Transmission of mitochondrial DNA following assisted reproduction and nuclear transfer

Review of the articleMitochondria are the organelles responsible for producing the majority of a cell's ATP and also play an essential role in gamete maturation and embryo development. ATP production within the mitochondria is dependent on proteins encoded by both the nuclear and the mitochondrial genomes, therefore co-ordination between the two genomes is vital for cell survival. To assist with this co-ordination, cells normally contain only one type of mitochondrial DNA (mtDNA) termed homoplasmy. Occasionally, however, two or more types of mtDNA are present termed heteroplasmy. This can result from a combination of mutant and wild-type mtDNA molecules or from a combination of wild-type mtDNA variants. As heteroplasmy can result in mitochondrial disease, various mechanisms exist in the natural fertilization process to ensure the maternal-only transmission of mtDNA and the maintenance of homoplasmy in future generations. However, there is now an increasing use of invasive oocyte reconstruction protocols, which tend to bypass mechanisms for the maintenance of homoplasmy, potentially resulting in the transmission of either form of mtDNA heteroplasmy. Indeed, heteroplasmy caused by combinations of wild-type variants has been reported following cytoplasmic transfer (CT) in the human and following nuclear transfer (NT) in various animal species. Other techniques, such as germinal vesicle transfer and pronuclei transfer, have been proposed as methods of preventing transmission of mitochondrial diseases to future generations. However, resulting embryos and offspring may contain mtDNA heteroplasmy, which itself could result in mitochondrial disease. It is therefore essential that uniparental transmission of mtDNA is ensured before these techniques are used therapeutically

Inoculum origin and soil legacy can shape plant–soil feedback outcomes for tropical grassland restoration

This is the author accepted manuscript. The final version is available from Wiley / Society for Ecological Restoration International via the DOI in this record.Restoration techniques tailored to grasslands are needed to improve the effectiveness of restoration in tropical landscapes. In this study, we investigated the joint effects of plant–soil legacies and soil inocula in native and invaded Cerrado grasslands to evaluate whether different microbial origins affect plant–soil feedbacks and the likelihood of restoration. Using two grass species, we measured aboveground biomass, and several plant traits over two growth cycles. Species responded differently to inocula and legacies. The legacy of the invasive Urochloa eminii and invaded soil inocula positively affected mycorrhizal colonization. The legacy of Diectomis fastigiata, a commonly used species in Cerrado restoration, resulted in a negative self-feedback potentially limiting its effectiveness for restoration. The success of the invasive species was in part due to its broad ecological niche and its ability to cope with a broad range of soil conditions. Our research suggests soil inocula and legacies could be used to aid restoration efforts in the tropics, allowing restoration practitioners to stimulate the growth of species targeting functional traits for a given ecosystem.Natural Environment Research Council (NERC)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasi

Whale, whale, everywhere: increasing abundance of western South Atlantic humpback whales (Megaptera novaeangliae) in their wintering grounds

The western South Atlantic (WSA) humpback whale population inhabits the coast of Brazil during the breeding and calving season in winter and spring. This population was depleted to near extinction by whaling in the mid-twentieth century. Despite recent signs of recovery, increasing coastal and offshore development pose potential threats to these animals. Therefore, continuous monitoring is needed to assess population status and support conservation strategies. The aim of this work was to present ship-based line-transect estimates of abundance for humpback whales in their WSA breeding ground and to investigate potential changes in population size. Two cruises surveyed the coast of Brazil during August-September in 2008 and 2012. The area surveyed in 2008 corresponded to the currently recognized population breeding area; effort in 2012 was limited due to unfavorable weather conditions. WSA humpback whale population size in 2008 was estimated at 16,410 (CV = 0.228, 95% CI = 10,563–25,495) animals. In order to compare abundance between 2008 and 2012, estimates for the area between Salvador and Cabo Frio, which were consistently covered in the two years, were computed at 15,332 (CV = 0.243, 95% CI = 9,595–24,500) and 19,429 (CV = 0.101, 95% CI = 15,958–23,654) whales, respectively. The difference in the two estimates represents an increase of 26.7% in whale numbers in a 4-year period. The estimated abundance for 2008 is considered the most robust for the WSA humpback whale population because the ship survey conducted in that year minimized bias from various sources. Results presented here indicate that in 2008, the WSA humpback whale population was at least around 60% of its estimated pre-modern whaling abundance and that it may recover to its pre-exploitation size sooner than previously estimated.Publisher PDFPeer reviewe

