Post-traumatic stress syndromes following childbirth influenced by birth mode-is an emergency cesarean section worst?

PURPOSE

The experience of birth is an emotional challenge for women. Traumatic birth experiences can cause psychological stress symptoms up to post-traumatic stress disorders (PTSD), with impact on women's wellbeing. Primarily unplanned interventions can trigger birth-mode-related traumatization. The aim of the study was to evaluate whether an emergency cesarean section (ECS) is the most traumatizing.

METHODS

A retrospective case-control study was undertaken. Therefore, data were collected by standardized questionnaires (Impact of Event Scale-Revised and City Birth Trauma Scale) that were sent to women with singleton pregnancies > 34 weeks of gestation who either give birth by ECS (case group, n = 139), unplanned cesarean section (UCS), operative vaginal birth (OVB), or natural birth (NB) (three control groups, n = 139 each). The investigation period was 5 years.

RESULTS

Overall, 126 of 556 (22%) sent questionnaires were returned and could be analyzed (32 ECS, 38 UCS, 36 OVB, and 20 NB). In comparison to other birth modes, women with ECS were associated with a higher degree of traumatization as revealed by statistically significant differences regarding the DSM-5 criteria intrusion and stressor. In addition, women who underwent ECS declared more frequently a demand for professional debriefing compared to other birth modes.

DISCUSSION

ECS is associated with more post-traumatic stress symptoms compared to other birth modes. Therefore, early interventions are recommended to reduce long-term psychological stress reactions. In addition, outpatient follow-ups by midwives or emotional support programs should be implemented as an integral component of postpartum debriefings.

Unrecognized diversity and distribution of soil algae from Maritime Antarctica (Fildes Peninsula, King George Island)

Introduction

Eukaryotic algae in the top few centimeters of fellfield soils of ice-free Maritime Antarctica have many important effects on their habitat, such as being significant drivers of organic matter input into the soils and reducing the impact of wind erosion by soil aggregate formation. To better understand the diversity and distribution of Antarctic terrestrial algae, we performed a pilot study on the surface soils of Meseta, an ice-free plateau mountain crest of Fildes Peninsula, King George Island, being hardly influenced by the marine realm and anthropogenic disturbances. It is openly exposed to microbial colonization from outside Antarctica and connected to the much harsher and dryer ice-free zones of the continental Antarctic. A temperate reference site under mild land use, SchF, was included to further test for the Meseta algae distribution in a contrasting environment.

Methods

We employed a paired-end metabarcoding analysis based on amplicons of the highly variable nuclear-encoded ITS2 rDNA region, complemented by a clone library approach. It targeted the four algal classes, Chlorophyceae, Trebouxiophyceae, Ulvophyceae, and Xanthophyceae, representing key groups of cold-adapted soil algae.

Results

A surprisingly high diversity of 830 algal OTUs was revealed, assigned to 58 genera in the four targeted algal classes. Members of the green algal class Trebouxiophyceae predominated in the soil algae communities. The major part of the algal biodiversity, 86.1% of all algal OTUs, could not be identified at the species level due to insufficient representation in reference sequence databases. The classes Ulvophyceae and Xanthophyceae exhibited the most unknown species diversity. About 9% of the Meseta algae species diversity was shared with that of the temperate reference site in Germany.

Discussion

In the small portion of algal OTUs for which their distribution could be assessed, the entire ITS2 sequence identity with references shows that the soil algae likely have a wide distribution beyond the Polar regions. They probably originated from soil algae propagule banks in far southern regions, transported by aeolian transport over long distances. The dynamics and severity of environmental conditions at the soil surface, determined by high wind currents, and the soil algae's high adaptability to harsh environmental conditions may account for the high similarity of soil algal communities between the northern and southern parts of the Meseta.

An improved method for intracellular DNA (iDNA) recovery from terrestrial environments

The simultaneous extraction of intracellular DNA (iDNA) and extracellular DNA (eDNA) can help to separate the living in situ community (represented by iDNA) from background DNA that originated both from past communities and from allochthonous sources. As iDNA and eDNA extraction protocols require separating cells from the sample matrix, their DNA yields are generally lower than direct methods that lyse the cells within the sample matrix. We, therefore, tested different buffers with and without adding a detergent mix (DM) in the extraction protocol to improve the recovery of iDNA from surface and subsurface samples that covered a variety of terrestrial environments. The combination of a highly concentrated sodium phosphate buffer plus DM significantly improved iDNA recovery for almost all tested samples. Additionally, the combination of sodium phosphate and EDTA improved iDNA recovery in most of the samples and even allowed the successful extraction of iDNA from extremely low-biomass iron-bearing rock samples taken from the deep biosphere. Based on our results, we recommend using a protocol with sodium phosphate in combination with either a DM (NaP 300 mM + DM) or EDTA (NaP + EDTA 300 mM). Furthermore, for studies that rely on the eDNA pool, we recommend using buffers solely based on sodium phosphate because the addition of EDTA or a DM resulted in a decrease in eDNA for most of the tested samples. These improvements can help reduce community bias in environmental studies and contribute to better characterizations of both modern and past ecosystems.

A microplate-based bioassay for toxicity testing using the large benthic algal species Closterium ehrenbergii

Pollution of water bodies by metals has long been studied but still remains a threat to healthy ecosystems. While most ecotoxicological studies on algae are performed with planktonic standard species such as Raphidocelis subcapitata, benthic algae may depict the majority of the algal flora in rivers and streams. These species encounter different exposure scenarios to pollutants as they are sedentary and not carried away by the current. This particular way of life leads to an integration of toxic effects over time. Therefore, in this study, the effects of six metals on the large unicellular benthic species Closterium ehrenbergii were examined. A miniaturized bioassay with low cell densities of 10-15 cells/mL using microplates was developed. Through chemical analysis, metal complexing properties in the culture medium were demonstrated, that could lead to an underestimation of metal toxicity. Thus, the medium was modified by excluding EDTA and TRIS. The toxicity of the six metals ranked by EC₅₀ values in descending order, was as follows: Cu (5.5 µg/L) > Ag (9.2 µg/L) > Cd (18 µg/L) > Ni (260 µg/L) > Cr (990 µg/L) > Zn (1200 µg/L). In addition, toxic effects on the cell morphology were visualized. Based on a literature review, C. ehrenbergii was shown to be partly more sensitive than R. subcapitata which suggests that it can be a useful addition to ecotoxicological risk assessment.

Testing for terrestrial and freshwater microalgae productivity under elevated CO2 conditions and nutrient limitation

BACKGROUND

Microalgae CO₂ fixation results in the production of biomass rich in high-valuable products, such as fatty acids and carotenoids. Enhanced productivity of valuable compounds can be achieved through the microalgae's ability to capture CO₂ efficiently from sources of high CO₂ contents, but it depends on the species. Culture collections of microalgae offer a wide variety of defined strains. However, an inadequate understanding of which groups of microalgae and from which habitats they originate offer high productivity under increased CO₂ concentrations hampers exploiting microalgae as a sustainable source in the bioeconomy.

