dynamin, Dyn, shibere
temperature-
sensitive period developmental phenotype
_________________________________________________________________________
1.5-3 hr loss of pole cells
3-4 hr fusion of cell membranes leading
to syncytium
5-12 hr disorganized proliferation of cells
leading to transplantable tumorous
masses
late third instar stubby legs; joints missing;
12 hr heat pulse clipped wings
48 hr before pupariation eye scar (loss of pigment cells
and cone cells). The later the
heat pulse, the more anterior the
position of the scar on eye
pupariation to pupation animals die and fail to undergo
pupation
14-24 hr after pupariation supernumerary microchaetae on head
and thorax; the temperature sensitive
period for each bristle site precedes
the final cell division of bristle
precursor; loss of macrochaetae on
head and thorax. Disruption of giant-
fiber pathway development (Hummon and
Costello, 1987, J. Neurosci. 7: 3633-38).
Reduced numbers of dorsal-longitudinal
flight muscles (Hummon and Costello,
1988, Roux's Arch. Dev. Biol.
197: 383-93)
24-36 hr after pupariation loss of head and thoracic micro-
chaetae; supernumerary abdominal
macrochaetae and microchaetae
28-42 hr after pupariation loss of abdominal macrochaetae
and microchaetae
32-48 hr after pupariation loss of abdominal microchaetae
48 hr after pupariation scimitar-shaped bristles
adult eggs fail to mature
GTPase involved in scission of clathrin-coated vesicles at the synapse and other sites of vesicle invagination - dynamin-mediated endocytosis is required for tube closure, cell intercalation, and biased apical expansion during epithelial tubulogenesis in the Drosophila ovary
Please see the JBrowse view of Dmel\shi for information on other features
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Gene model reviewed during 5.52
Tissue-specific extension of 3' UTRs observed during later stages (FBrf0218523, FBrf0219848); all variants may not be annotated.
Gene model reviewed during 5.46
Annotated transcripts do not represent all supported alternative splices within 5' UTR.
Annotated transcripts do not represent all possible combinations of alternative exons and/or alternative promoters.
Low-frequency RNA-Seq exon junction(s) not annotated.
Gene model reviewed during 5.50
Gene model reviewed during 5.55
5.1, 4.3 (northern blot)
3.3 (unknown)
883, 836 (aa); 100 (kD observed)
883, 836 (aa)
A form of shi protein which localizes
predominantly to the head. This form includes 6aa inserted at the first
alternate splice site (Alt1) that are absent in the "body" form of the
protein.
A form of shi protein which localizes
predominantly to the body. This form lacks 6aa inserted at the first
alternate splice site (Alt1) that are present in the "head" form of the
protein. An antibody to shi was generated in mouse that reacts primarily
with the body form of shi protein. This difference supports the
existence of different brain and body forms but the differential
immunoreactivity could not be completely explained by the splicing
variants identified here.
alternative 3' exon
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\shi using the Feature Mapper tool.
shi protein is found in the presynaptic membrane in neuromuscular junctions in wandering third instar larvae.
GBrowse - Visual display of RNA-Seq signals
View Dmel\shi in GBrowse 21-52
Please Note FlyBase no longer curates genomic clone accessions so this list may not be complete
Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see GBrowse for alignment of the cDNAs and ESTs to the gene model.
For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.
monoclonal
polyclonal
Source for merge of: shi CG18102
Source for merge of: shi anon-WO0153538.12 anon-WO0153538.13 anon-WO0153538.14
Source for merge of shi anon-WO0153538.12 anon-WO0153538.13 anon-WO0153538.14 was sequence comparison ( date:051113 ).
shi is required to coordinate recruitment of Clathrin and AP2 during synaptic vesicle formation.
dsRNA made from templates generated with primers directed against this gene tested in RNAi screen for effects on Kc167 and S2R+ cell morphology.
RNAi screen using dsRNA made from templates generated with primers directed against this gene causes a phenotype when assayed in Kc167 and S2R+ cells: binucleate cells.
A P{UAS-shits1.K} transgene has been used to show that synaptic transmission from mushroom body neurons is required during memory retrieval but not during acquisition or storage.
shi has a role in maintaining normal heart function.
shi mutants have been used to show that there are two functionally and topographically distinct pools of synaptic vesicles, exo/endo cycling and reserve pools.
Fluorescent Ca-sensitive dye, Ca Crimson, is used to monitor presynaptic Ca dynamics.
In presynaptic terminals α-Adaptin defines a network-like membrane structure to which the GTPase dynamin is recruited. α-Adaptin is necessary for the formation of clathrin coated pits and participates in the dynamin-dependent release of coated vesicles from the membrane surface. Results suggest an α-Adaptin-dependent control of the vesicle cycle that maintains the balance between the amount of vesicle- and surface-associated membranes.
Overexpression of different constitutively active forms of N in shi mutant flies indicates that shi function is not necessary for transduction of the signal downstream of N, even when the receptor, N, is integrated in the plasma membrane. When wild-type N is activated by its ligand Dl, shi is required in both signaling and receiving cells for normal singling out of precursors.
