Findings on three endocommensal scuticociliates(Protista,Ciliophora)from freshwater mollusks,including their morphology and molecular phylogeny with descriptions of two new species

Species of the ciliate genera Myxophyllum and Conchophthirus are found as endocommensals of terrestrial and freshwater mollusks,respectively.So far,there have been few studies of these genera and morphological data for most members are often incomplete.In the present work,two new species,Myxophyllum weishanense sp.nov.and Conchophthirus paracurtus sp.nov.,and a known species,Conchophthirus lamellidens,were isolated from hosts in Lake Weishan Wetland,China.Taxonomic studies indicate that M.weishanense sp.nov.can be recognized mainly by the combination of about 60 somatic kineties on both ventral and dorsal sides and the presence of caudal cilia.Conchophthirus paracurtus sp.nov.differs from congeners in its body shape and size,having a glabrous area on the posterior right side,and having fewer somatic kineties.In addition,differences in their ITS2(Internally Transcribed Spacer 2)secondary structures support the discrimination of the two new species from their highly similar congeners.An improved diagnosis for the poorly known species,C.lamel-lidens is also provided.Phylogenetic analyses reveal that members of the genus Myxophyllum belong to a fully supported clade that is sister to a large,poorly supported clade consisting of Hemispeiridae,Ancistridae,and several lineages of the nonmonophyletic Cyclidiidae.The Myxophyllum clade also includes Protophyra ovicola JQ956552,a possible misidenti-fication.Sequences of the two new Conchophthirus species cluster with other congeners in a fully supported clade that is unrelated to either the‘typical’thigmotrichs or to pleuronematids,thus conflicting with the traditional classification,and may represent an orphan scuticociliate lineage.

Clinical trials for the treatment of coronavirus disease 2019(COVID-19):A rapid response to urgent need

Emerging coronavirus disease 2019,known as COVID-19,is caused by the newly identified SARS-CoV-2 virus.Since the outbreak of COVID-19 in December 2019 in Wuhan(China),more than 70 thousand patients were affected.The disease resulted in 1,870 deaths by February 18,2020,according to the National Health Commission of People's Republic of China(http://www.nhc.gov.cn).

Cystic fibrosis: a rare disease emerging in China

Cystic fibrosis (CF) is an autosomal recessive disease that is caused by mutations in the CF transmembrane conductance regulator (CFTR) protein, an anion channel expressed on the epithelial surface (Rowe et al., 2005). The dysfunction of Cl–anion channels leads to pathophysiological changes such as airway surface liquid (ASL) decrement, delayed mucociliary clearance and defective bacterial killing, resulting in infection, mucus obstruction, inflammation and bronchiectasis(Rowe et al., 2005).

Reconsideration of the taxonomy of the marine ciliate Neobakuella aenigmatica Moon et al.,2019(Protozoa,Ciliophora,Hypotrichia)

The morphology and divisional morphogenesis in a Chinese population of Neobakuella aenigmatica Moon et al.,2019 are reinvestigated.The body size,number and arrangement of parabuccal cirri and development of nuclear nodules in this population are discussed in comparison with closely related genera.The 18S rRNA gene sequence of the Chinese population is identical to that of a Korean population,supporting a distant relationship between N.aenigmatica and the cluster of N.flava and Apobakuella fuse a.We deduce that this may be caused by the differences in the pattern of the parabuccal cirri and the number of parabuccal rows which are important for the phylogeny of Bakuella-like,species.