Allele Dmel\Sgt1^c01268

General Information
Symbol	Dmel\Sgt1^c01268	Species	D. melanogaster
Name		FlyBase ID	FBal0184573
Feature type	allele	Associated gene	Dmel\Sgt1

Map ( GBrowse )	Untitled Document
Allele class
Mutagen	piggyBac transposase
Recent Updates
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FB2013_03
FB2013_02
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Nature of the Allele
Allele class
Mutagen	piggyBac transposase (Gene Disruption Project members and Exelixis, 2005)
Mutations Mapped to the Genome

Type Location Additional Notes References transposable element insertion site 3R:4,130,925..4,130,925 (Gene Disruption Project members and Exelixis, 2005, Martins et al., 2009)
Associated Sequence Data
DDBJ / EMBL / GenBank	DNA sequence Protein sequence Name

UniProtKB/Swiss-Prot
UniProtKB/TrEMBL

Progenitor genotype
Nature of the lesion	Statement Reference Insertion at nucleotide +55 of the transcription unit, which is upstream of the initiator ATG codon. (Martins et al., 2009)
Caused by insertion	PBac{PB}Sgt1^c01268 (Gene Disruption Project members and Exelixis, 2005, Martins et al., 2009)
Cytology
Phenotypic Data
Phenotypic Class
	lethal (with Df(3R)CA3) (Martins et al., 2009) lethal \| recessive (Martins et al., 2009) mitotic cell cycle defective \| third instar larval stage (Martins et al., 2009)
Phenotype Manifest In
	centriole (Martins et al., 2009) centrosome (Martins et al., 2009) neuroblast (Martins et al., 2009) spindle (Martins et al., 2009)
Detailed Description
	Statement Reference Third larval instar Sgt1[c01268] neuroblasts have abnormal mitotic phenotypes, including a high proportion of prometaphases with hypercondensed chromosomes and anaphases with lagging chromatids. Sgt1[c01268] has no overall effect upon mitotic index. There is a significant reduction in the frequency of prophases, a severe increase in the frequency of prometaphases and a reduction of cells exiting mitosis compared to control cells. Compared to controls, many fewer mutant neuroblasts incorporate BrdU. Treatment of Sgt1[c01268] neuroblasts with colchicine does not lead to the accumulation of cells in mitosis, in contrast to control cells. 22% of Sgt1[c01268] neuroblasts have monopolar spindles, with either a dispersed or well-focused centrosome at the centre. 30% of cells have just one centrosome and 20% have a diffuse centrosome. When Sgt1[c01268] larval neuroblasts are observed in primary culture, the following mitotic behaviours are observed; 55% enter mitosis with no apparent microtubule-organizing centre (MTOC), but after nuclear envelope breakdown (NEBD) are able to form a microtubule array that grows out from the kinetochores, they are unable to focus at the spindle poles and mitotic progression is delayed in prometaphase for more than 1 hours. 15% of the cells enter mitosis with a single MTOC, form a bipolar spindle and reach metaphase with a short delay but eventually exit mitosis with a significant delay (35 minutes after NEBD). 5% of the cells enter mitosis with more than two MTOCs, fail to organise a proper bipolar spindle and consequently fail to congress the chromosomes and arrest for long periods. 25% of the mutant neuroblasts enter mitosis with two MTOCs (as occurs in wild type). Only 40% of Sgt1[c01268] neuroblasts have a normal set of centriole pairs, approximately 40% have more than two centriole pairs and some cells have less than two centriole pairs. There is a clear correlation between increase in centriole number and increase in ploidy in the mutant cells. (Martins et al., 2009)
External Data
Linkouts
Interactions
	Show the genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Suppressed by
Statement Reference Sgt1^c01268 has mitotic cell cycle defective \| third instar larval stage phenotype, suppressible \| partially by polo^{Scer\UAS.P\T.cMa}/Scer\GAL4^da.G32 (Martins et al., 2009)
Other
Statement Reference Bub3¹, Sgt1^c01268 has mitotic cell cycle defective phenotype (Martins et al., 2009)
Phenotype Manifest In
Suppressed by
Statement Reference Sgt1^c01268 has centrosome phenotype, suppressible \| partially by polo^{Scer\UAS.P\T.cMa}/Scer\GAL4^da.G32 (Martins et al., 2009) Sgt1^c01268 has neuroblast phenotype, suppressible \| partially by polo^{Scer\UAS.P\T.cMa}/Scer\GAL4^da.G32 (Martins et al., 2009) Sgt1^c01268 has spindle phenotype, suppressible \| partially by polo^{Scer\UAS.P\T.cMa}/Scer\GAL4^da.G32 (Martins et al., 2009)
Additional Comments
Genetic Interactions
Statement Reference Sgt1[c01268] ; Bub3[1] double mutant larval brain neuroblasts have a very low mitotic index. Compared to Sgt1[c01268] single mutant cells, the Sgt1[c01268] ; Bub3[1] double mutant cells enter mitosis more readily, do not accumulate in prometaphase and exit mitosis more frequently (as shown by the increase in anaphase and telophase figures). The double mutant cells do not show chromosome hypercondensation. Expression of polo[Scer\UAS.P\T.cMa] under the control of Scer\GAL4[da.G32] significantly rescues the mutant phenotypes of Sgt1[c01268] larval brain neuroblasts; there is an increase in cells with a normal number of centrosomes and a normal bipolar spindle and the cells show mostly normal mitotic progression. (Martins et al., 2009)
Xenogenetic Interactions
Statement Reference
Complementation & Rescue Data
Comments
Stocks ( 1 )
Harvard	- PBac{PB}Sgt1^c01268
Notes on Origin
Discoverer

Comments
	Precise excision of the insertion results in a full restoration of viability. (Martins et al., 2009)
External Crossreferences & Linkouts
Other Crossreferences

Linkouts

Synonyms & Secondary IDs ( 3 )
Reported As
Symbol Synonym	CG9617^c01268 Sgt1^c01268 sgt1^P1 (Martins et al., 2009)
Name Synonym
Secondary FlyBase IDs

References ( 2 )
Research paper	Martins et al., 2009, EMBO J. 28(3): 234--247 Sgt1, a co-chaperone of Hsp90 stabilizes Polo and is required for centrosome organization. [FBrf0207175]
Personal communication to FlyBase	Gene Disruption Project members and Exelixis, 2005, Genomic mapping of Exelixis insertion collection. (Computer file) Genomic mapping of Exelixis insertion collection. (Computer file) [FBrf0184340]

Allele Dmel\Sgt1c01268

Allele Dmel\Sgt1^c01268