Mutants of the visual pathway of Drosophila melanogaster.
TL;DR: New mutants of Drosophila melanogaster with single-step lesions on the genes controlling the visual pathway are generated, and ERG characteristics suggest genetic blocks in theVisual pathway of several of them.
Abstract: WITH the objective of analysing visual processes, we have attempted to generate mutants of Drosophila melanogaster with single-step lesions on the genes controlling the visual pathway1. One of these (x-7) had an abnormal electroretinogram (ERG) consisting apparently of responses from the photoreceptor layer alone. Similar ERGs could be obtained from the mutants tan1,2 and ebony2. Indeed, the mutants x-7 and tan seemed to be allelic1. We now have new mutants, and ERG characteristics suggest genetic blocks in the visual pathway of several of them.
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TL;DR: In situ hybridizations of norpA cDNA to adult tissue sections show that this gene is expressed abundantly in the retina and that PLC is an essential component of the Drosophila phototransduction pathway.
627 citations
TL;DR: Encodable phototriggers provide noninvasive control interfaces for studying the connectivity and dynamics of neural circuits, for assigning behavioral content to neurons and their activity patterns, and, potentially, for restoring information corrupted by injury or disease.
584 citations
Cites background from "Mutants of the visual pathway of Dr..."
...To exclude confounding visual input via UV-sensitive photoreceptors, flies were blinded with the help of the norpA7 allele (Hotta and Benzer, 1970; Pak et al., 1970), which eliminates an essential phototransduction component (Bloomquist et al., 1988)....
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TL;DR: After 100 years, fruit flies continue to be the choice model system for many neuroscientists and the combinational use of powerful research tools will ensure that this model organism will continue to lead to key discoveries that will impact vertebrate neuroscience.
Abstract: Studies in fruit flies have greatly aided our understanding of the nervous system. Bellen and colleagues take us through the key findings in the last century. They argue that thanks to the unmatched wealth of tools that can be used inDrosophila melanogaster, research in flies will continue to contribute to many aspects of vertebrate neuroscience. Discoveries in fruit flies have greatly contributed to our understanding of neuroscience. The use of an unparalleled wealth of tools, many of which originated between 1910–1960, has enabled milestone discoveries in nervous system development and function. Such findings have triggered and guided many research efforts in vertebrate neuroscience. After 100 years, fruit flies continue to be the choice model system for many neuroscientists. The combinational use of powerful research tools will ensure that this model organism will continue to lead to key discoveries that will impact vertebrate neuroscience.
397 citations
TL;DR: Many of the techniques that help assess the role of specific neurons by labeling, removing, or altering their activity are summarized and an attempt to acquaint the reader with available options and contexts to apply these methods.
392 citations
Cites background from "Mutants of the visual pathway of Dr..."
..., 1993), visual perception and retinal neurodegeneration (Benzer, 1967;Pak et al., 1970), synaptic transmission (Suzuki et al....
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...…specification (Hartenstein et al., 2008), growth cone guidance (Seeger et al., 1993), visual perception and retinal neurodegeneration (Benzer, 1967; Pak et al., 1970), synaptic transmission (Suzuki et al., 1971), diurnal rhythmicity (Konopka and Benzer, 1971), learning and memory (Dudai et al.,…...
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TL;DR: It has become apparent that most of the proteins central to Drosophila phototransduction are coupled into a supramolecular signaling complex, signalplex, through association with a PDZ-containing scaffold protein.
Abstract: ▪ Abstract The Drosophila phototransduction cascade has emerged as an attractive paradigm for understanding the molecular mechanisms underlying visual transduction, as well as other G protein–coupled signaling cascades that are activated and terminated with great rapidity. A large collection of mutants affecting the fly visual cascade have been isolated, and the nature and function of many of the affected gene products have been identified. Virtually all of the proteins, including those that were initially classified as novel, are highly related to vertebrate homologs. Recently, it has become apparent that most of the proteins central to Drosophila phototransduction are coupled into a supramolecular signaling complex, signalplex, through association with a PDZ-containing scaffold protein. The characterization of this complex has led to a re-evaluation of the mechanisms underlying the activation and deactivation of the phototransduction cascade.
284 citations
Cites background from "Mutants of the visual pathway of Dr..."
...Examples of mutants that display profound alterations in the LCRP includenorpA(no-receptor-potential A) (Hotta & Benzer 1970, Pak et al 1970, Heisenberg 1971a) andtrp (transient receptor potential) (Figure 2A) (Cosens & Manning 1969)....
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...Strong alleles ofnorpA are virtually unresponsive to light (Hotta & Benzer 1970, Pak et al 1970) and are deficient in a PLC activity present in wild-type fly heads (Inoue et al 1985)....
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References
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TL;DR: Two mutants of Drosophila, tan and ebony, have normal eye pigments but show abnormalities in visual behaviour, and both show in their electroretinograms that the primary photoreception process occurs normally, but genetic defects block the usual consequent neural events.
Abstract: Two mutants of Drosophila, tan and ebony, have normal eye pigments but show abnormalities in visual behaviour. Both show in their electroretinograms that the primary photoreception process occurs normally, but genetic defects block the usual consequent neural events. Ambient light has opposite effects on the two mutants.
237 citations
TL;DR: Most of the nonphototactic mutants of Drosophila respond to light stimuli with normal electroretinograms, but mutants x-7 and tan seem to represent mutants of the visual pathway.
Abstract: Most of the nonphototactic mutants of Drosophila respond to light stimuli with normal electroretinograms. Mutants x-7 and tan, however, seem to represent mutants of the visual pathway. Their electroretinograms have two components—a fast one and a slow one—representing separate processes.
197 citations
TL;DR: The spectral sensitivity of the photoreceptors of a white-eye mutant of the housefly Musca domestica has been measured to 250 nm, suggesting the presence of energy transfer from the protein component of the visual pigment to the chromophore.
Abstract: 1. The spectral sensitivity of the photoreceptors of a white-eye mutant of the housefly Musca domestica has been measured to 250 nm. in the mid-ultraviolet. Maximum sensitivity is at 340-350 nm., as in the wild-type eye, and decreases at shorter wavelengths with a distinct shoulder at 280 nm. 2. Microspectrophotometric measurements of individual corneal facets show little absorption at wavelengths longer than 300 nm. but a sharp band (peak density about 0.4) at 277 nm. Adjustment of the spectral sensitivity curve for the filtering effect of the cornea makes the 280 nm. shoulder more prominent, suggesting the presence of energy transfer from the protein component of the visual pigment to the chromophore. 3. The short-wavelength limit of the housefly9s visible spectrum is determined by the availability of ultraviolet light and is about 300 nm. in nature. The long-wavelength limit is set by the falling absorption of the visual pigment in the red.
41 citations