ABSTRACT. A field survey of algae and cyanobacteria from terrestrial and freshwater habitats in the vicinity of Ny-Ålesund and on Blomstrandhalvøya Island (Svalbard) was performed in June 2009, and results were compared with data from our fieldwork in June 2006. In total, we identified 30 taxa belonging to 23 genera from the specimens collected near Ny-Ålesund (26 taxa) and on Blomstrandhalvøya Island (24 taxa). Five species previously unrecorded from this locality are depicted, including astaxanthin-containing Haematococcus sp. collected from Blomstrandhalvøya Island. This is the first report on a Haematococcus species from the High Arctic.
Antarctica is considered a relatively uncontaminated region with regard to the infectious diseases because of its extreme environment, and isolated geography. For the genetic characterization and molecular epidemiology of the newly found penguin adenovirus in Antarctica, entire genome sequencing and annual survey of penguin adenovirus were conducted. The entire genome sequences of penguin adenoviruses were completed for two Chinstrap penguins (Pygoscelis antarctica) and two Gentoo penguins (Pygoscelis papua). The whole genome lengths and G+C content of penguin adenoviruses were found to be 24,630–24,662 bp and 35.5–35.6%, respectively. Notably, the presence of putative sialidase gene was not identified in penguin adenoviruses by Rapid Amplification of cDNA Ends (RACE-PCR) as well as consensus specific PCR. The penguin adenoviruses were demonstrated to be a new species within the genus Siadenovirus, with a distance of 29.9–39.3% (amino acid, 32.1–47.9%) in DNA polymerase gene, and showed the closest relationship with turkey adenovirus 3 (TAdV-3) in phylogenetic analysis. During the 2008–2013 study period, the penguin adenoviruses were annually detected in 22 of 78 penguins (28.2%), and the molecular epidemiological study of the penguin adenovirus indicates a predominant infection in Chinstrap penguin population (12/30, 40%). Interestingly, the genome of penguin adenovirus could be detected in several internal samples, except the lymph node and brain. In conclusion, an analysis of the entire adenoviral genomes from Antarctic penguins was conducted, and the penguin adenoviruses, containing unique genetic character, were identified as a new species within the genus Siadenovirus. Moreover, it was annually detected in Antarctic penguins, suggesting its circulation within the penguin population.
Although relatively a large number of the complete mitochondrial genome sequences have been determined from various decapod species (29 mtDNA sequences reported so far), the information for the infraorder Astacidea (including lobsters, crayfishes, and their relatives) is very limited and represented by only one complete sequence from the Australian freshwater crayfish species Cherax destructor. In this study, we determined the complete mitochondrial DNA sequence of Homarus americanus, the first representative of the family Nephropidae to be fully characterized. Comparison of the gene arrangement reveals that H. americanus mtDNA is identical to those of other pancrustacean species but differs from the other astacidean species (C. destructor). Based on these data, it can be assumed that an idiosyncratic gene order discovered in C. destructor mtDNA may be secondarily acquired from the ancestral lineage of the Astacidea.
S. (2012). The mitochondrial genomes of Cambaroides similis and Procambarus clarkii (Decapoda: Astacidea: Cambaridae): the phylogenetic implications for Reptantia. -Zoologica Scripta, 41, 281-292. We determined the complete mitochondrial (mt) genome sequences of two northern hemisphere freshwater crayfish species, Cambaroides similis and Procambarus clarkii (Decapoda: Astacidea: Cambaridae). These species have an identical gene order with typical metazoan mt genome compositions. However, their gene arrangement was very distinctive compared with the pan-crustacean ground pattern because of the presence of a long inverted block, which included 19 coding genes and a control region (CR). Because the CR was inverted, their nucleotide frequencies showed a reversed strand-specific bias compared with the other decapods. Based on a comparative analysis of mt genome arrangements between southern and northern hemisphere crayfish and their putative close marine relative (Homarus americanus, a true clawed lobster), we postulated that the ancestor of freshwater crayfish had a typical pan-crustacean mtDNA gene order, similar to its marine relatives. Based on this assumption, we traced the most parsimonious gene rearrangement scenario of the northern hemisphere crayfish. In a phylogenetic study on the infraordinal relationships in reptan decapods, the lineage Lineata [Thalassinidea (Brachyura, Anomura)] was well supported, while the infraorder positions of Achelata and Astacidea remained unidentified.Complete mitochondrial genomes of northern hemisphere crayfish d S. Kim et al.
Here, we report the first complete mitochondrial genome sequence of northern mauxia shrimp Acetes chinensis (Decapoda, Dendrobranchiata, Sergestoidae). The genome sequence was 15,740 bp in size, and the gene content, gene order and transcriptional polarity were almost identical to the pancrustacean ground pattern, with the one exception that an extra trnS(1)(AGC) was adjacent to the original trnS(1)(AGA). The two tandemly duplicated trnS(1) showed a high sequence similarity (82.3%), with almost identical secondary structure lacking a DHU arm. Comparison of codon usage suggests that both of the trnS(1) genes were functional.
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