RESULTS

A large variety of 81 defined algal strains, including new green algal isolates from various terrestrial environments, were studied for their growth under atmospheres with CO₂ levels of 5-25% in air. They were from a pool of 200 strains that had been pre-selected for phylogenetic diversity and high productivity under ambient CO₂. Green algae from terrestrial environments exhibited enhanced growth up to 25% CO₂. In contrast, in unicellular red algae and stramenopile algae, which originated through the endosymbiotic uptake of a red algal cell, growth at CO₂ concentrations above 5% was suppressed. While terrestrial stramenopile algae generally tolerated such CO₂ concentrations, their counterparts from marine phytoplankton did not. The tests of four new strains in liquid culture revealed enhanced biomass and chlorophyll production under elevated CO₂ levels. The 15% CO₂ aeration increased their total carotenoid and fatty acid contents, which were further stimulated when combined with the starvation of macronutrients, i.e., less with phosphate and more with nitrogen-depleted culture media.

CONCLUSION

Green algae originating from terrestrial environments, Chlorophyceae and Trebouxiophyceae, exhibit enhanced productivity of carotenoids and fatty acids under elevated CO₂ concentrations. This ability supports the economic and sustainable production of valuable compounds from these microalgae using inexpensive sources of high CO₂ concentrations, such as industrial exhaust fumes.

The Long chain Diol Index: A marine palaeotemperature proxy based on eustigmatophyte lipids that records the warmest seasons

Long chain 1,13- and 1,15-diols are lipids which are omnipresent in marine environments, and the Long chain Diol Index (LDI), based on their distributions, has previously been introduced as a proxy for sea surface temperature. The main biological sources for long chain 1,13- and 1,15-diols have remained unknown, but our combined lipid and 23S ribosomal RNA (23S rRNA) analyses on suspended particulate matter from the Mediterranean Sea demonstrate that these lipids are produced by a marine eustigmatophyte group that originated before the currently known eustigmatophytes diversified. The 18S rRNA data confirm the existence of early-branching marine eustigmatophytes, which occur at a global scale. Differences between LDI records and other paleotemperature proxies are generally attributed to differences between the seasons in which the proxy-related organisms occur. Our results, combined with available LDI data from surface sediments, indicate that the LDI primarily registers temperatures from the warmest month when mixed-layer depths, salinity, and nutrient concentrations are low. The LDI may not be applicable in areas where Proboscia diatoms contribute 1,13-diols, but this can be recognized by enhanced contributions of C28 1,12 diol. Freshwater input may also affect the correlation between temperature and the LDI, but relative C32 1,15-diol abundances help to identify and correct for these effects. When taking those factors into account, the calibration error of the LDI is 2.4 °C. As a well-defined proxy for temperatures of the warmest seasons, the LDI can unlock important and previously inaccessible paleoclimate information and will thereby substantially improve our understanding of past climate conditions.

The Draft Genome of Coelastrum proboscideum (Sphaeropleales, Chlorophyta)

Coelastrum proboscideum Bohlin, 1896 (Sphaeropleales, Scenedesmaceae, Chlorophyta) is a coenobial species with cosmopolitan distribution in diverse freshwater habitats. Coelastrum spp. are widely tested for biotechnological applications such as carotenoid and lipid production, and in bioremediation of wastewater. Here, we report the draft genome of C. proboscideum var. dilatatum strain SAG 217-2. The final assembly comprised 125,935,854 bp with over 8357 scaffolds. The whole-genome data is publicly available in the Nucleotide Sequence Archive (CNSA) of China National GeneBank (CNGB) (https://db.cngb.org/cnsa/) under the accession number CNA0014153.

Rationale and description of a lifestyle intervention programme to achieve moderate weight loss in women with non-metastatic breast cancer: the lifestyle intervention part of the SUCCESS C Study

Objective

There is growing evidence from observational studies that lifestyle factors such as obesity, an unhealthy diet and lack of physical activity are associated with poor long-term outcome in women with breast cancer. The primary objective of the lifestyle modification part of the Simultaneous Study of Docetaxel Based Anthracycline Free Adjuvant Treatment Evaluation, as well as Life Style Intervention Strategies (SUCCESS C) Trial is to investigate the effect of an individualised lifestyle intervention programme aiming at moderate weight loss on disease-free survival in women with HER2/neu-negative breast cancer. Secondary objectives include the effect of the intervention on body weight, cardiovascular risk and quality of life.

Methods

The SUCCESS C Trial is an open-label, multicentre, randomised controlled phase III study using a 2×2 factorial design in women with newly diagnosed HER2/neu-negative intermediate-risk to high-risk breast cancer. The first randomisation served to compare disease-free survival in patients treated with two different chemotherapy regimens (3642 participants). The second randomisation served to compare disease-free survival in patients with a body mass index of 24–40 kg/m² (2292 participants) receiving either a telephone-based individualised lifestyle intervention programme for moderate weight loss or general recommendations for a healthy lifestyle for 2 years. Outcome analyses will be conducted after 5 years of follow-up.

Perspective

This study will provide information on the efficacy and safety of a comprehensive lifestyle intervention programme on disease-free survival in a large cohort of women with breast cancer. EU Clinical Trials Identifier: 2008-005453-38.

The Draft Genome of Hariotina reticulata (Sphaeropleales, Chlorophyta) Provides Insight into the Evolution of Scenedesmaceae

Hariotina reticulata P. A. Dangeard 1889 (Sphaeropleales, Chlorophyta) is a common member of the summer phytoplankton of meso- to highly eutrophic water bodies with a worldwide distribution. Here, we report the draft whole-genome shotgun sequencing of H. reticulata strain SAG 8.81. The final assembly comprises 107,596,510bp with over 15,219 scaffolds (>100bp). This whole-genome project is publicly available in the CNSA (https://db.cngb.org/cnsa/) of CNGBdb under the accession number CNP0000705.

