Open Close
General Information
Symbol
Dmel\stg2
Species
D. melanogaster
Name
FlyBase ID
FBal0247234
Feature type
allele
Associated gene
Associated Insertion(s)
Carried in Construct
Also Known As
stg7B, stg7B69, stg7
Key Links
Nature of the Allele
Mutations Mapped to the Genome
 
Type
Location
Additional Notes
References
Associated Sequence Data
DNA sequence
Protein sequence
 
 
Progenitor genotype
Cytology
Nature of the lesion
Statement
Reference
Expression Data
Reporter Expression
Additional Information
Statement
Reference
 
Marker for
Reflects expression of
Reporter construct used in assay
Human Disease Associations
Disease Ontology (DO) Annotations
Models Based on Experimental Evidence ( 0 )
Disease
Evidence
References
Modifiers Based on Experimental Evidence ( 0 )
Disease
Interaction
References
Comments on Models/Modifiers Based on Experimental Evidence ( 0 )
 
Disease-implicated variant(s)
 
Phenotypic Data
Phenotypic Class
Phenotype Manifest In
Detailed Description
Statement
Reference

In a stg2 mutant context, Df(2L)200 mutant embryos induce a twofold increase in the number of crystal cells.

In some segments in mutant embryos tin or eve expressing cells fail to form. Mutants also show severe segmentation and other patterning defects.

Homozygous follicle cell clones have far fewer cells than their wild-type sister clones. The mean ratio of the number of cells in the mutant clone/number of cells in the wild-type sister clone is 0.1 (compared to a ratio of 1.0 in control experiments).

In embryos lacking zygotic stg+, neuroblasts form but arrest at G2 during interphase of cell-cycle stage 14 and fail to enter mitosis.

In homozygous mutant stg2 embryos, single large mononucleated cells with NB6-4 identity are seen in most of the thoracic segments and 90% of abdominal hemisegments. This is in contrast to wild-type where NB6-4T divides into 5 to 6 cells, and NB6-4A divides into 2 cells.

Postblastoderm cell divisions are completely blocked in stg2 mutants. Imaginal disc cells that are homozygous for stg2 divide only once, producing 2-celled clones that are eliminated by cell competition.

Eye of adults heterozygous with stghwy are normal, though missing macrochaetae phenotype remains.

The number of eve-expressing mesodermal cells per hemisegment is similar in stg2 single mutant and stg2; zfh12 double mutant embryos.

Mutant embryos arrest in G2 of cycle 14, while development continues well after the time of mitosis 14. Two centriole pairs are seen per cell. More than 95% of the pairs have incompletely assembled daughters (the daughter centrioles are significantly shorter than their mother centrioles and their tubular fine structure is not obvious).

Cells in homozygous clones induced in the wing pouch of the wing disc divide only once and become enlarged. These cells are gradually lost from the disc epithelium.

All cell divisions are blocked after the blastoderm stage. In embryos sense organ precursors do not divide but do differentiate into neurons, several md but only a few es neurons are observed.

Embryos derived from germ line clones proceed through cycles 1-13 normally and always transverse the maternal/zygotic transition (MZT) during interphase.

Cell division arrested.

Lethal interaction with noose1, noose2, noose3 and noose4. Transheterozygotes with stgknot are viable and fertile.

Expression of dapGMR.PdN transgene in stg2 flies has no effect on the eye phenotype.

Neuroblast formation occurs normally in stg mutant embryos.

Malpighian tubule phenotype examined in embryos and found to be similar to that of wg mutants: tubules remain as clusters of approximately 20 cells. However in stg2 all four primordia appear. Tip cells are present and tubules go on to elongate and produce uric acid.

No mitoses after mitosis 13 but individuals still develop to secrete a cuticle that is virtually devoid of differentiated pattern elements. Failure of head involution, few thoracic or abdominal denticles develop and tail structures are rudimentary. Introduction of the stghs.PE2 construct without heat shock causes differentiation of more cuticular structure due to leaky expression. Heat shock 2 hours after egg deposition synchronous cell divisions that bore no resemblance to the normal mitotic pattern. Greater number of heat pulses increased the extent of normal cuticle differentiation, 3 pulses gave normal cuticle. These embryos do not hatch as the there are too few CNS cells.

