Enhanced competence in the negotiation of a T maze by Drosophila melanogaster in response to a possible food reward

Starved Drosophila melanogaster were run individually in a T maze in which sucrose was provided as a reward. After three trials, flies were run similarly for a fourth trial in a clean maze lacking sucrose. The time in which the food area was located in the fourth trial compared with the first was significantly decreased. Control experiments rule out the possibility that smell. pheromones, or increased energy levels associated with the ingestion of sucrose are the basis of the highly significant differences. A likely alternative is that the flies to some degree learn the location of the food area.

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Sequence and phylogenetic analysis of the SNF4/AMPK gamma subunit gene from Drosophila melanogaster

Genome ◽

10.1139/g99-059 ◽

1999 ◽

Vol 42 (6) ◽

pp. 1077-1087 ◽

Cited By ~ 1

Author(s):

Erin N Yoshida ◽

Bernhard F Benkel ◽

Ying Fong ◽

Donal A Hickey

Keyword(s):

Phylogenetic Analysis ◽

Drosophila Melanogaster ◽

Gene Family ◽

Genomic Sequence ◽

Sequence Similarity ◽

Energy Levels ◽

Metabolic Stress ◽

Gene Copy ◽

Gamma Subunit ◽

Snf1 Kinase

To optimize gene expression under different environmental conditions, many organisms have evolved systems which can quickly up- and down-regulate the activity of other genes. Recently, the SNF1 kinase complex from yeast and the AMP-activated protein kinase complex from mammals have been shown to represent homologous metabolic sensors that are key to regulating energy levels under times of metabolic stress. Using heterologous probing, we have cloned the Drosophila melanogaster homologue of SNF4, the noncatalytic effector subunit from this kinase complex. A sequence corresponding to the partial genomic sequence as well as the full-length cDNA was obtained, and shows that the D. melanogaster SNF4 is encoded in a 1944-bp cDNA representing a protein of 648 amino acids (aa). Southern analysis of Drosophila genomic DNA in concert with a survey of mammalian SNF4 ESTs indicates that in metazoans, SNF4 is a duplicated gene, and possibly even a larger gene family. We propose that one gene copy codes for a short (330 aa) protein, whereas the second locus codes for a longer version (<410 aa) that is extended at the carboxy terminus, as typified by the Drosophila homologue presented here. Phylogenetic analysis of yeast, invertebrate, and multiple mammalian isoforms of SNF4 shows that the gene duplication likely occurred early in the metazoan lineage, as the protein products of the different loci are relatively divergent. When the phylogeny was extended beyond the SNF4 gene family, SNF4 shares sequence similarity with other cystathionine-β-synthase domain-containing proteins, including IMP dehydrogenase and a variety of uncharacterized Methanococcus proteins.Key words: SNF4, AMPK gamma subunit, derepression, gene family, phylogeny.

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Rest is Required to Learn an Appetitively-Reinforced Operant Task in Drosophila

10.1101/2020.08.28.272047 ◽

2020 ◽

Author(s):

Timothy D. Wiggin ◽

Yung-Yi Hsiao ◽

Jeffrey B. Liu ◽

Robert Huber ◽

Leslie C. Griffith

Keyword(s):