Heterocyte glycolipids indicate polyphyly of stigonematalean cyanobacteria

The cyanobacterial phylum is currently divided into five subsections (I-V), with the latter two containing no or false-branching (nostocalean) and true-branching (stigonematalean) cyanobacteria. Although morphological traits (such as cellular division and secondary branches) clearly separate both types of heterocytous cyanobacteria, molecular evidence indicates that stigonematalean cyanobacteria (Subsection V) do not form a monophyletic group but instead are interspersed and nested within the nostocalean cyanobacteria (Subsection IV). To further resolve the phylogeny of heterocytous cyanobacteria, we here analyzed the distribution of heterocyte glycolipids (HGs) in the true-branching cyanobacterium Stigonema ocellatum SAG 48.90 (type genus of Subsection V) and compared it with the HG inventory of other stigonematalean and nostocalean cyanobacteria. The most dominant HGs in S. ocellatum SAG 48.90 were 1-(O-hexose)-27-keto-3,25-octacosanediol (HG₂₈ keto-diol) and 1-(O-hexose)-3,25,27-octacosanetriol (HG₂₈ triol), which together constituted ca. 94% of all HGs. In addition, 1-(O-hexose)-3-keto-27-octacosanols (HG₂₈ keto-ols), 1-(O-hexose)-3,27-octacosanediols (HG₂₈ diols), 1-(O-hexose)-3-keto-27,29-triacontanediol (HG₃₀ keto-diol) and 1-(O-hexose)-3,27,29-triacontanetriol (HG₃₀ triol) occurred in minor abundances. Heterocyte glycolipids previously reported to be unique for stigonematalean cyanobacteria, i.e. 1-(O-hexose)-3,29,31-dotriacontanetriols (HG₃₂ triols) and 1-(O-hexose)-3-keto-29,31-dotriacontanediols (HG₃₂ keto-diols), were not detected in S. ocellatum SAG 48.90. Comparison of the HG distribution pattern with those of other heterocytous cyanobacteria indicated that S. ocellatum SAG 48.90 is most closely related to the nostocalean families Rivulariaceae and Scytonemataceae, which is complementary to reconstructed 16S rRNA gene sequence phylogenies. Our HG-based data thus provides evidence for the polyphyly of stigonematalean cyanobacteria, independent from molecular approaches, and points to the need for a critical re-evaluation of the current taxonomy of heterocytous cyanobacteria.

Abstract OT1-11-01: The BRandO BiO registry – A multicenter regional registry for patients with primary breast and ovarian cancer with longitudinal biobanking and evaluation of epidemiological, life style and quality of life factors

Background:

Further progress in the treatment of breast cancer will likely come from contributions of molecular biology and immunologic approaches. The search for druggable molecular aberrations may enable treatment based on the molecular profile. A better identification of patients with a high risk of relapse facilitates the selection of these pts for clinical trials investigating early therapeutic molecular-based interventions.

Trial Design:

The BRandO BiO Registry is a multi-center regional registry to record clinical, epidemiological, and biological data from patients with newly diagnosed breast and ovarian cancer at the University of Ulm, Dept. of Gynecology and 19 affiliated network hospitals and practices in the Alb-Allgäu Bodensee region (outreach area of the Comprehensive Cancer Center Ulm). Longitudinal biobanking is included with collection of paraffin-embedded samples of the primary tumor as well as blood samples at first diagnosis, after 6 and 12 months and at first relapse to isolate and investigate cell-free and germline DNA. Epidemiological, life style and quality of life (QOL) questionnaires are collected at first diagnosis, after 12, 36 and 60 months. The follow up is planned for 10 years.

Eligibility criteria:

Patients with primary newly diagnosed untreated breast or ovarian cancer of ≥ 18 years are eligible; primary metastatic untreated disease is allowed. Exclusion criteria comprise severe neurological or psychiatric disorders interfering with the ability to give an informed consent, no consent for registration, storage and processing of the individual disease characteristics and bio samples, and any malignant tumor in the last 3 years (except in situ disease).

Specific aims:

To register the majority of patients with newly diagnosed breast or ovarian cancer in all BRandO-BiO participating centers of a well-defined geographical area. To assess clinical characteristics and outcome data (event-free survival, overall survival) of these patients. To evaluate the primary tumor of all patients for mutational (druggable) aberrations. Further to assess cell-free DNA in the serial blood samples at baseline, 6 and 12 months and correlate these results with clinical outcome data as well as tumor and patient characteristics to look for early markers predicting relapse. To perform a longitudinal assessment of the patients' sociodemographic factors, comorbidities, lifestyle and QOL factors by analyzing serial questionnaires collected at recruitment and at 12, 36 and 60 months.

Present accrual and target accrual:

The BRandO BiO Registry started January 2016 in the Dept. of Gynecology, University of Ulm and February 2017 at the network hospitals and practices. Until June 2018, 1180 patients with primary breast or ovarian cancer have been enrolled. The current adherence to serial blood testing and serial questionnaires is good with a return rate of 90%. A sample size of 3000 patients is planned.

Contact information:

Jens Huober, University of Ulm, Dept of Gynecology, Breast Center, jens.huober@uniklinik-ulm.de

Amelie de Gregorio, University of Ulm, Dept of Gynecology, Breast Center, Amelie.de Gregorio@uniklinik-ulm.de

Citation Format: Huober J, Nagel G, Rempen A, Schlicht E, Flock F, Fritz S, Thiel F, Wiesmüller L, Felderbaum R, Heilmann V, Bekes I, Fink V, Albrecht S, De Gregorio N, Tzschaschel M, Ernst K, Wolf C, Kuhn P, Friedl T, Janni W, De Gregorio A. The BRandO BiO registry – A multicenter regional registry for patients with primary breast and ovarian cancer with longitudinal biobanking and evaluation of epidemiological, life style and quality of life factors [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT1-11-01.

Abstract OT2-07-01: DETECT V/CHEVENDO – Comparison of dual HER2-targeted therapy with trastuzumab plus pertuzumab in combination with chemo- or endocrine therapy in addition with CDK4/6 inhibition in patients with HER2-positive and hormone-receptor positive metastatic breast cancer

Background:

Metastatic breast cancer (MBC) is usually an incurable disease and maintenance of quality of life (QoL) is one of the main aims of therapy. In patients with HER2-positive MBC taxane-based chemotherapy in combination with dual HER2 targeted therapy with trastuzumab and pertuzumab,is the standard of care. Adverse events are well-known side effects of any cytostatic treatment and can seriously impact the patients' QoL. The synergistic combination of dual HER2-targeted therapy with trastuzumab and pertuzumab plus endocrine therapy might offer a better treatment option for these patients. First clinical trials suggest an additional benefit when a CDK4/6 inhibitor is added to the combination of endocrine therapy and anti HER2 treatment. DETECT V is a randomized phase III study comparing the safety and efficacy of trastuzumab plus pertuzumab and the CDK 4/6 inhibitor ribociclib in combination with either endocrine therapy or chemotherapy.

Trial design:

Patients with HER2 positive and hormone-receptor positive MBC are 1:1 randomized to receive trastuzumab and pertuzumab combined with endocrine therapy and ribociclib or to chemotherapy with trastuzumab and pertuzumab followed by maintenance therapy with trastuzumab, pertuzumab, endocrine therapy and ribociclib. Chemotherapy and the endocrine agents can be chosen from a variety of available regimens according to the physicians discretion.

