Novel Gq alpha isoform is a candidate transducer of rhodopsin signaling in a Drosophila testes-autonomous pacemaker.

Álvarez, Carlos E.; Robison, Keith; Gilbert, Walter

doi:10.1073/pnas.93.22.12278

Cited by 20 publications

(16 citation statements)

References 34 publications

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“…Yet, it is clear that environmental LD cycles can drive rhythms of stem cell activity. Interestingly, the production of several components of the light transduction pathway in the testis (37,38) suggests that testis cells may receive direct light inputs.…”

Section: Discussionmentioning

confidence: 99%

Day–night cycles and the sleep-promoting factor, Sleepless, affect stem cell activity in the Drosophila testis

Tulina

Chen²,

Chen

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

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Adult stem cells maintain tissue integrity and function by renewing cellular content of the organism through regulated mitotic divisions. Previous studies showed that stem cell activity is affected by local, systemic, and environmental cues. Here, we explore a role of environmental day-night cycles in modulating cell cycle progression in populations of adult stem cells. Using a classic stem cell system, the Drosophila spermatogonial stem cell niche, we reveal daily rhythms in division frequencies of germ-line and somatic stem cells that act cooperatively to produce male gametes. We also examine whether behavioral sleep-wake cycles, which are driven by the environmental day-night cycles, regulate stem cell function. We find that flies lacking the sleep-promoting factor Sleepless, which maintains normal sleep in Drosophila, have increased germ-line stem cell (GSC) division rates, and this effect is mediated, in part, through a GABAergic signaling pathway. We suggest that alterations in sleep can influence the daily dynamics of GSC divisions.

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Section: Discussionmentioning

confidence: 99%

Day–night cycles and the sleep-promoting factor, Sleepless, affect stem cell activity in the Drosophila testis

Tulina

Chen²,

Chen

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

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“…We have previously described the phylogenetic relationships and placement of cnidarian opsin [4] and CNG [12] using these methods and a global arrestin phylogeny has been described elsewhere [60]. The details of our methods and a phylogenetic analysis aimed specifically at the β arrestin subclass, which includes bilaterian visual arrestins, are provided in Additional files 1 and 2.…”

Section: Methodsmentioning

confidence: 99%

Cnidocyte discharge is regulated by light and opsin-mediated phototransduction

2012

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BackgroundCnidocytes, the eponymous cell type of the Cnidaria, facilitate both sensory and secretory functions and are among the most complex animal cell types known. In addition to their structural complexity, cnidocytes display complex sensory attributes, integrating both chemical and mechanical cues from the environment into their discharge behavior. Despite more than a century of work aimed at understanding the sensory biology of cnidocytes, the specific sensory receptor genes that regulate their function remain unknown.ResultsHere we report that light also regulates cnidocyte function. We show that non-cnidocyte neurons located in battery complexes of the freshwater polyp Hydra magnipapillata specifically express opsin, cyclic nucleotide gated (CNG) ion channel and arrestin, which are all known components of bilaterian phototransduction cascades. We infer from behavioral trials that different light intensities elicit significant effects on cnidocyte discharge propensity. Harpoon-like stenotele cnidocytes show a pronounced diminution of discharge behavior under bright light conditions as compared to dim light. Further, we show that suppression of firing by bright light is ablated by cis-diltiazem, a specific inhibitor of CNG ion channels.ConclusionsOur results implicate an ancient opsin-mediated phototransduction pathway and a previously unknown layer of sensory complexity in the control of cnidocyte discharge. These findings also suggest a molecular mechanism for the regulation of other cnidarian behaviors that involve both photosensitivity and cnidocyte function, including diurnal feeding repertoires and/or substrate-based locomotion. More broadly, our findings highlight one novel, non-visual function for opsin-mediated phototransduction in a cnidarian, the origins of which might have preceded the evolution of cnidarian eyes.

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“…In Drosophila, six opsin-encoding genes have been isolated so far. The ninaE (Rh1 opsin) gene is expressed in the most abundant cells of the compound eye's ommatidia, retinular cells R1-R6 (Scavarada et al, 1983;O'Tousa et al, 1985;Zuker et al, 1985;Feiler et al, 1988), whereas the Rh2 opsin gene is expressed predominantly in the fly's ocelli (Cowman et al, 1986;Feiler et al, 1988;Pollock and Benzer, 1988;Alvarez et al, 1996). Expression of the remaining four opsins identified so far has been localized within the tiered central cells of the ommatidium, R7 and R8, its basal partner.…”

Section: Visual Pigment Is Expressed In Eyeletmentioning

confidence: 99%

Extraretinal Photoreceptors at the Compound Eye's Posterior Margin inDrosophila melanogaster

Yasuyama

Meinertzhagen

1999

J. Comp. Neurol.

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Many invertebrates have supplementary extraocular photoreceptors that often are implicated in circadian rhythms. An extraretinal group of candidate photoreceptors in the fruit fly, Drosophila melanogaster, has been revealed previously at the posterior margin of the compound eye by using a photoreceptor‐specific monoclonal antibody (Hofbauer and Buchner [1989] Naturwissen 76:335–336), but it never has been characterized. Here, we report the fine structure of this cell cluster reported by Hofbauer and Buchner, which is called “eyelet,” as well as the further candidacy of their visual pigment and neurotransmitter. Eyelet forms a specialized, pigmented organ with cells that have numerous microvilli arranged into coherent rhabdomeres. The presence of rhabdomeric microvilli is a defining feature of a photoreceptor, reported here for the first time in eyelet. The rhabdomeres exhibit Rh6 opsin‐like immunoreactivity, which provides evidence that the photoreceptors are functional: they fail to immunostain with antibodies against NINAE (Rh1), Rh4, or Rh5. The photoreceptors have been shown previously to exhibit histamine‐like immunoreactivity, but they also stain with a monoclonal antiserum raised against Drosophila choline acetyltransferase (ChAT), suggesting that the photoreceptors not only may contain histamine but also can synthesize acetylcholine. A ChAT‐immunoreactive axon bundle originating from eyelet terminates in the cortex of the anterior medulla. This bundle also is seen with reduced silver stains. Electron microscopic examination revealed four axon profiles of similar size in this bundle, indicating that eyelet contains at least four photoreceptors. The pathway of eyelet's axon bundle coincides with the precocious pathway of Bolwig's nerve that arises from the larval organ of sight. The origin and possible function of eyelet are discussed. J. Comp. Neurol. 412:193–202, 1999. © 1999 Wiley‐Liss, Inc.

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Novel Gq alpha isoform is a candidate transducer of rhodopsin signaling in a Drosophila testes-autonomous pacemaker.

Cited by 20 publications

References 34 publications

Day–night cycles and the sleep-promoting factor, Sleepless, affect stem cell activity in the Drosophila testis

Day–night cycles and the sleep-promoting factor, Sleepless, affect stem cell activity in the Drosophila testis

Cnidocyte discharge is regulated by light and opsin-mediated phototransduction

Extraretinal Photoreceptors at the Compound Eye's Posterior Margin inDrosophila melanogaster

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