Allele Dmel\Fmr1^Δ50M

General Information
Symbol	Dmel\Fmr1^Δ50M	Species	D. melanogaster
Name		FlyBase ID	FBal0131033
Feature type	allele	Created / Updated	2006-08-22/2006-08-22
Associated gene	Dmel\Fmr1

Allele class	amorph, loss of function
Mutagen	Δ2-3
Nature of the Allele
Allele class	amorph (Morales et al., 2002) loss of function (Zhang et al., 2001)
Mutagen	Δ2-3 (Zhang et al., 2001)
Mapped Features and Mutations
Type Symbol & Location Additional Notes References
Associated Sequence Data
DDBJ / EMBL / GenBank	DNA sequence Protein sequence Name

UniProtKB/Swiss-Prot
UniProtKB/TrEMBL

Progenitor genotype	Fmr1^EP3517 (Zhang et al., 2001)
Nature of the lesion	Statement Reference Deletion removing P{EP} and flanking DNA including the 5' non coding exons and the first coding exon of the Fmr1 gene. (Zhang et al., 2001)
Assay mode
Cytology
Phenotypic Data
Phenotypic Class
	viable (Zhang et al., 2001) lethal \| pharate adult stage (Morales et al., 2002) semi-sterile (Zhang et al., 2004) flight behavior defective (with Df(3R)by62) (Zhang et al., 2001) neurophysiology defective (Zhang et al., 2001) neuroanatomy defective (Zhang et al., 2001, Michel et al., 2004) neuroanatomy defective (with Fmr1^Δ113M) (Morales et al., 2002, Michel et al., 2004) neuroanatomy defective \| somatic clone (Pan et al., 2004)
Phenotype Manifest In
	photoreceptor cell & synapse & lamina receptor cell (Zhang et al., 2001) neuromuscular junction (Zhang et al., 2001) testis (Zhang et al., 2004) spermatid (Zhang et al., 2004) spermatid axoneme (Zhang et al., 2004) beta-lobe (Pan et al., 2004, Michel et al., 2004) mushroom body & neuron \| somatic clone (Pan et al., 2004) mushroom body & neuron & dendrite \| somatic clone (Pan et al., 2004) gamma-lobe & neuron \| somatic clone (Pan et al., 2004) bouton \| somatic clone (Pan et al., 2004) synaptic vesicle \| somatic clone \| supernumerary (Pan et al., 2004) mushroom body (Michel et al., 2004) ventral adult lateral neuron (with Fmr1^Δ113M) (Morales et al., 2002) dorsal cluster neuron (with Fmr1^Δ113M) (Morales et al., 2002) dorsal cluster neuron & neurite (with Fmr1^Δ113M) (Morales et al., 2002) alpha-lobe (with Fmr1^Δ113M) (Michel et al., 2004) mushroom body (with Fmr1^Δ113M) (Michel et al., 2004) beta-lobe (with Fmr1^Δ113M) (Michel et al., 2004)
Detailed Description
	Statement Reference Mutants show no morphological defects. When tested for bang sensitivity, temperature sensitivity and phototaxis there is no detectable difference between wild type and mutant. However there are defects in coordination in a simple flight test. Synaptic transmission is reduced (as indicated by a reduction in off-transient mean amplitude as assayed by ERG). Null mutants show pronounced synaptic overgrowth and overelaboration of synaptic terminals. Muscle 4 has 51% increase in number of boutons over controls. Arboreal branching is increased - with muscle 4 showing 50% more branches than wild type. Evoked synaptic transmission at the NMJ is elevated. Mean EJC amplitude is increased. Average synaptic efficacy is upregulated. (Zhang et al., 2001) Mutants show a fibre extension defect in the DC and LNv neurons. Extension of DC axons from the lobula to the medulla is incomplete, some axons show guidance errors. LNv neurons may over extend, show guidance defects or show aberrant morphology. The LVn defects are less consistent than those in the DC neurons. Stereotypical grid-like array of neurites entering the medulla is disrupted in mutant flies - short and thin branches fail to connect. This occurs even for neurons that do cross towards the distal medulla. Homozygotes show 0% eclosion from pupal case. (Morales et al., 2002) When mutant female are mated with wild-type males, only 21% of the expected progeny produced. Mutant males have enlarged testes. The diameter of the tip of the testis is similar to controls, but the diameter in the middle of the testis is about 50% larger than wild-type. This phenotype is 100% penetrant in newly enclosed flies, but it abates with aging. Other than this the morphology of mutant testes appears normal. The testis phenotype appears to be caused by the accumulation of misarranged spermatid bundles within the testis lumen. The coiled spermatid bundles normally seen at the testis base are missing in mutants. Instead of mature spermatids, degenerated cell debris fill the base of mutant testes. The early individualisation process of spermatogenesis does appear to progress largely as normal (occasional defects are seen). However, the orientation of spermatid tails within a cyst is often arranged in an irregular fashion in mutants. In addition the configuration of mitochondria and axoneme within a sperm flagellum is variably skewed, as well as some unknown ring structures present at the inner-space between spermatid tails which is not seen in controls. There is also a specific disruption of the microtubule axoneme structure in the sperm flagellum which becomes progressively more pronounced at spermatid differentiation proceeds. The central pair microtubules are missing in mutant axonemes, although the outer microtubules are still present. this phenotype is progressive, 30% of early stage spermatids, and 56% of late-stage spermatid. (Zhang et al., 2004) Mutant adults have normal gross brain morphology, including an architecturally normal mushroom body. Mild β lobe overgrowth is seen at a slightly higher frequency than wild type. Single cell mutant clones in the mushroom body (in a wild-type background) produce additional cell