Allele Dmel\asl²

General Information
Symbol	Dmel\asl²	Species	D. melanogaster
Name		FlyBase ID	FBal0093161
Feature type	allele	Associated gene	Dmel\asl

Allele class
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.
Update Feed	Click the icon below to subscribe to this FlyBase record and receive updates automatically through your feed reader.
FB2013_03
FB2013_02
All updates	Click here to see a list of all updates to this record from FB2010_08 and on.
Nature of the Allele
Allele class
Mutagen	ethyl methanesulfonate (Bonaccorsi et al., 1998)
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 No lesion detected in the asl transcription unit. (Varmark et al., 2007)
Cytology
Phenotypic Data
Phenotypic Class
	lethal (with asl³) (Bonaccorsi et al., 2000, Bonaccorsi et al., 1998) lethal \| recessive (Bonaccorsi et al., 2000, Bonaccorsi et al., 1998) viable (with asl¹) (Bonaccorsi et al., 1998)
Phenotype Manifest In
	anaphase & condensed nuclear chromosome (Giansanti et al., 2001) anaphase & condensed nuclear chromosome (with asl³) (Giansanti et al., 2001) aster (Bonaccorsi et al., 2007) centrosome (Giansanti et al., 2001) centrosome (with asl³) (Giansanti et al., 2001) larval brain & ganglion mother cell (Bonaccorsi et al., 2000) larval brain & ganglion mother cell (with asl³) (Bonaccorsi et al., 2000) larval brain & ganglion mother cell & aster (Bonaccorsi et al., 2000) larval brain & ganglion mother cell & aster (with asl³) (Bonaccorsi et al., 2000) larval brain & ganglion mother cell & centrosome (Bonaccorsi et al., 2000) larval brain & ganglion mother cell & centrosome (with asl³) (Bonaccorsi et al., 2000) larval brain & neuroblast (Bonaccorsi et al., 2000) larval brain & neuroblast (with asl³) (Bonaccorsi et al., 2000) larval brain & neuroblast & aster (Bonaccorsi et al., 2000, Wakefield et al., 2001) larval brain & neuroblast & aster (with asl³) (Bonaccorsi et al., 2000) larval brain & neuroblast & centrosome (Bonaccorsi et al., 2000, Wakefield et al., 2001) larval brain & neuroblast & centrosome (with asl³) (Bonaccorsi et al., 2000) microtubule (Giansanti et al., 2001) microtubule (with asl³) (Giansanti et al., 2001) microtubule basal body & spermatocyte (with Df(3R)ED5177) (Blachon et al., 2008) mitosis & nuclear chromosome (Giansanti et al., 2001) mitosis & nuclear chromosome (with asl³) (Giansanti et al., 2001) neuroblast & nucleus (Giansanti et al., 2001) neuroblast & nucleus (with asl³) (Giansanti et al., 2001) spermatocyte & aster (Bonaccorsi et al., 1998) spermatocyte & aster (with asl¹) (Bonaccorsi et al., 1998) spermatocyte & aster (with asl³) (Bonaccorsi et al., 1998)
Detailed Description
	Statement Reference asl[2]/Df(3R)ED5177 spermatocytes completely lack basal bodies. (Blachon et al., 2008) The anastral mitotic spindles have a microtubule density similar to that of wild type in asl² larval brains. The spindles of mutant ganglion mother cells are morphologically indistinguishable from wild type. The average length of ganglion mother cell and neuroblast spindles in homozygous larval brains is similar to that of wild type. (Bonaccorsi et al., 2007) Mutant neuroblasts show robust chromatin-mediated microtubule nucleation and spindle assembly producing fairly normal spindles during mitosis. Spindles poles emerge from a disorganised microtubule array near the chromosomes that focusses as the spindle lengthens. Spindles do not rotate during formation, always forming along the initial pole separation axis, but do rotate during metaphase. Consecutive divisions in the mutants usually produce adjacent or near-adjacent daughters, as in wild type. In a few cases, spindles form parallel to the ganglion mother cell cap, these neuroblasts divide symmetrically. (Rusan and Peifer, 2007) The mitotic index and frequencies of metaphase and anaphase figures in homozygous and asl²/asl³ larval brains is comparable to wild type. 4-5% of anaphases have lagging chromosomes. A small fraction of metaphases appear to be polyploid; 5-6% hyperploid and 2.6-2.8% tetraploid metaphases are seen. Homozygous and asl²/asl³ larval neuroblasts lack functional centrosomes and are completely devoid of astral microtubules. However, they form central spindles that are indistinguishable from wild type. The central spindle is tightly associated with the nascent ganglion mother cell nucleus, which is in turn closely apposed to the polar cortex, as occurs in wild-type cells. However, wild-type and mutant telophases differ in the positioning of the neuroblast (NB) nucleus; in wild-type, the NB nucleus lies very close to the central spindle but is separated from the polar cortex by a large astral array of microtubules, however the situation is reversed in mutant telophases; the NB nucleus is usually disconnected from the central spindle and located much closer to the polar cortex than in wild type. (Giansanti et al., 2001) Neuroblasts in mutant larval brains lack functional centrosomes and astral microtubules, but have well-focused spindle poles. In homozygous testes, telophases show a morphologically normal central spindle and cytokinesis occurs normally. (Wakefield et al., 2001) Lethality acts at the larval/pupal boundary. Prophase neuroblasts are completely devoid of centrosomes and asters, however a bipolar spindle does form and generates a normal central spindle in anaphase. Chromosome segregation and cytokinesis appear to be normal. Mitosis in GMCs reveals an absence of centrosomes and prophase asters. (Bonaccorsi et al., 2000) Homozygotes and asl²/asl³ larvae die at the larval/pupal boundary. asl²/asl¹ animals are viable. Homozygous, asl²/asl¹ and asl²/asl³ spermatocytes are completely devoid of asters. (Bonaccorsi et al., 1998)
External Data
Linkouts
Interactions
	Show the genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Phenotype Manifest In
Enhancer of
Statement Reference asl² is an enhancer of meiotic telophase II & spindle phenotype of asp¹ (Wakefield et al., 2001)
Additional Comments
Genetic Interactions
Statement Reference The microtubule density of mitotic spindles in lkb1³¹⁵ asl² double mutant larval brains is similar to that seen in lkb1³¹⁵ single mutants. (Bonaccorsi et al., 2007) The microtubule minus ends of asl² asp¹ double mutant larval brain neuroblasts are splayed at metaphase and fail to converge into focused spindle poles. (Wakefield et al., 2001)
Xenogenetic Interactions
Statement Reference
Complementation & Rescue Data
Fails to complement	asl¹ (Bonaccorsi et al., 1998) asl³ (Bonaccorsi et al., 2000)
Comments	Fails to complement asl¹ for male and female sterility and aberrant spermatid phenotype. (Bonaccorsi et al., 1998)
Stocks ( 0 )

