The making of an olfactory specialist

Mapping Intimacies ◽

10.1101/546507 ◽

2019 ◽

Cited By ~ 4

Author(s):

Thomas O. Auer ◽

Mohammed A. Khallaf ◽

Ana F. Silbering ◽

Giovanna Zappia ◽

Kaitlyn Ellis ◽

...

Keyword(s):

Nervous System ◽

Mutational Analysis ◽

Functional Change ◽

Central Projection ◽

Host Fruit ◽

Specific Behaviour ◽

Molecular Determinants ◽

Differential Tuning ◽

Nervous System Evolution ◽

Species Specific

AbstractThe evolution of animal behaviour is poorly understood. Despite numerous correlations of behavioural and nervous system divergence, demonstration of the genetic basis of interspecific behavioural differences remains rare. Here we develop a novel neurogenetic model, Drosophila sechellia, a close cousin of D. melanogaster that displays profound behavioural changes linked to its extreme host fruit specialisation. Through calcium imaging, we identify olfactory pathways detecting host volatiles. Mutational analysis indicates roles for individual receptors in long- and short-range attraction. Cross-species allele transfer demonstrates that differential tuning of one receptor is important for species-specific behaviour. We identify the molecular determinants of this functional change, and characterise their behavioural significance and evolutionary origin. Circuit tracing reveals that receptor adaptations are accompanied by increased sensory pooling onto interneurons and novel central projection patterns. This work links molecular and neuronal changes to behavioural divergence and defines a powerful model for investigating nervous system evolution and speciation.

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Your Brain Is Not an Onion With a Tiny Reptile Inside

Current Directions in Psychological Science ◽

10.1177/0963721420917687 ◽

2020 ◽

Vol 29 (3) ◽

pp. 255-260

Author(s):

Joseph Cesario ◽

David J. Johnson ◽

Heather L. Eisthen

Keyword(s):

Nervous System ◽

Behavioral Flexibility ◽

Brain Structures ◽

Introductory Psychology ◽

Complex Structures ◽

Accurate Model ◽

Nervous System Evolution ◽

Neural Evolution ◽

Human Brains ◽

Unanimous Agreement

A widespread misconception in much of psychology is that (a) as vertebrate animals evolved, “newer” brain structures were added over existing “older” brain structures, and (b) these newer, more complex structures endowed animals with newer and more complex psychological functions, behavioral flexibility, and language. This belief, although widely shared in introductory psychology textbooks, has long been discredited among neurobiologists and stands in contrast to the clear and unanimous agreement on these issues among those studying nervous-system evolution. We bring psychologists up to date on this issue by describing the more accurate model of neural evolution, and we provide examples of how this inaccurate view may have impeded progress in psychology. We urge psychologists to abandon this mistaken view of human brains.

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Sight of parasitoid wasps accelerates sexual behavior and upregulates a micropeptide gene in Drosophila

Nature Communications ◽

10.1038/s41467-021-22712-0 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Shimaa A. M. Ebrahim ◽

Gaëlle J. S. Talross ◽

John R. Carlson

Keyword(s):

Gene Expression ◽

Nervous System ◽

Sexual Behavior ◽

Behavioral Response ◽

Mutational Analysis ◽

Parasitoid Wasp ◽

Parasitoid Wasps ◽

Wasp Species ◽

Defensive Responses ◽

Vast Range

AbstractParasitoid wasps inflict widespread death upon the insect world. Hundreds of thousands of parasitoid wasp species kill a vast range of insect species. Insects have evolved defensive responses to the threat of wasps, some cellular and some behavioral. Here we find an unexpected response of adult Drosophila to the presence of certain parasitoid wasps: accelerated mating behavior. Flies exposed to certain wasp species begin mating more quickly. The effect is mediated via changes in the behavior of the female fly and depends on visual perception. The sight of wasps induces the dramatic upregulation in the fly nervous system of a gene that encodes a 41-amino acid micropeptide. Mutational analysis reveals that the gene is essential to the behavioral response of the fly. Our work provides a foundation for further exploration of how the activation of visual circuits by the sight of a wasp alters both sexual behavior and gene expression.

