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Rhodopsin Gene (rhodopsin + gene)

Distribution by Scientific Domains
Life Sciences100%

Selected Abstracts

A new Minos vector for eye-specific expression of white+ marker in Ceratitis capitata and in distantly related dipteran species

INSECT MOLECULAR BIOLOGY, Issue 3 2006
M. Salvemini
Abstract The genetic transformation of insects by transposable elements is based on the use of selectable genetic markers required to identify transgenic individuals. Conserved regulatory sequences can be used to develop single constructs capable of adequate expression of a marker, across a range of different species. We present evidence that the Drosophila GBS regulatory element (Glass-binding site), derived from the Rh1 rhodopsin gene, is able to drive in vivo eye-specific expression of a Ccwhite+ transgene in the Mediterranean fruitfly Ceratitis capitata. The Ceratitis lineage diverged from that of Drosophila,120 Myr ago. As the GBS regulatory sequence seems to be partially conserved in the more distantly related dipteran species Anopheles gambiae (250 Myr), we propose that the GBS may be widely useful for driving eye-specific expression in a wide range of dipteran species. [source]

Rhodopsin population genetics and local adaptation: variable dim-light vision in sand gobies is illuminated

MOLECULAR ECOLOGY, Issue 20 2009
DANIEL EBERT
The visual pigments of fish are thought to be adapted to the variable spectral qualities of aquatic light environments. Most research on the role of natural selection on the evolution of rhodopsins and dim-light vision in fish has focused on variation among species and higher taxa. In this issue, Larmuseau et al. reveal substantial intraspecific sequence variation in RH1 (the rhodopsin gene) in sand gobies (Pomatoschistus minutus). Using population genetics and molecular evolution approaches, they detect positive selection on RH1 and find evidence for adaptation to local light conditions. [source]

To see in different seas: spatial variation in the rhodopsin gene of the sand goby (Pomatoschistus minutus)

MOLECULAR ECOLOGY, Issue 20 2009
MAARTEN H. D. LARMUSEAU
Abstract Aquatic organisms living in a range of photic environments require specific mechanisms to tune their visual pigments. Maximum absorbance (,max) of retinal rods in populations of the marine demersal sand goby, (Pomatoschistus minutus; Gobiidae, Teleostei) correlates with the local optic environment. It has been shown that this is not regulated through a physiological response by exchanging the rhodopsin chromophore. To test for evolutionary adaptation, the sequence of the rhodopsin (RH1) gene was analysed in 165 Pomatoschistus minutus individuals from seven populations across its distribution range. Analysis showed a high level of intraspecific polymorphism at the RH1 gene, including nonsynonymous mutations on amino acids, known as spectral tuning sites. Population differentiation at these sites was in agreement with the observed differentiation in ,max values. Analyses of dN/dS substitution rate ratios and likelihood ratio tests under site-specific models detected a significant signal of positive Darwinian selection on the RH1 gene. A strong discrepancy in differentiation was noticed between RH1 gene variation and the presumably neutral microsatellites and mitochondrial data. Samples did not cluster according to geographical or historical proximity with regards to RH1, but according to the general photic conditions of the habitat environment of the sand goby. This study highlights the usefulness of sensory genes, like rhodopsin, for studying the characteristics of local adaptation in marine nonmodel organisms. [source]

Actinorhodopsins: proteorhodopsin-like gene sequences found predominantly in non-marine environments

ENVIRONMENTAL MICROBIOLOGY, Issue 4 2008
Adrian K. Sharma
Summary Proteorhodopsins are light-energy-harvesting transmembrane proteins encoded by genes recently discovered in the surface waters of the world's oceans. Metagenomic data from the Global Ocean Sampling expedition (GOS) recovered 2674 proteorhodopsin-related sequences from 51 aquatic samples. Four of these samples were from non-marine environments, specifically, Lake Gatun within the Panama Canal, Delaware Bay and Chesapeake Bay and the Punta Cormorant Lagoon in Ecuador. Rhodopsins related to but phylogenetically distinct from most sequences designated proteorhodopsins were present at all four of these non-marine sites and comprised three different clades that were almost completely absent from marine samples. Phylogenomic analyses of genes adjacent to those encoding these novel rhodopsins suggest affiliation to the Actinobacteria, and hence we propose to name these divergent, non-marine rhodopsins ,actinorhodopsins'. Actinorhodopsins conserve the acidic amino acid residues critical for proton pumping and their genes lack genomic association with those encoding photo-sensory transducer proteins, thus supporting a putative ion pumping function. The ratio of recA and radA to rhodopsin genes in the different environment types sampled within the GOS indicates that rhodopsins of one type or another are abundant in microbial communities in freshwater, estuarine and lagoon ecosystems, supporting an important role for these photosystems in all aquatic environments influenced by sunlight. [source]

Diversity of bacteriorhodopsins in different hypersaline waters from a single Spanish saltern

ENVIRONMENTAL MICROBIOLOGY, Issue 11 2003
R. Thane Papke
Summary Haloarchaeal rhodopsins are a diverse group of transmembrane proteins that use light energy to drive several different cellular processes. Two rhodopsins, bacteriorhodopsin and halorhodopsins, are H+ and Cl, ion pumps, respectively, and two rhodopsins, sensory rhodopsin I and II, regulate phototaxis. Bacteriorhodopsin is of special interest as it is a non-chlorophyll-based type of phototrophy (i.e. generation of chemical energy from light energy). However, very little is known about the diversity and distribution of rhodopsin genes in hypersaline environments. Here, we have used environmental PCR and cloning techniques to directly retrieve rhodopsin genes from three different salinity ponds located in a sea salt manufacturing facility near Alicante, Spain. Our survey resulted in the discovery of previously concealed variation including what is hypothesized to be bacteriorhodopsin genes from the uncultivated square morphotype that dominates these environments. In some instances, identical genes were discovered in seemingly different habitats suggesting that some haloarchaea are present over widely varying concentrations of salt. [source]

Primers and polymerase chain reaction conditions for DNA barcoding teleost fish based on the mitochondrial cytochrome b and nuclear rhodopsin genes

MOLECULAR ECOLOGY RESOURCES, Issue 5 2007
RAFAEL G. SEVILLA
Abstract This report describes a set of 21 polymerase chain reaction primers and amplification conditions developed to barcode practically any teleost fish species according to their mitochondrial cytochrome b and nuclear rhodopsin gene sequences. The method was successfully tested in more than 200 marine fish species comprising the main Actinopterygii family groups. When used in phylogenetic analyses, its combination of two genes with different evolutionary rates serves to identify fish at the species level. We provide a flow diagram indicating our validated polymerase chain reaction amplification conditions for barcoding and species identification applications as well as population structure or haplotyping analyses, adaptable to high-throughput analyses. [source]