Papers by Teiichi Tanimura
Communications Biology, 2019
Animals need to detect in the food essential amino acids that they cannot synthesize. We found th... more Animals need to detect in the food essential amino acids that they cannot synthesize. We found that the odorant binding protein OBP19b, which is highly expressed in Drosophila melanogaster taste sensilla, is necessary for the detection of several amino acids including the essential l-phenylalanine. The recombinant OBP19b protein was produced and characterized for its binding properties: it stereoselectively binds to several amino acids. Using a feeding-choice assay, we found that OBP19b is necessary for detecting l-phenylalanine and l-glutamine, but not l-alanine or D-phenylalanine. We mapped the cells expressing OBP19b and compared the electrophysiological responses of a single taste sensillum to several amino acids: OBP19b mutant flies showed a reduced response compared to control flies when tested to preferred amino acids, but not to the other ones. OBP19b is well conserved in phylogenetically distant species suggesting that this protein is necessary for detection of specific ami...
Medical Entomology and Zoology, 1999
Frontiers in Behavioral Neuroscience, 2018
Journal of Experimental Zoology, 1986
Drosophila mutants with defects in their proboscis extension reflex (PER) were isolated for a gen... more Drosophila mutants with defects in their proboscis extension reflex (PER) were isolated for a genetic dissection of the PER system. Five mutant strains were screened from 35,000 mutagenized flies through a twostep screening: a mass test of sugar intake, followed by an individual PER test. Mutants were classified into three complementation groups: aperA (genetical map position, 1-22.11, aperB (1-0.6) and aperC (1-0.4). The aperA mutants showed incomplete penetrance and expressivity. Some flies did not extend their proboscises at all, while others did so only to either the right or the left side; the PERs of the rest were apparently normal. The aperB mutants showed abnormality in the direction of the PER: they extended their proboscises backward, instead of straight forward. The aperB mutation was temperaturesensitive and its phenotype was expressed at a culture temperature above 25°C. The aperC mutation caused a PER defect in aged flies. Within 2 days of eclosion they showed normal PER, but 2 or more days after eclosion most of them had become unable to extend their proboscises. Later, about half of the aperC mutants recovered the PER ability. The anatomical site of action of these mutations seems to be in the neuromuscular or skeletomuscular system. Address reprint requests to Ken-ichi Kimura, Zoological Institute,
Development of PDF‐immunoreactive cells, possible clock neurons, in the housefly Musca domestica
Microscopy Research and Technique, 2003
Even though the housefly Musca domestica shows clear circadian rhythms in its behavioural and phy... more Even though the housefly Musca domestica shows clear circadian rhythms in its behavioural and physiological processes, a circadian pacemaker system controlling these rhythms has not yet been described morphologically in this species. In M. domestica, neurons immunoreactive to pigment‐dispersing factor (PDF), a neurotransmitter/neuromodulator of circadian information arising from a circadian clock and transmitted to target cells, are similar in their number and distribution to the PDF neurons of Drosophila melanogaster. In D. melanogaster these neurons co‐localize PER protein and have been identified as clock neurons in that species. Here we report PDF‐immunoreactive cells in the housefly's brain during postembryonic development in the larval and pupal stages, as well as in the adult fly soon after eclosion. In the housefly's brain, there are three groups of PDF‐immunoreactive neurons: two groups with small (sPDFMe) and large (lPDFMe) cell bodies in the proximal medulla of th...
Suppression of inherited muscle degeneration in a Drosophila mutant by mechanical and genetical immobilizations
Journal of Neurogenetics, 1987
The aperC (abnormal proboscis extension reflex C) mutation of Drosophila causes the degeneration ... more The aperC (abnormal proboscis extension reflex C) mutation of Drosophila causes the degeneration of a particular pair of head muscles involved in the proboscis extension. To define the mechanisms underlying the muscle degeneration, we studied the influence of use or disuse on the muscle degeneration by two kinds of immobilization experiments. In the first experiment, the rostrum was fixed onto the cranium and the extension of the proboscis was mechanically prevented. In the second experiment, we created an aperC aperA double mutant, genetically preventing proboscis extension with the aperA mutation. Both immobilizations suppressed the muscle degeneration in aperC mutant flies.