Chemical warfare between leafcutter ant symbionts and a co-evolved pathogen

Acromyrmex leafcutter ants form a mutually beneficial symbiosis with the fungus Leucoagaricus gongylophorus and with Pseudonocardia bacteria. Both are vertically transmitted and actively maintained by the ants. The fungus garden is manured with freshly cut leaves and provides the sole food for the ant larvae, while Pseudonocardia cultures are reared on the ant-cuticle and make antifungal metabolites to help protect the cultivar against disease. If left unchecked, specialized parasitic Escovopsis fungi can overrun the fungus-garden and lead to colony collapse. We report that Escovopsis upregulates the production of two specialized metabolites when it infects the cultivar. These compounds inhibit Pseudonocardia and one, shearinine D, also reduces worker behavioral defences and is ultimately lethal when it accumulates in ant tissues. Our results are consistent with an active evolutionary arms race between Pseudonocardia and Escovopsis, which modifies both bacterial and behavioral defences such that colony collapse is unavoidable once Escovopsis infections escalate

Capacidade Funcional: estudo prospectivo em idosos residentes em uma instituição de longa permanência

The Short Physical Performance Balance - SPPB has been largely used in researches related to the effects of aging, as a practical and efficient instrument to estimate the physical conditions and screening of elderly people with future disability risk. The SPPB estimates the performance of lower limbs in three aspects: muscle strength, gait and balance, all recognized as fundamental to achieve good quality of life, being accepted as universal indicators to value the health conditions of the elderly. PURPOSE: Analyze the SPPB effectiveness to detect functional capacity changes among institutionalized elderly patients and how it is influenced by cognitive, clinical and global functional variables. METHODS: a prospective study, involving 30 residents of a philanthropic long-term care facility in São Paulo (17 women and 13 men), with ages above 60 years old (43% older than 80 years old) and an average of seven years of residence. After 18 months, these old people were reevaluated and data were compared. RESULTS: Considering the evaluated elderly who had good performance (17%), all of them showed up loss of strength during the research. It was observed that there was an improvement of 16% and 1%, respectively, in the balance and in gait, respectively. There was one or more falls in 47% of them. Comparing the Katz's Index of Independency in the Daily Living, the SPPB was more sensitive to the functional decline, indicating 39%, as compared to the 14% of the loss indentified by Katz. CONCLUSIONS: the data confirm the previous studies, which indicate the functional capacity decline of institutionalized elderly and for the SPPB applicability in the routine of functional attendance of this population.A Short Physical Performance Balance - SPPB vem sendo utilizada largamente em pesquisas sobre o envelhecimento, como instrumento prático e eficaz na avaliação do desempenho físico e rastreamento de idosos com riscos futuros de incapacidades. Ela avalia o desempenho de membros inferiores em três aspectos: força muscular, marcha e equilíbrio, reconhecidos como componentes fundamentais para a qualidade de vida, sendo aceitos como indicadores universais do estado de saúde em idosos. OBJETIVO: Analisar a eficácia da SPPB em detectar alterações na capacidade funcional do idoso institucionalizado e como esta é influenciada pelas variáveis cognitivas, clínicas e funcionais globais. METODOLOGIA: estudo prospectivo do qual participaram 30 residentes de uma instituição de longa permanência, filantrópica, em São Paulo (17 mulheres e 13 homens), com idades acima de 60 anos ou mais (43% maiores de 80 anos) e média de sete anos de residência. Após 18 meses, estes idosos foram reavaliados e os dados, comparados. RESULTADOS: Dos idosos avaliados que obtiveram bom desempenho (17%), todos apresentaram perda de força ao longo do seguimento. Quanto ao equilíbrio e marcha, notou-se melhora de 16% e 1%, respectivamente. Apresentaram uma ou mais quedas, 47% dos sujeitos. Quando comparada com o Índex de Independência nas Atividades de Vida Diária de Katz, a SPPB se mostrou mais sensível em relação ao declínio funcional, apontando 39% em comparação aos 14% de perda identificada pelo Katz. CONCLUSÃO: os dados corroboram estudos anteriores, que apontam para o declínio da capacidade funcional de idosos institucionalizados e para a aplicabilidade da SPPB na rotina de acompanhamento funcional dessa população.Universidade Federal de São Paulo (UNIFESP) Curso de Especialização em Reabilitação GerontológicaLar Escola São Francisco Centro de Reabilitação Setor de Reabilitação GerontológicaUniversidade de São Paulo Faculdade de Medicina Hospital das ClínicasUNIFESP, Curso de Especialização em Reabilitação GerontológicaSciEL

