Comparative gene co-expression networks show enrichment of brassinosteroid and vitamin B processes in a seagrass under simulated ocean warming and extreme climatic events.

Introduction: Ocean warming combined with extreme climatic events, such as marine heatwaves and flash flooding events, threaten seagrasses globally. How seagrasses cope with these challenges is uncertain, particularly for range-edge populations of species such as Posidonia australis in Shark Bay, Western Australia. Analyzing gene expression while manipulating multiple stressors provides insight into the genetic response and resilience of seagrasses to climate change. We conducted a gene expression study on a polyploid clone of P. australis during an 18-week mesocosm experiment to assess the responses to single and combined future climate change-associated stressors. Methods: Plants were exposed to (1) future ocean warming temperature (baseline +1.5°C) followed by a simulated marine heat wave (baseline +5.5°C), (2) light deprivation simulating observed marine heatwave driven turbidity (95% shade) at baseline temperatures, or (3) both stressors simultaneously. Basal leaf meristems were sampled for gene expression analysis using RNA-seq at four time points during the experiment. Weighted gene co-expression network analysis, GO term enrichment, and KEGG pathway enrichment analyses were used to identify stress responses. Results: Shaded plants showed specific gene enrichment for shade avoidance (programmed cell death) after three weeks of stress, and before any heated tanks showed a specific heat response. Shaded plants were positively correlated with programmed cell death and stress-related processes at the end of the experiment. Once ocean warming temperatures (+1.5°C) were in effect, gene enrichment for heat stress (e.g., ROS scavenging and polyamine metabolism) was present. Vitamin B processes, RNA polymerase II processes. and light-related meristematic phase changes were expressed with the addition of simulated MHW. Heated plants showed meristematic growth signatures as well as trehalose and salicylic acid metabolism. Brassinosteroid-related processes were significantly enriched in all stressor treatments at all time points, except for the isolated heat-stressed plants three weeks after stressor initiation. Discussion: Gene expression responses to the interaction between heat waves and turbidity-induced light reduction support the observed geographical scale mortality in seagrasses observed for P. australis in Shark Bay, suggesting that even this giant polyploid clone will be negatively impacted by more extreme climate change projections.

Extensive polyploid clonality was a successful strategy for seagrass to expand into a newly submerged environment.

Polyploidy has the potential to allow organisms to outcompete their diploid progenitor(s) and occupy new environments. Shark Bay, Western Australia, is a World Heritage Area dominated by temperate seagrass meadows including Poseidon's ribbon weed, Posidonia australis. This seagrass is at the northern extent of its natural geographic range and experiences extremes in temperature and salinity. Our genomic and cytogenetic assessments of 10 meadows identified geographically restricted, diploid clones (2n = 20) in a single location, and a single widespread, high-heterozygosity, polyploid clone (2n = 40) in all other locations. The polyploid clone spanned at least 180 km, making it the largest known example of a clone in any environment on earth. Whole-genome duplication through polyploidy, combined with clonality, may have provided the mechanism for P. australis to expand into new habitats and adapt to new environments that became increasingly stressful for its diploid progenitor(s). The new polyploid clone probably formed in shallow waters after the inundation of Shark Bay less than 8500 years ago and subsequently expanded via vegetative growth into newly submerged habitats.

Persistence and stochasticity are key determinants of genetic diversity in plants associated with banded iron formation inselbergs.

The high species endemism characteristic of many of the world's terrestrial island systems provides a model for studying evolutionary patterns and processes, yet there has been no synthesis of studies to provide a systematic evaluation of terrestrial island systems in this context. The banded iron formations (BIFs) of south-western Australia are ancient terrestrial island formations occurring within a mosaic of alluvial clay soils, sandplains and occasional granite outcropping, across an old, gently undulating, highly weathered, plateau. Notably, these BIFs display exceptionally high beta plant diversity. Here, we address the determinants and consequences of genetic diversity for BIF-associated plant species through a comprehensive review of all studies on species distribution modelling, phylogenetics, phylogeography, population genetics, life-history traits and ecology. The taxa studied are predominantly narrowly endemic to individual or a few BIF ranges, but some have more regional distributions occurring both on and off BIFs. We compared genetic data for these BIF-endemic species to other localised species globally to assess whether the unique history and ancestry of BIF landscapes has driven distinct genetic responses in plants restricted to this habitat. We also assessed the influence of life-history parameters on patterns of genetic diversity. We found that BIF-endemic species display similar patterns of genetic diversity and structure to other species with localised distributions. Despite often highly restricted distributions, large effective population size or clonal reproduction appears to provide these BIF-endemic species with ecological and evolutionary resilience to environmental stochasticity. We conclude that persistence and stochasticity are key determinants of genetic diversity and its spatial structure within BIF-associated plant species, and that these are key evolutionary processes that should be considered in understanding the biogeography of inselbergs worldwide.