Mutants with Delayed Cell Death of the Ptilinal Head Muscles in Drosophila
Journal of Neurogenetics, 1992
The emergence of adult Drosophila melanogaster from the puparium is followed by the programmed de... more The emergence of adult Drosophila melanogaster from the puparium is followed by the programmed degeneration of a number of muscle groups. We have isolated two X-linked mutants that delay the programmed death of at least some of these muscles. During eclosion, the fly makes use of a membranous sac, the ptilinum, which is later retracted into the head capsule. Six of the eight sets of muscles involved in the retraction then undergo degeneration. The muscle fibers initially show a gradual atrophy and then degenerate rapidly through fragmentation followed by absorption. In wild-type flies, this degeneration is obvious by 12 h after eclosion due to the loss of the birefringence of the muscles. Through mutagenesis with ethyl methanesulfonate, we isolated four mutants whose birefringence of the doomed muscles was retained even at 12 h. Mutants were genetically classified into two complementation groups; mcd-1 and mcd-2 (mcd: muscle cell death). The muscles of the mcd-1 mutants degenerate more slowly than that of the wild-type flies; the fibers enter the fragmentation step but are then not rapidly absorbed. In the mcd-2 mutants, the fibers atrophy more slowly than that in the wild-type flies and fail to undergo fragmentation. The difference in the process of the muscle death between the mcd-1 and the mcd-2 mutants suggests that at least two genes act on different steps in the process of muscle cell death.
Neurohormonal control of the mating interval in the male cricket, Gryllus bimaculatus DeGeer
Journal of Comparative Physiology A, 1991
... Discussion Spermatophore protrusion (SP) is followed by courtship stridulation (CS) after a f... more ... Discussion Spermatophore protrusion (SP) is followed by courtship stridulation (CS) after a fixed period (PSPS). ... Neuroscience 3:851-860 Breen CA, Atwood HL (1983) Octopamine-a neurohormone with presynaptic activity-dependent effects at crayfish neuromuscular junctions. ...
GETDB, a database compiling expression patterns and molecular locations of a collection of gal4 enhancer traps
genesis, 2002
Regulatory genes important for development and physi-ology are often transcribed in tissue-and te... more Regulatory genes important for development and physi-ology are often transcribed in tissue-and temporary-specific manners. Differential gene expression is there-fore an important aspect of genome function in multicellular organisms. Transcriptional enhancers are often ...
Temperature cycles driveDrosophilacircadian oscillation in constant light that otherwise induces behavioural arrhythmicity
European Journal of Neuroscience, 2005
The fruit fly, Drosophila melanogaster, shows a clear circadian locomotor rhythm in light cycles ... more The fruit fly, Drosophila melanogaster, shows a clear circadian locomotor rhythm in light cycles and constant darkness. Although the rhythm disappears in constant light, we found that temperature cycles drive the circadian rhythm both in locomotor activity and molecular abundance of PERIOD (PER) and TIMELESS (TIM). The thermoperiodically induced locomotor rhythm entailed an anticipatory activity at the late thermophase, which required several transient cycles to establish a steady-state entrainment, suggesting that the rhythm is endogenous and driven by a circadian clock. Western blot analysis revealed that PER and TIM increased during the cryophase, peaking at the middle to late cryophase. PER was also cyclically expressed under the temperature cycle in the known per-expressing neurons, i.e. so-called lateral (LNs) and dorsal neurons (DNs), and two pairs of cells (LPNs) that were located in the lateral posterior protocerebrum. It is thus suggested that the temperature cycle induces the cycling of PER and TIM either by blocking somewhere in the photic entrainment pathway during the cryophase or temporally activating their translation to sufficient protein levels to drive a circadian oscillation. In flies lacking pigment-dispersing factor (PDF) or PDF-expressing cells, the anticipatory activity was relatively dispersed. disco(2) mutant flies lacking the lateral neurons still showed an anticipatory activity, but with dispersed activity. These behavioural results suggest that not only LNs but also DNs and LPNs can, at least, partially participate in regulating the thermoperiodically induced rhythm.