Specific aims:

The primary objective of this study is to compare safety and tolerability in both arms, as assessed by the occurrence of AEs during the treatment period. Secondary endpoints are progression free survival, overall survival, quality-adjusted survival using the quality-adjusted time without symptoms and toxicity (Q-TWiST) method. A translational program is included investigating detection and phenotyping of circulating tumor cells (CTC)-and the assessment of marker expression on CTCs in order to validate an endocrine responsiveness score.

Present accrual and target accrual:

The DETECT V trial started 2015 in the Dept. of Gynecology, University of Ulm and at the up to 120 sites in Germany. Until June 2018 97 patients with HER2-positive, hormone-receptor positive metastatic breast cancer have been enrolled. A sample size of 270 patients is planned.

Contact information:

Jens Huober, University of Ulm, Dept of Gynecology, Breast Center, jens.huober@uniklinik-ulm.de

Sabrina Krause, University of Ulm, Dept of Gynecology, sabrina.krause@uniklinik-ulm.de

Citation Format: Krause S, Friedl T, Fehm T, Romashova T, Fasching PA, Schneeweiss A, Müller V, Taran F-A, Polasik A, Tzschaschel M, De Gregorio A, Meier-Stiegen F, Janni W, Huober J. DETECT V/CHEVENDO – Comparison of dual HER2-targeted therapy with trastuzumab plus pertuzumab in combination with chemo- or endocrine therapy in addition with CDK4/6 inhibition in patients with HER2-positive and hormone-receptor positive metastatic breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT2-07-01.

Day and Night: Metabolic Profiles and Evolutionary Relationships of Six Axenic Non-Marine Cyanobacteria

Cyanobacteria are dominant primary producers of various ecosystems and they colonize marine as well as freshwater and terrestrial habitats. On the basis of their oxygenic photosynthesis they are known to synthesize a high number of secondary metabolites, which makes them promising for biotechnological applications. State-of-the-art sequencing and analytical techniques and the availability of several axenic strains offer new opportunities for the understanding of the hidden metabolic potential of cyanobacteria beyond those of single model organisms. Here, we report comprehensive genomic and metabolic analyses of five non-marine cyanobacteria, that is, Nostoc sp. DSM 107007, Anabaena variabilis DSM 107003, Calothrix desertica DSM 106972, Chroococcidiopsis cubana DSM 107010, Chlorogloeopsis sp. PCC 6912, and the reference strain Synechocystis sp. PCC 6803. Five strains that are prevalently belonging to the order Nostocales represent the phylogenetic depth of clade B1, a morphologically highly diverse sister lineage of clade B2 that includes strain PCC 6803. Genome sequencing, light and scanning electron microscopy revealed the characteristics and axenicity of the analyzed strains. Phylogenetic comparisons showed the limits of the 16S rRNA gene for the classification of cyanobacteria, but documented the applicability of a multilocus sequence alignment analysis based on 43 conserved protein markers. The analysis of metabolites of the core carbon metabolism showed parts of highly conserved metabolic pathways as well as lineage specific pathways such as the glyoxylate shunt, which was acquired by cyanobacteria at least twice via horizontal gene transfer. Major metabolic changes were observed when we compared alterations between day and night samples. Furthermore, our results showed metabolic potential of cyanobacteria beyond Synechocystis sp. PCC 6803 as model organism and may encourage the cyanobacterial community to broaden their research to related organisms with higher metabolic activity in the desired pathways.

ATP Content and Cell Viability as Indicators for Cryostress Across the Diversity of Life

In many natural environments, organisms get exposed to low temperature and/or to strong temperature shifts. Also, standard preservation protocols for live cells or tissues involve ultradeep freezing in or above liquid nitrogen (-196°C or -150°C, respectively). To which extent these conditions cause cold- or cryostress has rarely been investigated systematically. Using ATP content as an indicator of the physiological state of cells, we found that representatives of bacteria, fungi, algae, plant tissue, as well as plant and human cell lines exhibited similar responses during freezing and thawing. Compared to optimum growth conditions, the cellular ATP content of most model organisms decreased significantly upon treatment with cryoprotectant and cooling to up to -196°C. After thawing and a longer period of regeneration, the initial ATP content was restored or even exceeded the initial ATP levels. To assess the implications of cellular ATP concentration for the physiology of cryostress, cell viability was determined in parallel using independent approaches. A significantly positive correlation of ATP content and viability was detected only in the cryosensitive algae Chlamydomonas reinhardtii SAG 11-32b and Chlorella variabilis NC64A, and in plant cell lines of Solanum tuberosum. When comparing mesophilic with psychrophilic bacteria of the same genera, and cryosensitive with cryotolerant algae, ATP levels of actively growing cells were generally higher in the psychrophilic and cryotolerant representatives. During exposure to ultralow temperatures, however, psychrophilic and cryotolerant species showed a decline in ATP content similar to their mesophilic or cryosensitive counterparts. Nevertheless, psychrophilic and cryotolerant species attained better culturability after freezing. Cellular ATP concentrations and viability measurements thus monitor different features of live cells during their exposure to ultralow temperatures and cryostress.

New Taxa of Streptophyte Algae (Streptophyta) from Terrestrial Habitats Revealed Using an Integrative Approach

Two new genera (Streptosarcina and Streptofilum) and three new species (Streptosarcina arenaria, S. costaricana and Streptofilum capillatum) of streptophyte algae were detected in cultures isolated from terrestrial habitats of Europe and Central America and described using an integrative approach. Additionally, a strain isolated from soil in North America was identified as Hormidiella parvula and proposed as an epitype of this species. The molecular phylogeny based on 18S rRNA and rbcL genes, secondary structure of ITS-2, as well as the morphology of vegetative and reproductive stages, cell ultrastructure, ecology and distribution of the investigated strains were assessed. The new genus Streptosarcina forms a sister lineage to the genus Hormidiella (Klebsormidiophyceae). Streptosarcina is characterized by packet-like (sarcinoid) and filamentous thalli with true branching and a cell organization typical for Klebsormidiophyceae. Streptofilum forms a separate lineage within Streptophyta. This genus represents an easily disintegrating filamentous alga which exhibits a cell coverage of unique structure: layers of submicroscopic scales of piliform shape covering the plasmalemma and exfoliate inside the mucilage envelope surrounding cells. The implications of the discovery of the new taxa for understanding evolutionary tendencies in the Streptophyta, a group of great evolutionary interest, are discussed.

Abstract P6-13-01: Withdrawn

This abstract was withdrawn by the authors.

