Novel insights into the genomic basis of citrus canker based on the genome sequences of two strains of Xanthomonas fuscans subsp. aurantifolii

Background: Citrus canker is a disease that has severe economic impact on the citrus industry worldwide. There are three types of canker, called A, B, and C. The three types have different phenotypes and affect different citrus species. The causative agent for type A is Xanthomonas citri subsp. citri, whose genome sequence was made available in 2002. Xanthomonas fuscans subsp. aurantifolii strain B causes canker B and Xanthomonas fuscans subsp. aurantifolii strain C causes canker C. Results: We have sequenced the genomes of strains B and C to draft status. We have compared their genomic content to X. citri subsp. citri and to other Xanthomonas genomes, with special emphasis on type III secreted effector repertoires. In addition to pthA, already known to be present in all three citrus canker strains, two additional effector genes, xopE3 and xopAI, are also present in all three strains and are both located on the same putative genomic island. These two effector genes, along with one other effector-like gene in the same region, are thus good candidates for being pathogenicity factors on citrus. Numerous gene content differences also exist between the three cankers strains, which can be correlated with their different virulence and host range. Particular attention was placed on the analysis of genes involved in biofilm formation and quorum sensing, type IV secretion, flagellum synthesis and motility, lipopolysacharide synthesis, and on the gene xacPNP, which codes for a natriuretic protein. Conclusion: We have uncovered numerous commonalities and differences in gene content between the genomes of the pathogenic agents causing citrus canker A, B, and C and other Xanthomonas genomes. Molecular genetics can now be employed to determine the role of these genes in plant-microbe interactions. The gained knowledge will be instrumental for improving citrus canker control.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Conselho Nacional de Desenvolvimento CientIfico e Tecnologico (CNPq)Coordenacao para Aperfeicoamento de Pessoal de Ensino Superior (CAPES)Fundo de Defesa da Citricultura (FUNDECITRUS

One thousand DNA barcodes of piranhas and pacus reveal geographic structure and unrecognised diversity in the Amazon

Piranhas and pacus (Characiformes: Serrasalmidae) are a charismatic but understudied family of Neotropical fishes. Here, we analyse a DNA barcode dataset comprising 1,122 specimens, 69 species, 16 genera, 208 localities, and 34 major river drainages in order to make an inventory of diversity and to highlight taxa and biogeographic areas worthy of further sampling effort and conservation protection. Using four methods of species discovery - incorporating both tree and distance based techniques - we report between 76 and 99 species-like clusters, i.e. between 20% and 33% of a priori identified taxonomic species were represented by more than one mtDNA lineage. There was a high degree of congruence between clusters, with 60% supported by three or four methods. Pacus of the genus Myloplus exhibited the most intraspecific variation, with six of the 13 species sampled found to have multiple lineages. Conversely, piranhas of the Serrasalmus rhombeus group proved difficult to delimit with these methods due to genetic similarity and polyphyly. Overall, our results recognise substantially underestimated diversity in the serrasalmids, and emphasise the Guiana and Brazilian Shield rivers as biogeographically important areas with multiple cases of across-shield and within-shield diversifications. We additionally highlight the distinctiveness and complex phylogeographic history of rheophilic taxa in particular, and suggest multiple colonisations of these habitats by different serrasalmid lineages. © 2018 The Author(s)

Depressão e envelhecimento: estudo nos participantes do Programa Universidade Aberta à Terceira Idade Depression and aging: study comprising participants of the "Senior Citizens Open University"

OBJETIVOS: identificar a presença de depressão em idosos que freqüentaram o Programa Universidade Aberta à Terceira Idade, da Universidade Federal de Pernambuco, considerando variáveis demográficas e socioeconômicas. MÉTODOS: estudo epidemiológico, descritivo e de corte transversal. Foi realizado um censo com os 358 idosos sendo 312 mulheres e 46 homens (>60 anos), utilizando o questionário "Brasil Old Age Schedule" (BOAS), do qual foi selecionada a seção de saúde mental, quanto à depressão, verificando a freqüência das variáveis solidão, tristeza, pouca disposição, pessimismo em relação ao futuro, irritação, auto-acusação, idéias suicidas, dor de cabeça, insatisfação, distúrbios do sono e do apetite. RESULTADOS: foi encontrado um percentual importante de depressão (24,02%) na população estudada, cuja maioria está classificada em depressão menor, entre a faixa etária de 70-79 anos, do sexo feminino e separados. Foi observada associação significante entre baixa escolaridade e depressão. Os casos de depressão apresentam relevante relação com as variáveis preocupação, dor de cabeça, pouca disposição, irritação, tristeza e insatisfação. CONCLUSÕES: a presença de depressão na população estudada aponta para a importância do planejamento, por parte do Programa, de ações direcionadas à saúde de seus participantes, em particular, os transtornos mentais relativos à depressão.<br>OBJECTIVES: to identify depression in the elderly enrolled at the Senior Citizens Open University, a program of the Federal University of Pernambuco, considering demographic, social and economic variables. METHODS: epidemiological, descriptive, cross sectional cohort study. A census comprising 358 elderly subjects being 312 women and 46 men (>60 yr) through the Brasil Old Age Schedule (BOAS) was completed from which the section related to mental health was selected focusing on depression variables such as loneliness, sadness, listlessness, pessimistic view of the future, irritation, selfaccusa RESULTS: an important depression percentage was determined (24.02%) in the population under study, the majority of which, between 70-79 years old, female and single. A significant association between low education level and depression was established. Depression cases had relevant connection with distress, headache, listlessness, irritation, sadness and dissatisfaction. CONCLUSIONS: depression among the subjects of the study demonstrates the need for the Program to consider actions directed towards participants' health, particularly depression related mental disorders