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Cytogenetic abnormalities associated with viral infections, including from viruses of the Herpesvirales order, have been reported in vertebrate species. Ostreid herpesvirus 1 (Os HV-1) has been detected worldwide during mortality outbreaks of the Pacific oyster Crassostrea gigas. On the other hand, a high proportion of aneuploid cells in somatic tissues have been observed in C. gigas. In this study, we analysed the putative association between aneuploidy levels and the detection of Os HV-1 in gills of C. gigas, the Portuguese oyster C. angulata and their F1 hybrids cultured in Ria Formosa (Portugal). Os HV-1 was detected by PCR in 5.4% of the total of oysters analysed ( n = 111) namely in 11.1%, 8.0% and 1.7% of C. gigas, C. angulata and F1 hybrid respectively. Sequencing analysis of a viral fragment amplified with the C2/C6 primer pair revealed a high similarity with the Os HV-1 reference type. Moreover, in situ hybridization confirmed the presence of Os HV-1 in gill tissue. Oysters where Os HV-1 was detected had a significantly higher mean percentage of aneuploid cells (25%) than the ones where the virus was not detected (18%). However, the overall low percentage of positive samples contrasted with the high mean percentage of aneuploidy observed, with 50% of the oysters analysed showing a percentage of aneuploid cells between 20% and 30%. We hypothesize that somatic aneuploidy may adversely affect oysters making them more prone to Os HV-1 infection, but the virus is unlikely to be the cause of somatic aneuploidy. [ABSTRACT FROM AUTHOR]

The near-neutral model of B chromosome evolution predicts that the invasion of a new population should last some tens of generations, but the details on how it proceeds in real populations are mostly unknown. Trying to fill this gap, we analyze here a natural population of the grasshopper Eyprepocnemis plorans at three time points during the last 35 years. Our results show that B chromosome frequency increased significantly during this period and that a cline observed in 1992 had disappeared in 2012 once B chromosome frequency reached an upper limit at all sites sampled. This indicates that, during B chromosome invasion, transient clines for B chromosome frequency are formed at the invasion front on a microgeographic scale. Computer simulation experiments showed that the pattern of change observed for genotypic frequencies is consistent with the existence of B chromosome drive through females and selection against individuals with a high number of B chromosomes. [ABSTRACT FROM AUTHOR]

Perkinsosis is a disease of gastropod and bivalve molluscs caused by protozoan parasites of the Perkinsus genus. These parasites have been responsible for mass mortalities worldwide, with a significant impact in both fisheries and aquaculture, and resulting in severe economic losses. This review focuses mainly on current knowledge of diagnostic methods and on the distribution of Perkinsus spp. in the Northeastern Atlantic and Mediterranean Sea, which infect the grooved carpet shell clam Ruditapes decussatus and the Japanese carpet shell clam Ruditapes philippinarum . The association between perkinsosis and high mortality rates of R. decussatus and R. philippinarum in southern European countries such as Portugal and Italy is discussed as is the role of environmental factors in those mortality outbreaks. The putative introduction of Perkinsus olseni into the Northeastern Atlantic and Mediterranean Sea is also discussed, as are management strategies that could be used to mitigate the impact of perkinsosis in production of R. decussatus and R. philippinarum . [ABSTRACT FROM AUTHOR]

Simple sequence repeats (SSRs), also known as microsatellites, are one of the prominent DNA sequences shaping the repeated fraction of eukaryotic genomes. In spite of their profuse use as molecular markers for a variety of genetic and evolutionary studies, their genomic location, distribution, and function are not yet well understood. Here we report the first thorough joint analysis of microsatellite motifs at both genomic and chromosomal levels in animal species, by a combination of 454 sequencing and fluorescent in situ hybridization (FISH) techniques performed on two grasshopper species. The in silico analysis of the 454 reads suggested that microsatellite expansion is not driving size increase of these genomes, as SSR abundance was higher in the species showing the smallest genome. However, the two species showed the same uneven and nonrandom location of SSRs, with clear predominance of dinucleotide motifs and association with several types of repetitive elements, mostly histone gene spacers, ribosomal DNA intergenic spacers (IGS), and transposable elements (TEs). The FISH analysis showed a dispersed chromosome distribution of microsatellite motifs in euchromatic regions, in coincidence with chromosome location patterns previously observed for many mobile elements in these species. However, some SSR motifs were clustered, especially those located in the histone gene cluster. [ABSTRACT FROM AUTHOR]

