B Chromosomes in Free-Living Flatworms of the Genus Macrostomum (Platyhelminthes, Macrostomorpha)

B chromosomes (Bs) or supernumerary chromosomes are extra chromosomes in the species karyotype that can vary in their copy number. Bs are widespread. Usually, the Bs of specimens collected from natural populations are involved in studies. We applied another approach analyzing the Bs in animals of laboratory cultures. In this study, three species of the Macrostomum genus that underwent a recent whole-genome duplication (WGD) were involved. In laboratory lines of M. lignano and M. janickei, the frequency of Bs was less than 1%, while in the laboratory culture of M. mirumnovem, it was nearer 30%. Their number in specimens of the culture varied from 1 to 14. Mosaicism on Bs was discovered in parts of these animals. We analyzed the distribution of Bs among the worms of the laboratory cultures during long-term cultivation, the transmission rates of Bs in the progeny obtained from crosses of worms with different numbers of Bs, and from self-fertilized isolated worms. The DNA content of the Bs in M. mirumnovem was analyzed with the chromosomal in situ suppression (CISS) hybridization of microdissected DNA probes derived from A chromosomes (As). Bs mainly consisted of repetitive DNA. The cytogenetic analysis also revealed the divergence and high variation in large metacentric chromosomes (LMs) containing numerous regions enriched for repeats. The possible mechanisms of the appearance and evolution of Bs and LMs in species of the Macrostomum genus were also discussed.

Chronic Urinary Infection in Overactive Bladder Syndrome: A Prospective, Blinded Case Control Study

ObjectivesTo investigate whether women with overactive bladder (OAB) symptoms and no evidence of clinical infection by conventional clean-catch midstream urine cultures have alternative indicators of sub-clinical infection.Patients/Subjects, Materials & MethodsThe study was a prospective, blinded case-control study with 147 participants recruited, including 73 OAB patients and 74 controls. The OAB group comprised female patients of at least 18 years of age who presented with OAB symptoms for more than 3 months. Clean-catch midstream urine samples were examined for pyuria by microscopy; subjected to routine and enhanced microbiological cultures and examined for the presence of 10 different cytokines, chemokines, and prostaglandins by ELISA.ResultsThe mean age and BMI of participants in both groups were similar. No significant difference in the number of women with pyuria was observed between OAB and control groups (p = 0.651). Routine laboratory cultures were positive in three (4%) of women in the OAB group, whereas the enhanced cultures isolated bacteria in 17 (23.2%) of the OAB patients. In the control group, no positive cultures were observed using routine laboratory cultures, whereas enhanced culture isolated bacteria in 8 (10.8%) patients. No significant differences were observed in the concentrations of PGE2, PGF2α, MCP-1, sCD40L, MIP-1β, IL12p70/p40, IL12/IL-23p40, IL-5, EGF and GRO-α between the OAB and control groups.ConclusionsPatients with OAB symptoms have significant bacterial growth on enhanced culture of the urine, which is often not detectable through routine culture, suggesting a subclinical infection. Enhanced culture techniques should therefore be used routinely for the effective diagnosis and management of OAB.

A new species of Zercon (Parasitiformes: Mesostigmata) from Norway, with notes on sexual dimorphism in Zerconidae

In this paper we describe and illustrate Zercon hamaricus sp. nov. based on all postembryonic stages obtained from soil samples and laboratory cultures. The new species belongs to a species group in which dorsal setae J1–J4 in females are short and similar in length, and J5 are considerably longer. In most species of this group opisthonotal setae J5 and Z4 are clearly displaced anteriorly. Zercon hamaricus sp. nov. is most similar to Z. forsslundi Sellnick, 1958 and to a less extent to Z. polonicus Błaszak, 1970. The females of Z. forsslundi, Z. polonicus and Z. hamaricus sp. nov. can be distinguished based on the range of J5, the length and character of the Z and S-series setae, the distance between setae Z5 and the location of gdZ3. We also include comparative information on other related species of Zercon. The new species is one of the six known species that have clearly visible sexual dimorphism in opisthonotal chaetotaxy.

