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La alelopatía, que es la liberación de fitotoxinas por parte de las plantas, puede ser un mecanismo clave por el cual una especie invasora desplaza a las especies nativas residentes. Sin embargo, en la literatura todavía se cuestionan los procedimientos metodológicos utilizados. En este trabajo se evaluaron los efectos fitotóxicos de las gramíneas más invasoras de los pastizales del Río de la Plata: Cynodon dactylon y Eragrostis plana. Aunque se sugiere que la alelopatía es uno de los mecanismos involucrados en el establecimiento y el impacto de dichas especies, hay pocas evidencias que lo respaldan de forma convincente. Se realizó un experimento para evaluar el efecto de ambas especies invasoras sobre la germinación de Eragrostis bahiensis, una gramínea nativa de la región. Se utilizaron extractos acuosos de hojas frescas y secas de tres especies donantes: las dos invasoras (C. dactylon y E. plana) y una nativa (Coelorachis selloana). Este enfoque permite relativizar el efecto de las especies invasoras de las nativas residentes, en el marco de la hipótesis clásica de armas novedosas (novel weapon hypothesis). Como resultado, sólo los extractos acuosos de hojas secas inhibieron la germinación y el crecimiento temprano de E. bahiensis. La magnitud de estos efectos varió entre las especies donantes, sin consenso para concluir que ambas especies invasoras tendrían mayores efectos. Cynodon dactylon causó el mayor efecto inhibidor sobre E. bahiensis. Sin embargo, la especie nativa C. selloana también presentó una inhibición potente; incluso, fue mayor a la que presentó E. plana. Así, el rol de la alelopatía en la invasión de E. plana en los pastizales del Río de la Plata debería ser cuestionado. Por último, abordamos algunas sugerencias para mejorar el diseño experimental para evaluar cuán novedosos son los efectos fitotóxicos en la comunidad invadida.

The first breath of air at birth marks the beginning of extrauterine life, and breathing problems due to incomplete lung development or acute respiratory distress are common in premature babies and respiratory diseases. However, the underlying molecular mechanisms remain poorly understood. Here we show that the microtubule plus-end-tracking protein CLASP1 is required for neonatal lung function and survival. CLASP1 is expressed in the lungs and associated respiratory structures throughout embryonic development. Clasp1 disruption in mice caused intrauterine growth restriction and neonatal lethality due to acute respiratory failure. Knockout animals showed impaired lung inflation associated with smaller rib cage formation and abnormal diaphragm innervation. Live-cell analysis of microtubule dynamics in cultured hippocampal neurons revealed an increased catastrophe rate, consistent with a role of CLASP1 in neurite outgrowth. Histological and gene expression studies indicated that CLASP1 is required for normal pneumocyte differentiation and fetal lung maturation. Thus, CLASP1-mediated regulation of microtubule dynamics assists multiple systems essential for neonatal lung function and survival.

One hundred accessions of a "core collection" of Diplotaxis tenuifolia (L.) DC. and Eruca spp. were screened at seedling stage for resistance to downy mildew. Accessions tested at the seedling stage were assigned to 0-6 interaction phenotypes. All cultivated rocket (Eruca spp.) accessions exhibited a resistant (R) response both in cotyledons and in young leaves. The wild rocket (D. tenuifolia) accessions exhibited higher susceptibility in cotyledons than in the 1st and 2nd leaves, with 16 and 47 accessions classified as resistant or partially resistant (PR) in the cotyledon and in leaves stages, respectively. Only three wild rocket accessions displayed an R phenotype in cotyledons and leaves. The most frequent response in cotyledons vs. leaves was the highly susceptible/susceptible (HS/S) combination (33 accessions), followed by the S/PR combination (18 accessions). A significant correlation (r = 0.917, P < .000) was observed between the disease index in cotyledons and leaves. The molecular markers analyses revealed a wide genetic distance between Diplotaxis and Eruca, which gather in two clearly separated species clusters. The molecular variability is accompanied by a wide diversity of interactions with the pathogen isolate. The closest similarities among D. tenuifolia accessions were found in accessions provided by the same breeding company. Future studies will be focused on two main objectives: (a) the assessment of the accessions behavior that have evidenced an R/R, S/PR, and HS/PR cotyledon and leaf response under greenhouse or field production and (b) the genome mapping of genetic features that provide downy mildew resistance. info:eu-repo/semantics/publishedVersion