No cell division occurs in the ectoderm after the blastoderm stage in homozygotes.

stg2 embryos first deviate from normal development during the early stages of gastrulation, when they fail to initiate the 14th mitosis. There is no evidence of chromosome condensation, nuclear envelope breakdown or spindle formation between 3 and 12 hours after egg deposition (at 25oC), in contrast to wild type embryos. The cells are arrested in G2. Mutants show a nonspecific reduction in the number of differentiated cuticular structures.

strong allele

External Data
Interactions
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Enhancer of
Statement
Reference
NOT Enhancer of
Statement
Reference
Suppressor of
Statement
Reference
NOT Suppressor of
Statement
Reference

stg2/stg2 is a non-suppressor of visible phenotype of DpGMR.PD, E2f1GMR.PD

Other
Phenotype Manifest In
Enhancer of
Statement
Reference
NOT Enhancer of
Statement
Reference

stg2/stg2 is a non-enhancer of phenotype of Mybunspecified

Suppressor of
Statement
Reference

stg2, stg2, stg[+] is a suppressor of eye phenotype of shtd1

stg2, stg2, stg[+] is a suppressor of ommatidium phenotype of shtd1

NOT Suppressor of
Statement
Reference

stg2/stg2 is a non-suppressor of phenotype of Mybunspecified

stg2, stg2, stg[+] is a non-suppressor of lamina anlage & mitotic cell cycle phenotype of dally06464

Other
Additional Comments
Genetic Interactions
Statement
Reference

The addition of stg2 has no effect on Mybunspecified viability.

One copy of stg2 does not rescue the second division in dally06464 lamina precursor neurons and appears to expand the first G2/M domain of lamina precursor neuron division.

Expression of cdc2AF.hs in a stg2 mutant background drives the G2-arrested stg mutant cells into mitosis.

In stg2/stg4,Df(3L)ri-79c double mutant embryos no post-blastoderm cell divisions occur and gastrulation is normal.

Simultaneous deletion of stg2/stg2 twe1/twe1 causes a block in germ cell proliferation, no ovarioles or eggs are produced.

Xenogenetic Interactions
Statement
Reference
Complementation and Rescue Data
Fails to complement
Partially rescued by

stg2/stg2 is partially rescued by stgBCD

stg2/stg2 is partially rescued by stgBCD

stg2/stg2 is partially rescued by stgt31.6

stg2/stg2 is partially rescued by stgCD

stg2/stg2 is partially rescued by stgt6.0

stg2/stg2 is partially rescued by stghs.PE2

Comments

stgBCD partially rescues the clone size of stg2 follicle cell clones; mutant clones half the size of wild-type sister clones are detected. The nuclei of the follicle cells are twice the size of the nuclei of wild-type sister clone cells.

The cell division phenotype is partially rescued by stgt31.6; cell cycle progression is seen in a subset of the wild-type division pattern, and the embryos die with mild cuticular defects which can be attributed to a partial loss of cell division in mitotic domain 11 (the dorsolateral epidermis). The imaginal disc phenotype is rescued by stgt31.6, stgBCD, stgCD or stgt6.0; stg2 cells in the imaginal disc carrying one of these transgenes divide many times and produce large clones of cells. stg2 clones rescued by stgt31.6 are equal in size to their wild-type sister clones, while stg2 clones rescued by any of the other transgenes are smaller than their wild-type sister clones and show increased cell size. stg2 cells rescued by stgt6.0 have an increased G2 phase.

Complements stghwy for ommatidial phenotype, fails to complement stghwy for bristle phenotype.

Images (0)
Mutant
Wild-type
Stocks (0)
Notes on Origin
Discoverer
Comments
Comments

Strong stg allele.

External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (7)
References (61)