Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Cruzipain promotes Trypanosoma cruzi adhesion to Rhodnius prolixus midgut

Submitted by Sandra Infurna ([email protected]) on 2016-10-13T16:52:52Z No. of bitstreams: 1 livia_uehara_etal_IOC_2012.pdf: 574657 bytes, checksum: 001227bfb1811283a09795b5e95f7acf (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2016-10-13T17:07:57Z (GMT) No. of bitstreams: 1 livia_uehara_etal_IOC_2012.pdf: 574657 bytes, checksum: 001227bfb1811283a09795b5e95f7acf (MD5)Made available in DSpace on 2016-10-13T17:07:57Z (GMT). No. of bitstreams: 1 livia_uehara_etal_IOC_2012.pdf: 574657 bytes, checksum: 001227bfb1811283a09795b5e95f7acf (MD5) Previous issue date: 2012Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ, Brasil / Instituto Federal de Educação, Ciência e Tecnologia do Rio de Janeiro. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Instituto de Biofísica Carlos Chagas Filho (IBCCF). Laboratório de Imunologia Molecular. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bioquímica e Fisiologia de Insetos. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Instituto de Biofísica Carlos Chagas Filho (IBCCF). Laboratório de Bioquímica e Biologia Molecular de Proteases. Rio de janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Centro de Ciências da Saúde. Instituto de Biofísica Carlos Chagas Filho. Departamento de Microbiologia Celular. Laboratório de Estudos Integrados em Bioquímica Microbiana. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Centro de Ciências da Saúde. Instituto de Biofísica Carlos Chagas Filho. Departamento de Microbiologia Celular. Laboratório de Estudos Integrados em Bioquímica de Proteases. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ, Brasil.Background: Trypanosoma cruzi is the etiological agent of Chagas’ disease. Cysteine peptidases are relevant to several aspects of the T. cruzi life cycle and are implicated in parasite-mammalian host relationships. However, little is known about the factors that contribute to the parasite-insect host interaction. Methodology/Principal Findings: Here, we have investigated whether cruzipain could be involved in the interaction of T. cruzi with the invertebrate host. We analyzed the effect of treatment of T. cruzi epimastigotes with anti-cruzipain antibodies or with a panel of cysteine peptidase inhibitors (cystatin, antipain, E-64, leupeptin, iodocetamide or CA-074-OMe) on parasite adhesion to Rhodnius prolixus posterior midgut ex vivo. All treatments, with the exception of CA074-OMe, significantly decreased parasite adhesion to R. prolixus midgut. Cystatin presented a dose-dependent reduction on the adhesion. Comparison of the adhesion rate among several T. cruzi isolates revealed that the G isolate, which naturally possesses low levels of active cruzipain, adhered to a lesser extent in comparison to Dm28c, Y and CL Brener isolates. Transgenic epimastigotes overexpressing an endogenous cruzipain inhibitor (pCHAG), chagasin, and that have reduced levels of active cruzipain adhered to the insect gut 73% less than the wild-type parasites. The adhesion of pCHAG parasites was partially restored by the addition of exogenous cruzipain. In vivo colonization experiments revealed low levels of pCHAG parasites in comparison to wild-type. Parasites isolated after passage in the insect presented a drastic enhancement in the expression of surface cruzipain. Conclusions/Significance: These data highlight, for the first time, that cruzipain contributes to the interaction of T. cruzi with the insect host

<i>In vivo</i> infection of <i>R</i>. <i>prolixus</i> by <i>T. cruzi</i> is reduced upon chagasin overexpression.

<p>The insects were fed with defibrinated rabbit blood containing 9×10⁶ parasites/mL (Wild-type, pTEX, pCHAG) <i>ad libitum.</i> Twenty days later, intact pools of 4 midguts or 8 recta were excised from the insects, and processed as described in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001958#s2" target="_blank">Methods</a> section. The parasites were quantified by the following methods: (A) microscopic counts of the infection levels of <i>T. cruzi</i> in the rectum of <i>R</i>. <i>prolixus</i>, (B, C) quantitative PCR (qPCR) for estimating the infection levels of <i>T. cruzi</i> in the midgut or rectum of <i>R</i>. <i>prolixus</i>. The results are shown as the mean ± SEM of three independent experiments. Parasites pCHAG showed a rate of adhesion to the cells not statistically different from control and pTEX by means of Students' <i>t</i> test, due to intrinsic biological triatomine variance.</p

Cruzipain expression in <i>T. cruzi</i> cells is enhanced after passage in <i>R. prolixus</i>.

<p>Cells re-isolated after the colonization (3) or cells obtained from cultivation in axenic medium (BHI) (2) were incubated in the presence or absence (1) of anti-cruzipain antibodies at 1∶2000 dilution and then analyzed by flow cytometry. Representative data of the analysis of 10,000 cells from one of three experiments are shown. The curve 3 represents 10,000 events positive for cruzipain.</p

Antibodies to cruzipain affect the interaction between <i>T. cruzi</i> and <i>R. prolixus</i> midgut.

<p>The epimastigotes (2.0×10⁷ cells) were treated for 60 min at room temperature with anti-cruzipain antibodies at 1∶1000 or 1∶2500 dilution, or pre-immune serum at 1∶1000. The viability of the parasites was not affected by the treatment used in this set of experiments. Following interaction for 15 min with the insect gut, the number of adhered parasites/insect gut epithelial cells was estimated by randomly counting at least 100 epithelial cells in quadruplicate. The results are shown as the mean ± SEM of two independent experiments. Symbols indicate systems significantly different from untreated (control) cells by means of Students' <i>t</i> test (, <i>P = </i>0.000802; , <i>P</i> = 0.004351).</p

Dose dependent effect of cystatin on the interaction between <i>T. cruzi</i> and <i>R. prolixus</i> midgut.

<p>Epimastigotes (2.0×10⁷ cells) were treated for 60 min at room temperature with different concentrations of cystatin from chicken egg white (0.1, 1, 2.5 or 10 µg/mL). The viability of the parasites was not affected by the treatments used in this set of experiments. Following interaction for 15 min with the insect gut, the number of parasites/insect gut epithelial cells was estimated by randomly counting at least 100 epithelial cells in quadruplicate. The results are shown as the mean ± SEM of two independent experiments. Symbols indicate systems significantly different from untreated (control) cells by means of Students' <i>t</i> test (, <i>P</i><0.001).</p