Supernumerary (B) chromosomes have been shown to contain a wide variety of repetitive sequences. For this reason, fluorescent in situ hybridisation (FISH) is a useful tool for ascertaining the origin of these genomic elements, especially when combined with painting from microdissected B chromosomes. In order to investigate the origin of B chromosomes in the fish species Astyanax paranae, these two approaches were used along with PCR amplification of specific DNA sequences obtained from the B chromosomes and its comparison with those residing in the A chromosomes. Remarkably, chromosome painting with the one-arm metacentric B chromosome probe showed hybridization signals on entire B chromosome, while FISH mapping revealed the presence of H1 histone and 18S rDNA genes symmetrically placed in both arms of the B chromosome. These results support the hypothesis that the B chromosome of A. paranae is an isochromosome. Additionally, the chromosome pairs Nos. 2 or 23 are considered the possible B chromosome ancestors since both contain syntenic H1 and 18S rRNA sequences. The analysis of DNA sequence fragments of the histone and rRNA genes obtained from the microdissected B chromosomes showed high similarity with those obtained from 0B individuals, which supports the intraspecific origin of B chromosomes in A. paranae. Finally, the population hereby analysed showed a female-biased B chromosome presence suggesting that B chromosomes in this species could influence sex determinism. [ABSTRACT FROM AUTHOR]

The original article can be found online at https://doi.org/10.1186/s12915-021-01216-9. B Correction to: BMC Biology 20, 1-24 (2021) b B https://doi.org/10.1186/s12915-021-01216-9 b The original article contained an error by the production team whereby Figs. [Extracted from the article]

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An amendment to this paper has been published and can be accessed via a link at the top of the paper. [ABSTRACT FROM AUTHOR]

The article evaluates the efficiency of the process for removing bacteria from commercial bivalves in removing Cryptosporidium from bivalves consumed in Portugal. Cryptosporidum parvum is an enteric zoonotic parasite that is often discharged into rivers and seas by rain and sewage treatment effluents. The author discusses the factors that contribute to possible failure of the currently used cleansing protocol.

Introduction: Exposure to cat allergens is often difficult to avoid. Here, we evaluated the safety and effectiveness of a depigmented, polymerized cat epithelium extract (Dpg-pol-cat) for the treatment of allergic rhinoconjunctivitis and asthma. Methods: Real-world, retrospective study of patients ≥12 years of age with cat allergy and moderate to severe allergic rhinitis/rhinoconjunctivitis, with or without asthma, who started allergen immunotherapy (AIT) with Dpg-pol-cat extract during routine visits to the Allergy Department. Safety and effectiveness (improvement in FEV1) of AIT were evaluated. The use of rescue medication and patient perceptions were also assessed. Results: A total of 62 patients were included, of whom 34 (54.8%) received AIT for at least 12 months. There were 15 adverse events, 8 local and 7 systemic, of which 3 led to discontinuation of AIT. Patients with moderate to severe rhinitis decreased from 88.2% at baseline to 29.4% at 12 months (p < 0.0001) and patients with moderate asthma decreased from 76.5% to 38.2% (p = 0.0004). FEV1 improved from a mean (standard deviation) of 3,188.9 (771.4) mL to 3,419.6 (878.4) mL (p = 0.0023). The use of rescue medication for rhinitis decreased from 94.1% to 23.5% (p < 0.0001). All patients requiring rescue medication for conjunctivitis (20.6%) were off medication at 12 months, and 97.1% and 92.6% of patients reported improvement in rhinitis and asthma symptoms, respectively. Conclusion: AIT with Dpg-pol-cat extract shows a favorable safety and effectiveness profile in patients with allergic rhinitis/rhinoconjunctivitis due to cat allergy, with or without allergic asthma, representing a valuable treatment option for these patients. [ABSTRACT FROM AUTHOR]

Papillary fibroelastoma is an uncommon primary cardiac tumor, predominantly associated with left-sided valvular endocardium. Affectation of tricuspid valve leaflets is rare, and management in asymptomatic patients remains controversial. We present a 30-year-old female referred for evaluation prior to bariatric surgery. A routine echocardiogram revealed a mobile cardiac mass attached to the tricuspid valve. A patent foramen ovale was also present. Tumor was surgically removed. Histology confirmed the definite diagnosis of a papillary fibroelastoma. In our case, the presence of a patent foramen ovale associated with the right-sided fibroelastoma was decisive in the decision for surgery. [ABSTRACT FROM AUTHOR]

In some eukaryotes, germline and somatic genomes differ dramatically in their composition. Here we characterise a major germline–soma dissimilarity caused by a germline-restricted chromosome (GRC) in songbirds. We show that the zebra finch GRC contains >115 genes paralogous to single-copy genes on 18 autosomes and the Z chromosome, and is enriched in genes involved in female gonad development. Many genes are likely functional, evidenced by expression in testes and ovaries at the RNA and protein level. Using comparative genomics, we show that genes have been added to the GRC over millions of years of evolution, with embryonic development genes bicc1 and trim71 dating to the ancestor of songbirds and dozens of other genes added very recently. The somatic elimination of this evolutionarily dynamic chromosome in songbirds implies a unique mechanism to minimise genetic conflict between germline and soma, relevant to antagonistic pleiotropy, an evolutionary process underlying ageing and sexual traits. Songbirds have extensive germline–soma genome differences due to developmental elimination of a germline-specific chromosome (GRC). Here, the authors show that the GRC contains dozens of expressed developmental genes, some of which have been on the GRC since the ancestor of all songbirds. [ABSTRACT FROM AUTHOR]