Biodiversity of green algae covering artificial hard substrate surfaces in a suburban environment: a case study using molecular approaches

In Middle European suburban environments green algae often cover open surfaces of artificial hard substrates. Microscopy reveals the Apatococcus/Desmococcus morphotype predominant over smaller coccoid forms. Adverse conditions such as limited water availability connected with high PAR and UV irradiance may narrow the algal diversity to a few specialists in these subaerial habitats. We used rRNA gene cloning/sequencing from both DNA extracts of the biofilms without culturing as well as cultures, for the unambiguous determination of the algal composition and to assess the algal diversity more comprehensively. The culture independent approach revealed mainly just two genera (Apatococcus, Trebouxia) for all study sites and five molecular operational taxonomic units (OTUs) for a particular study site, which based on microscopic observation was the one with the highest morphological diversity. The culture approach, however, revealed seven additional OTUs from five genera (Chloroidium, Coccomyxa, Coenochloris, Pabia, Klebsormidium) and an unidentified trebouxiophyte lineage for that same site; only two OTUs were shared by both approaches. Two OTUs or species were recovered for which references have been isolated only from Antarctica so far. However, the internal transcribed spacer (ITS) sequence differences among them supported they are representing distinct populations of the same species. Within Apatococcus five clearly distinct groups of ITS sequences, each putatively representing a distinct species, were recovered with three or four such ITS types co-occurring at the same study site. Except for the streptophyte Klebsormidium only members of Trebouxiophyceae were detected suggesting these algae may be particularly well-adapted to subaerial habitats.

Taxonomic revision and species delimitation of coccoid green algae currently assigned to the genus Dictyochloropsis (Trebouxiophyceae, Chlorophyta)

Coccoid green algae traditionally classified in Dictyochloropsis have a complex, reticulate chloroplast, when mature, without a pyrenoid. They occupy remarkably diverse ecological niches as free-living organisms or in association with lichen-forming fungi and were recently shown to form two distinct lineages within Trebouxiophyceae. We used a polyphasic approach to revise the taxonomy of the genus. Based on phylogenetic analysis of the 18S rRNA gene, and detailed morphological investigation using comparative conventional light and confocal microscopy, we have assigned these lineages to two genera, Dictyochloropsis and Symbiochloris gen. nov. We have reconsidered the diagnostic generic features as follows: Dictyochloropsis comprises only free-living algae with a reticulate chloroplast, forming lobes in a parallel arrangement at some ontogenetic stages, and which reproduce only by means of autospores. This agrees with Geitler's original diagnosis of Dictyochloropsis, but not with the later emendation by Tschermak-Woess. Consequently, the species of Dictyochloropsis sensu Tschermak-Woess are assigned to Symbiochloris, with new combinations proposed. Symbiochloris encompasses free-living and/or lichenized algae with lobed chloroplasts and that reproduce by forming zoospores characterized by two subapical isokont flagella that emerge symmetrically near the flattened apex. In addition, using coalescent-based approaches, morphological characters and secondary structure of ITS transcripts, we inferred species boundaries and taxonomic relationships within the newly proposed genera. Two species of Dictyochloropsis and nine species of Symbiochloris are delimited, including the newly described species D. asterochloroides, S. handae, S. tropica, and S. tschermakiae. Our results further support the non-monophyly of autosporine taxa within Trebouxiophyceae.

Widespread green algae Chlorella and Stichococcus exhibit polar-temperate and tropical-temperate biogeography

Chlorella and Stichococcus are morphologically simple airborne microalgae, omnipresent in terrestrial and aquatic habitats. The minute cell size and resistance against environmental stress facilitate their long-distance dispersal. However, the actual distribution of Chlorella- and Stichococcus-like species has so far been inferred only from ambiguous morphology-based evidence. Here we contribute a phylogenetic analysis of an expanded SSU and ITS2 rDNA sequence dataset representing Chlorella- and Stichococcus-like species from terrestrial habitats of polar, temperate and tropical regions. We aim to uncover biogeographical patterns at low taxonomic levels. We found that psychrotolerant strains of Chlorella and Stichococcus are closely related with strains originating from the temperate zone. Species closely related to Chlorella vulgaris and Muriella terrestris, and recovered from extreme terrestrial environments of polar regions and hot deserts, are particularly widespread. Stichococcus strains from the temperate zone, with their closest relatives in the tropics, differ from strains with the closest relatives being from the polar regions. Our data suggest that terrestrial Chlorella and Stichococcus might be capable of intercontinental dispersal; however, their actual distributions exhibit biogeographical patterns.

Determination of Interleukin-4, -5, -6, -8 and -13 in Serum of Patients with Breast Cancer Before Treatment and its Correlation to Circulating Tumor Cells

BACKGROUND/AIM

Circulating tumor cells (CTCs) in women with breast cancer are an indication of prognosis before starting systemic treatment. The aim of this study was the evaluation of cytokine profiles as marker for CTC involvement.

MATERIALS AND METHODS

The analysis of CTCs, the time of blood sampling and the methodology were prospectively designed. There were two groups of patients: 100 women with a positive result for presence of CTCs and 100 women negative for CTCs. These groups were matched into pairs by tumor factors and survival/death. A multi-array ELISA was used to screen T-helper cell (Th) 2 cytokines. The results were analyzed by Spearman correlation coefficient and Mann-Whitney U-test.

RESULTS

In patients who were CTC-negative, expression of interleukin-8 (IL-8) and IL-13 was increased (p=0.017 and p=0.045, respectively) if they were negative for progesterone receptor. In patients who died from their tumor, correlation between hormone receptor negativity and an increase in IL-4 was found. IL-5 was increased in patients with lymph node-positive and human epidermal growth factor receptor 2 (HER2)-positive disease (p=0.042). Moreover IL-4 was increased in patients with progesterone receptor-positive and estrogen receptor-negative status (p=0.024). Furthermore, the level of IL-6 was increased in patients with tumor grade G3 without progesterone receptor expression.

CONCLUSION

Th2 cytokines are significantly modified in patients who are CTC-negative and progesterone receptor-positive. We suppose that an increase of IL-4 depends on hormone receptor status. In literature, a correlation between IL-4 and resistance to apoptosis is described. We suspect that IL-4 is responsible for the poor outcome of these cases.

Abstract P1-12-03: Short term quality of life with epirubicin-fluorouracil-cyclophosphamid (FEC) and sequential epirubicin/cyclophosphamid-docetaxel (EC-DOC) chemotherapy in patients with primary breast cancer – Results from the prospective multi-center randomized Adebar trial

Background:

The grade of recommendation for adjuvant dose-dense chemotherapy in patients with high risk primary breast cancer is heterogeneous among international guidelines. Understanding the impact on quality of life (QOL) by adjuvant dose dense chemotherapy in comparison to standard adjuvant chemotherapy is thereby a crucial factor, especially if the benefit is potentially low. This study aims to assess the impact on QOL by adjuvant dose dense chemotherapy in the prospective randomized multi-center ADEBAR trial.