The pathogenesis mechanisms of Campylobacter fetus subsp. venerealis (Cfv), the etiologic agent of Bovine Genital Campylobacteriosis remain elusive. This study evaluated the virulence potential and biovar characteristics of Cfv isolates (n = 13) by PCR screening of putative virulence-factor (VF) genes, Multilocus Sequence Typing (MLST) analysis, antimicrobial susceptibility to tetracycline, penicillin, enrofloxacin and streptomycin testing and whole-genome sequencing (WGS, n = 5), also comparing the latter with 26 other whole-genome sequences of Cfv strains. The putative VF genes encoding type IV secretion system of Cfv (virB2-virB11/virD4) were absent in 92% of isolates, including isolates from aborted foetuses, evidencing that these VF genes are not essential for Cfv pathogenicity. The parA gene, used as a Cfv diagnostic molecular target, was detected in only 3 of 13 isolates, invalidating its use for diagnosis purposes. Three novel sequence types were identified by MLST. Although no in vitro antimicrobial resistance was detected, WGS identified antimicrobial resistance-related genes, including those encoding the multidrug efflux pumps CmeABC and YkkCD, indicating that their presence is not enough to provide antimicrobial resistance. The SNP and accessory protein families analysis segregated the Cfv and Cfv biovar intermedius (Cfvi) strains into different clusters. In conclusion, this study evidenced virulence potential and biovar characteristics of Cfv and Cfvi, which are of relevance for the control of Bovine Genital Campylobacteriosis.

Keratinocyte infection with high-risk human papillomavirus genotypes has been linked to cancer development. In cervix, the alpha HPV16 and HPV18 have been reported as the mayor causative agents of cervical cancer. Oncogenic progression and chronic inflammation are closely related processes, with IL-6 as one of the main pro-inflammatory cytokines involved. However, there are limited studies about the regulation of IL-6 by low and high risk HPVs and the HPV proteins implicated in this modulation. In this work, we report the overexpression of IL-6 in HPV infected cervical cancer derived cell lines (HeLa and SiHa) compared to non-tumorigenic keratinocytes (HaCaT), and in Cervical Intraepithelial Neoplasia grade 1 HPV16 and HPV18 positive cervical samples compared to HPV negative samples without lesions. Moreover, we generated HaCaT keratinocytes that express E5, E6, and E7 from high risk (16 or 18) or low risk (62 and 84) HPVs. E5 proteins do not modify IL-6 expression, while E7 modestly increase it. Interestingly, E6 proteins in HaCaT cells upregulate IL-6 mRNA expression and protein secretion. Indeed, in HaCaT cells that express high risk HPV16E6 or HPV18E6 proteins, only the truncated E6* isoforms were expressed, showing the stronger IL-6 overexpression, while in HaCaT cells that express low risk HPV62 and HPV84 full length E6 proteins, IL-6 was also upregulated but not so drastically. Since HaCaT cells have a mutated p53 form that is not degraded by the introduction of E6 or E6/E7, it seems that E6/E7 regulate IL-6 by an additional mechanism independent of p53. In addition, basal keratinocytes showed a strong expression of IL-6R using immunohistochemistry, suggesting an autocrine mechanism over proliferative cells. Altogether, IL-6 cytokine expression in keratinocytes is upregulated by E6 and E7 proteins from HPVs 16, 18, 62, and 84, especially by high risk HPV16 and HPV18 E6*, which may contribute to promote a pro-inflammatory and highly proliferative microenvironment that can persist over time and lead to cervical tumorigenesis.

OBJECTIVE: To assess the prevalence of underweight (UW), overweight (OW), and obesity in children and adolescents with type 1 diabetes (T1D).METHODS: An international cross-sectional study including 23 026 T1D children (2-18 years, duration of diabetes ≥1 year) participating in the SWEET prospective, multicenter diabetes registry. Body mass index SD score (BMI-SDS) was calculated using the World Health Organization BMI charts. Children were categorized as UW (BMI-SDS +2SD). Hierarchic regression models were applied with adjustment for sex, age, and duration of diabetes.RESULTS: The prevalence of UW, OW, and obesity was: 1.4%, 22.3%, and 7.3% in males and 0.6%, 27.2%, and 6.8% in females. Adjusted BMI-SDS was significantly higher in females than in males (mean ± SEM: 0.54 ± 0.05 vs 0.40 ± 0.05, P CONCLUSIONS: The high rate of OW and obesity (31.8%) emphasize the need for developing further strategies to prevent and treat excess fat accumulation in T1D.