Drosophila Melanogaster ◽

Operant Conditioning ◽

Food Reward ◽

Molecular Mechanisms ◽

Genetic Model ◽

Fruit Fly ◽

Model Organisms ◽

Neural Basis ◽

Operant Task ◽

Insight Into

ABSTRACTMaladaptive operant conditioning contributes to development of neuropsychiatric disorders. Candidate genes have been identified that contribute to this maladaptive plasticity, but the neural basis of operant conditioning in genetic model organisms remains poorly understood. The fruit fly Drosophila melanogaster is a versatile genetic model organism that readily forms operant associations with punishment stimuli. However, operant conditioning with a food reward has not been demonstrated in flies, limiting the types of neural circuits that can be studied. Here we present the first sucrose-reinforced operant conditioning paradigm for flies. Flies of both sexes walk along a Y-shaped track with reward locations at the terminus of each hallway. When flies turn in the reinforced direction at the center of the track, sucrose is presented at the end of the hallway. Only flies that rest during training show evidence of learning the reward contingency. Flies rewarded independently of their behavior do not form a learned association but have the same amount of rest as trained flies, showing that rest is not driven by learning. Optogenetically-induced rest does not promote learning, indicating that rest is not sufficient for learning the operant task. We validated the sensitivity of this assay to detect the effect of genetic manipulations by testing the classic learning mutant dunce. Dunce flies are learning impaired in the Y-Track task, indicating a likely role for cAMP in the operant coincidence detector. This novel training paradigm will provide valuable insight into the molecular mechanisms of disease and the link between sleep and learning.SIGNIFICANCE STATEMENTOperant conditioning and mental health are deeply intertwined: maladaptive conditioning contributes to many pathologies, while therapeutic operant conditioning is a frequently used tool in talk therapy. Unlike drug interventions which target molecules or mechanisms, it is not known how operant conditioning changes the brain to promote wellness or distress. To gain mechanistic insight into how this form of learning works, we developed a novel operant training task for the fruit fly Drosophila melanogaster. We made three key discoveries. First, flies are able to learn an operant task to find food reward. Second, rest during training is necessary for learning. Third, the dunce gene is necessary for both classical and operant conditioning in flies, indicating that they may share molecular mechanisms.

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A recombinational hotspot at the triplo-lethal locus of Drosophila melanogaster.

Genetics ◽

10.1093/genetics/122.2.397 ◽

1989 ◽

Vol 122 (2) ◽

pp. 397-401

Author(s):

D R Dorer ◽

A C Christensen

Keyword(s):

Drosophila Melanogaster ◽

High Frequency ◽

Wild Type ◽

Site Specific ◽

Interchromosomal Effect ◽

Dominant Lethals ◽

Hypomorphic Alleles ◽

Rule Out

Abstract In the genome of Drosophila melanogaster there is only one locus, Tpl, that is triplo-lethal; it is also haplo-lethal. Previous work has identified 3 hypomorphic alleles of Tpl which rescue animals carrying a duplication of Tpl, but which are not dominant lethals as null mutations or deficiencies would be. We have found that all three hypomorphic alleles act as site-specific hotspots for recombination when heterozygous with a wild-type homolog. Recombination between the flanking markers ri and Ki is increased 6.5-10.5-fold in the presence of Tpl hypomorphic alleles. The increased recombination was found to occur between Tpl and Ki, while recombination in other adjacent regions is unchanged. The use of isogenic Tpl+ controls, and the use of flanking intervals in the mutant chromosomes allows us to rule out the interchromosomal effect as a cause. We have also observed premeiotic recombination occurring at the Tpl hypomorphic alleles in male heterozygotes. We hypothesize that transposons are responsible for both the hypomorphic phenotype and the high frequency of recombination.

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Tarsus determination in Drosophila melanogaster

Genome ◽

10.1139/g05-021 ◽

2005 ◽

Vol 48 (4) ◽

pp. 712-721 ◽

Cited By ~ 11

Author(s):

Anthony Percival-Smith ◽

Wendy A Teft ◽

Jodi Lynn Barta

Keyword(s):

Drosophila Melanogaster ◽

Ectopic Expression ◽

Imaginal Discs ◽

Sex Combs Reduced ◽

Appendage Development ◽

Sex Combs ◽

Ectopic Overexpression ◽

A Cell ◽

Hox Protein ◽

Rule Out

Arista versus tarsus determination is well investigated in Drosophila, yet it remains unresolved whether Antennapedia (ANTP) cell autonomously or noncell autonomously determines tarsus identity and whether Sex combs reduced (SCR) is the HOX protein required for normal tarsus determination. Three observations rule out a cell autonomous role for ANTP in tarsus determination. (i) Clonal ectopic overexpression of ANTP did not repress the expression of the arista determining protein Homothorax (HTH) in early 3rd stadium antennal imaginal discs. (ii) Clonal ectopic expression of ANTP did not transform the arista to a tarsus. (iii) Ectopic overexpression of ANTP, Labial (LAB), Deformed (DFD), SCR, Ultrabithorax (UBX), Abdominal-A (ABD-A), or Abdominal-B (ABD-B), using the dppGAL4 driver, resulted in arista-to-tarsus transformations, and repressed HTH/Extradenticle (EXD) activity noncell autonomously in early 3rd stadium antennal imaginal discs. SCR may not be the HOX protein required for normal tarsus determination, because co-ectopic expression of Proboscipedia (PB) inhibited the arista-to-tarsus transformations induced by ectopic expression of DFD, SCR, ANTP, UBX, ABD-A, and ABD-B. The proposal that SCR is the HOX protein required for normal tarsus determination is dependent on SCR being the sole target of PB suppression, which is not the case. Therefore, the possibility exists that normal tarsus determination is HOX independent.Key words: appendage development, Antennapedia, proboscipedia, sex combs reduced, homothorax.

