The food safety of sushi and the health of consumers are currently of high concern for food safety agencies across the world due to the globally widespread consumption of these products. The ...microbiological and toxicological risks derived from the consumption of raw fish and seafood have been highlighted worldwide, while the practice of species substitution in sushi products has attracted the interest of researchers more than food safety agencies. In this study, samples of sushi were processed for species authentication using the Cytochrome Oxidase I (COI) gene as a DNA barcode. The approach of Citizen Science was used to obtain the sushi samples by involving people from eighteen different Italian cities (Northern, Central and Southern Italy). The results indicate that a considerable rate of species substitution exists with a percentage of misdescription ranging from 31.8% in Northern Italy to 40% in Central Italy. The species most affected by replacement was
followed by the flying fish roe substituted by eggs of
. These results indicate that a standardization of fish market names should be realized at the international level and that the indication of the scientific names of species should be mandatory for all products of the seafood supply chain.
Mitochondrial oxidative phosphorylation (OXPHOS) genes are a system subject to selection under determined environmental constraints despite a neutral evolution model that has long been hypothesized ...for the mitochondrial genome. In this study, the sequences of
,
, and
OXPHOS genes were analyzed in six populations of the eurythermal and euryhaline killifish
, to detect non-synonymous mutations leading to amino acid changes and to check whether selection acted on them using tests of recombination and selection. The results indicate a high
and
gene diversity and a high percentage of private haplotypes in all populations. In the Greek population, non-synonymous nucleotide substitutions were observed in the N-terminal region of
and
. Positively selected sites were also found. The information we obtained from the mitochondrial DNA sequences of
adds to the growing data on selective pressure acting on mitochondrial DNA in non-model species. These results should be explored from the perspective of the local adaptation of eurythermal and euryhaline species and supported using experimental evidence to better understand the interplay between historical climatic events and local adaptation and how each of them contributes to shaping the genetic structure of this species.
Mitochondrial DNA easily undergoes alterations due to exposure to stress factors. In particular, mitochondrial DNA copy number (mtDNAcn) variation can be used as a biomarker of the effect of exposure ...to various environmental contaminants. In this study, a molecular investigation based on the evaluation of mtDNAcn variation was applied for the first time to individuals belonging to the species Opsius heydeni. A total of 20 samples were collected from two sites in eastern Sicily: Priolo Gargallo, a site with a strong anthropic impact, and the Simeto river Oasis, a control site. Specimens identified based on morphological traits were used to obtain COI gene sequences from this species that were not previously available in GenBank. After processing, the relative mtDNAcn was evaluated using real-time PCR of a portion of the COI and 18S genes. A decrease in the mtDNAcn in the specimens from the polluted site was observed. These results highlight how environmental contaminants can alter the mitochondrial genome and how Opsius heydeni can be considered a potential bioindicator species of environmental quality.
The DNA analysis is the best approach to authenticate species in seafood products and to unveil frauds based on species substitution. In this study, a molecular strategy coupling Cytochrome Oxidase I ...(COI) DNA barcoding with the consolidated methodology of Restriction Fragment Length Polymorphisms (RFLPs), named COIBar-RFLP, was applied for searching pattern of restriction enzyme digestion, useful to discriminate seven different fish species (juveniles of
and
sold in Italy as "bianchetto" and
sold as "rossetto"; icefish
; European perch,
and the Nile Perch,
striped catfish,
). A total of 30 fresh and frozen samples were processed for DNA barcoding, analyzed against a barcode library of COI sequences retrieved from GenBank, and validated for COIBar-RFLP analysis. Cases of misdescription were detected: 3 samples labeled as "bianchetto" were substituted by
(2 samples) and
(1 sample); 3 samples labeled as "persico reale" (
) were substituted by
and
All species were simultaneously discriminated through the restriction pattern obtained with
I enzyme. The results highlighted that the COIBar-RFLP could be an effective tool to authenticate fish in seafood products by responding to the emerging interest in molecular identification technologies.
