scholarly journals Heterotrimeric kinesin-2 motor subunit, KLP68D, localises Drosophila odour receptor coreceptor in the distal domain of the olfactory cilia

2020 ◽  
Author(s):  
Swadhin C. Jana ◽  
Akanksha Jain ◽  
Priya Dutta ◽  
Anjusha Singh ◽  
Lavanya Adusumilli ◽  
...  
Keyword(s):  
Sensory Neurons ◽  
Outer Segment ◽  
Developmental Stages ◽  
Olfactory Sensory Neurons ◽  
List Type ◽  
Tail Domain ◽  
Specific Domain ◽  
Electrophysiological Response ◽  
Olfactory Cilia ◽  
Specific Regulation

AbstractCiliary localisation of the odour receptor coreceptor (Orco) is essential for insect olfaction. Here, we show that in the Drosophila antenna Orco enters the bipartite cilia expressed on the olfactory sensory neurons in two discrete, one-hour intervals after the adult eclosion. Genetic analyses suggest that the heterotrimeric kinesin-2 is essential for Orco transfer from the base into the cilium. Using in vitro pulldown assay, we show that Orco binds to the C-terminal tail domain of KLP68D, the β-subunit of kinesin-2. Reduced Orco enrichment decreases electrophysiological response to odours and loss of olfactory behaviour. Finally, we show that kinesin-2 function is necessary to compact Orco to an approximately four-micron stretch at the distal portion of the ciliary outer-segment bearing singlet microtubule filaments. Altogether, these results highlight an independent, tissue-specific regulation of Orco entry at specific developmental stages and its localisation to a ciliary subdomain by kinesin-2.Graphical AbstractAuthor SummaryJana, Jain, Dutta et al., show that the odour receptor coreceptor only enters the cilia expressed on olfactory sensory neurons at specified developmental stages requiring heterotrimeric kinesin-2. The motor also helps to localise the coreceptor in a compact, environment-exposed domain at the ciliary outer-segment.Highlights:Odorant receptor coreceptor (Orco) selectively enters the olfactory cilia.Orco localises in a specific domain at the distal segment of the olfactory cilium.Orco/ORx binds to the C-terminal tail domain of the kinesin-2β motor subunit.Orco entry across the transition zone and its positioning require Kinesin-2.

scholarly journals Kinesin-2 transports Orco into the olfactory cilium of Drosophila melanogaster at specific developmental stages

PLoS Genetics ◽  
2021 ◽  
Vol 17 (8) ◽  
pp. e1009752
Author(s):  
Swadhin Chandra Jana ◽  
Priya Dutta ◽  
Akanksha Jain ◽  
Anjusha Singh ◽  
Lavanya Adusumilli ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Outer Segment ◽  
Developmental Stages ◽  
Transmembrane Protein ◽  
Developmental Regulation ◽  
Cell Signalling ◽  
Intraflagellar Transport ◽  
Distal Portion ◽  
Electrophysiological Response ◽  
Associated Proteins

The cilium, the sensing centre for the cell, displays an extensive repertoire of receptors for various cell signalling processes. The dynamic nature of ciliary signalling indicates that the ciliary entry of receptors and associated proteins must be regulated and conditional. To understand this process, we studied the ciliary localisation of the odour-receptor coreceptor (Orco), a seven-pass transmembrane protein essential for insect olfaction. Little is known about when and how Orco gets into the cilia. Here, using Drosophila melanogaster, we show that the bulk of Orco selectively enters the cilia on adult olfactory sensory neurons in two discrete, one-hour intervals after eclosion. A conditional loss of heterotrimeric kinesin-2 during this period reduces the electrophysiological response to odours and affects olfactory behaviour. We further show that Orco binds to the C-terminal tail fragments of the heterotrimeric kinesin-2 motor, which is required to transfer Orco from the ciliary base to the outer segment and maintain within an approximately four-micron stretch at the distal portion of the ciliary outer-segment. The Orco transport was not affected by the loss of critical intraflagellar transport components, IFT172/Oseg2 and IFT88/NompB, respectively, during the adult stage. These results highlight a novel developmental regulation of seven-pass transmembrane receptor transport into the cilia and indicate that ciliary signalling is both developmentally and temporally regulated.

