Joe Cummins The identity of organisms and species Two kinds of techniques, DNA fingerprints and DNA barcodes, have revolutionized the identification of individual organisms and species.
Advanced Search Abstract Chironomidae Diptera pupal exuviae samples are commonly used for biological monitoring of aquatic habitats. DNA barcoding has proved useful for species identification of chironomid life stages containing cellular tissue, but the barcoding success of chironomid pupal exuviae is unknown.
We assessed whether standard DNA barcoding could be efficiently used for species identification of chironomid pupal exuviae when compared with morphological techniques and if there were differences in performance between temperate and tropical ecosystems, subfamilies, and tribes.
PCR, sequence, and identification success differed significantly between geographic regions and taxonomic groups. For Norway, 27 out of For Costa Rica, 69 out of Standard DNA barcoding of chironomid pupal exuviae had limited success in species identification of unknown specimens due to contaminations and lack of matching references in available barcode libraries, especially from Costa Rica.
Therefore, we recommend future biodiversity studies that focus their efforts on understudied regions, to simultaneously use morphological and molecular identification techniques to identify all life stages of chironomids and populate the barcode reference library with identified sequences.
Benthic macroinvertebrates are regularly used for biological monitoring of aquatic habitats, as they are common and widespread, with high species diversity and varying sensitivity to environmental disturbances Rosenberg and ReshResh Among benthic macroinvertebrates, the family Chironomidae Dipteracommonly referred to as the non-biting midges or chironomids, is a species-rich aquatic insect group that is particularly sensitive to changes in water quality PinderLindegaardNicacio and Juen Additionally, chironomids are usually the most abundant aquatic insect group in all types of freshwater with larval densities of many thousands per square meter Anderson et al.
An efficient, low-cost, and easy-to-use method for assessing chironomid communities involves collections of pupal exuviae Raunio and MuotkaWilson and RuseRaunio et al. Some advantages offered by collections of pupal exuviae over larval sampling for biological monitoring and assessment are that: A few disadvantages of collections of pupal exuviae over larval sampling are that: These constraints lead to widespread use of generic or higher taxonomic resolution for bioassessments with chironomids, which is problematic since species within a genus or family can display a broad range of sensitivities to various environmental stresses Sweeney et al.
DNA barcoding provides an alternative tool for species identification based on a short DNA sequence from a standardized genetic locus Hebert et al. A partial region bp of the cytochrome c oxidase I COI gene has been useful for separating cryptic, small, or rare species Hebert et al.
Life-stage associations with molecular tools can be particularly valuable for chironomids, since the immature life stages larvae and pupae are difficult to separate morphologically to species, and can be difficult to rear, especially in Neotropical settings with relatively high natural water temperatures Spies et al.
Recently, non-destructive DNA isolation methods from chironomid pupal exuviae have been explored, since pupal exuviae yield DNA in the form of muscle tissue, hairs, and epithelial cells lining the foregut, hindgut and trachea that are left behind on the inner surface of the cuticle by the emerging adult NationKrosch and CranstonKranzfelder et al.
Krosch and Cranston obtained sequences from 27 out of 58 chironomid pupal exuviae, and more recently, Kranzfelder et al. However, we did not study the success of chironomid pupal exuviae species delimitation using DNA barcodes, which is an important precursor for using DNA barcoding as part of bioassessment studies.
DNA barcoding has the potential to improve the use of chironomids in bioassessment studies of aquatic ecosystems by providing increased taxonomic resolution, improved accuracy and objectivity of data quality, and enhanced diagnostic ability of existing assessment tools Pilgrim et al. Currently, comprehensive DNA reference libraries for certain taxonomic groups and geographic ranges of chironomids remain poorly developed.
In addition, Chironomidae pupal exuviae decomposition rates depend on biotic and abiotic environmental factors, such as microbial activity, nutrient concentration, temperature and turbulence. Specifically, higher microbial i.
Additional abiotic factors in aquatic habitats, such as ultraviolet radiation, temperature, oxygen, pH, salinity, and substrate, can differ and impact DNA degradation Barnes et al. For example, Strickler et al.Identification of animal tissue samples using cytochrome b DNA sequences (mitochondrial DNA) Introduction In September of , an ultracold freezer meltdown occurred in one of the AMNH's collection units.
In order to salvage the samples, the staff rushed them to the museum's newest cryogenic collection: the Ambrose Monell Cryo Collection (AMCC). Evaluating Ethanol-based Sample Preservation to Facilitate Use of DNA Barcoding in Routine Freshwater Biomonitoring Programs Using Benthic selected from each treatment and processed to produce DNA barcodes from the mitochondrial gene cytochrome c oxidase I (COI).
On average, we obtained successful COI sequences (i.e. either full or partial. Standard cytochrome C oxidase subunit I (COI) gene fragments were sequenced for DNA barcoding of 39 samples from 9 snake species, including Bungarus multicinctus, the officially recognized origin animal by Chinese Pharmacopoeia, and other 8 adulterate species.
The aligned sequences, base pairs in length, were analyzed for divergence using. Introduction to DNA Barcoding. A sequence page contains the COI gene sequence (DNA barcode) obtained from the same organism COI gene sequence using bioinformatics tools tissue sample Benefits of participating in this global biodiversity project as a citizen scientist.
Species identification through barcoding is usually achieved by the retrieval of a short DNA sequence (the barcode) from a standard part of the genome (i.e., a specific gene region, cytochrome oxidase 1), from the specimen under investigation.
A region of the mitochondrial gene COI (cytochrome c oxidase This laboratory uses DNA barcoding to identify plants, fungi, or animals—or products made from them. environment. A small leaf disc, a whole insect, or samples of muscle are suitable sources.
DNA is extracted from the tissue sample, and the barcode portion of the rbc L, COI.