Before chromosomes segregate into daughter cells, they align at the mitotic spindle equator, a process known as chromosome congression. Centromere-associated protein E (CENP-E)/Kinesin-7 is a microtubule plus-end-directed kinetochore motor required for congression of pole-proximal chromosomes. Because the plus-ends of many astral microtubules in the spindle point to the cell cortex, it remains unknown how CENP-E guides pole-proximal chromosomes specifically toward the equator. We found that congression of pole-proximal chromosomes depended on specific posttranslational detyrosination of spindle microtubules that point to the equator. In vitro reconstitution experiments demonstrated that CENP-E-dependent transport was strongly enhanced on detyrosinated microtubules. Blocking tubulin tyrosination in cells caused ubiquitous detyrosination of spindle microtubules, and CENP-E transported chromosomes away from spindle poles in random directions. Thus, CENP-E-driven chromosome congression is guided by microtubule detyrosination. We thank F. I. Ataullakhanov for help with the laser trap and data analysis; A. Kiyatkin, V. Mustyatsa, M. Molodtsov, A. Gautreau, G. Lakisic, and M. Barisic for technical assistance; and members of our laboratories for stimulating discussions. This work was supported by National Institutes of Health grant R01-GM098389 and RSG-14-018-01-CCG from the American Cancer Society to E.L.G.; by the Institut Curie, the Centre National de la Recherche Scientifique, the Institut National de la Sante et de la Recherche Medicale, the L'Agence Nationale de la Recherche (ANR) award ANR-12-BSV2-0007, INCA_6517, ANR-10-LBX-0038, part of the IDEX Idex PSL, ANR-10-IDEX-0001-02 PSL to C.J.; and Fundacao Luso-Americana para o Desenvolvimento (FLAD) Life Science 2020 and PRECISE grant from the European Research Council to H.M. A.V.Z. is supported by the RAS Presidium Grants "Mechanisms of the Molecular Systems Integration," " Molecular and Cell Biology programs," and Russian Fund for Basic Research Grant 12-04-00111-a and 13-00-40188. R.S.S. is supported by a fellowship from the Programa Graduado em Areas da Biologia Basica e Aplicada (GABBA) PhD program from the University of Porto. A.L.P. is supported by fellowship SFRH/BPD/66707/2009 from Fundacao para a Ciencia e a Tecnologia of Portugal. M.B., R.S.S., S.K.T., M.M.M., C.J., E.L.G., and H.M. designed the experiments; M.B. performed all experiments in cells; M. M. M. established and performed the tubulin purification protocol from HeLa cells; R.S.S. performed single-molecule experiments; S.K.T. performed force measurements; A.L.P. provided reagents; all authors analyzed data; H.M., E.L.G., and M.B. wrote the paper, with contributions from all authors; H.M. conceived and coordinated the project. Data described can be found in the main figures and supplementary materials. The authors declare no conflict of interests.

Microtubules are dynamic cytoskeletal components necessary for several intracellular processes, including cell division, differentiation, migration and intracellular transport. Microtubule plus-end-tracking proteins (+TIPs) consist of a highly diversified group of evolutionary conserved families of proteins that preferentially accumulate at the plus-ends of microtubules. Importantly, +TIPs are capable of interacting with each other, which allows the establishment of complex protein networks greatly implicated in the regulation of microtubule behaviour. These networks play an important role mediating the interactions between microtubules and several cellular structures, such as membranes, kinetochores and the actin cytoskeleton, thereby influencing cellular architecture and coordinating diverse biological processes. For these reasons, +TIPs have been extensively studied, including the peculiar structural features allowing for the generation of networks, the mechanisms behind microtubule plus-end-tracking and their respective roles in the cell. Key Concepts +TIPs consist of an evolutionarily conserved, yet highly diversified group of proteins that preferentially accumulate at the plus-end of microtubules regulating their dynamics. In their structure +TIPs can comprise specialized domains fit to directly interact with tubulin, or able to bind proteins capable of autonomously associating with tubulin. The establishment of +TIPs networks responsible for the regulation of microtubule dynamics is important for numerous biological processes in interphase and mitosis. Keywords: microtubule; microtubule dynamics; microtubule-associated proteins; mitosis; plus-end-tracking; cytoskeleton

