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General Information
Symbol
Dmel\TlMhc.PR
Species
D. melanogaster
Name
Myosin heavy chain promoter construct of Rose
FlyBase ID
FBal0061574
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
Associated Sequence Data
DNA sequence
Protein sequence
 
 
Progenitor genotype
Carried in construct
Cytology
Nature of the lesion
Statement
Reference

Muscle-specific promoter from Mhc drives expression of Tl cDNA.

Allele components
Product class / Tool use(s)
Regulatory region(s)
Encoded product / tool
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 )
 
Phenotypic Data
Phenotypic Class
Phenotype Manifest In

abdominal posterior fascicle & growth cone

filopodium & abdominal ventral longitudinal muscle 3

RP3 neuron & growth cone

Detailed Description
Statement
Reference

The nerve terminals synapsed to muscle M12 are greatly reduced in size compared to controls in embryos expressing TlMhc.PR. The projection of other motor nerves (such as the ISN and SNa) appears normal.

The growth cone of the RP3 neuron often stalls near its target muscles in embryos expressing TlMhc.PR, failing to retract its filopodia and initiate synaptogenesis. The muscle 6/7 cleft is innervated in only 53% of hemisegments by the end of embryogenesis. Myopodia extending from muscle 6 are initially present at numbers similar to wild type (at 12 hours), but myopodia clustering can only be detected in 26% of hemisegments at 13 hours (compared to 46% of hemisegments in wild type).

The RP3 growth cone stalls underneath the muscle 6/7 cleft in 16 hour TlMhc.PR embryos (which ectopically express Tl in muscles 6 and 7) and synaptogenesis does not occur. In 87% of cases the RP3 growth cone remains stalled underneath the 6/7 cleft during hours 16-18. The cleft itself is wider than in wild type and is crowded with unlabelled axonal growth cones from the SNb/d motor pathway at 16 hours (in contrast to this stage in the wild type, where the 6/7 cleft is mainly occupied by the RP3 growth cone). Most neuromuscular innervation outside of the 6/7 cleft appears normal.

Embryos expressing TlMhc.PR in the muscles show no difference in the number or overall morphology of muscles. Embryos carrying TlMhc.PR show virtually wild-type-like overall development of the nervous system. However, the RP3 neuron often fails to reach the muscle 6/7 cleft. In most cases, the growth cone stalls just beneath and external to the cleft and fails to initiate synaptogenesis.

SNa growth cones develop normally, SNb growth cones look immature on muscle 6, 7 and 12. 6/7 cleft is often missing. RP3 growth cones reaches just below the correct target, cleft between muscle 6 and 7, but fails to innervate normally due to inhibition of synaptogenesis initiation.

External Data
Interactions
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Other
Statement
Reference
Phenotype Manifest In
Suppressed by
Statement
Reference
Suppressor of
Statement
Reference

TlMhc.PR is a suppressor of RP3 motor neuron phenotype of Fas3Mhc.PC

Additional Comments
Genetic Interactions
Statement
Reference

Embryos expressing both Fas3Mhc.PC and TlMhc.PR in the muscles show no difference in the number or overall morphology of muscles. In contrast to embryos expressing either Fas3Mhc.PC or TlMhc.PR alone, the muscle 6/7 cleft remains innervated at a high frequency in embryos expressing both Fas3Mhc.PC and TlMhc.PR and the morphology of the innervation is very similar to wild type. The few RP3 growth cones that do not innervate the 6/7 cleft either stall beneath the 6/7 cleft (the most common phenotype in embryos expressing TlMhc.PR alone) or mistarget to other muscles (a common phenotype in embryos expressing Fas3Mhc.PC alone). Varying the dosage of Fas3Mhc.PC and TlMhc.PR indicates that there is an inverse relationship between the level of Tl/Fas3 dosage disparity and the frequency of muscle 6/7 innervation.

Xenogenetic Interactions
Statement
Reference
Complementation and Rescue Data
Comments
Images (0)
Mutant
Wild-type
Stocks (0)
Notes on Origin
Discoverer
External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (2)
Reported As
Symbol Synonym
TlMhc.PR
Name Synonyms
Myosin heavy chain promoter construct of Rose
Secondary FlyBase IDs
    References (5)