[First reporting of the signal crayfish (Decapoda, Astacidae) in the Province of Savona, Italy]

In this short note we report the sudden and numerically significant expansion of signal crayfish (P. leniusculus) from Piedmont towards Liguria. P. leniusculus (Decapode Astacidae) is native to northwestern America, introduced in Italy in 1981 in the province of Bolzano, a few years later it was reported in Brugneto Lake (Genova district) and during the 2009 in the Valla stream (Alessandria district). The peculiarities of this species, originally from "cold water", making it potentially invasive in the Apennine watercourses and also the presence of this allochthonous decapod in the Savona district, would like to suggest the implementation of containment plans, acts at least to limit its spread

Higher-order organisation of extremely amplified, potentially functional and massively methylated 5S rDNA in European pikes (Esox sp.)

Background Pikes represent an important genus (Esox) harbouring a pre-duplication karyotype (2n = 2x = 50) of economically important salmonid pseudopolyploids. Here, we have characterized the 5S ribosomal RNA genes (rDNA) in Esox lucius and its closely related E. cisalpinus using cytogenetic, molecular and genomic approaches. Intragenomic homogeneity and copy number estimation was carried out using Illumina reads. The higher-order structure of rDNA arrays was investigated by the analysis of long PacBio reads. Position of loci on chromosomes was determined by FISH. DNA methylation was analysed by methylation-sensitive restriction enzymes. Results The 5S rDNA loci occupy exclusively (peri)centromeric regions on 30-38 acrocentric chromosomes in both E. lucius and E. cisalpinus. The large number of loci is accompanied by extreme amplification of genes (>20,000 copies), which is to the best of our knowledge one of the highest copy number of rRNA genes in animals ever reported. Conserved secondary structures of predicted 5S rRNAs indicate that most of the amplified genes are potentially functional. Only few SNPs were found in genic regions indicating their high homogeneity while intergenic spacers were more heterogeneous and several families were identified. Analysis of 10-30 kb-long molecules sequenced by the PacBio technology (containing about 40% of total 5S rDNA) revealed that the vast majority (96%) of genes are organised in large several kilobase-long blocks. Dispersed genes or short tandems were less common (4%). The adjacent 5S blocks were directly linked, separated by intervening DNA and even inverted. The 5S units differing in the intergenic spacers formed both homogeneous and heterogeneous (mixed) blocks indicating variable degree of homogenisation between the loci. Both E. lucius and E. cisalpinus 5S rDNA was heavily methylated at CG dinucleotides. Conclusions Extreme amplification of 5S rRNA genes in the Esox genome occurred in the absence of significant pseudogenisation suggesting its recent origin and/or intensive homogenisation processes. The dense methylation of units indicates that powerful epigenetic mechanisms have evolved in this group of fish to silence amplified genes. We discuss how the higher-order repeat structures impact on homogenisation of 5S rDNA in the genome

Higher-order organisation of extremely amplified, potentially functional and massively methylated 5S rDNA in European pikes (Esox sp.)

16 p., tablas, ilustraciones[Background] Pikes represent an important genus (Esox) harbouring a pre-duplication karyotype (2n = 2x = 50) of economically important salmonid pseudopolyploids. Here, we have characterized the 5S ribosomal RNA genes (rDNA) in Esox lucius and its closely related E. cisalpinus using cytogenetic, molecular and genomic approaches. Intragenomic homogeneity and copy number estimation was carried out using Illumina reads. The higher-order structure of rDNA arrays was investigated by the analysis of long PacBio reads. Position of loci on chromosomes was determined by FISH. DNA methylation was analysed by methylation-sensitive restriction enzymes.[Results] The 5S rDNA loci occupy exclusively (peri)centromeric regions on 30–38 acrocentric chromosomes in both E. lucius and E. cisalpinus. The large number of loci is accompanied by extreme amplification of genes (>20,000 copies), which is to the best of our knowledge one of the highest copy number of rRNA genes in animals ever reported. Conserved secondary structures of predicted 5S rRNAs indicate that most of the amplified genes are potentially functional. Only few SNPs were found in genic regions indicating their high homogeneity while intergenic spacers were more heterogeneous and several families were identified. Analysis of 10–30 kb-long molecules sequenced by the PacBio technology (containing about 40% of total 5S rDNA) revealed that the vast majority (96%) of genes are organised in large several kilobase-long blocks. Dispersed genes or short tandems were less common (4%). The adjacent 5S blocks were directly linked, separated by intervening DNA and even inverted. The 5S units differing in the intergenic spacers formed both homogeneous and heterogeneous (mixed) blocks indicating variable degree of homogenisation between the loci. Both E. lucius and E. cisalpinus 5S rDNA was heavily methylated at CG dinucleotides.[Conclusions] Extreme amplification of 5S rRNA genes in the Esox genome occurred in the absence of significant pseudogenisation suggesting its recent origin and/or intensive homogenisation processes. The dense methylation of units indicates that powerful epigenetic mechanisms have evolved in this group of fish to silence amplified genes. We discuss how the higher-order repeat structures impact on homogenisation of 5S rDNA in the genome.This study was supported by a young researchers fellowship (NWF15/BIO-7) of the University of Innsbruck, Austria to RS (design of the study, sample collection, cytogenetic analysis, writing the manuscript); the Czech Science Foundation projects P501/12/G090 to AK (design of the study, epigenetic analysis, bioinformatics procedures, writing the manuscript) and 14-02940S to RS and ŠP (sample collection, DNA isolation); a project financed by University of Warmia and Mazury in Olsztyn, Poland (No. 18.610.003-300) to KO (writing the manuscript, cytogenetic analysis) and a project from the government of Spain (CGL2016-75694-P) to SG (genomic data analysis, manuscript editing).Peer reviewe