Methods:

QOL was assessed at baseline (t1), before cycle 4 FEC (Epirubicin 60mg/m2 i.v. d 1 + 8, 5-Fluoruracil 500mg/m2 i.v. d 1 + 8, Cyclophosphamide 75mg/m2 p.o. d 1–14, q4w x 6) and cycle 5 EC-DOC (Epirubicin 90mg/m2 plus Cyclophosphamide 600mg/m2 q3w x 4, sequentially followed by Docetaxel 100mg/m2 q3w x 4) (t2), 4 weeks after chemotherapy (t3), 6 weeks after radiation (t4) and 1 year after baseline (t5) using the European Organization for Research and Treatment for Cancer (EORTC) Quality of Life Core Questionnaire (QLQ-C30) and the Breast Cancer-Specific Module (QLQ-BR23). A multivariate mixed model was fitted to test for differences between the two treatment arms. Primary endpoint was global QOL, secondary endpoints physical functioning, nausea&vomiting, fatigue and systemic therapy side effects. A minimum clinically meaningful difference was considered to be 10 points.

Results:

1306 patients were recruited between 3/2002 and 5/2005 675 were assigned to the FEC and 688 to the EC-DOC arm. Compliance to QOL assessment was 74% at baseline and 58% four weeks after therapy, but dropped to 11% after one year follow up. After the beginning of treatment global QOL dropped in both arm by 3 to 4 points. In the EC-DOC arm QOL dropped further at t3 by 7 points and stayed stable in the FEC arm. 6 weeks after radiation QOL exceeded baseline in both arms by 6 to 8 points. The differences between treatment arms were strongest at t3 (54.1 vs. 49.7) but did not reach clinical relevance at any point in time. Physical functioning, nausea vomiting, fatigue and systemic therapy side effects followed with some minor exceptions similar patterns, but showed higher amplitudes.

Conclusion:

In conclusion we could not detect a statistically significant difference between the two treatment arms in QOL parameters, indicating that dose dense adjuvant chemotherapy did not impact QOL at a clinically relevant level compared to standard adjuvant chemotherapy.

Citation Format: Schwentner L, Harbeck N, Singer S, Eichler M, Rack B, Forstbauer H, Wischnik A, Scholz C, Fink V, Huober J, Friedl T, Weissenbacher T, Härtl K, Kiechle M, Janni W. Short term quality of life with epirubicin-fluorouracil-cyclophosphamid (FEC) and sequential epirubicin/cyclophosphamid-docetaxel (EC-DOC) chemotherapy in patients with primary breast cancer – Results from the prospective multi-center randomized Adebar trial. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-12-03.

Abstract P4-01-03: Prognostic relevance of circulating tumor cells across different molecular subgroups in the adjuvant SUCCESS-A study

Aim: The prognostic value of circulating tumor cells (CTCs) in the adjuvant setting has recently been demonstrated in the SUCCESS A Study (Rack et al. JNCI 2014). As breast carcinomas depend on partly different pathways for progression, the relevance of CTCs could differ between molecular intrinsic subtypes of breast cancer. Aim of this study was therefore to analyze the prognostic impact of CTCs in molecular subtypes of a large patient cohort.

Methods: Within the adjuvant SUCCESS A Study, patients were treated either with 5-Flourouracil, Epirubicin and Cyclophosphamid (FEC) followed by Docetaxel (D) or with FEC followed by D and Gemcitabine (DG). There was no restriction with regard to molecular subtype, however a high recurrence risk was required for study entry. In addition patients were assessed prospectively for the presence of CTCs before chemotherapy. Molecular subtypes were defined as: triple negative (TN), hormone receptor positive and grading 1/2 (LUM A like), hormone receptor positive and grading 3 (LUM B like), HER2 positive (HER2 like). We studied whether the addition of CTC status (0 CTC vs > 0 CTCs) to well-known predictors such as age, BMI, tumor size, lymph node status improved the prediction of overall survival (OS) and disease free survival (DFS) across all patients and especially within molecular subtypes using likelihood ratio tests, which compared multivariable Cox regression models with and without CTC and the interaction between CTC and molecular subtype.

Results: Information about molecular subtype and CTCs was available in a total of 1994 patients. At least one CTC was seen in 422 (21.2%) of patients. 383 (19.2%) were TN, 798 were LUM A like (40.0%), 328 (16.4%) were LUM B like (16.4%) and 485 (24.3%) were HER2 like. The effect of CTC on overall survival had a HR of 2.50 (95%: 1.75 to 3.58) for the entire cohort. However as the effect was different across subtypes (p=0.04, likelihood ratio test), subtype specific HR were calculated. The effects on OS were most prominent in LUM B like patients (HR=3.96; 95%CI: 1.93 to 8.14) and LUM A like patients (HR=3.57; 95%CI: 1.81 to 7.03), less strong in HER2 like (HR=2.35; 95%CI: 1.04 to 5.32) and not present in TN patients (HR=1.18; 95%CI: 0.62 to 2.24). CTC status had a clear effect on DFS as well (HR=1.93, 95%CI: 1.48 to 2.52). It could not be shown that this effect was different across subtypes (p=0.07, likelihood ratio test). However, the effect size was similarly distributed like the ones for OS.

Conclusion: With regard to OS the prognostic effect of CTCs in this study cohort seems most prominent in patients with hormone receptor positive disease. It is still significant in HER2 positive, but not in TN breast cancer patients. Results with regard to DFS trended into the same direction, differences within subgroups could however not be shown, possibly due to power reasons.

Citation Format: Wolfgang Janni, Andreas Schneeweiss, Lothar Häberle, Peter A Fasching, Lukas Schwentner, Mahdi Rezai, Jörn Hilfrich, Hans Tesch, Georg Heinrich, Helmut Forstbauer, Thomas Friedl, Fabienne Schochter, Susanne Albrecht, Bernadette Jäger, Julia Jückstöck, Tanja Fehm, Volkmar Müller, Klaus Friese, Werner Lichtenegger, Matthias B Beckmann, Brigitte Rack. Prognostic relevance of circulating tumor cells across different molecular subgroups in the adjuvant SUCCESS-A study [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P4-01-03.

Biodiversity of soil cyanobacteria in the hyper-arid Atacama Desert, Chile

The cyanobacterial diversity of soils of the Atacama Desert (Chile) was investigated using 16S rRNA gene cloning/sequencing directly from soil samples and 16S rRNA gene sequencing from unialgal cultures. Within the hyper-arid Atacama Desert, one of the driest parts of the world, 10 sites with differing altitude and distance to the shore were sampled along a total air-line distance (from south to north) of ~1,100 km. Filamentous cyanobacteria belonging to Nostocophycideae and Synechococcophycideae were present. Oscillatoriophycideae exhibited the highest species richness among the subclasses of cyanobacteria, and included mostly filamentous species along with some coccoids (e.g., Chroococcidiopsis). Thirty species-level phylotypes could be recognized using a cut-off of 99% 16S rRNA sequence similarity within the 22 genera defined at 97% 16S rRNA sequence similarity. Eight of the 30 taxa could be detected by both clonal and culture sequences. Five taxa were observed only in cultures, whereas the cloning approach revealed 17 additional taxa, which might be in the collection but unsequenced, hard-to-cultivate, or entirely unculturable species using standard cultivation media. The Atacama Desert soils have a high diversity of phylotypes, among which are likely both new genera and new species awaiting characterization and description.

