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901.
Construction of a taste-blind medaka fish and quantitative assay of its preference-aversion behavior 总被引:1,自引:0,他引:1
In vertebrates, the taste system provides information used in the regulation of food ingestion. In mammals, each cell group within the taste buds expresses either the T1R or the T2R taste receptor for preference-aversion discrimination. However, no such information is available regarding fish. We developed a novel system for quantitatively assaying taste preference-aversion in medaka fish. In this study, we prepared fluorescently labeled foods with fine cavities designed to retain tastants until they were bitten by the fish. The subjects were fed food containing a mixture of amino acids and inosine monophosphate (AN food), denatonium benzoate (DN food) or no tastant (NT food), and the amounts of ingested food were measured by fluorescence microscopy. Statistical analysis of the fluorescence intensities yielded quantitative measurements of AN food preference and DN food aversion. We then generated a transgenic fish expressing dominant-negative Galpha(i2) both in T1R-expressing and in T2R-expressing cells. The feeding assay revealed that the transgenic fish was unable to show a preference for AN food and an aversion to DN food. The assay system was useful for evaluating taste-blind behaviors, and the results indicate that the two taste signaling pathways conveying preferable and aversive taste information are conserved in fish as well as in mammals. 相似文献
902.
Amado MV Hrbek T Gravena W Fantin C DE Assunção EN Astolfi-Filho S Farias IP 《Molecular ecology resources》2008,8(6):1451-1453
The discus fishes (Symphysodon spp.) are economically important ornamental species. Thirteen microsatellite markers were developed from a CT(12) - and CA(12) -enriched whole genomic DNA library of Symphysodon discus. Allelic variability was tested on 44 individuals of two species (S. discus and S. aequifasciatus). Allelic richness ranged from two to 11 alleles per locus and observed heterozygosities from 0.083 to 0.998. All loci were at Hardy-Weinberg equilibrium, and no pair of loci showed linkage disequilibrium within a species. Cross-species amplification was also successfully performed in the Neotropical cichlids Uaru amphiacanthoides, Hoplarchus psittacus, Hypselecara coryphaenoides, Pterophyllum sp., Mesonauta sp. and Heros sp. 相似文献
903.
Eleven microsatellite markers were isolated and characterized for the ice goby, Leucopsarion petersii, from genomic libraries enriched for (ATG)(9) and (CA)(16) . Twenty individuals from a single population were used to screen polymorphism in these loci. The number of alleles per locus and observed heterozygosity ranged from four to 22 and from 0.35 to 1.00, respectively. All loci did not significantly deviated from Hardy-Weinberg equilibrium, and there was no evidence of linkage disequilibrium between all loci-pairs. These loci showed Mendelian inheritance in a full-sib family. The high level of polymorphism of these loci will be useful for studies of population genetics. 相似文献
904.
Studies using archived scales and otoliths to examine ancient fish populations have become increasingly common, despite many methodological challenges in ancient DNA research. Here, we describe a case of DNA contamination in both modern and historical samples of Pacific herring (Clupea pallasii), where the source of the contamination is likely from milt spillage during collection. We describe a series of experiments to remove contamination using pre-extraction wash treatments. Though contamination was easily removed from contemporary fin clippings, no method was successful at removing contamination from historical scales. We discuss the implications of our findings to the genetic analysis of archived samples. 相似文献
905.
Taylor DL Booth MG McFarland JW Herriott IC Lennon NJ Nusbaum C Marr TG 《Molecular ecology resources》2008,8(4):742-752
High throughput sequencing methods are widely used in analyses of microbial diversity, but are generally applied to small numbers of samples, which precludes characterization of patterns of microbial diversity across space and time. We have designed a primer-tagging approach that allows pooling and subsequent sorting of numerous samples, which is directed to amplification of a region spanning the nuclear ribosomal internal transcribed spacers and partial large subunit from fungi in environmental samples. To test the method for phylogenetic biases, we constructed a controlled mixture of four taxa representing the Chytridiomycota, Zygomycota, Ascomycota and Basidiomycota. Following cloning and colony restriction fragment length polymorphism analysis, we found no significant difference in representation in 19 of the 23 tested primers. We also generated a clone library from two soil DNA extracts using two primers for each extract and compared 456 clone sequences. Community diversity statistics and contingency table tests applied to counts of operational taxonomic units revealed that the two DNA extracts differed significantly, while the pairs of tagged primers from each extract were indistinguishable. Similar results were obtained using UniFrac phylogenetic comparisons. Together, these results suggest that the pig-tagged primers can be used to increase ecological inference in high throughput sequencing projects on fungi. 相似文献
906.
The relatively long pelagic larval duration of Pomacentrus amboinensis, a tropical fish, suggests the potential for long-distance dispersal; however, several nongenetic studies have found substantial self-recruitment at one location. To analyse patterns of connectivity of this species, primers for nine independent microsatellite loci were developed for P. amboinensis using a magnetic bead enrichment protocol. Twenty individuals from one location were analysed and observed heterozygosities ranged from 0.7 to 0.95. Eight of nine loci were in Hardy-Weinberg equilibrium and no evidence of linkage or null alleles were found. 相似文献
907.
Twelve polymorphic dinucelotide microsatellites in the freshwater eel Anguilla anguilla L. were isolated and characterized. Genetic diversity was assessed in eels from Lake Constance, Germany. Allele numbers ranged from five to 26 per locus with observed heterozygosities between 0.125 and 0.875. A portion of locus AangCT77 aligns with a transcribed region of the zebrafish gene crystallin beta B2. Cross-species amplification of most markers was possible for nine other Anguilla eel species. The newly developed primer pairs will facilitate population and conservation genetic studies in order to refine the understanding of the subtle population genetic structure typical of eels, and to identify interspecies admixture due to global trade. 相似文献
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