body processes compared to wild-type single cell clones (converting the characteristic unipolar mushroom body neurons seen in wild-type into multipolar neurons); there is a 3-fold increase in the number of cell body processes in the mutant cells. The mutant cells show a more complex and disordered dendritic structure compared to wild type; primary dendrites display clear secondary branches and the fine dendritic processes that are normally restricted to the termini spread aberrantly along the primary branches. Single cell mutant γ neurons in the mushroom body always have significantly increased axonal branching and significantly more and longer axonal branches than control cells. The large, extra branches do not follow the main axon trajectory, but instead extend in apparently random directions to invade inappropriate territory. Neurons in large mutant clones in the mushroom body show a significantly enlarged average bouton area and more variable distribution of bouton sizes than wild type. The mutant presynaptic boutons are almost filled with vesicles; the average area of the bouton occupied by vesicles is increased 50% in mutant boutons to nearly 75% of the bouton. (Pan et al., 2004) In just under 10% of homozygous Fmr1[Δ50M] mutants, the β lobe of the mushroom body is misdirected or missing. Just under 20% of homozygous Fmr1[Δ50M] mutants display a misdirected or missing α-lobe. In just under 70%, both the α- and β lobes of the mushroom body are either misdirected or missing. Where the β-lobe is present, just under 10% display severe midline crossing (defined as a densely strained band equal to or greater in width and thickness than those of the adjacent β-lobes), with approximately 25% displaying moderate midline crossing (defined as when the thickness of the fiber bundle crossing the midline is considerable but less than the width of the β-lobe termini). Just under 10% display mild midline crossing phenotypes in the β lobe (defined as when a thin band of fibers cross the midline). Approximately 10% of Fmr1[Δ50M]/Fmr1[Δ113M] transheterozygotes display misdirecting or missing α lobes. Approximately just over 70% of transheterozygous Fmr1[Δ50M]/Fmr1[Δ113M] mutants exhibit severe midline crossing in the β-lobe of the mushroom body (defined as a densely strained band equal to or greater in width and thickness than those of the adjacent β-lobes). The rest appear phenotypically normal. No sexual dimorphism in penetrance or expressivity is found. (Michel et al., 2004)
Interactions
	Show the genetic interaction network for Enhancers & Suppressors
Phenotypic Class
NOT Enhanced by
Statement Reference Fmr1^Δ50M has semi-sterile phenotype, non-enhanceable by futsch^N94 (Zhang et al., 2004)
Suppressed by
Statement Reference Fmr1^Δ50M has neurophysiology defective phenotype, suppressible by futsch^N94 (Zhang et al., 2001) Fmr1^Δ50M has neuroanatomy defective phenotype, suppressible by futsch^N94 (Zhang et al., 2001)
NOT suppressed by
Statement Reference Fmr1^Δ50M has semi-sterile phenotype, non-suppressible by futsch^N94 (Zhang et al., 2004)
NOT Enhancer of
Statement Reference Fmr1^Δ50M/Df(3R)by62 is a non-enhancer of neuroanatomy defective phenotype of Hsap\SCA8^{CTG112.Scer\UAS}, Scer\GAL4^GMR.PF (Mutsuddi et al., 2004) Fmr1^Δ50M is a non-enhancer of visible phenotype of Hsap\MAPT^{V337M.Scer\UAS}, Scer\GAL4^GMR.PF (Shulman and Feany, 2003)
Suppressor of
Statement Reference Fmr1^Δ50M is a suppressor of neurophysiology defective phenotype of futsch^N94 (Zhang et al., 2001) Fmr1^Δ50M is a suppressor of neuroanatomy defective phenotype of futsch^N94 (Zhang et al., 2001)
NOT Suppressor of
Statement Reference Fmr1^Δ50M/Df(3R)by62 is a non-suppressor of neuroanatomy defective phenotype of Hsap\SCA8^{CTG112.Scer\UAS}, Scer\GAL4^GMR.PF (Mutsuddi et al., 2004) Fmr1^Δ50M is a non-suppressor of visible phenotype of Hsap\MAPT^{V337M.Scer\UAS}, Scer\GAL4^GMR.PF (Shulman and Feany, 2003)
Phenotype Manifest In
Suppressed by
Statement Reference Fmr1^Δ50M has bouton phenotype, suppressible by futsch^N94 (Zhang et al., 2001) Fmr1^Δ50M has neuromuscular junction phenotype, suppressible by futsch^N94 (Zhang et al., 2001) Fmr1^Δ50M has synapse phenotype, suppressible by futsch^N94 (Zhang et al., 2001)
NOT Enhancer of
Statement Reference Fmr1^Δ50M is a non-enhancer of eye phenotype of Hsap\MAPT^{V337M.Scer\UAS}, Scer\GAL4^GMR.PF (Shulman and Feany, 2003) Fmr1^Δ50M is a non-enhancer of ommatidium phenotype of Hsap\MAPT^{V337M.Scer\UAS}, Scer\GAL4^GMR.PF (Shulman and Feany, 2003)
Suppressor of
Statement Reference Fmr1^Δ50M is a suppressor of bouton phenotype of futsch^N94 (Zhang et al., 2001) Fmr1^Δ50M is a suppressor of neuromuscular junction phenotype of futsch^N94 (Zhang et al., 2001) Fmr1^Δ50M is a suppressor of synapse phenotype of futsch^N94 (Zhang et al., 2001)
NOT Suppressor of
Statement Reference Fmr1^Δ50M is a non-suppressor of eye phenotype of Hsap\MAPT^{V337M.Scer\UAS}, Scer\GAL4^GMR.PF (Shulman and Feany, 2003) Fmr1^Δ50M is a non-suppressor of ommatidium phenotype of Hsap\MAPT^{V337M.Scer\UAS}, Scer\GAL4^GMR.PF (Shulman and Feany, 2003)
Additional Comments
Genetic Interactions
Statement Reference
Xenogenetic Interactions
Statement Reference The rough eye phenotype caused by expression of Hsap\MAPT^{V337M.Scer\UAS} under the control of Scer\GAL4^GMR.PF is not modified if the flies are also carrying Fmr1^Δ50M. (Shulman and Feany, 2003)
Complementation & Rescue Data
Comments
Stocks ( 1 )
Bloomington	6930 w¹¹¹⁸; Fmr1^Δ50M/TM6B, Tb¹
Notes on Origin
Discoverer

