Allele Dmel\Dscam²³

General Information
Symbol	Dmel\Dscam²³	Species	D. melanogaster
Name		FlyBase ID	FBal0148064
Feature type	allele	Associated gene	Dmel\Dscam

Allele class	loss of function allele
Mutagen	ethyl methanesulfonate
Recent Updates
Description	What does this section display? This section contains items that were added to this record for each release. It currently only tracks new links between this FlyBase report and other FlyBase data classes (e.g. genes, references, stocks) or controlled vocabulary terms (e.g. GO, anatomy terms). What does this section not display? This section does not currently display links that were removed or gene model changes.
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FB2013_03
FB2013_02
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Nature of the Allele
Allele class	loss of function allele (Hummel et al., 2003)
Mutagen	ethyl methanesulfonate (Hummel et al., 2003)
Mutations Mapped to the Genome

Type Location Additional Notes References
Associated Sequence Data
DDBJ / EMBL / GenBank	DNA sequence Protein sequence Name

UniProtKB/Swiss-Prot
UniProtKB/TrEMBL

Progenitor genotype
Nature of the lesion	Statement Reference
Cytology
Phenotypic Data
Phenotypic Class
	lethal (with Dscam²¹) (Hattori et al., 2007) lethal (with Dscam^Df6055) (Hattori et al., 2007) neuroanatomy defective (with Dscam²¹) (Matthews et al., 2007) neuroanatomy defective (with Dscam⁴⁷) (Matthews et al., 2007) neuroanatomy defective \| embryonic stage (with Dscam^3.31.8) (Hattori et al., 2007) neuroanatomy defective \| embryonic stage (with Dscam^6.5.9) (Hattori et al., 2007) neuroanatomy defective \| embryonic stage (with Dscam^10.27.25) (Hattori et al., 2007) neuroanatomy defective \| embryonic stage (with Dscam²¹) (Hattori et al., 2007) neuroanatomy defective \| larval stage \| somatic clone (Zhan et al., 2004) neuroanatomy defective \| somatic clone (Hummel et al., 2003)
Phenotype Manifest In
	antennal lobe \| somatic clone (Hummel et al., 2003) dendrite & abdominal dorsal/lateral multidendritic neuron \| somatic clone \| cell autonomous (Matthews et al., 2007) dendrite & abdominal dorsal multidendritic neuron ddaA \| somatic clone \| cell autonomous (Matthews et al., 2007) dendrite & abdominal dorsal multidendritic neuron ddaC \| somatic clone \| cell autonomous (Matthews et al., 2007) dendrite & abdominal dorsal multidendritic neuron ddaD (with Dscam²¹) (Matthews et al., 2007) dendrite & abdominal dorsal multidendritic neuron ddaD (with Dscam⁴⁷) (Matthews et al., 2007) dendrite & abdominal dorsal multidendritic neuron ddaD \| somatic clone \| cell autonomous (Matthews et al., 2007) dendrite & abdominal dorsal multidendritic neuron ddaE (with Dscam²¹) (Matthews et al., 2007) dendrite & dendritic arborising neuron \| somatic clone \| cell autonomous (Matthews et al., 2007) dendritic arborizing neuron (with Dscam²¹) (Matthews et al., 2007) embryonic/larval mushroom body \| somatic clone (Zhan et al., 2004) lobe system of mushroom body \| larval stage \| somatic clone (Zhan et al., 2004) longitudinal connective (with Dscam^3.31.8) (Hattori et al., 2007) longitudinal connective (with Dscam^6.5.9) (Hattori et al., 2007) longitudinal connective (with Dscam^10.27.25) (Hattori et al., 2007) longitudinal connective (with Dscam²¹) (Hattori et al., 2007) mushroom body medial lobe (with Dscam^R496W) (Sawaya et al., 2008) mushroom body vertical lobe (with Dscam^R496W) (Sawaya et al., 2008) presumptive embryonic/larval central nervous system (with Dscam^3.31.8) (Hattori et al., 2007) presumptive embryonic/larval central nervous system (with Dscam^6.5.9) (Hattori et al., 2007) presumptive embryonic/larval central nervous system (with Dscam^10.27.25) (Hattori et al., 2007) presumptive embryonic/larval central nervous system (with Dscam²¹) (Hattori et al., 2007)
Detailed Description
	Statement Reference In Dscam[R496W]/Dscam[23] flies, the dorsal lobe nerve tract of the mushroom body does not form and the the medial lobe fails to extend to the midline. These phenotypes are 100% penetrant and exhibit similar but slightly weaker expressivity than Dscam[23]. (Sawaya et al., 2008) 100% of Dscam^FRT/Dscam²³ animals survive to late pupal stages. Less than 25% of Dscam²¹/Dscam²³ or Dscam^Df6055/Dscam²³ larvae survive to late pupal stages. Over 75% of Dscam^3.31.8/Dscam²³, Dscam^10.27.25/Dscam²³ and Dscam^6.5.9/Dscam²³ animals survive to late pupal stages. Dscam²¹/Dscam²³ embryos show defects in the organisation of the central nervous system, showing severely disrupted longitudinal tracts and some aberrant midline crossing. Dscam^3.31.8/Dscam²³, Dscam^10.27.25/Dscam²³ and Dscam^6.5.9/Dscam²³ embryos show defects in the organisation of the central nervous system, showing disrupted longitudinal tracts. (Hattori et al., 2007) Class I da neurons show defects in self-avoidance in Dscam²¹/Dscam²³ larvae, such that in contrast to wild type, class I dendrites from the same cell overlap extensively and fasciculate in the mutant animals. Arbors of each cell project to the same general location as in wild type, but there are significant gaps in territory coverage. Individual ddaD neurons of Dscam²³/Dscam⁴⁷ larvae show significant dendrite crossing, indicating defects in self-avoidance. Single cell homozygous da neuron clones show defects in self-avoidance, with dendrites of the single cell overlapping extensively. These defects are seen in single cell clones of class I da neurons (such as ddaD), class II da neurons (such as ldaA), class III da neurons (such as ddaA) and class IV da neurons (such as ddaC). Targeting is grossly normal in these mutant clones, with two exceptions; in several clones, main dendritic trunks fail to properly segregate, leaving some regions of the body wall devoid of dendrites, and dendrites in the lateral regions of the body wall (from ldaB, ddaA and ldaA) form dense accumulations near the lateral chordotonal organ. Class IV da neurons in Dscam²¹/Dscam²³ larvae show self-avoidance defects, but the tiling pattern is not obviously disrupted compared to wild type. (Matthews et al., 2007) Small clones of Dscam²¹ cells induced in the mushroom body at the early third instar and then examined 24-36 hours later are often seen as multiple fascicles (in contrast to wild-type control clones which form single fascicles). Defects in branching are also seen in the mushroom body lobes; the mutant clones still form two distinct branches, but often the branches fail to segregate dorsally and medially. (Zhan et al., 2004) Or47a-expressing olfactory receptor neurons (ORNs) that are mutant for Dscam²³ show marked mis-targeting of axons in the antennal lobe as they project towards wild-type targets (glomerulus DM3) on the ipsilateral side. The penetrance of the mistargeting phenotype is 100% with variable expressivity (on average about half of the mutant axons terminate in their correct glomerulus). P{GAL4}GH298-expressing ORNs that are mutant for Dscam²³ often fail to project to their normal target (the V glomerulus). In about 50% of cases, mutant axons leave the nerve, turn ventrally as in wild type and innervate ectopic positions within the ventral region of the antennal lobe. In the remaining cases the mutant axons do not turn ventrally and terminate more dorsally, typically in more central and lateral regions of the lobe. Or22a-expressing and Or23a-expressing Dscam²³ mutant ORNs target normally to the correct glomerulus. Or47b-expressing Dscam²³ mutant ORNs show mistargeting to more dorsal regions of the antennal lobe than the normal target (the VA1 l/m glomerulus) and also targeting defects in the contralateral lobe. Or46a-expressing Dscam²³ mutant ORNs frequently terminate upon entering the ventral central nervous system before reaching the antennal lobe, either immediately prior to entering the suboesophageal ganglion or upon exiting it, just ventral to the antennal lobe. The mutant ORNs form a structure with the appearance of a glomerulus where they terminate. (Hummel et al., 2003)
External Data
Linkouts
Interactions
Phenotypic Class
Phenotype Manifest In
Additional Comments
Genetic Interactions
Statement Reference
Xenogenetic Interactions
Statement Reference
Complementation & Rescue Data
Rescued by	Dscam²⁰/Dscam²³ is rescued by Dscam^{+tCH321-22M14} (Venken et al., 2009) Dscam²¹/Dscam²³ is rescued by Dscam^{4.3-6.36-9.25-17.1}/Scer\GAL4²²¹ (Matthews et al., 2007)
Partially rescued by	Dscam²¹/Dscam²³ is partially rescued by Dscam^{1.30.30.1.Scer\UAS}/Scer\GAL4²²¹ (Matthews et al., 2007) Dscam²¹/Dscam²³ is partially rescued by Dscam^{1.30.30.2.cMa.Scer\UAS}/Scer\GAL4²²¹ (Matthews et al., 2007)
Not rescued by	Dscam²¹/Dscam²³ is not rescued by Dscam^{4.3-6.36-9.25-17.2}/Scer\GAL4²²¹ (Matthews et al., 2007)
Comments
Stocks ( 0 )