scholarly journals Aldehyde-specific responses of olfactory sensory neurons in the praying mantis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kota Ezaki ◽  
Takashi Yamashita ◽  
Thomas Carle ◽  
Hidehiro Watanabe ◽  
Fumio Yokohari ◽  
...  
Keyword(s):  
Sensory Neurons ◽  
Activity Patterns ◽  
Critical Role ◽  
Response Spectra ◽  
Olfactory Cues ◽  
Olfactory Sensory Neurons ◽  
Praying Mantis ◽  
Pheromonal Communication ◽  
Class B ◽  
Excitatory Responses

AbstractAlthough praying mantises rely mainly on vision for predatory behaviours, olfaction also plays a critical role in feeding and mating behaviours. However, the receptive processes underlying olfactory signals remain unclear. Here, we identified olfactory sensory neurons (OSNs) that are highly tuned to detect aldehydes in the mantis Tenodera aridifolia. In extracellular recordings from OSNs in basiconic sensilla on the antennae, we observed three different spike shapes, indicating that at least three OSNs are housed in a single basiconic sensillum. Unexpectedly, one of the three OSNs exhibited strong excitatory responses to a set of aldehydes. Based on the similarities of the response spectra to 15 different aldehydes, the aldehyde-specific OSNs were classified into three classes: B, S, and M. Class B broadly responded to most aldehydes used as stimulants; class S responded to short-chain aldehydes (C3–C7); and class M responded to middle-length chain aldehydes (C6–C9). Thus, aldehyde molecules can be finely discriminated based on the activity patterns of a population of OSNs. Because many insects emit aldehydes for pheromonal communication, mantises might use aldehydes as olfactory cues for locating prey habitat.

scholarly journals Region-specific amyloid-β accumulation in the olfactory system influences olfactory sensory neuronal dysfunction in 5xFAD mice

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Gowoon Son ◽  
Seung-Jun Yoo ◽  
Shinwoo Kang ◽  
Ameer Rasheed ◽  
Da Hae Jung ◽  
...  
Keyword(s):  
Olfactory Bulb ◽  
Sensory Neurons ◽  
Olfactory System ◽  
Amyloid Β ◽  
Olfactory Sensory Neurons ◽  
Basal Cells ◽  
Irreversible Damage ◽  
5Xfad Mouse ◽  
Peripheral Areas ◽  
5Xfad Mice

Abstract Background Hyposmia in Alzheimer’s disease (AD) is a typical early symptom according to numerous previous clinical studies. Although amyloid-β (Aβ), which is one of the toxic factors upregulated early in AD, has been identified in many studies, even in the peripheral areas of the olfactory system, the pathology involving olfactory sensory neurons (OSNs) remains poorly understood. Methods Here, we focused on peripheral olfactory sensory neurons (OSNs) and delved deeper into the direct relationship between pathophysiological and behavioral results using odorants. We also confirmed histologically the pathological changes in 3-month-old 5xFAD mouse models, which recapitulates AD pathology. We introduced a numeric scale histologically to compare physiological phenomenon and local tissue lesions regardless of the anatomical plane. Results We observed the odorant group that the 5xFAD mice showed reduced responses to odorants. These also did not physiologically activate OSNs that propagate their axons to the ventral olfactory bulb. Interestingly, the amount of accumulated amyloid-β (Aβ) was high in the OSNs located in the olfactory epithelial ectoturbinate and the ventral olfactory bulb glomeruli. We also observed irreversible damage to the ectoturbinate of the olfactory epithelium by measuring the impaired neuronal turnover ratio from the basal cells to the matured OSNs. Conclusions Our results showed that partial and asymmetrical accumulation of Aβ coincided with physiologically and structurally damaged areas in the peripheral olfactory system, which evoked hyporeactivity to some odorants. Taken together, partial olfactory dysfunction closely associated with peripheral OSN’s loss could be a leading cause of AD-related hyposmia, a characteristic of early AD.

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