Notes on Origin
Discoverer

External Crossreferences & Linkouts
Other Crossreferences

Linkouts

Synonyms & Secondary IDs ( 1 )
Reported As
Symbol Synonym	asl² (Varmark et al., 2007, Bonaccorsi et al., 2007, Rusan and Peifer, 2007, Blachon et al., 2008)
Name Synonym
Secondary FlyBase IDs

References ( 9 )
Research paper	Blachon et al., 2008, Genetics 180(4): 2081--2094 Drosophila asterless and vertebrate Cep152 Are orthologs essential for centriole duplication. [FBrf0207122] Giansanti et al., 2008, Curr. Biol. 18(4): 303--309 Drosophila SPD-2 is an essential centriole component required for PCM recruitment and astral-microtubule nucleation. [FBrf0203058] Bonaccorsi et al., 2007, Development 134(11): 2183--2193 The Drosophila Lkb1 kinase is required for spindle formation and asymmetric neuroblast division. [FBrf0201104] Rusan and Peifer, 2007, J. Cell Biol. 177(1): 13--20 A role for a novel centrosome cycle in asymmetric cell division. [FBrf0201849] Varmark et al., 2007, Curr. Biol. 17(20): 1735--1745 Asterless is a centriolar protein required for centrosome function and embryo development in Drosophila. [FBrf0201492] Giansanti et al., 2001, Development 128(7): 1137--1145 The role of centrosomes and astral microtubules during asymmetric division of Drosophila neuroblasts. [FBrf0134560] Wakefield et al., 2001, J. Cell Biol. 153(4): 637--648 The Drosophila protein asp is involved in microtubule organization during spindle formation and cytokinesis. [FBrf0135841] Bonaccorsi et al., 2000, Nat. Cell Biol. 2(1): 54--56 Spindle assembly in Drosophila neuroblasts and ganglion mother cells. [FBrf0122970] Bonaccorsi et al., 1998, J. Cell Biol. 142(3): 751--761 Spindle self-organization and cytokinesis during male meiosis in asterless mutants of Drosophila melanogaster. [FBrf0104411]

Allele Dmel\asl2

Allele Dmel\asl²