Search

The present paper summarizes acanthocephalan parasites of the family Illiosentidae Golvan, 1960, collected from the intestine of common carp (Cyprinus carpio L.) from Taihu Lake in Wuxi, Jiangsu Province, China. A total of 21 acanthocephalan specimens were found in 6 carps (prevalence of 35%). All the studied specimens were assigned to the family Illiosentidae based on the family-specific morphology of the worms and the presence of 8 cement glands in the males. However, the specimens recently found in common carp differed from all 14 extant genera of the family Illiosentidae in the structure of the reproductive system of both sexes, i.e. i) a vagina lacking a muscular sphincter; ii) the presence of a terminally pointed protruding tail end in the form of a dome with a muscular base; iii) the female genital muscles are fan-shaped cells, each of which has a nucleus and is not attached to the anterior wall of the body; iv) the muscular lip of the bursa of males repeats the curved shape of the posterior end of females, which en copula allows the lip of the bursa to seal to the posterior end of the female. Morphologically Neotegorhynchus n. g. is closest to the genus Tegorhynchus, but differs from it, in addition above features in i) the terminal position of the genital pores of females without a hollow genital vestibule and without a transverse cleft connected to the dorsal terminal genital pore, as in Tegorhynchus brevis; ii) cerebral ganglion at the border of the anterior and middle third of the proboscis vessel; iii) spherical cement reservoir. Molecular studies confirmed Neotegorhynchus n. g. as belonging to the family Illiosentidae, showing less than 98.9% sequence similarity in SSU rDNA and 81.8% in COI with the genus Dentitruncus. Therefore, a new acanthocephalan genus, Neotegorhynchus n. g., is erected, and Neotegorhynchus cyprini n. comb. is designated as the type species and its neotype.

Helminths of 12 fish species collected near the South Orkney Islands, West Antarctica were studied. In the whole sample of 115 fish specimens, we identified one species of Monogenea, 5 species of Trematoda, 4 species of Cestoda, 5 species of Nematoda, and 7 species of Acanthocephala. All cestode species, 3 species of nematodes, and 5 species of acanthocephalans were represented only by larval stages; fish are definitive hosts for the remaining 10 helminth species. Details of composition and structure of helminth communities were studied in 3 fish species: Chaenocephalus aceratus (Lönnberg, 1906), Champsocephalus gunnari Lönnberg, 1905, and Pseudochaenichthys georgianus Norman, 1937, each represented by more than 20 specimens in a sample. In these hosts, 19, 8, and 16 helminth species were found, correspondingly. In the helminth communities of C. aceratus and P. georgianus, the highest values of the infection prevalence and abundance were recorded for larval cestodes (Diphyllobothrium sp., Tetrabothriidea), nematodes (Pseudoterranova sp., Contracaecum sp.), acanthocephalans (Corynosoma spp.), as well as adults of the trematode Neolebouria georgiensis Gibson, 1976. The same trematode species and larval cestodes predominated in the helminth community of C. gunnari. All recorded species of parasites are generalists, each known from a range of fish hosts in Antarctica.

This research has been supported by the Leverhulme Trust (grant no. RC-2018-023), the European Research Council (grant no. 694481), the German Research Foundation (grant no. FE-1096/6-1), the Swiss Government Excellence Postdoctoral Scholarships (grant no. FIRECO 2016.0310), the National Science Centre of Poland (grant no. 2015/17/B/ST10/01656), the SCIEX Scholarship Fund (grant no. PSPB-013/2010), and the Estonian Research Council (grant no. MOBJD313)., Sedimentary charcoal records are widely used to reconstruct regional changes in fire regimes through time in the geological past. Existing global compilations are not geographically comprehensive and do not provide consistent metadata for all sites. Furthermore, the age models provided for these records are not harmonised and many are based on older calibrations of the radiocarbon ages. These issues limit the use of existing compilations for research into past fire regimes. Here, we present an expanded database of charcoal records, accompanied by new age models based on recalibration of radiocarbon ages using IntCal20 and Bayesian age-modelling software. We document the structure and contents of the database, the construction of the age models, and the quality control measures applied. We also record the expansion of geographical coverage relative to previous charcoal compilations and the expansion of metadata that can be used to inform analyses. This first version of the Reading Palaeofire Database contains 1676 records (entities) from 1480 sites worldwide. The database (RPDv1b – Harrison et al., 2021) is available at https://doi.org/10.17864/1947.000345., Leverhulme Trust RC-2018-023, European Research Council (ERC) European Commission 694481, German Research Foundation (DFG) FE-1096/6-1, Swiss Government Excellence Postdoctoral Scholarships FIRECO 2016.0310, SCIEX Scholarship Fund PSPB-013/2010, Estonian Research Council MOBJD313

Sedimentary charcoal records are widely used to reconstruct regional changes in fire regimes through time in the geological past. Existing global compilations are not geographically comprehensive and do not provide consistent metadata for all sites. Furthermore, the age models provided for these records are not harmonised and many are based on older calibrations of the radiocarbon ages. These issues limit the use of existing compilations for research into past fire regimes. Here, we present an expanded database of charcoal records, accompanied by new age models based on recalibration of radiocarbon ages using INTCAL2020 and Bayesian age-modelling software. We document the structure and contents of the database, the construction of the age models, and the quality control measures applied. We also record the expansion of geographical coverage relative to previous charcoal compilations and the expansion of metadata that can be used to inform analyses. This first version of the Reading Palaeofire Database contains 1681 records (entities) from 1477 sites worldwide. The database (DOI: 10.17864/1947.319) is available from https://researchdata.reading.ac.uk/id/eprint/319.

The majority of known nucleolar proteins are freely exchanged between the nucleolus and the surrounding nucleoplasm. One way proteins are retained in the nucleoli is by the presence of specific amino acid sequences, namely nucleolar localization signals (NoLSs). The mechanism by which NoLSs retain proteins inside the nucleoli is still unclear. Here, we present data showing that the charge-dependent (electrostatic) interactions of NoLSs with nucleolar components lead to nucleolar accumulation as follows: (i) known NoLSs are enriched in positively charged amino acids, but the NoLS structure is highly heterogeneous, and it is not possible to identify a consensus sequence for this type of signal; (ii) in two analyzed proteins (NF-κB-inducing kinase and HIV-1 Tat), the NoLS corresponds to a region that is enriched for positively charged amino acid residues; substituting charged amino acids with non-charged ones reduced the nucleolar accumulation in proportion to the charge reduction, and nucleolar accumulation efficiency was strongly correlated with the predicted charge of the tested sequences; and (iii) sequences containing only lysine or arginine residues (which were referred to as imitative NoLSs, or iNoLSs) are accumulated in the nucleoli in a charge-dependent manner. The results of experiments with iNoLSs suggested that charge-dependent accumulation inside the nucleoli was dependent on interactions with nucleolar RNAs. The results of this work are consistent with the hypothesis that nucleolar protein accumulation by NoLSs can be determined by the electrostatic interaction of positively charged regions with nucleolar RNAs rather than by any sequence-specific mechanism.