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General Information
D. melanogaster
FlyBase ID
Feature type
Associated gene
Associated Insertion(s)
Carried in Construct
Also Known As
Key Links
Nature of the Allele
Mutations Mapped to the Genome
Additional Notes
Associated Sequence Data
DNA sequence
Protein sequence
Progenitor genotype

Polytene chromosomes normal.

Nature of the lesion

Molecular deletion specific to the tsh gene in 40A.

40kb deletion.

Precise excision of P{A92} insertion.

Expression Data
Reporter Expression
Additional Information
Marker for
Reflects expression of
Reporter construct used in assay
Human Disease Associations
Disease Ontology (DO) Annotations
Models Based on Experimental Evidence ( 0 )
Modifiers Based on Experimental Evidence ( 0 )
Comments on Models/Modifiers Based on Experimental Evidence ( 0 )
Disease-implicated variant(s)
Phenotypic Data
Phenotypic Class
Phenotype Manifest In
Detailed Description

In tsh8 larvae, the T1 segment adopts a labial identity. Such larvae also show severe disruption of the naked cuticle and in the abdominal segments, denticle types 1-4 are missing.

Changes in cuticle pattern in tsh8/tsh8 embryos indicate that T1 identity is transformed to labial identity (characterized by loss of T1 cuticle). In addition, trunk segments exhibit a weak segment polarity phenotype.

Mutant embryos have reduced denticle belts containing only tapered denticle of rows 5 and 6.

Homozygous clones in the ventral margin of the eye result in ventral eye enlargements. Internal ventral clones in the eye do not significantly affect eye development. Clones in the dorsal eye suppress eye formation (there is an eye-to-cuticle transformation).

Mutant embryos show a weak segment polarity phenotype with disruption of both naked cuticle and denticle belt organisation. Only denticle types 5 and 6 are made.

Mutant larvae have abnormal denticle belts, and denticles are present in the regions of naked cuticle, especially in the ventral midline.

X ray induced clones in the developing eye show normal ommatidial organization.

Heterozygotes display minaturized maxillary palps, characterized by fewer bristles.

The trunk segments of homozygous larvae are reduced in size compared to wild-type. The Keilin's organs fail to develop. Partial rescue of the abdominal segment and Keilin's organ phenotypes are seen if the flies also carry tshmCa, tsh220.mCa or tshbcd.mCa, with the greatest rescue occurring with flies carrying tsh220.mCa.

tsh8/tsh04319 and tsh8/tshB4-2-12 heterozygotes are lethal. Weak tsh phenotype (halteres droop, wings held up) when heterozygous with tsh4-3. There are some escapers when heterozygous with tsh51.

Mutant embryos fail to form the central constriction and often contain a misplaced anterior constriction. In 87% of the mutant animals an indentation forms close to the gastric caeca; occasionally a small anterior compartment is evident. In 13% of embyos an apparently normal anterior constriction forms.

Scr4, tsh8 double mutants develop the dorsal part of the thoracic trunk segment, whereas tsh8 mutants do not.

Trunk ventral denticle belts are disorganized. Dorsal and ventral parts of the prothorax are deleted. Ectopic papilla-like sense organs differentiate in the thorax region. The anal opening is sclerotized. Neuronal defects: disruption or deletion of ventral groups of neurons in the trunk region and misrouting of axons towards the head.

External Data
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Phenotype Manifest In
Enhanced by
Suppressed by
NOT suppressed by

tsh8 has denticle row 1 phenotype, non-suppressible by tioUAS.cLa/Scer\GAL469B

tsh8 has denticle row 2 phenotype, non-suppressible by tioUAS.cLa/Scer\GAL469B

Enhancer of
Suppressor of
Additional Comments
Genetic Interactions

Embryos hemizygous for gtQ292 and homozygous for tsh8 show normal lobe-like morphology of the labial segment. The dorsal ridge is enlarged, but is separate from the labial segment in late-stage mutant embryos.

Expression of tioScer\UAS.cLa, under the control of Scer\GAL469B, partially rescues the denticle row phenotype of tsh8 mutants at 25oC, but fails to rescue this phenotype at 22oC. At 25oC, the partially-rescued larvae have five denticle rows, but types 1 and 2 are missing and types 3-6 are not in the same sequential order seen in wild-type larvae. The identity of the T1 segment is restored, shown by the presence of a T1 beard. However, expression of tioScer\UAS.cLa causes a new phenotype: ectopic denticles appear in the head region.

The addition of ciScer\UAS.cAa (driven by Scer\GAL4αTub84B.PP) to tsh8 mutant embryos, can suppress denticle belt formation in the thorax and the abdomen.

brkM68 tsh8 double mutant larvae show an essentially naked cuticle phenotype, with only single tiny denticles occasionally seen scattered in the posterior abdomen.

The denticle types present (5 and 6) in tsh8 mutant embryos are unchanged if they are also expressing hhScer\UAS.cIa under the control of Scer\GAL4prd.RG1, although in some segments the denticle belts are reduced and the shape of the denticle belt is modified. Cuticle from tsh8 ; ci94 double mutant embryos produces only weakly pigmented, type 5 denticles and no naked cuticle.

The naked cuticle phenotype produced by armS10.Scer\UAS.T:Hsap\MYC expressed under the control of Scer\GAL469B is suppressed by tsh8.

Antenna to leg transformation is seen in an Antp73b mutant background.

tsh8 embryos expressing Scrhs.PZ develop supernumerary salivary glands in parasegments PS0-PS1 and in PS3-PS13.

In the presence of construct P{HS-Scr.Z} ectopic salivary glands do not form in parasegment 3.

Xenogenetic Interactions

At 22oC, the presence of Mmus\Sdccag33Scer\UAS.T:Hsap\MYC and Scer\GAL469B results in partial rescue of the T1 segment and trunk cuticle phenotypes of tsh8/tsh8 embryos. At 29oC this rescue is more complete. At 22oC, the presence of Mmus\Sdccag33lScer\UAS.T:Hsap\MYC and Scer\GAL469B leads to little or no rescue of the segment transformations apparent in the cuticle phenotype of tsh8/tsh8 embryos. However, at 29oC this phenotype is partially rescued. At 22oC, the presence of Mmus\Zfp537Scer\UAS.T:Hsap\MYC and Scer\GAL469B results in partial rescue of the T1 segment and trunk cuticle phenotypes of tsh8/tsh8 embryos. All these larvae show significant but incomplete rescue of the T1 denticle belt phenotype but none of them displays beard-specific denticles. The size of the naked cuticle bands in the trunk appears normal. At 29oC this rescue is more complete.

Complementation and Rescue Data
Rescued by
Partially rescued by

tsh8 is partially rescued by tshmCa

tsh8 is partially rescued by tshbcd.mCa

tsh8 is partially rescued by tsh220.mCa

tsh8 is partially rescued by tshhs.PdZ


Expression of tshScer\UAS.cGa at 22oC, under the control of Scer\GAL469B, rescues the denticle and naked cuticle phenotype of tsh8 mutants and Ti segment identity is restored. However, this expression induces ectopic denticle formation in the head region.

Phenotype is partially rescued by heat shock treatment of embryos carrying tshhs.PdZ.

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Synonyms and Secondary IDs (4)
References (37)