Genetic approaches to the taste receptor mechanisms
Chemical Senses, 1987
Distribution of biogenic amines in the cricket central nervous system
Analytical Biochemistry, 1988
The distribution of biogenic amines, their precursors, and metabolites in the central nervous sys... more The distribution of biogenic amines, their precursors, and metabolites in the central nervous system (CNS) of the cricket was determined using HPLC with electrochemical detection. Three biogenic amines, octopamine (OA), dopamine (DA), and 5-hydroxytryptamine (5-HT); two precursors, tyramine and tryptophan; and two metabolites, synephrine and 5-hydroxyindole-3-acetic acid, were detected in all ganglia. In the brain, 5-HT occurred in the largest quantities followed by OA, while in other ganglia OA occurred in the largest quantities followed by 5-HT and DA. In all ganglia, the amount of OA was two to nine times greater than that of DA. The results are discussed in comparison with different insect species.
The Journal of general physiology, 1988
When the fruitfly, Drosophila melanogaster, was reared on media deficient in carotenoids and reti... more When the fruitfly, Drosophila melanogaster, was reared on media deficient in carotenoids and retinoids, the level of 3-hydroxyretinal (the chromophore of fly rhodopsin) in the retina decreased to less than 1% compared with normal flies. The level of 3-hydroxyretinal increased markedly in flies that were given a diet supplemented with retinoids or carotenoids. The retinas of flies fed on all-trans retinoids and maintained in the dark predominantly contained the all-trans form of 3-hydroxyretinal, and showed no increase in the level of either the 11-cis isomer or the visual pigment. Subsequent illumination of the flies converted substantial amounts of all-trans 3-hydroxyretinal to its 11-cis isomer. The action spectrum of the conversion by illumination showed the optimum wavelength to be approximately 420 nm, which is significantly greater than the absorption maximum of free, all-trans 3-hydroxyretinal. Flies that were fed on carotenoids showed a rapid increase of the levels of 11-cis...
The role of the peptide PAP coded in pdf gene
Zoological letters, 2017
Animals exhibit circadian rhythms with a period of approximately 24 h in various physiological fu... more Animals exhibit circadian rhythms with a period of approximately 24 h in various physiological functions, including locomotor activity. This rhythm is controlled by an endogenous oscillatory mechanism, or circadian clock, which consists of cyclically expressed clock genes and their product proteins. cryptochrome (cry) genes are thought to be involved in the clock mechanism, and their functions have been examined extensively in holometabolous insects, but in hemimetabolous insects their role is less well understood. In the present study, the role of cry genes was investigated using RNAi technology in a hemimetabolous insect, the cricket Gryllus bimaculatus. Using a molecular cloning approach, we obtained cDNAs for two cry genes: Drosophila-type cry1 (Gb'cry1) and mammalian-type cry2 (Gb'cry2). Gb'cry2 has six splicing variants, most of which showed rhythmic mRNA expression. Gb'cry1(RNAi) treatment had only a limited effect at the behavioral and molecular levels, while...
Analysis of Hunger-Driven Gene Expression in the Drosophila melanogaster Larval Central Nervous System
Zoological Science, 2008
A transposon-inserted mutant of Drosophila melanogaster was recently identified, and the larvae s... more A transposon-inserted mutant of Drosophila melanogaster was recently identified, and the larvae show no food preference (Ryuda and Hayakawa, 2005). To reveal the genetic mechanism underlying the preference change in this mutant, a large-scale oligo-DNA microarray screening was carried out to identify genes whose expression is different in control and mutant strains. We focused especially on hunger-driven changes in gene expression in the larval central nervous system (CNS) of both strains, because the state of food depletion should promote a feeding response due to changed expression of certain genes in the CNS. We identified 22 genes whose expression changed after starvation in either or both of the two strains. Quantitative RT-PCR analyses confirmed the expression changes in four genes, CG6271, CG6277, CG7953, and new glue 3 (ng3, encoding a putative structural molecule). CG6271 and CG6277 encode triacylglycerol lipase, and CG7953 produces a protein homologous to a juvenile hormone (JH) binding protein. The expression of these two groups of genes was enhanced in control strain larvae with a normal food preference but not in GS1189 strain larvae. Given that these genes contribute to mediating hunger-driven changes in food preference and intake in D. melanogaster larvae, the dysfunction of these key genes could cause the defect in food preference observed in GS1189-strain larvae.