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The Influence of Wiring Economy on Nervous System Evolution

Current Biology ◽

10.1016/j.cub.2016.08.053 ◽

2016 ◽

Vol 26 (20) ◽

pp. R1101-R1108 ◽

Cited By ~ 10

Author(s):

Irving E. Wang ◽

Thomas R. Clandinin

Keyword(s):

Nervous System ◽

System Evolution ◽

Nervous System Evolution

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Species specific behaviour and catchability of gadoid fish to floated and bottom set pots

ICES Journal of Marine Science ◽

10.1093/icesjms/fsw200 ◽

2016 ◽

Vol 74 (3) ◽

pp. 769-779 ◽

Cited By ~ 7

Author(s):

Neil Anders ◽

Anders Fernö ◽

Odd-Børre Humborstad ◽

Svein Løkkeborg ◽

Anne Christine Utne-Palm

Keyword(s):

Water Column ◽

Gadus Morhua ◽

Capture Efficiency ◽

Escape Rate ◽

Melanogrammus Aeglefinus ◽

Encounter Rate ◽

Specific Behaviour ◽

Upstream Direction ◽

Species Specific ◽

Specific Food

To increase our understanding of the interaction between fish and baited fishing gear we quantitatively described the behaviour of cod (Gadus morhua), saithe (Pollachius virens), and haddock (Melanogrammus aeglefinus) to baited pots in a fjord in northern Norway. Detailed video analyses were made to describe species specific responses and examine the effect of lifting the pot off the bottom. The majority of both cod and saithe approached the pots in an upstream direction, and fish approached floated pots higher in the water column than bottom set pots. Cod tended to approach a pot along the seabed and were more likely to encounter the bottom set pot than the floated pot, whereas saithe more often approached in the water column. The capture efficiency was low for all species, but cod were more likely to be caught than saithe and haddock. Cod showed a high encounter rate, low entrance rate and high escape rate. For saithe, a low encounter rate was the chief factor limiting capture efficiency. The observed differences between cod and saithe were explained by species-specific food-search strategies. No difference in entrance rate, escape rate or catch efficiency between the two pot types were found.

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Drosophila Homeodomain-Interacting Protein Kinase (Hipk) Phosphorylates the Homeodomain Proteins Homeobrain, Empty Spiracles, and Muscle Segment Homeobox

International Journal of Molecular Sciences ◽

10.3390/ijms20081931 ◽

2019 ◽

Vol 20 (8) ◽

pp. 1931

Author(s):

Eva Louise Steinmetz ◽

Denise Nicole Dewald ◽

Nadine Luxem ◽

Uwe Walldorf

Keyword(s):

Nervous System ◽

Protein Kinase ◽

Mutational Analysis ◽

Bimolecular Fluorescence Complementation ◽

Physical Interaction ◽

Homeodomain Proteins ◽

Interacting Protein ◽

Enzyme Substrate

The Drosophila homeodomain-interacting protein kinase (Hipk) is the fly representative of the well-conserved group of HIPKs in vertebrates. It was initially found through its characteristic interactions with homeodomain proteins. Hipk is involved in a variety of important developmental processes, such as the development of the eye or the nervous system. In the present study, we set Hipk and the Drosophila homeodomain proteins Homeobrain (Hbn), Empty spiracles (Ems), and Muscle segment homeobox (Msh) in an enzyme-substrate relationship. These homeoproteins are transcription factors that function during Drosophila neurogenesis and are, at least in part, conserved in vertebrates. We reveal a physical interaction between Hipk and the three homeodomain proteins in vivo using bimolecular fluorescence complementation (BiFC). In the course of in vitro phosphorylation analysis and subsequent mutational analysis we mapped several Hipk phosphorylation sites of Hbn, Ems, and Msh. The phosphorylation of Hbn, Ems, and Msh may provide further insight into the function of Hipk during development of the Drosophila nervous system.

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Molecular dissection of pheromone selectivity in the competence signaling system ComRS of streptococci

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1916085117 ◽

2020 ◽

Vol 117 (14) ◽

pp. 7745-7754

Author(s):

Laura Ledesma-Garcia ◽

Jordhan Thuillier ◽

Armando Guzman-Espinola ◽

Imke Ensinck ◽

Inès Li de la Sierra-Gallay ◽

...

Keyword(s):

Biomedical Applications ◽

Rational Design ◽

Mutational Analysis ◽

Point Mutations ◽

Streptococcus Thermophilus ◽

Activation Mechanism ◽

Toggle Switch ◽

Exogenous Dna ◽

C Terminus ◽

Molecular Determinants

Competence allows bacteria to internalize exogenous DNA fragments for the acquisition of new phenotypes such as antibiotic resistance or virulence traits. In most streptococci, competence is regulated by ComRS signaling, a system based on the mature ComS pheromone (XIP), which is internalized to activate the (R)RNPP-type ComR sensor by triggering dimerization and DNA binding. Cross-talk analyses demonstrated major differences of selectivity between ComRS systems and raised questions concerning the mechanism of pheromone-sensor recognition and coevolution. Here, we decipher the molecular determinants of selectivity of the closely related ComRS systems fromStreptococcus thermophilusandStreptococcus vestibularis. Despite high similarity, we show that the divergence in ComR-XIP interaction does not allow reciprocal activation. We perform the structural analysis of the ComRS system fromS. vestibularis.Comparison with its ortholog fromS. thermophilusreveals an activation mechanism based on a toggle switch involving the recruitment of a key loop by the XIP C terminus. Together with a broad mutational analysis, we identify essential residues directly involved in peptide binding. Notably, we generate a ComR mutant that displays a fully reversed selectivity toward the heterologous pheromone with only five point mutations, as well as other ComR variants featuring XIP bispecificity and/or neofunctionalization for hybrid XIP peptides. We also reveal that a single XIP mutation relaxes the strictness of ComR activation, suggesting fast adaptability of molecular communication phenotypes. Overall, this study is paving the way toward the rational design or directed evolution of artificial ComRS systems for a range of biotechnological and biomedical applications.