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Evolution of the Proportions of Two Sigma Viral Types in Experimental Populations of Drosophila melanogaster in the Absence of the Allele That Is Restrictive of Viral Multiplication

Genetics ◽

10.1093/genetics/153.4.1799 ◽

1999 ◽

Vol 153 (4) ◽

pp. 1799-1808

Author(s):

Annie Fleuriet

Keyword(s):

Drosophila Melanogaster ◽

Natural Populations ◽

Selective Advantage ◽

Type I ◽

Type Ii ◽

Viral Type ◽

Viral Multiplication ◽

Experimental Populations ◽

P Type ◽

Rule Out

Abstract A minority of flies in natural populations of Drosophila melanogaster are endemically infected by a rhabdovirus, sigma. The virus is vertically transmitted through male and female gametes. Two alleles of a fly locus, the ref(2)P locus, are present as a polymorphism in all populations: O permissive, and P restrictive for viral multiplication and transmission. Two viral types are known, Type I, which is very sensitive to the P allele, and Type II, which is more resistant. Previous observations have shown that, in presence of the P allele, viral Type II is selected for, in both natural and experimental populations. The aim of the present study was to determine whether, in the absence of P, Type I is selected for, or whether the two types are equivalent. For this purpose, experimental populations deprived of the P allele and differing in the initial proportions of the two viral types were established. After several generations, and despite a possible bias toward Type I, the frequencies of Type I and Type II clones differed in the various populations, depending on their initial values. These findings do not rule out selective advantage of viral Type I in the absence of P, but suggest that, if any, this advantage is in no way comparable to that displayed by viral Type II in the presence of P.

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African grey parrots ( Psittacus erithacus ) use inference by exclusion to find hidden food

Biology Letters ◽

10.1098/rsbl.2011.0500 ◽

2011 ◽

Vol 7 (6) ◽

pp. 875-877 ◽

Cited By ~ 26

Author(s):

Sandra Mikolasch ◽

Kurt Kotrschal ◽

Christian Schloegl

Keyword(s):

Associative Learning ◽

Food Reward ◽

Great Apes ◽

The Other ◽

Olfactory Cues ◽

Food Type ◽

Food Items ◽

Empty Location ◽

Inference By Exclusion ◽

Rule Out

Exclusion allows the detection of hidden food when confronted with the choice between an empty and a potentially baited food location. However, exclusion may be based on avoidance of the empty location without drawing inferences about the presence of the food in the baited location. So far, such inferences have been demonstrated in the great apes only: after seeing an experimenter eating one of two food types, which both had been hidden previously in two boxes, the apes were able to choose the box that still contained the other food type. African grey parrots are capable of exclusion, and we here assessed if they are capable of inference by exclusion. In our task, two different but equally preferred food items were hidden in full view of the birds under two opaque cups. Then, an experimenter secretly removed one food type and showed it to the bird. Similarly to the apes, one out of seven parrots significantly preferred the baited cup; control conditions rule out that its choice was based on associative learning or the use of olfactory cues. Thus, we conclude that—like the apes—some grey parrots are able to infer the location of a hidden food reward.

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A Perturbation Theory for the Population of Atomic Energy Levels in Non-Lte Plasmas

International Astronomical Union Colloquium ◽

10.1017/s025292110010805x ◽

1988 ◽

Vol 102 ◽

pp. 343-347

Author(s):

M. Klapisch

Keyword(s):

Perturbation Theory ◽

Small Parameter ◽

Classification Scheme ◽

Sum Rules ◽

Energy Levels ◽

Natural Classification ◽

Quantum Numbers ◽

Formal Expansion ◽

Atomic Energy Levels ◽

As Effects

AbstractA formal expansion of the CRM in powers of a small parameter is presented. The terms of the expansion are products of matrices. Inverses are interpreted as effects of cascades.It will be shown that this allows for the separation of the different contributions to the populations, thus providing a natural classification scheme for processes involving atoms in plasmas. Sum rules can be formulated, allowing the population of the levels, in some simple cases, to be related in a transparent way to the quantum numbers.

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