Allele Dmel\Dscam²¹

General Information
Symbol	Dmel\Dscam²¹	Species	D. melanogaster
Name		FlyBase ID	FBal0148065
Feature type	allele	Associated gene	Dmel\Dscam

Allele class	loss of function allele
Mutagen	ethyl methanesulfonate
Recent Updates
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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 Dscam²³) (Hattori et al., 2007) neuroanatomy defective (with Dscam²³) (Matthews et al., 2007) neuroanatomy defective \| embryonic stage (with Dscam²³) (Hattori et al., 2007) neuroanatomy defective \| larval stage \| somatic clone (Zhan et al., 2004) neuroanatomy defective \| somatic clone (Hummel et al., 2003) neuroanatomy defective \| third instar larval stage (Han et al., 2012)
Phenotype Manifest In
	antennal lobe \| somatic clone (Hummel et al., 2003) anterior scutellar bristle & mechanosensory neuron \| somatic clone (Chen et al., 2006) dendrite & abdominal dorsal multidendritic neuron ddaD (with Dscam²³) (Matthews et al., 2007) dendrite & abdominal dorsal multidendritic neuron ddaE (with Dscam²³) (Matthews et al., 2007) dendritic arborizing neuron (with Dscam²³) (Matthews et al., 2007) dorsal multidendritic neuron ddaC \| third instar larval stage (Han et al., 2012) 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 Dscam²³) (Hattori et al., 2007) posterior dorsocentral bristle & mechanosensory neuron \| somatic clone (Chen et al., 2006) posterior scutellar bristle & mechanosensory neuron (with Dscam^ΔR265) (Chen et al., 2006) posterior scutellar bristle & mechanosensory neuron (with Dscam^ΔR272) (Chen et al., 2006) posterior scutellar bristle & mechanosensory neuron \| somatic clone (Chen et al., 2006) presumptive embryonic/larval central nervous system (with Dscam²³) (Hattori et al., 2007)
Detailed Description
	Statement Reference Dscam[21] homozygous mutant third instar larvae show a mild but statistically significant increase in the proportion of dorsal midline ddaC dendrite length that is enclosed within the epidermis rather than attached to the ECM. The enclosed dendrite segments are often in the middle of stabilized dendritic branches. Most of the dendritic crossings seen in these mutants are between two dendrites that both contact the ECM and thus the dendrites are making contact. (Han et al., 2012) Less than 25% of Dscam²¹/Dscam²³ larvae 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. (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. 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) Dscam²¹ posterior Dorsocentral (pDc), anterior Scutellar (aSc) and posterior Scutellar (pSc) neuron clones enter the thoracic ganglion at the correct position but are unable to correctly target axonal branches and fail to elaborate any arbors. These neurons are able to form axonal branches but these remain clustered in a small bolus around a presumptive decision point. This phenotype is 100% penetrant for all tested neuron clones. (Chen et al., 2006) Small clones of Dscam²¹ cells induced in the mushroom body at the early third instar and then examined 24-36 hours later are seen as multiple fascicles in 15% of cases (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 the branches fail to segregate dorsally and medially in 68% of cases. (Zhan et al., 2004) Dscam²¹ mutant antennal olfactory receptor neurons often form discrete dense aggregates when they terminate in the glomeruli (in contrast to wild type, where the axons elaborate processes that extend throughout the glomeruli). Or47a-expressing olfactory receptor neurons (ORNs) that are mutant for Dscam²¹ show marked mis-targeting of axons in the antennal lobe, often failing to project to the normal target (glomerulus DM3) and instead innervating abnormal locations on the ipsilateral side. P{GAL4}GH298-expressing ORNs that are mutant for Dscam²¹ often fail to project to their normal target (the V glomerulus), innervating abnormal locations on the ipsilateral side. In 20% of cases none of the mutant fibres innervate the correct target. Single Dscam²¹ mutant Or47a-expressing ORNs exit the antennal nerve and often terminate in abnormal locations between glomeruli. Mutant terminals that do reach the appropriate glomerulus fail to elaborate the network of thin arbors characteristic of wild-type terminals. Single Dscam²¹ mutant P{GAL4}GH298-expressing ORNs show both ectopic targeting and defects in the morphology of terminals within the V glomerulus. Or22a-expressing and Or23a-expressing Dscam²¹ mutant ORNs target normally to the correct glomerulus, although they show a marked reduction in branches to the contralateral antennal lobe. Or47b-expressing Dscam²¹ 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 Dscam²¹ 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. (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/Dscam²¹ 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) Dscam²¹ is partially rescued by Dscam^{1.30.30.2.A.Scer\UAS}/Scer\GAL4^elav.PLu (Chen et al., 2006) Dscam²¹ is partially rescued by Dscam^{1.34.30.2.Scer\UAS}/Scer\GAL4^elav.PLu (Chen et al., 2006) Dscam²¹ is partially rescued by Dscam^{7.6.19.2.Scer\UAS}/Scer\GAL4^elav.PLu (Chen et al., 2006)
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	Expression of transgenes that encode different isoforms of Dscam, under the control of Scer\GAL4^elav.PLu, partially rescue the axonal targeting phenotype of Dscam²¹ mechanosensory clones. Both the Dscam^{1.34.30.2.Scer\UAS} and Dscam^{7.6.19.2.Scer\UAS} transgenes rescue primary axon extension posteriorly. Occasionally, Dscam^{1.30.30.2.A.Scer\UAS} rescues the proximal, anterior-extending secondary axonal branch and a distal ipsilateral branch. (Chen et al., 2006)
Stocks ( 0 )

Notes on Origin
Discoverer

External Crossreferences & Linkouts
Other Crossreferences

Linkouts

Synonyms & Secondary IDs ( 2 )
Reported As
Symbol Synonym	DScam²¹ (Venken, 2006) Dscam²¹ (Chen et al., 2006, Hattori et al., 2007, Zhan et al., 2004, Wang et al., 2004, Matthews et al., 2007, Venken et al., 2009, Han et al., 2012)
Name Synonym
Secondary FlyBase IDs

References ( 9 )
Research paper	Han et al., 2012, Neuron 73(1): 64--78 Integrins Regulate Repulsion-Mediated Dendritic Patterning of Drosophila Sensory Neurons by Restricting Dendrites in a 2D Space. [FBrf0217239] 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] Chen et al., 2006, Cell 125(3): 607--620 The molecular diversity of Dscam is functionally required for neuronal wiring specificity in Drosophila. [FBrf0189904] 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] Venken, 2006, Science 314(5806): Supporting Online Material. [FBrf0199318]

Allele Dmel\Dscam21

Allele Dmel\Dscam²¹