior to the MF and in the antennal part of the disc. No increase in cell death is seen in the posterior part of the disc.
The temperature-sensitive lethality of su(f)8 animals can be partially rescued by exogenous application of the compounds 20-hydroxyecdysone, RH-5849 and RH-5992; the compounds can stimulate abortive pupariation in the animals maintained at the restrictive temperature from the third larval instar stage.
Homozygotes are phenotypically wild type at 18oC.
temperature-sensitive lethal The first allele recovered specifically as a temperature-sensitive lethal completely lethal at 29oC; suppresses f at 25oC but not at 18oC. Temperature-sensitive period for lethality from 50 to 140 h after oviposition, for f suppression coincident with bristle differentiation. Shift up to 30oC before end of the second instar causes failure to pupariate; full-sized third instar larvae produced, which live 10-14 days; salivary-gland-secretion proteins specifically reduced or absent in these larvae, although the associated chromosome puffs appear normally; other proteins unaffected (Hansson, Lineruth and Lambertsson, 1982); shift up prior to 70 h leads to little or no accumulation of Sgs transcripts as detected in Northern blots probed with sequences from Sgs3, Sgs4, Sgs7 and Sgs8, whereas a 48-h pulse beginning at 75 h is without effect on transcription or translation of Sgs genes (Hansson and Lambertsson, 1983). Shift up to 30oC in early third instar blocks the increase in ecdysterone titer normally occurring at the end of L3; ecdysterone supplementation induces abortive pupariation and stimulates prepupal polypeptide synthesis (Hansson and Lambertsson, 1984); leg discs of such larvae unable to evert, either in vivo or in vitro (Fekete and Lambertsson, 1980). Homozygous females raised under permissive conditions, when shifted up to 30oC cease laying eggs and the ovarian oocytes degenerate; fertility recoverable after pulses of three but not eleven hours (Dudick, Wright and Brothers, 1974). Heterozygotes with su(f)- deletion at 25oC, su(f)1 at 29oC and su(f)3 at 30oC exhibit the M-like syndrome. Enhances RpS17, as indicated by reduced viability of su(f)8 versus su(f)+ sibs that are RpS17/+ (Girton, Langner and Cejka, 1986). Enhances gypsy expression, more at 25oC than at 18oC (Parkhurst and Corces, 1986). temperature-sensitive lethal
su(f)8, vg[+]/vgunspecified has visible | heat sensitive phenotype
Dfd[+]/Dfdunspecified, su(f)8 has visible | heat sensitive phenotype
Dfdunspecified, su(f)8 has visible | dominant | heat sensitive phenotype
su(f)8, vgunspecified has visible | dominant | heat sensitive phenotype
Dfdunspecified, su(f)8 has eye phenotype
Dfdunspecified, su(f)8 has maxillary palp | ectopic phenotype
cp[+]/cp1, su(f)8 has adult cuticle phenotype
su(f)8, vg[+]/vgunspecified has macrochaeta phenotype
su(f)8, vg[+]/vgunspecified has wing phenotype
su(f)8, vg[+]/vgunspecified has adult cuticle phenotype
Dfd[+]/Dfdunspecified, su(f)8 has eye phenotype
Dfd[+]/Dfdunspecified, su(f)8 has maxillary palp | ectopic phenotype
su(f)8, vgunspecified has macrochaeta phenotype
su(f)8, vgunspecified has wing phenotype
su(f)8, vgunspecified has adult cuticle phenotype
cp1, su(f)8 has macrochaeta phenotype
cp1, su(f)8 has adult cuticle phenotype
cp[+]/cp1, su(f)8 has macrochaeta phenotype
Homozygotes survive and suppress the f1 phenotype at intermediate temperatures.
su(f)8/Y ; cp1/+ flies are normal at 22oC. At 28oC they have nicked wings and show a bb-like phenotype, having small bristles, slow development and cuticular defects. su(f)8/Y ; vgunspecified/+ flies are normal at 22oC. At 28oC they have nicked wings and show a bb-like phenotype, having small bristles, slow development and cuticular defects. su(f)8/Y ; Dfdunspecified/+ flies are normal at 22oC. At 28oC they have extremely reduced eyes and their maxillary palps are frequently duplicated with mirror image symmetry.
su(f)8 is rescued by su(f)UAS.cAa/Scer\GAL4da.G32
su(f)8 is rescued by su(f)UAS.cAa/Scer\GAL4da.G32
su(f)8 is not rescued by su(f)G.lacZ
Wright.
Sgs4 transcription in cultured wild-type and su(f)8 third instar larval salivary glands in the presence and absence of 20-OH-ecdysone has been studied.
Strength of enhancement of the wa phenotype: su(f)1 > su(f)12 > su(f)8 > su(f)4. Strength of suppression of the f1 phenotype: su(f)1 > su(f)4 > su(f)12 > su(f)8.