Genes of intestinal Escherichia coli and their relation to the inflammatory activity in patients with ulcerative colitis and Crohn's disease.

Escherichia coli gene fimA was the most frequent gene that occurred in the intestine of all investigated groups. All subjects with fimA gene had significantly higher values of tumor necrosis factor alpha (TNF-α) and CRP than those with other E. coli genes. There was also a tendency to increased serum interleukin (IL)-6 levels in patients carrying the fimA gene; however, no relation was observed to serum IL-8 and IL-10. Patients with Crohn's disease had significantly higher IL-6 than those with ulcerative colitis (UC) and controls. The highest levels of TNF-α were detected in the UC group. There were no significant differences in serum IL-8 and IL-10 between all three groups. The presence of E. coli gene fimA in the large bowel of patients with IBD is related to the immunological activity of the disease which may be important from the aspect of therapeutical strategy.

Impact of TTV and SENV infection in chronic hepatitis B or C on liver histology and therapy outcome.

AIM: To determine the influence of TTV and SENV on histological findings and viral response in patients with chronic viral hepatitis B and C. BACKGROUND: The clinical impact of TTV or SENV coinfections in these patients remains unclear. METHODS: Serum and liver biopsy specimens from chronic hepatitis B and C patients, 107 with liver biopsy and 105 who had finished complete antiviral therapy, were investigated for the presence of TTV and SENV. RESULTS: The Ishak score determined from 107 liver biopsy samples compared according to TTV or SENV coinfection was similar. Among 39 chronic hepatitis C patients with and 43 without virological response, we have found 9 and 3 SENV positive (p < 0.05) and 18 and 28 TTV positive patients, respectively (not significant). However 11 of 32 biopsy samples obtained in the responder's group and 19 of 31 in non-responders were TTV positive (p < 0.05). No similar differences were observed among 23 chronic hepatitis B patients. TTV clearance after interferon therapy exceeded 80%, clearance of SENV 90%. CONCLUSION: TTV or SENV infections did not negatively influence the severity of histological features or the antiviral response in patients with chronic hepatitis B and C. Both viruses were highly sensitive to interferon therapy (Tab. 5, Ref. 29).

Detection of SEN virus in the general population and different risk groups in Slovakia.

Sera of 426 adult persons were examined to assess the prevalence of SEN virus (SENV) infection in Slovakia and to determine the importance of different risk factors for parenteral transmission. SENV prevalence was determined by the PCR method using primers of SENV-D and SENV-H strains. Positive results were found in 10 of 37 patients with acute hepatitis of unknown etiology, 7 of 38 with acute hepatitis B, 17 of 44 with chronic hepatitis B, 29 of 102 with chronic hepatitis C, 36 of 72 hemodialysis patients, 2 of 33 health care workers and 24 of 100 persons from the control group. The highest prevalence of SENV was among hemodialysis patients, significantly higher than in the groups of health care workers, acute hepatitis B and controls. The lowest prevalence was in health care workers group, significantly lower also in comparison with groups of chronic hepatitis B and C. Among the possible risk factors of virus transmission the average duration of hemodialysis (1.15 vs. 0.50 years), number of surgeries (1.60 vs. 1.10) and transfusions (1.34 vs. 0.94) showed notable differences in terms of SENV infection. Bilirubin and aminotransferase levels did not differ between SENV-positive and -negative groups. No pathogenetic role of SEN virus in liver injury was confirmed.

Erythrocyte indexes, iron metabolism, and hyperhomocysteinemia in adults with cyanotic congenital cardiac disease.

A high percentage of cyanotic adults (37%) with cyanotic congenital cardiac disease (CCD) presented with depleted iron stores (13 of 52) or latent iron deficiency (6 of 52), even in a CCD center in which cyanotic patient phlebotomy is mostly avoided. In many of these patients, hypochromia and microcytosis was frequent, whereas hyperchromia and macrocytosis were relatively common.Furthermore, 50% of patients presented with hyperhomocysteinemia, possibly related to folate or B vitamin deficiencies, which may increase red blood cell size and color, explaining the lack of microcytosis and hypochromia in many cyanotic patients with iron deficiency.

Occurrence and genetic association of selected virulence factors in clinical Escherichia coli isolates.

Occurrence of cnf1+ E. coli pathogenic strains among extraintestinal E. coli isolates was evaluated to explain an impact of cytotoxic necrotizing factor type 1 (CNF1) in human infections. A total of 120 E. coli isolates were characterized for presence of virulence factors cnf1- and pap--specific sequences by PCR, and the production of alpha-hemolysin using blood agar-plate test. Different association patterns among the detected virulence factors were obtained by comparison of various groups of clinical E. coli isolates. These differences probably reflect a potential impact of CNF1 in the colonization of vaginal environment.

