An insight into the Chinese traditional seafood market: Species characterization of cephalopod products by DNA barcoding and phylogenetic analysis using COI and 16SrRNA genes

Squids, cuttlefish and octopus are used for the preparation of traditional products sold on the Chinese market without a specific denomination. In this study DNA barcoding and phylogenetic distance analysis of COI and 16S rRNA genes' fragments were used to characterize the most commonly processed species in dried whole, grilled shredded and salted cephalopod preparations. Ninety-five products (23 sold as cuttlefish, 4 as octopus and 68 as squid) purchased in Chinese local markets were analyzed. Overall, the study identified 10 different species: Sepia pharaonis, S. esculenta, S. recurvirostra, S. lycidas in cuttlefish; Amphioctopus marginatus in octopus; Uroteuthis chinensis, U. edulis, Ommastrephes bartramii, Illex argentinus and Dosidicus gigas in squids. This latter species, characterized by a low commercial value, was found in the majority of the samples (50.5%) and in all the shredded products. By comparing the molecular results with the declared macrocategory (cuttlefish, octopus and squid), two cases of misdescription were pointed out, involving shredded cuttlefish and octopus which were identified as D. gigas. Our results are of particular interest in the light of the scarcity of data regarding the identification of cephalopods on international markets and considering that China is one of the leading cephalopod-producing countries

Low frequency of the scrapile resistance-associated allele and presence of lysine-171 allele of the prion protein gene in Italian Biellese ovine breed

Frequencies of polymorphisms at codons 136, 154 and 171 of the prion protein (PrP) gene were studied in 1207 pure-bred and cross-bred Italian Biellese rams, a small ovine breed of about 65 000 head in Italy. Aside from the five most common alleles (VRQ, ARQ, ARR, AHQ and ARH), the rare ARK allele was also found, with the highest frequency reported so far in an ovine breed (2·5 %). ARK/--- genotypes had a total frequency of 4·9 %. The resistance-associated ARR allele was seen at a low frequency (8·3 %). Only 1·4 % of animals examined had a resistant ARR/ARR PrP genotype. Semi-resistant (ARR/ARQ, ARR/ARH and ARR/AHQ) PrP genotypes had a total frequency of 12·6 % and PrP genotypes that are associated with high scrapie susceptibility (e.g. VRQ/VRQ and ARQ/ARQ) had a total frequency of 81·1 %. Statistical analysis comparing PrP allele frequencies between pure-bred and cross-bred animals showed that the ARR allele occurred at a significantly lower frequency in pure-bred rams. Furthermore, comparison of PrP allele frequencies between pure-bred rams over 18 months of age and those below 18 months of age showed a significant decrease in the ARR allele in breeding rams over 18 months of age. Based on these results, breeding for scrapie resistance in the Biellese breed will have to take into account the low frequency of the ARR allele, which also seems to be subject to negative selection by farmers. Further investigation is required to understand whether the ARK allele is also associated with resistance to transmissible spongiform encephalopathie

Prevalence and phylogenetic analysis of OsHV-1 in wild populations of Pacific oyster Crassostrea gigas in Italy

International audienc

Ostreid herpesvirus type 1 genomic diversity in wild populations of Pacific oyster Crassostrea gigas from Italian coasts

International audienceOstreid herpesvirus 1 (OsHV-1) is a significant pathogen affecting the young Pacific oyster Crassostrea gigas, worldwide. A new variant, OsHV-1 μVar, has been associated with recurrent mortality events in Europe since 2008. Epidemiological data collection is key for global risk assessment; however little is known about health status and genotypes present in European wild oyster beds. Most studies to date have involved only cultivated individuals during mortality events, and reported low genotype diversity. With this study, conducted along the Italian coasts, we investigated for the first time the presence of OsHV-1 in European natural oyster beds. Analysis of three genomic regions revealed the presence of at least nine different genotypes, including two variants close to the OsHV-1 reference, known since the early 1990s but with no European record reported since 2010, and highlights relevant genotype diversity in natural environment. Phylogenetic analysis distinguished two distinct clusters and geographical distribution of genotypes, with the exception of a variant very closely related to the μVar, which appeared the single genotype present in all the Adriatic sites. Interestingly, these wild symptom free populations could represent, in Europe, an accessible alternative to the import of OsHV-1-resistant oyster strains from the East Pacific, the native area of C. gigas, avoiding the high-risk of non-native marine species and new pathogen introductions

Identification of prion protein gene polymorphisms in goats from Italian scrapie outbreaks

Susceptibility to scrapie in sheep is influenced by polymorphisms of the prion protein (PrP) gene, whereas no strong association between genetics and scrapie has yet been determined in goats due to the limited number of studies on these animals. In this case¿control study on 177 goats from six Italian scrapie outbreaks, the association between PrP alleles and the occurrence of scrapie was studied. Three silent mutations and 11 PrP polymorphisms were identified, of which two polymorphisms (L133Q and M137I) and one silent mutation (T202T) have not been reported previously. Twelve alleles were determined by cloning. Statistical analysis suggested a possible protective role against scrapie for the glutamine to lysine mutation at codon 22

Genetic variability of the PRNP gene in goat breeds from Northern and Southern Italy

Aims: To determine the variability of the prion protein gene (PRNP) in goats from Northern and Southern Italy. Methods and results: Genomic DNA isolated from goat blood was polymerase chain reaction (PCR)-amplified for the coding region of the PRNP gene and then sequenced. In total, 13 polymorphic sites were identified: G37V, T110P, G127S, M137I, I142M, I142T, H143R, R154H, P168Q, T194P, R211Q, Q222K and S240P (substitutions I142T and T194P are novel) giving rise to 14 haplotypes. Clear frequency differences between Northern and Southern breeds were found and confirmed by genetic distance analysis.Conclusions: Differences in allele distribution were found between Northern and Southern goats, in particular regarding the M142 and K222 alleles, possibly associated to scrapie resistance; philogeographical analysis supported the idea that Northern and Southern breeds may be considered as separate clusters. Significance and impact of the study: In Italy only limited studies have been carried out on caprine PRNP genotype distribution; this study is important to fill this lack of information. Moreover the finding of significant differences among allele distributions in Northern and Southern goats, especially if involved in modulating resistance/susceptibility, need to be carefully considered for the feasibility of selection plans for resistance to scrapie