The two isoforms of dynamin detected in wild type and shi mutants are associated with two different pellet fractions of head homogenates. At least one isoform is membrane-associated. Normal distribution of dynamin is not affected by heat shock, block of the GTP cycle or the presence of stabilised microtubules in wild type or shi mutants. Results suggest the two isoforms are likely to be involved in separate cellular compartments rather than different functional states in the same membrane-cycling pathway.
Recycling of synaptic vesicle proteins is blocked in temperature sensitive mutants of shi. Similar inhibition of dye uptake is also seen. Vesicle recycling after the block can occur in the absence of extracellular calcium. BWSV induces calcium-independent exocytosis at nerve terminals. It is most likely that calcium is required for the endocytic recycling of synaptic vesicles.
shi gene product is thought to provide the motor for vesicular transport during endocytosis.
Expression of shi is particularly high in CNS and PNS throughout neuronal development.
The shi locus encodes Drosophila dynamin.
shi has been cloned and sequenced.
Studies of the neuromuscular junctions of heat-treated shi1 flies indicate that paralysis is associated with loss of synaptic vesicles. Examination of the neurogenic region of the embryos reveals numerous packets of extracellular vesicles and coated pits blocked in endocytosis.
The shibire locus is characterized by its temperature-sensitive alleles, which are reversibly paralyzed by exposure to 29oC, but are essentially normal at 22oC (Grigliatti, Hall, Rosenbluth and Suzuki, 1973). Exposure of developing animals to the restrictive temperature for pulses of one to several hours leads to a plethora of developmental defects, which are specific for the stage treated (Poodry, Hall and Suzuki, 1973) (see shi1 allele record. Short exposures to restrictive temperatures at the time of delamination of the neuroblasts from the neurogenic ectoderm leads to excess neurogenesis at the expense of epidermogenesis, as seen in the neurogenic mutants (Poodry, 1990). Differentiation of myoblasts and neuroblasts is inhibited in shi1 embryonic cells in vitro at 30oC (Buzin, Dewhurst and Seecof, 1978). Embryonic neurons cultured at 30oC show reduced adhesion to the substrate, retardation of growth cone formation and suppressed neuron formation and elongation; reversed by shift to permissive temperature (Kim and Wu, 1987). Lethal embryos disorganized by the restrictive temperature can be cultured in vivo as tumorous masses (Poodry). Eye-antenna discs can also be cultured as tumorous masses for several transfer generations (Williams, 1981). Primary in vivo culture of cut leg imaginal discs leads to an exceptionally high rate of transdetermination (Poodry). The temperature-sensitive alleles differ in the severity of their paralysis, recovery period, the restrictive temperature for developmental effects and in their viability as hemizygotes. They are all hypomorphs, being recessive and having a more extreme expression in combination with a deficiency than when homozygous. A wild-type paternal gene can rescue an egg from a homozygous mother only after 10 hr of development (Swanson and Poodry, 1976). Of the developmental effects tested, all are autonomous in mosaics generated by somatic recombination or in gynandromorphs (Poodry). The developmental effects on bristles is not enhanced or suppressed by the presence of temperature-sensitive alleles of N; shi is epistatic to N (Lujan, 1981). Physiological studies of shi have revealed the loss of transients in electroretinograms (Kelley and Suzuki, 1974) and failure of neuromuscular transmission at the restrictive temperature (Ikeda, Ozawa and Hagiwara, 1976; Siddiqi and Benzer, 1976), though axonal conduction and muscle membrane excitability are unimpaired (Ikeda, Ozawa and Hagiwara, 1976). Exposure of shi1 adults to 29oC causes the depletion of synaptic vesicles from the neuromuscular synapse and their replacement with large cisternae (Poodry and Edgar, 1979; Koenig, Saito and Ikeda, 1983). Accumulation of acetyl choline is reduced at the restrictive temperature, not because of reduced synthesis but because of an abnormally rapid rate of release from the cell, which is not reduced by inhibiting tetrodotoxin-sensitive nerve activity (Wu, Merneking and Barker, 1983). Endocytosis is reversibly blocked in the nerve terminus (Kosaka and Ikeda, 1983a; Masur, Kim and Wu, 1990) and may limit the ability of nerves to regenerate synaptic vesicles. Neuromuscular transmission temperature is sensitive in mosaics in which the neuron but not the muscle is mutant, but not in the converse situation (Koenig and Ikeda, 1983b). During recovery from exposure to 30oC shi1 muscles display a multimodal distribution of miniature excitatory junction potential amplitudes never seen in wild type (Ikeda and Koenig, 1987). Further, as the temperature is increased the amplitude of evoked excitatory junction potentials decreases; the numbers of vesicles per synapse displays a correlated decrease (Koenig, Kosaka and Ikeda, 1989). Endocytosis is also blocked in the garland cells (Kosaka and Ikeda, 1983a). Vesiculation of cell membranes results in fusion of blastoderm cells (Swanson and Poodry, 1981) and vesiculation of surface membranes accompanies secretion of protein epicuticle (Poodry).
Grigliatti, 1971.
"shibire" means "paralysed" in Japanese.