Human articular cartilage functions under a wide range of mechanical loads in synovial joints, where hydrostatic pressure (HP) is the prevalent actuating force. We hypothesized that the formation of engineered cartilage can be augmented by applying such physiologic stimuli to chondrogenic cells or stem cells, cultured in hydrogels, using custom-designed HP bioreactors. To test this hypothesis, we investigated the effects of distinct HP regimens on cartilage formation in vitro by either human nasal chondrocytes (HNCs) or human adipose stem cells (hASCs) encapsulated in gellan gum (GG) hydrogels. To this end, we varied the frequency of low HP, by applying pulsatile hydrostatic pressure or a steady hydrostatic pressure load to HNC-GG constructs over a period of 3 weeks, and evaluated their effects on cartilage tissue-engineering outcomes. HNCs (10 · 106 cells/ mL) were encapsulated in GG hydrogels (1.5%) and cultured in a chondrogenic medium under three regimens for 3 weeks: (1) 0.4MPa Pulsatile HP; (2) 0.4MPa Steady HP; and (3) Static. Subsequently, we applied the pulsatile regimen to hASC-GG constructs and varied the amplitude of loading, by generating both low (0.4 MPa) and physiologic (5 MPa) HP levels. hASCs (10x106 cells/mL) were encapsulated in GG hydrogels (1.5%) and cultured in a chondrogenic medium under three regimens for 4 weeks: (1) 0.4MPa Pulsatile HP; (2) 5MPa Pulsatile HP; and (3) Static. In the HNC study, the best tissue development was achieved by the pulsatile HP regimen, whereas in the hASC study, greater chondrogenic differentiation and matrix deposition were obtained for physiologic loading, as evidenced by gene expression of aggrecan, collagen type II, and sox-9; metachromatic staining of cartilage extracellular matrix; and immunolocalization of collagens. We thus propose that both HNCs and hASCs detect and respond to physical forces, thus resembling joint loading, by enhancing cartilage tissue development in a frequency- and amplitude-dependant manner., Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/42316/2007

CLASPs are widely conserved microtubule plus-end–tracking proteins with essential roles in the local regulation of microtubule dynamics. In yeast, Drosophila, and Xenopus, a single CLASP orthologue is present, which is required for mitotic spindle assembly by regulating microtubule dynamics at the kinetochore. In mammals, however, only CLASP1 has been directly implicated in cell division, despite the existence of a second paralogue, CLASP2, whose mitotic roles remain unknown. Here, we show that CLASP2 localization at kinetochores, centrosomes, and spindle throughout mitosis is remarkably similar to CLASP1, both showing fast microtubule-independent turnover rates. Strikingly, primary fibroblasts from Clasp2 knockout mice show numerous spindle and chromosome segregation defects that can be partially rescued by ectopic expression of Clasp1 or Clasp2. Moreover, chromosome segregation rates during anaphase A and B are slower in Clasp2 knockout cells, which is consistent with a role of CLASP2 in the regulation of kinetochore and spindle function. Noteworthy, cell viability/proliferation and spindle checkpoint function were not impaired in Clasp2 knockout cells, but the fidelity of mitosis was strongly compromised, leading to severe chromosomal instability in adult cells. Together, our data support that the partial redundancy of CLASPs during mitosis acts as a possible mechanism to prevent aneuploidy in mammals.

Reasons for the practice of fitness activities as leisure activities One of the greatest manifestations in our changing times concerns the gradual decreasing of work time that will lead to a natural free time increasing. Therefore, there’s a generalized necessity for fulfilling this free time, and this can be a profit one, if well spared. The goal of our study is to analyse and to find out who are the persons that practice physical activity in their leisure time and choose places like health-clubs or gym academies for it. We intend to perceive the meaning of their choice and why do they continue practicing the kind of physical activities that are offered in health-clubs and gym academies. Our methodology includes a fieldwork in which we adopted an “insider role” in three gym/health-clubs in the city of Porto, and was supported by a set of semi-structured interviews. After this study, we might consider the person who chooses this kind of physical activity, in its leisure time, as a person who gives a special importance to ones own body image. But, there are other things we must consider, in one hand people should enjoy their practice, in the other hand, they are also looking for connections, relationships that give them reasons to continue, otherwise, they might give up.