The flora and vegetation of rocky outcrops in three municipalities in the northern region of Ceará, Brazil: phytosociological characterization

Veja material suplementar em <https://doi.org/10.6084/m9.figshare.5915233.v2O presente estudo teve como objetivo identificar a flora e a vegetação dos afloramentos rochosos isolados e de baixa altitude (lajedos), na vegetação de Caatinga Arbustiva Aberta, que se encontram nos municípios de Sobral, Groaíras e Santa Quitéria, no estado do Ceará, Brasil e propor uma classificação fitossociológica para estas comunidades xerófilas. Foram definidas cinco áreas de coleta de dados com elevada proporção de rochas expostas (> 80%) onde as excursões de campo decorreram em março de 2014 e 2015 (3º56’S e 40º23’W, 4º01’S e 40º05’W, 4º07’S e 40º08’W, 4º09’S e 40º09’W e 4º03’S e 40º00’W). No estudo da vegetação aplicou-se os métodos TWINSPAN (two-way indicator species analysis) e o clássico sigmatista de Braun-Blanquet. As áreas mínimas dos inventários fitossociológicos variaram de 8 a 16 m2. Foram coletadas as espécies vegetais que crescem em fissuras, fendas e ilhas de vegetação que se encontram em afloramentos rochosos. Foram registradas 88 espécies, distribuídas em 59 gêneros e 30 famílias botânicas. Fabaceae foi a família que se destacou em riqueza específica (20 spp.), seguida por Poaceae (dez spp.), Euphorbiaceae (sete spp.) e Convolvulaceae (seis spp.). Quanto ao endemismo foram registradas, em vegetação rupestre, 19 espécies endêmicas para o Brasil. Na análise fitossociológica da vegetação propôs-se estudar a comunidade de Pilosocereus gounellei (FA.C.Weber) Byles & Rowley e Encholirium spectabile Mart. ex Schult. & Schult.f. e a de Crateva tapia L. e Combretum leprosum Martinfo:eu-repo/semantics/publishedVersio

The vegetation of granite rock outcrops in Rio de Janeiro, Brazil, and the need for its protection

Rock outcrop communities usually receive very little attention from scientists and environmentalists. We examined the vegetation occurring in eight gneiss-granite rock outcrops at Rio de Janeiro State (Brazilian Atlantic coast) which exists in natural associations on soil islands. A total of 86 vascular plant species, belonging to 30 families, was found on 347 soil islands. Bromeliaceae, Asteraceae and Velloziaceae species were the most frequent plants, many of them endemic to these habitats. Ordination and cluster analyses using species frequency on each site made evident some major distinctions related to local influences, most probably the proximity to the sea. Each outcrop presented high values of the Shannon-Wiener index of species diversity. Species richness was very dependent on the total area, and high beta diversity was observed amongst sites. Similarities with the South American and African rock-outcrop communities were found. Despite their uniqueness as habitats, their possession of several endemic species and the fragility of the ecosystem involved, Brazilian rock outcrops are not protected by specific environmental legislation and we propose urgent actions for their protection.o TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE AGOSTO DE 2015.261102