Science, 2000
The molecular nature of sweet taste receptors has not been fully explored. Employing a differenti... more The molecular nature of sweet taste receptors has not been fully explored. Employing a differential screening strategy, we identified a taste receptor gene, Tre1 , that controls the taste sensitivity to trehalose in Drosophila melanogaster . The Tre1 gene encodes a novel protein with similarity to G protein–coupled seven-transmembrane receptors. Disruption of the Tre1 gene lowered the taste sensitivity to trehalose, whereas sensitivities to other sugars were unaltered. Overexpression of the Tre1 gene restored the taste sensitivity to trehalose in the Tre1 deletion mutant. The Tre1 gene is expressed in taste sensory cells. These results provide direct evidence that Tre1 encodes a putative taste receptor for trehalose in Drosophila .
Theperiodgene and allochronic reproductive isolation inBactrocera cucurbitae
Proceedings of the Royal Society of London. Series B: Biological Sciences, 2002
Chronobiological Analysis of a New Clock Mutant,Toki, inDrosophila Melanogaster
Journal of Neurogenetics, 1994
We have isolated a new semidominant clock mutant Toki on the second chromosome in Drosophila mela... more We have isolated a new semidominant clock mutant Toki on the second chromosome in Drosophila melanogaster. This mutant differs from the wild-type Canton-S in several properties as follows. Larger values are obtained in the phase angle difference (phi, the time from lights-off in a 24-hr light-dark cycle to an activity offset), the ratio of activity time to rest time (alpha/rho) and the activity level. The free-running period (tau) is 25.3 hr, one hour longer than in the wild-type. In the phase response curve (PRC), the ratio between the delay and the advance portion is larger and the cross-over point occurs later, although there is no difference in amplitude of the mutant's PRC (Type I). The rhythm is more sensitive to the light intensity, becoming obscure in darker condition. Toki interacts with other clock mutations, pers, perL and And, in such a way that tau s associated with these three X-linked mutations are lengthened and phi values become smaller.
Drosophila cry mutation reveals two circadian clocks that drive locomotor rhythm and have different responsiveness to light
Journal of Insect Physiology, 2004
Cryptochrome (CRY) is a blue-light-absorbing protein involved in the photic entrainment of the ci... more Cryptochrome (CRY) is a blue-light-absorbing protein involved in the photic entrainment of the circadian clock in Drosophila melanogaster. We have investigated the locomotor activity rhythms of flies carrying cryb mutant and revealed that they have two separate circadian oscillators with different responsiveness to light. When kept in constant light conditions, wild-type flies became arrhythmic, while cryb mutant flies exhibited free-running rhythms with two rhythmic components, one with a shorter and the other with a longer free-running period. The rhythm dissociation was dependent on the light intensities: the higher the light intensities, the greater the proportion of animals exhibiting the two oscillations. External photoreceptors including the compound eyes and the ocelli are the likely photoreceptors for the rhythm dissociation, since rhythm dissociation was prevented in so1;cryb and norpAP41;cryb double mutant flies. Immunohistochemical analysis demonstrated that the PERIOD expression rhythms in ventrally located lateral neurons (LNvs) occurred synchronously with the shorter period component, while those in the dorsally located per-expressing neurons showed PER expression most likely related to the longer period component, in addition to that synchronized to the LNvs. These results suggest that the Drosophila locomotor rhythms are driven by two separate per-dependent clocks, responding differentially to constant light.
Uploads
Papers by Teiichi Tanimura