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General Information
Symbol
Dmel\msi1
Species
D. melanogaster
Name
FlyBase ID
FBal0050164
Feature type
allele
Associated gene
Associated Insertion(s)
Carried in Construct
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

Imprecise excision of an enhancer trap element, deletion of the entire element and 600bp of flanking genomic DNA (including the initiator codon).

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
Detailed Description
Statement
Reference

msi1 and msi1/msi2 mutant testes exhibit fewer brightly stained cells at the apex of the testis, indicative of a loss of early germ cells. msi1 mutant testis also exhibit a swelling of the apical region in ~90% of testes analyzed.

msi1 mutant third-instar larvae exhibit a hub in 97% of testes analysed and exhibit milder morphological defects than those observed in pharate adults.

In msi1 mutants, there are on average 3.9 germ stem cells per testis, compared to 8.4 per testis in wild-type.

Germline stem cell clones homozygous for msi1 are found at the same frequency as control clones 2 days after clone induction. Although wild-type clones are maintained at similar levels over time, msi1 stem cell clones are not maintained at the same frequency. At 8 days after induction, msi1 mutant clones are observed significantly less frequently than control wild-type germ line stem cells of the same age.

msi1 spermatogonia clones are found in 47% of testes 5 days after clone induction, this is a similar number to that found in control clones.

Acridine orange staining does not reveal the presence of any excess dying cells in msi1 mutant clones. In 15% of cases, msi1 spermatogonial clones are found 8 days after induction in the absence of msi1 germline stem cells, indicating that msi1 germline stem cells can differentiate into spermatogonial cells without regeneration of germline stem cells.

In msi1 mutants, early round spermatids commonly contain two or four nuclei and a large mitochondrial derivative, indicating that one or both meiotic cytokinetic divisions have failed. These mutants often display haploid nuclei of different sizes, resulting from errors in chromosome segregation during meiosis.

Mutants show a double bristle phenotype.

Homozygotes show a low penetrance phenotype of abnormal ommatidia with deformed rhabdomeres and abnormal ommatidial orientation. The number of photoreceptor cells is normal, in affected ommatidia.

Lethality occurs during late pupal and early adult stages. The total number of sensilla is similar to wild type but the number of outer support cells (sockets and shafts) is variable. Microchaetae on the notum have variable phenotypes, some having up to 4 sockets and no shaft. The presence of extra support cells is correlated to the absence of neurons. Macrochaetae also display variability, the most frequent phenotype is two shafts and one socket. Macrochaetae with additional support cells frequently had one or more neurons but did not typically contain glial cells. Anterior wing margin has extra support cells in the singly innervated bristles and multiple innervated bristles and extra outer support cells in the twin campaniform sensilla.

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

msi1 has visible | recessive phenotype, enhanceable by sina3/sina2

msi1 has visible phenotype, enhanceable by sina3/sina2

Suppressed by
Statement
Reference

msi1 has visible | recessive phenotype, suppressible by ttk[+]/ttkosn

NOT suppressed by
Statement
Reference
Enhancer of
Statement
Reference

msi[+]/msi1 is an enhancer of visible | dominant phenotype of N55e11

msi1/msi1 is an enhancer of visible phenotype of sina3/sina2

NOT Enhancer of
NOT Suppressor of
Other
Statement
Reference
Phenotype Manifest In
Enhanced by
Statement
Reference

msi1 has ommatidium phenotype, enhanceable by sina3/sina2

NOT Enhanced by
Statement
Reference

msi2/msi1 has male germline stem cell phenotype, non-enhanceable by Rbp61

Suppressed by
NOT suppressed by
Statement
Reference
Enhancer of
NOT Suppressor of
Other
Additional Comments
Genetic Interactions
Statement
Reference

A msi1 background weakly enhances the dorsalisation phenotype observed in ImpScer\UAS.cGa overexpression (Scer\GAL4mat.αTub67C.T:Hsim\VP16) mutants.

Dominantly enhances the Df(1)N-54l9/+ and N55e11/+ wing nicking phenotypes.

NECN.Scer\UAS (Scer\GAL4sca-109-68), msi1 double mutants show a dense double bristle phenotype. The IIb precursor takes the non-neuronal fate as there are no neurons in the subepidermal layer.

Double mutants of sina2/sina3 with msi1 show a synergistic, not additive, eye phenotype. Ommatidial arrays are disturbed, eyes consequently roughened and ommatidia do not contain more than five rhabdomeres. Cone cell array is disturbed. 30% of the ommatidia of sina2 msi1 ttkosn/sina3 msi1 show the normal number and arrangement of photoreceptor cells. The cone cell defects of sina2 msi1/sina3 msi1 are also suppressed by ttkosn.

Xenogenetic Interactions
Statement
Reference
Complementation and Rescue Data
Rescued by
Not rescued by

msi1 is not rescued by msiA.B

Comments
Images (0)
Mutant
Wild-type
Stocks (2)
Notes on Origin
Discoverer
External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (1)
References (10)