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General Information
Symbol
Dmel\l(3)mbtts1
Species
D. melanogaster
Name
FlyBase ID
FBal0028387
Feature type
allele
Associated gene
Associated Insertion(s)
Carried in Construct
Allele class
Nature of the Allele
Allele class
Mutations Mapped to the Genome
 
Type
Location
Additional Notes
References
point mutation
Nucleotide change:

C27267549T

Amino acid change:

P1130S | l(3)mbt-PB

Reported amino acid change:

P1130S

Comment:

Site of nucleotide substitution in mutant inferred by FlyBase based on reported amino acid change.

Associated Sequence Data
DNA sequence
Protein sequence
 
 
Progenitor genotype
Cytology
Nature of the lesion
Statement
Reference

Amino acid replacement: P1130S.

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 ( 1 )
Disease
Evidence
References
Modifiers Based on Experimental Evidence ( 0 )
Disease
Interaction
References
Comments on Models/Modifiers Based on Experimental Evidence ( 0 )
 
Phenotypic Data
Phenotypic Class
Phenotype Manifest In
Detailed Description
Statement
Reference

The neuroepithelia of both inner and outer optic anlagen are massively expanded in mutant early third instar larvae. This initially leads to a delay in optic lobe neuroblast formation, but optic lobe neuroblasts do form later and their number is significantly increased compared to wild type. Neuroblast formation is seen in the centre of the optic lobe epithelium, in contrast to wild type.

Homozygous larval brain tissue develops into tumours after allograft into adult host flies (taking over the entire abdomen of the host) in 70% of cases.

When pieces of brain from l(3)mbtts1 9-12-day-old larvae, which show tissue overgrowth, are transplanted into the abdomens of adult hosts, tumors of the abdomen develop.

Homozygous larvae carrying l(3)mbt+t6.8 show normal development of the brain, pupate like wild-type and viable fertile adults hatch.

Homozygotes develop into fertile adults at the permissive temperature (22oC), but die shortly after pseudo-puparium formation at the restrictive temperature (29oC). The third larval instar stage is greatly extended at 29oC, and can last up to three weeks. The brain hemispheres are up to five times larger in older homozygous larvae raised at the restrictive temperature than in mature wild-type larvae. The mutant brain hemispheres show a highly distorted internal morphology, and are composed of numerous large neuroblasts and ganglion mother cells. The central neuropile is destroyed by the invasively growing neoplastic cells and in advanced tumours the cells may also invade the ventral ganglion. Mutant brain tissue injected into the abdomens of wild-type females develops into immense lethal tumours, indicating that the mutant cells are malignant. Mutant larvae raised at 29oC begin to show abnormalities in the spatial separation of the outer and inner optic anlagen of the brain by 40 hours of development. As the larvae age, the abnormalities in the presumptive adult optic centres become more pronounced. Mutant imaginal discs show growth abnormalities at 29oC; the growth rate of the discs is slower than wild-type during early development, so that at 72 hours of development the mutant wing imaginal disc is often five times smaller than the wild-type. However, mutant and wild-type wing imaginal discs are a similar size at the time at which wild-type pupariation occurs. The wing disc epithelium becomes progressively hyperplastic and abnormally folded during the extended larval instar period. Wing imaginal disc tissue transplanted into wild-type larvae can differentiate into normal adult structures. Wing imaginal disc tissue transplanted into the abdomens of wild-type females retains the epithelial overgrowth phenotype, but does not kill the host, indicating that mutant imaginal discs are non-tumorous. Temperature-shift experiments indicate that the temperature-sensitive period for brain tumour suppression and normal imaginal disc development encompasses the first six hours of embryonic development. l(3)mbt function is also required throughout the remainder of development for the proper differentiation of the brain and imaginal discs.

Homozygous larvae develop malignant neuroblastomas in the presumptive adult optic centres of the brain at 29oC. These tumours consist of neuroblasts and ganglion mother cells which are unable to differentiate into optic neurons and show a characteristic pattern of malignant growth. All portions of the brain become invaded by the tumorous cells, and ultimately the larvae become bloated. These larvae fail to pupariate, or form a puparium with a delay of 2 to 7 days, and die shortly thereafter. Implantation of l(3)mbtts1 brain pieces into wild-type flies leads to malignant tumours, which invade the fat body, gut, thoracic muscles and the head, causing death of the host in 10 to 14 days. Imaginal discs are slightly enlarged at the restrictive temperature, but have an apparently normal folded pattern. These imaginal discs differentiate into cuticular structures when transplanted into wild-type larvae which are about to pupariate.

External Data
Interactions
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Suppressed by
Statement
Reference

l(3)mbtts1 has tumorigenic phenotype, suppressible | partially by Pxtf01000

l(3)mbtts1 has tumorigenic phenotype, suppressible | partially by piwi1

l(3)mbtts1 has tumorigenic phenotype, suppressible by aubQC42

NOT suppressed by
Statement
Reference

l(3)mbtts1 has tumorigenic phenotype, non-suppressible by zpg2553

l(3)mbtts1 has tumorigenic phenotype, non-suppressible by AGO3t3

Phenotype Manifest In
Additional Comments
Genetic Interactions
Statement
Reference

The frequency with which l(3)mbtts1 larval brain tissue develops into tumours after allograft into adult host flies (taking over the entire abdomen of the host) is not significantly altered if the transplanted tissue is also homozygous for either zpg2553 or AGO3t3.

The frequency with which l(3)mbtts1 larval brain tissue develops into tumours after allograft into adult host flies (taking over the entire abdomen of the host) is moderately reduced if the transplanted tissue is also homozygous for Pxtf01000.

The frequency with which l(3)mbtts1 larval brain tissue develops into tumours after allograft into adult host flies (taking over the entire abdomen of the host) is markedly reduced if the transplanted tissue is also homozygous for either aubQC42 or piwi1.

The frequency with which l(3)mbtts1 larval brain tissue develops into tumours after allograft into adult host flies (taking over the entire abdomen of the host) is markedly reduced if the transplanted tissue is also carrying either vasPH165/Df(2L)A267 or nos17/Df(3R)Dl-FX1.

Xenogenetic Interactions
Statement
Reference
Complementation and Rescue Data
Rescued by
Comments
Images (0)
Mutant
Wild-type
Stocks (0)
Notes on Origin
Discoverer
Comments
Comments

In trans Df(3R)D605 or Df(3R)mbtPE3, l(3)mbt alleles form the following phenotypic series: l(3)mbtGM161 < l(3)mbtts1 < l(3)mbtGM79 < l(3)mbtE2 < l(3)mbtGM76. Phenotypes range from weak maternal-effect mitotic asynchrony to a severe mitotic block to oogenesis defects in trans-heterozygous females. Each of these phenotypes is temperature sensitive: phenotypes increase in severity as the temperature is raised from 18 to 29oC.

Temperature shift experiments show that l(3)mbt function is required from the onset of embryonic life until the beginning of the third larval instar.

External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (1)
Reported As
Name Synonyms
Secondary FlyBase IDs
    References (10)