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Novel Approach for Detecting Prohibited Species-Specific Central Nervous System Tissue Contamination in Meat by One-Step Real-Time Reverse Transcriptase PCR

Journal of Food Protection ◽

10.4315/0362-028x-72.5.1063 ◽

2009 ◽

Vol 72 (5) ◽

pp. 1063-1069 ◽

Cited By ~ 4

Author(s):

M. M. NAGARAJAN ◽

D. LONGTIN ◽

C. SIMARD

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Reverse Transcriptase ◽

Real Time ◽

Compliance Monitoring ◽

Reverse Transcriptase Pcr ◽

Qrt Pcr ◽

Tissue Contamination ◽

One Step ◽

Species Specific

The dissemination of prohibited species-specific central nervous system (CNS) tissue contamination in meat must be tracked to mitigate human health risk associated with bovine spongiform encephalopathy. The efficiency of compliance monitoring and risk control measures taken by concerned regulatory authorities at meat production facilities to avoid such contamination depends on the ability to detect CNS tissue with a reliable and adequately sensitive quantitative method. A rapid and convenient one-step real-time quantitative reverse transcriptase PCR (qRT-PCR) assay was developed based on the absolute quantification of glial fibrillary acidic protein (GFAP) mRNA as a marker for CNS tissue contamination in meat. The GFAP RNA quantity corresponding to a percentage of CNS tissue in artificially spiked meat was determined using an appropriate in vitro transcribed target GFAP RNA as a calibration standard in the assay. The assay had a linear dynamic range of 102 to 109 copies of target RNA and was able to detect 0.01% CNS contamination in meat. Further evaluation consisted of an analysis of 272 random meat cuts from carcasses and 109 ground meat samples received from a federally inspected abattoir and two meat processing facilities, respectively, over a 5-month period. The analyzed samples were all negative for CNS tissue contamination at an arbitrarily set lower threshold of 0.025%. Overall, the newly developed one-step qRT-PCR may be useful as an objective quantitative compliance monitoring tool and for setting an acceptable low tolerance threshold for such contamination in meat.

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Functional morphology of the platyhelminth nervous system

Parasitology ◽

10.1017/s0031182000077891 ◽

1996 ◽

Vol 113 (S1) ◽

pp. S47-S72 ◽

Cited By ~ 86

Author(s):

D. W. Halton ◽

M. K. S. Gustafsson

Keyword(s):

Nervous System ◽

Sense Organ ◽

Neuronal Cell ◽

Cell Types ◽

Target Cells ◽

Life Styles ◽

Wide Range ◽

Paracrine Secretion ◽

Nervous System Evolution ◽

Neuronal Vesicles

SUMMARYAs the most primitive metazoan phylum, the Platyhelminthes occupies a unique position in nervous system evolution. Centrally, their nervous system consists of an archaic brain from which emanate one or more pairs of longitudinal nerve cords connected by commissures; peripherally, a diverse arrangement of nerve plexuses of varying complexity innervate the subsurface epithelial and muscle layers, and in the parasitic taxa they are most prominent in the musculature of the attachment organs and egg-forming apparatus. There is a range of neuronal-cell types, the majority being multi- and bipolar. The flatworm neuron is highly secretory and contains a heterogeneity of vesicular inclusions, dominated by densecored vesicles, whose contents may be released synaptically or by paracrine secretion for presumed delivery to target cells via the extracellular matrix. A wide range of sense organ types is present in flatworms, irrespective of life-styles. The repertoire of neuronal substances identified cytochemically includes all of the major candidate transmitters known in vertebrates. Two groups of native flatworm neuropeptides have been sequenced, neuropeptide F and FMRFamide-related peptides (FaRPs), and immunoreactivities for these have been localised in dense-cored neuronal vesicles in representatives of all major fiatworm groups. There is evidence of co-localisation of peptidergic and cholinergic elements; serotoninergic components generally occupy a separate set of neurons. The actions of neuronal substances in flatworms are largely undetermined, but FaRPs and 5-HT are known to be myoactive in all of the major groups, and there is immuno-cytochemical evidence that they have a role in the mechanism of egg assembly.

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