Detection of pap-, sfa- and afa-specific DNA sequences in Escherichia coli strains isolated from extraintestinal material.

P-fimbriae, S-fimbriae and AFA-adhesins are virulence factors responsible for adherence of Escherichia coli strains to extraintestinal host-cell surface. Detection of pap-, sfa- and afa-specific sequences performed by PCR revealed 74% pap+, 65% sfa+, and 8.3% afa+ strains in a group of 84 extraintestinal E. coli isolates. Detection in a group of fecal strains showed 29% pap+, 21% sfa+ and 4% afa+ strains. pap together with sfa were found as the most frequent combination (56%) among extraintestinal isolates probably due to localization of pap- and sfa-operons on a common pathogenicity island. The occurrence of afa-specific sequence among 56 urine strains was 11%, although no afa+ strain was detected among 28 gynecological isolates. No strains with detected adhesin operons were found among twenty (24%) extraintestinal E. coli strains.

[Virulence factors in strains of Escherichia coli isolated in urinary tract infections]. / Faktory virulencie u kmenov Escherichia coli izolovaných pri mocových infekciách.

In 21 strains of E. coli isolated from patients with cystitis and asymptomatic bacteriuria the authors assessed the group, mannososensitive and mannoresistant agglutination of human, bovine, chick, guinea pig, sheep and pig erythrocytes, the production of haemolysis, colicins, aerobactin, the capacity of strains to induce oedema on mouse paws, the lethal effect in mice, the resistance to tetracycline, streptomycin, chloramphenicol, kanamycin, ampicillin and sulfamethoxidine, the transmission of resistance and sensitivity of strains to the action of fresh human serum. In ten strains the authors recorded also the production of haemolysin and the lethality for mice, in four strains the production of colicin V. production of aerobactin and serum resistance. In three strains the aerobactin production was recorded concurrently with the haemolysin production. In none of the samples P. fimbriae were found.

Intestinal multiplication of Mycobacterium paratuberculosis in athymic nude gnotobiotic mice.

In this study gnotobiotic mice were inoculated with a human isolate of Mycobacterium paratuberculosis (strain Linda; ATCC 43015) in an attempt to investigate the pathogenesis of intestinal paratuberculosis. Mycobacterium paratuberculosis-monoassociated nu/+ mice developed a persistent low-level intestinal infection but did not support progressive bacillary multiplication. In contrast, monoassociated nu/nu mice eventually harbored approximately 10(7) M. paratuberculosis per g of intestinal tissue. Acid-fast bacilli and granulomas were observed in the intestinal mucosa and livers of nu/nu but not nu/+ mice. Similar results were obtained after intragastric inoculation of M. paratuberculosis into nu/+ and nu/nu flora-defined mice. These observations suggest that the presence of an intact cellular immune system is important for limiting intestinal multiplication of M. paratuberculosis. The results of this study may be relevant to our understanding of the pathogenesis of Johne's disease in ruminants and of human inflammatory bowel diseases that have a mycobacterial etiology (e.g., some cases of Crohn's disease and Mycobacterium avium-Mycobacterium intracellulare enteritis in patients with acquired immunodeficiency syndrome).

Chronic response of normal porcine fat and muscle to focused ultrasound hyperthermia.

Annular focused ultrasound (1.13 MHz) hyperthermia was used to evaluate chronic histologic effects of a range of high thermal dosages on normal porcine tissues. The effects of three peak temperatures (45, 47, and 49 degrees C) at a focal depth of 2 cm in thirty 4-cm-diameter sites were studied as a function of exposure time (10-60 min). Relative fat and muscle damage were histologically graded 1 month post-treatment. Unlike reports of radiofrequency hyperthermia, no necrosis or abscess formation was observed, even at 49 degrees C for 40 min. Fat sustained a greater percentage maximal tissue damage than muscle, although less than 4% of sections evaluated had histologic evidence of severe injury. Focused ultrasound provides a relatively uniform heat distribution in normal tissues. It should therefore be possible to raise normal tissues surrounding tumors to high temperatures using focused ultrasound, potentiating tumoricidal effects with minimal associated complications.

Neoplasms identified in free-flying birds.

Nine neoplasms were identified in carcasses of free-flying wild birds received at the National Wildlife Health Laboratory; gross and microscopic descriptions are reported herein. The prevalence of neoplasia in captive and free-flying birds is discussed, and lesions in the present cases are compared with those previously described in mammals and birds.