Cell size matters: nano- and micro-plastics preferentially drive declines of large marine phytoplankton due to co-aggregation

Marine plastic pollution represents a key environmental concern. Whilst ecotoxicological data for plastic is increasingly available, its impact upon marine phytoplankton remains unclear. Owing to their predicted abundance in the marine environment and likely interactions with phytoplankton, here we focus on the smaller fraction of plastic particles (~50 nm and ~2 μm polystyrene spheres). Exposure of natural phytoplankton communities and laboratory cultures revealed that plastic exposure does not follow traditional trends in ecotoxicological research, since large phytoplankton appear particularly susceptible towards plastics exposure despite their higher surface-to-volume ratios. Cell declines appear driven by hetero-aggregation and co-sedimentation of cells with plastic particles, recorded visually and demonstrated using confocal microscopy. As a consequence, plastic exposure also caused disruption to photosynthetic functioning, as determined by both photosynthetic efficiency and high throughput proteomics. Negative effects upon phytoplankton are recorded at concentrations orders of magnitude above those estimated in the environment. Hence, it is likely that impacts of NPs and MPs are exacerbated at the high concentrations typically used in ecotoxicological research (i.e., mg L-1).

Genome of a novel Sediminibacterium discovered in association with two species of freshwater stream Cyanobacteria in Southern California

ABSTRACTHere we report the discovery of a novel Sediminibacterium sequenced from laboratory cultures of freshwater stream cyanobacteria from sites in Southern California, grown in BG11 media.

Ontogenetic description of Proctolaelaps bickleyi (Bram) (Acari: Melicharidae), newly recorded from lepidopteran insect cultures in Japan

Proctolaelaps bickleyi (Bram) (Acari: Melicharidae) is an edaphic predatory mite commonly associates with insects. Although P. bickleyi has been reported from many countries worldwide, it is reported herein for the first time in Japan from laboratory cultures of Chilo suppressalis (Walker) and Cossus insularis (Staudinger) (Lepidoptera: Crambidae, Cossidae). Proctolaelaps bickleyi is redescribed and illustrated from females, males, deutonymphs, protonymphs and larvae. The morphological ontogeny of idiosomal and leg chaetotaxy is discussed and a key to the Japanese species of Proctolaelaps is provided.

Removal of Cyanotoxins–Microcystins from Water by Filtration through Granulated Composites of Bentonite with Micelles of the Cation Octadecyltrimethyl Ammonium (ODTMA)

Cyanobacteria and their toxins present potential hazards to consumers of water from lakes, reservoirs and rivers; thus, their removal via water treatment is essential. Previously, we demonstrated that nanocomposites of octadecyltrimethyl ammonium (ODTMA) complexed with clay could efficiently remove cyanobacteria and their toxins from laboratory cultures and lake water. In this study, we determined the capacity of ODTMA nanocomposites to remove cyanotoxins, namely microcystins (MCs), from water to below 1 µg/L via filtration. This capacity was 1500 mg MC-LR per Kg of nanocomposite. Similar capacities were estimated for the removal of other MC congeners (MC-WR, MC-3aspWR and MC-YR), whereas substantially lower capacities were recorded for more positively charged MC congeners, such as MC-RR and MC-3aspRR. Filtration results were simulated with a filtration model, which considers convection and adsorption/desorption of one to several toxins. Model calculations for the removal of MC-LR, under a variety of situations, fitted well with all the experimentally measured values and also estimated the co-removal of several MC congeners. In agreement with model predictions, results demonstrated that in the presence of MC-WR, the emerging concentrations of MC-RR congeners eventually exceed their solution values. In conclusion, granulated nanocomposites of ODTMA–bentonite can be applied for the removal of microcystins from drinking water.