Biotechnological screening of microalgal and cyanobacterial strains for biogas production and antibacterial and antifungal effects

Microalgae and cyanobacteria represent a valuable natural resource for the generation of a large variety of chemical substances that are of interest for medical research, can be used as additives in cosmetics and food production, or as an energy source in biogas plants. The variety of potential agents and the use of microalgae and cyanobacteria biomass for the production of these substances are little investigated and not exploited for the market. Due to the enormous biodiversity of microalgae and cyanobacteria, they hold great promise for novel products. In this study, we investigated a large number of microalgal and cyanobacterial strains from the Culture Collection of Algae at Göttingen University (SAG) with regard to their biomass and biogas production, as well antibacterial and antifungal effects. Our results demonstrated that microalgae and cyanobacteria are able to generate a large number of economically-interesting substances in different quantities dependent on strain type. The distribution and quantity of some of these components were found to reflect phylogenetic relationships at the level of classes. In addition, between closely related species and even among multiple isolates of the same species, the productivity may be rather variable.

Phytoplankton diversity and community composition along the estuarine gradient of a temperate macrotidal ecosystem: combined morphological and molecular approaches

Microscopical and molecular analyses were used to investigate the diversity and spatial community structure of spring phytoplankton all along the estuarine gradient in a macrotidal ecosystem, the Baie des Veys (eastern English Channel). Taxa distribution at high tide in the water column appeared to be mainly driven by the tidal force which superimposed on the natural salinity gradient, resulting in a two-layer flow within the channel. Lowest taxa richness and abundance were found in the bay where Teleaulax-like cryptophytes dominated. A shift in species composition occurred towards the mouth of the river, with the diatom Asterionellopsis glacialis dramatically accumulating in the bottom waters of the upstream brackish reach. Small thalassiosiroid diatoms dominated the upper layer river community, where taxa richness was higher. Through the construction of partial 18S rDNA clone libraries, the microeukaryotic diversity was further explored for three samples selected along the surface salinity gradient (freshwater - brackish - marine). Clone libraries revealed a high diversity among heterotrophic and/or small-sized protists which were undetected by microscopy. Among them, a rich variety of Chrysophyceae and other lineages (e.g. novel marine stramenopiles) are reported here for the first time in this transition area. However, conventional microscopy remains more efficient in revealing the high diversity of phototrophic taxa, low in abundances but morphologically distinct, that is overlooked by the molecular approach. The differences between microscopical and molecular analyses and their limitations are discussed here, pointing out the complementarities of both approaches, for a thorough phytoplankton community description.

Abstract P1-04-06: Discordance of the ER- and HER2-status on disseminated tumor cells compared to the primary tumor in patients with early breast cancer

Background: Differences in ER- and HER2-expression on metastases compared to the primary tumor (PT) are a known phenomenon and may have clinical implications in respect of targeted systemic treatment approaches. The aim of this study was to evaluate both ER- and HER2-status on disseminated tumor cells (DTCs) in the bone marrow (BM) of patients (pts) with early breast cancer (EBC) and to compare these with the corresponding PT.

Methods: BM aspirates were obtained at the time of first surgery. After Ficoll enrichment for mononuclear cells two cytospins with 106 BM cells were evaluated for ER-, HER2- and cytokeratin (CK) -expressions simultaneously by immunocytochemistry using a triple fluorescence staining method with antibodies directed against human ER (secondly labeled with Cy3, red), HER2 (Coumarin-AMCA, blue) and CK (DyLight488, green). The manual analysis was conducted using a computerized fluorescence microscope (Axioskop, Zeiss, Germany). Criteria for CK- and HER2-positivity were the ring-like appearance of the respective membrane stainings and for ER-expression a nuclear staining. Only pts with the detection of CK positive cells (DTC+) and known ER- and HER2-status of the PT (n = 54) were selected for this analysis.

Results: The median number of DTCs was 13 (range 1-95; total number of DTCs detected: 1082). 40 (74%) of the pts had at least one ER-positive (pos) DTC, 24 (44%) at least one HER2-pos DTC, 14 (26%) at least one ER-pos/HER2-pos DTC, and 50 (93%) at least one ER-negative/HER2-negative (neg) DTC, while 10 (19%) pts had only ER-neg/HER2-neg DTCs.

The concordance rate between ER-status on DTCs and PT was 74%. Pts with an ER-pos PT were significantly more likely to have at least one ER-pos DTC (34 out of 42) than pts with an ER-neg PT (6 out of 12; Chi-square test, χ2 = 4.66, p = 0.031). 39 (93%) of the 42 pts with ER-pos PT had at least 1 ER-neg DTC.

The concordance rate between HER2-status on DTCs and PT was 52%. The probability of having at least one HER2-pos DTC was not related to the HER2-status of the PT (Chi-square test, χ2 = 0.34, p = 0.56). 22 (46%) of the 48 pts with a HER2-neg PT had at least one HER2-pos DTC. All of the 6 pts with a HER2-pos PT had at least one HER2-neg DTC.

7 out of 10 pts with a triple-neg PT had at least one DTC pos for ER, HER2 or both. Further the heterogeneity of the ER- and HER2-expression on DTCs compared to the PT for different DTC counts was evaluated. We detected all possible combinations of ER- and HER2-experssion on DTCs regardless of the respective status of the PT.

Conclusions: Our study confirms that the ER- and/or HER2-status on DTCs may differ compared to the PT. This discordance could be especially important for pts with a triple-neg PT and ER-pos or HER2-pos DTCs, since they might respond favorably to an endocrine or HER2-targeted therapy. On the other hand, the presence of ER-neg or HER2-neg DTCs in pts with ER-pos or HER2-pos PT might explain some of the failures of adjuvant endocrine or HER2 targeted therapy.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-04-06.

Congruence of chloroplast- and nuclear-encoded DNA sequence variations used to assess species boundaries in the soil microalga Heterococcus (Stramenopiles, Xanthophyceae)

Background

Heterococcus is a microalgal genus of Xanthophyceae (Stramenopiles) that is common and widespread in soils, especially from cold regions. Species are characterized by extensively branched filaments produced when grown on agarized culture medium. Despite the large number of species described exclusively using light microscopic morphology, the assessment of species diversity is hampered by extensive morphological plasticity.