Notes on Origin
Discoverer

External Crossreferences & Linkouts
Other Crossreferences

Linkouts

Synonyms & Secondary IDs ( 2 )
Reported As
Symbol Synonym	Dscam²³ (Hattori et al., 2007, Zhan et al., 2004, Wang et al., 2004, Matthews et al., 2007, Sawaya et al., 2008, Venken et al., 2009) Dscam^null (Sawaya et al., 2008)
Name Synonym
Secondary FlyBase IDs

References ( 7 )
Research paper	Sawaya et al., 2008, Cell 134(6): 1007--1018 A double S shape provides the structural basis for the extraordinary binding specificity of Dscam isoforms. [FBrf0206032] Hattori et al., 2007, Nature 449(7159): 223--227 Dscam diversity is essential for neuronal wiring and self-recognition. [FBrf0205027] Matthews et al., 2007, Cell 129(3): 593--604 Dendrite self-avoidance is controlled by Dscam. [FBrf0200892] Wang et al., 2004, Neuron 43(5): 663--672 Transmembrane/juxtamembrane domain-dependent Dscam distribution and function during mushroom body neuronal morphogenesis. [FBrf0180573] Zhan et al., 2004, Neuron 43(5): 673--686 Analysis of Dscam diversity in regulating axon guidance in Drosophila mushroom bodies. [FBrf0180574] Hummel et al., 2003, Neuron 37(2): 221--231 Axonal targeting of olfactory receptor neurons in Drosophila is controlled by Dscam. [FBrf0156018]
Supplementary material	Venken et al., 2009, Nat. Methods 6(6): Supplementary figures and text. [FBrf0210704]

Allele Dmel\Dscam23

Allele Dmel\Dscam²³