The old world killifish Aphanius fasciatus is a typical inhabitant of transition waters along the coasts of the central and eastern Mediterranean Sea, where it lives in environments (salt ponds, ...estuaries, and coastal lagoons) with large variations in salt, oxygen, and temperature. Therefore, A. fasciatus could be an interesting non-model species to be studied to evaluate the response of the mitochondrial oxidative phosphorylation (OXPHOS) genes to the variations and extremes of environmental factors. In this study, the sequences of three OXPHOS genes were analyzed in six populations of A. fasciatus to detect mutations and sites subject to selection. The results indicate that mutations were detected in two genes of the Greek population. Moreover, positively selected sites were also found. The information we obtained from the mitochondrial DNA sequences of A. fasciatus adds to the growing data on selective pressure acting on mitochondrial DNA. These results should be explored from the perspective of the local adaptation of a species highly tolerant to wide fluctuations of environmental parameters and should be supported using experimental evidence to better understand the interplay between historical climatic events and local adaptation and how each of them contributes to shaping the genetic structure of this species. Mitochondrial oxidative phosphorylation (OXPHOS) genes are a system subject to selection under determined environmental constraints despite a neutral evolution model that has long been hypothesized for the mitochondrial genome. In this study, the sequences of ND1, Cytb, and COI OXPHOS genes were analyzed in six populations of the eurythermal and euryhaline killifish A. fasciatus, to detect non-synonymous mutations leading to amino acid changes and to check whether selection acted on them using tests of recombination and selection. The results indicate a high COI and Cytb gene diversity and a high percentage of private haplotypes in all populations. In the Greek population, non-synonymous nucleotide substitutions were observed in the N-terminal region of COI and Cytb. Positively selected sites were also found. The information we obtained from the mitochondrial DNA sequences of A. fasciatus adds to the growing data on selective pressure acting on mitochondrial DNA in non-model species. These results should be explored from the perspective of the local adaptation of eurythermal and euryhaline species and supported using experimental evidence to better understand the interplay between historical climatic events and local adaptation and how each of them contributes to shaping the genetic structure of this species.
Industrial activities significantly damage the surrounding environment due to the release of contaminants of various types. Therefore, the search for parameters that can provide information on the ...quality of the environment is of great relevance. In this research, for the first time, specimens belonging to Opsius heydeni, an insect living on Tamarix plants, were sampled and analyzed at two Sicilian sites (the polluted industrial site Priolo Gargallo and the control site Oasi del Simeto) to study the effect of pollution on wildlife organisms. Using molecular biology techniques, it has been seen that environmental pollutants can modify the mitochondrial DNA in these specimens; in particular, a decrease in the number of DNA molecules was observed in the specimens sampled at Priolo Gargallo. In conclusion, these results highlight how the studied species can be useful to monitor the effects of pollutants on biota. Mitochondrial DNA easily undergoes alterations due to exposure to stress factors. In particular, mitochondrial DNA copy number (mtDNAcn) variation can be used as a biomarker of the effect of exposure to various environmental contaminants. In this study, a molecular investigation based on the evaluation of mtDNAcn variation was applied for the first time to individuals belonging to the species Opsius heydeni. A total of 20 samples were collected from two sites in eastern Sicily: Priolo Gargallo, a site with a strong anthropic impact, and the Simeto river Oasis, a control site. Specimens identified based on morphological traits were used to obtain COI gene sequences from this species that were not previously available in GenBank. After processing, the relative mtDNAcn was evaluated using real-time PCR of a portion of the COI and 18S genes. A decrease in the mtDNAcn in the specimens from the polluted site was observed. These results highlight how environmental contaminants can alter the mitochondrial genome and how Opsius heydeni can be considered a potential bioindicator species of environmental quality.
Processed seafood products are subject to fraudulent species substitution practices that pose problems not only economically but also for human health due to the risk of allergies. DNA-based ...molecular techniques offer an undoubted contribution to unraveling commercial fraud in processed seafood products, and several investigations have been conducted to develop specific and rapid assays for the identification of fish species. In this context, we hypothesize that the Cytochrome Oxidase I (COI) Barcode-Restriction Fragment Length Polymorphisms (COIBar- RFLP) strategy may be a useful molecular tool to quickly assess the authenticity of seafood products because (i) it takes advantage of the specific discriminatory power of the COI gene as a barcode and of the robust Restriction Fragment Length Polymorphism methodology and (ii) the interspecific variation in the digestion pattern obtained using the restriction enzymes allows bypassing the gene sequencing step. The Sparidae family includes species of high commercial value and many sparid species are difficult to recognize considering only their morphological features; thus, misidentifications are frequent. The aim of this work was to identify sparid species in processed products using the COIBar-RFLP strategy with the MspI restriction enzyme which yielded differential digestion patterns and unveiled two cases of species substitution. The proposed methodology could be used in food control laboratories to combat the widespread habit of fraudulent species substitution in the fishing industry.
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