La Biosicurezza: Caposaldo Nelle Strategie Di Lotta Alle Specie Aliene In Ambiente Acquatico

\uc8 ormai consolidato che le invasioni biologiche costituiscono una seria minaccia alla biodiversit\ue0 acquatica, rappresentando una sfida molto difficile sia per la societ\ue0, che per le amministrazioni pubbliche e i politici che devono legiferare a riguardo. All\u2019interno dell\u2019Unione Europea sono presenti diverse norme e approcci gestionali redatti al fine di contrastare l\u2019introduzione e limitare la diffusione di specie aliene, in particolare di quelle invasive, anche se poi \ue8 assente o inadeguata l\u2019applicazione effettiva a livello territoriale. Questo probabilmente \ue8 dovuto ad uno scarso coordinamento a livello internazionale in primis, ma anche a livello nazionale e locale, per la corretta gestione di questa problematica. Nonostante alcuni autori abbiano sottolineato pi\uf9 volte la necessit\ue0 di utilizzare un approccio di lotta alla diffusione di queste specie basato sulla biosicurezza, la conoscenza di questa strategia e il suo corretto utilizzo \ue8 oggi limitato a pochi Stati del nord (Irlanda e Regno Unito), ad alcune realt\ue0 locali o ad alcuni taxa. Infatti, la strategia pi\uf9 efficace e meno dispendiosa dal punto di vista economico per evitare nuove introduzioni o per ridurre o limitare completamente la diffusione di specie aliene \ue8 la promozione e l\u2019implementazione di buone pratiche di biosicurezza. La biosicurezza si riferisce all\u2019insieme delle misure, delle politiche e delle procedure utili a ridurre al minimo il rischio di introduzione e di diffusione di una specie aliena che, in determinate condizioni, pu\uf2 diventare invasiva, rappresentando una minaccia per le specie autoctone e per gli ecosistemi. La buona applicazione di tali misure a livelli adeguati, ridurrebbe al minimo anche i rischi sanitari che derivano da tali introduzioni. Tutti possono contribuire alla corretta applicazione di tali misure: e\u300 importante che gli sforzi volti ad aumentare la consapevolezza sulle misure di biosicurezza riguardino tutti i livelli della societ\ue0 civile e soprattutto i portatori di interesse (pescatori, commercianti, allevatori). Nel corso della presentazione verranno illustrate le misure da applicare sulla base della bibliografia presente e sulle esperienze maturate in campo

Biobanking for COVID-19 research

Biobanks are imperative infrastructures, particularly during outbreaks, when there is an obligation to acquire and share knowledge as quick as possible to allow for implementation of science-based preventive, diagnostic, prognostic and therapeutic strategies

Assessing the status of amphibian breeding sites in Italy: a national survey

The ecological status of 203 amphibian aquatic breeding sites, selected from the national database of the Societas Herpetologica Italica (SHI), was surveyed in the period 2008-2009 to assess their ecological status. Sites were randomly extracted, after stratification by the three biogeographical regions present in Italy, besides Sardinia and Sicily. The field surveys, conducted by professionals, amateurs and volunteers, showed that since 1979 about 11% of the sites were destroyed or no more suitable for the reproduction of amphibians that bred in the same site in the past. The percentage of destroyed or altered sites was 8%, both in the Mediterranean and Alpine biogeographical regions, and 15% in the Continental one. However, there were no statistical significant differences among the regions, suggesting that the rate of amphibian site loss was similar in different parts of Italy. This nation-wide monitoring project demonstrated that in Italy, during the last thirty years, a relevant proportion of amphibian breeding habitats has been destroyed or altered. The main cause of site alteration were land reclamation and water extraction