Before chromosomes segregate into daughter cells, they align at the mitotic spindle equator, a process known as chromosome congression. Centromere-associated protein E (CENP-E)/Kinesin-7 is a microtubule plus-end-directed kinetochore motor required for congression of pole-proximal chromosomes. Because the plus-ends of many astral microtubules in the spindle point to the cell cortex, it remains unknown how CENP-E guides pole-proximal chromosomes specifically toward the equator. We found that congression of pole-proximal chromosomes depended on specific posttranslational detyrosination of spindle microtubules that point to the equator. In vitro reconstitution experiments demonstrated that CENP-E-dependent transport was strongly enhanced on detyrosinated microtubules. Blocking tubulin tyrosination in cells caused ubiquitous detyrosination of spindle microtubules, and CENP-E transported chromosomes away from spindle poles in random directions. Thus, CENP-E-driven chromosome congression is guided by microtubule detyrosination.

Microtubules are cellular components that are required for a variety of essential processes such as cell motility, mitosis, and intracellular transport. This is possible because of the inherent dynamic properties of microtubules. Many of these properties are tightly regulated by a number of microtubule plus-end-binding proteins or +TIPs. These proteins recognize the distal end of microtubules and are thus in the right context to control microtubule dynamics. In this review, we address how microtubule dynamics are regulated by different +TIP families, focusing on how functionally diverse +TIPs spatially and temporally regulate microtubule dynamics during animal cell division.

Microtubules are cellular components that are required for a variety of essential processes such as cell motility, mitosis, and intracellular transport. This is possible because of the inherent dynamic properties of microtubules. Many of these properties are tightly regulated by a number of microtubule plus-end-binding proteins or +TIPs. These proteins recognize the distal end of microtubules and are thus in the right context to control microtubule dynamics. In this review, we address how microtubule dynamics are regulated by different +TIP families, focusing on how functionally diverse +TIPs spatially and temporally regulate microtubule dynamics during animal cell division.

Mammalian CLASPs are microtubule plus-end tracking proteins whose essential function as regulators of microtubule behavior has been studied mainly in cultured cells. We show here that absence of murine CLASP2 in vivo results in thrombocytopenia, progressive anemia, and pancytopenia, due to defects in megakaryopoiesis, in erythropoiesis, and in the maintenance of hematopoietic stem cell activity. Furthermore, microtubule stability and organization are affected upon attachment of Clasp2 knockout hematopoietic stem-cell-enriched populations, and these cells do not home efficiently toward their bone marrow niche. Strikingly, CLASP2-deficient hematopoietic stem cells contain severely reduced mRNA levels of c-Mpl, which encodes the thrombopoietin receptor, an essential factor for megakaryopoiesis and hematopoietic stem cell maintenance. Our data suggest that thrombopoietin signaling is impaired in Clasp2 knockout mice. We propose that the CLASP2-mediated stabilization of microtubules is required for proper attachment, homing, and maintenance of hematopoietic stem cells and that this is necessary to sustain c-Mpl transcription.

SummaryEfficient chromosome segregation during mitosis relies on the coordinated activity of molecular motors with proteins that regulate kinetochore attachments to dynamic spindle microtubules [1]. CLASPs are conserved kinetochore- and microtubule-associated proteins encoded by two paralog genes, clasp1 and clasp2, and have been previously implicated in the regulation of kinetochore microtubule dynamics [2–4]. However, it remains unknown how CLASPs work in concert with other proteins to form a functional kinetochore microtubule interface. Here we have identified mitotic interactors of human CLASP1 via a proteomic approach. Among these, the microtubule plus-end-directed motor CENP-E [5] was found to form a complex with CLASP1 that colocalizes to multiple structures of the mitotic apparatus in human cells. We found that CENP-E recruits both CLASP1 and CLASP2 to kinetochores independently of its motor activity or the presence of microtubules. Depletion of CLASPs or CENP-E by RNA interference in human cells causes a significant and comparable reduction of kinetochore microtubule poleward flux and turnover rates and rescues spindle bipolarity in Kif2a-depleted cells. We conclude that CENP-E integrates two critical functions that are important for accurate chromosome movement and spindle architecture: one relying directly on its motor activity, and the other involving the targeting of key microtubule regulators to kinetochores.