Synonyms & Secondary IDs ( 6 )
Reported As
Symbol Synonym	dfmr^50M (Pan et al., 2004) dfmr^del50 (Mutsuddi et al., 2004) dfxr null (Zhang et al., 2001) dxfr1^50M (Zhang et al., 2004, Shulman and Feany, 2003) Fmr1^Δ50 (Morales et al., 2002, Michel et al., 2004) Fmr1^Δ50M
Name Synonym
Secondary FlyBase IDs

References ( 7 )
Research paper	Michel et al., 2004, J. Neurosci. 24(25): 5798--5809 Defective neuronal development in the mushroom bodies of Drosophila Fragile X Mental Retardation 1 Mutants. [FBrf0179339] Mutsuddi et al., 2004, Curr. Biol. 14(4): 302--308 The spinocerebellar ataxia 8 noncoding RNA causes neurodegeneration and associates with staufen in Drosophila. [FBrf0174476] Pan et al., 2004, Curr. Biol. 14(20): 1863--1870 The Drosophila fragile X gene negatively regulates neuronal elaboration and synaptic differentiation. [FBrf0180069] Zhang et al., 2004, Dev. Biol. 270(2): 290--307 The Drosophila fragile X-related gene regulates axoneme differentiation during spermatogenesis. [FBrf0178963] Shulman and Feany, 2003, Genetics 165(3): 1233--1242 Genetic modifiers of tauopathy in Drosophila. [FBrf0167629] Morales et al., 2002, Neuron 34(6): 961--972 Drosophila Fragile X protein, DFXR, regulates neuronal morphology and function in the brain. [FBrf0149142] Zhang et al., 2001, Cell 107(5): 591--603 Drosophila fragile X-related gene regulates the MAP1B homolog Futsch to control synaptic structure and function. [FBrf0141416]

Allele Dmel\Fmr1Δ50M

Allele Dmel\Fmr1^Δ50M