Results

Two independent types of molecular data, the chloroplast-encoded psbA/rbcL spacer complemented by rbcL gene and the internal transcribed spacer 2 of the nuclear rDNA cistron (ITS2), congruently recovered a robust phylogenetic structure. With ITS2 considerable sequence and secondary structure divergence existed among the eight species, but a combined sequence and secondary structure phylogenetic analysis confined to helix II of ITS2 corroborated relationships as inferred from the rbcL gene phylogeny. Intra-genomic divergence of ITS2 sequences was revealed in many strains. The ‘monophyletic species concept’, appropriate for microalgae without known sexual reproduction, revealed eight different species. Species boundaries established using the molecular-based monophyletic species concept were more conservative than the traditional morphological species concept. Within a species, almost identical chloroplast marker sequences (genotypes) were repeatedly recovered from strains of different origins. At least two species had widespread geographical distributions; however, within a given species, genotypes recovered from Antarctic strains were distinct from those in temperate habitats. Furthermore, the sequence diversity may correspond to adaptation to different types of habitats or climates.

Conclusions

We established a method and a reference data base for the unambiguous identification of species of the common soil microalgal genus Heterococcus which uses DNA sequence variation in markers from plastid and nuclear genomes. The molecular data were more reliable and more conservative than morphological data.

Molecular diversity of phototrophic biofilms on building stone

Composition and diversity of aeroterrestrial phototrophic microbial communities are up to now poorly understood. Here, we present a comparative study addressing the composition of algal communities on sandstone substrata based upon the analysis of rRNA gene clone libraries from environmental samples and crude cultures. From a west-facing, shaded wall area of the mediaeval castle ruin Gleichen (Thuringia, Germany), sequences mainly related to the green algae Prasiococcus and Trebouxia (Trebouxiophyceae) were retrieved. A south-west-facing, sun-exposed wall area was mainly colonized by Apatococcus and a Phyllosiphon-related alga. Just a few species, in particular Stichococcus-related strains, were ubiquitous in both areas. Samples from a basement vault exposed to low irradiance exhibited Chlorophyceae like Chromochloris and Bracteacoccus. Thus, most green algae on the daylight-exposed walls were affiliated to Trebouxiophyceae, whereas Chlorophyceae were dominant in samples taken from the site kept under low irradiance. Accordingly, cyanobacterial communities were different: the sun-exposed area was dominated by Synechococcus-related organisms, while on the shaded wall area, cyanobacteria were almost absent. The filamentous Leptolyngbya dominated samples from the basement vault. Scanning electron microscopy revealed endolithic algal morphotypes (coccoid algae and diatoms) dominant in open pores between mineral particles. Here, the organisms may be also involved in biogenic weathering of stone.

'Y'Scenedesmus (Chlorophyta, Chlorophyceae): the internal transcribed spacer 2 rRNA secondary structure re-revisited

Including RNA secondary structures improves accuracy and robustness in reconstruction of phylogenetic trees. It is possible to simultaneously infer alignments and phylogenies on the primary sequence and the secondary structure information. For the internal transcribed spacer 2 (ITS2), a phylogenetic RNA transcript marker, two different structure conformations (I or Y shape for helix I) were published for Scenedesmaceae, and a third appeared in the ITS2 database. We contrast the effects on phylogenetic tree reconstruction of different structure sets for a small scenedesmacean subset, using neighbour-joining, maximum parsimony and, for the first time, maximum likelihood, on sequence-structure alignments. Generally our study supports inclusion of secondary structure information. However, we found that any of the three structure conformations is equally fit for phylogenetic studies, but prefer the I shape for helix I. Moreover, our results enable us to give general recommendations on how to build a phylogenetic tree using ITS2 sequence-structure alignments, including different methods to obtain the secondary structures. Thus, we hope to provide a valuable contribution not only for scenedesmacean ITS2 phylogeny, but also for other approaches using RNA transcript markers.

Phylogenetic relationships of the Physciaceae inferred from rDNA sequence data and selected phenotypic characters

The monophyletic origin of the ascomycete family Physciaceae, its position within the Lecanorales and the phylogenetic structure within the family were investigated using nuclear rDNA sequence analyses. The common origin of the Caliciaceae and Physciaceae as previously shown (Wedin et al 2000) was confirmed. Further it could be shown that the Caliciaceae are nested within the Physciaceae. A unique region in loop 37 of the SSU rRNA secondary structure model was identified, which characterizes the Physciaceae/Caliciaceae. The SSU rDNA sequence data did not support a particular relationship with any other Lecanoralean family. Analyses of ITS rDNA sequences revealed a bifurcation of the Physciaceae/Caliciaceae clade, which was found to be congruent with the distribution of certain morphological characters. The congruence with the ITS phylogeny demonstrated the phylogenetic significance of ascus type, hypothecium pigmentation, ascospore characters and excipulum type. Fine-structure details of ascospores and the structure of excipula were found to be important in the recognition of convergences in these traits. Other previously used characters, i.e., growth habit, certain ascospore types or structure of the upper cortex, were found to be of multiple origins within the Physciaceae. All monophyletic lineages of noncrustose growth habit exhibit uniform ascospore types, indicating a higher evolutionary age of ascospore types than foliose growth habit. The taxonomic segregation of the Physciaceae into the Physciaceae and Caliciaceae is proposed here.

Molecular Evidence for the Wide Distribution of Two Lineages of Terrestrial Green Algae (Chlorophyta) over Tropics to Temperate Zone

Phylogenetic analyses of 18S rDNA sequences from environmental clones and culture strains revealed a widespread distribution of two subaerial green algal lineages, Jenufa and Xylochloris, recently described from rainforests in southeast Asia. A new lineage of Jenufa (Chlorophyceae), most closely related to or even conspecific with J. minuta, was formed by sequences of European origin. Two more lineages of Jenufa were formed by three additional sequences from Ecuador and Panama. The other lineage was a close relative of Xylochloris irregularis (Trebouxiophyceae), probably representing a new species of the genus and distinct from the only so far described species, X. irregularis. It comprised two distinct clades each containing almost identical sequences from Germany and Ecuador. Analyses of the new sequences for both genera allowed to presume a preference of J. minuta to subaerial growth on rock or artificial hard substrates combined with a remarkable adaptation to extended periods of darkness, whereas Xylochloris may preferably occur on tree bark or in the soil.

Biodiversity effects on ecosystem functioning change along environmental stress gradients

Positive relationship between biodiversity and ecosystem functioning has been observed in many studies, but how this relationship is affected by environmental stress is largely unknown. To explore this influence, we measured the biomass of microalgae grown in microcosms along two stress gradients, heat and salinity, and compared our results with 13 published case studies that measured biodiversity-ecosystem functioning relationships under varying environmental conditions. We found that positive effects of biodiversity on ecosystem functioning decreased with increasing stress intensity in absolute terms. However, in relative terms, increasing stress had a stronger negative effect on low-diversity communities. This shows that more diverse biotic communities are functionally less susceptible to environmental stress, emphasises the need to maintain high levels of biodiversity as an insurance against impacts of changing environmental conditions and sets the stage for exploring the mechanisms underlying biodiversity effects in stressed ecosystems.