Genetic discoveries of Alzheimer’s disease are the drivers of our understanding, and together with polygenetic risk stratification can contribute towards planning of feasible and efficient preventive and curative clinical trials. We first perform a large genetic association study by merging all available case-control datasets and by-proxy study results (discovery n = 409,435 and validation size n = 58,190). Here, we add six variants associated with Alzheimer’s disease risk (near APP, CHRNE, PRKD3/NDUFAF7, PLCG2 and two exonic variants in the SHARPIN gene). Assessment of the polygenic risk score and stratifying by APOE reveal a 4 to 5.5 years difference in median age at onset of Alzheimer’s disease patients in APOE ɛ4 carriers. Because of this study, the underlying mechanisms of APP can be studied to refine the amyloid cascade and the polygenic risk score provides a tool to select individuals at high risk of Alzheimer’s disease.

Plastome Evolution in Opuntioideae (Cactaceae) with primers designed for continued evolutionary studies across Cactaceae. These results bring new insights into the evolution of plastomes in cacti, suggesting that further analyses should be carried out to address how ecological drivers, physiological constraints and morphological traits of cacti may be related with the common rearrangements in plastomes that have been reported across the family.

No abstract

Cactaceae comprise a diverse and iconic group of flowering plants which are almost exclusively indigenous to the New World. The wide variety of growth forms found amongst the cacti have led to the trafficking of many species throughout the world as ornamentals. Despite the evolution and physiological properties of these plants having been extensively studied, little research has focused on cactus-associated viral communities. While only single-stranded RNA viruses had ever been reported in cacti, here we report the discovery of cactus-infecting single-stranded DNA viruses. These viruses all apparently belong to a single divergent species of the family Geminiviridae and have been tentatively named Opuntia virus 1 (OpV1). A total of 79 apparently complete OpV1 genomes were recovered from 31 different cactus plants (belonging to 20 different cactus species from both the Cactoideae and Opuntioideae clades) and from nine cactus-feeding cochineal insects (Dactylopius sp.) sampled in the USA and Mexico. These 79 OpV1 genomes all share > 78.4% nucleotide identity with one another and < 64.9% identity with previously characterized geminiviruses. Collectively, the OpV1 genomes display evidence of frequent recombination, with some genomes displaying up to five recombinant regions. In one case, recombinant regions span ~40% of the genome. We demonstrate that an infectious clone of an OpV1 genome can replicate in Nicotiana benthamiana and Opuntia microdasys. In addition to expanding the inventory of viruses that are known to infect cacti, the OpV1 group is so distantly related to other known geminiviruses that it likely represents a new geminivirus genus. It remains to be determined whether, like its cactus hosts, its geographical distribution spans the globe.

The genus Opuntia Miller (1754) (Cactaceae Juss., Opuntioideae K.Schum., Opuntieae DC.) is native to the Americas, where is distributed from southern Argentina to Canada (Anderson 2001), and represents one of the largest genus of Cactaceae with ca. 150 species (see e.g., Stuppy 2002). Members of Opuntia shares a combination of peculiar morphological traits, including shrubs or trees with flattened photosynthetic stem shoots (cladodes), areoles with large smooth or retrorsely barbed spines and glochids, reduced and small caducous leaves , rotaceous diurnal flowers with inferior ovaries inner the pericarpels and stigma plurilobed, stamens with thigmonasty, reticulate semitectate pollen, and seeds covered by a sclerified funicular aril (Buxbaum 1953, Anderson 2001, Stuppy 2002, Hunt 2006, Majure & Puente 2014, Majure et al. 2017).

No abstract

Resumo O Brasil é o país com a maior biodiversidade conhecida no mundo, mas sua flora alimentícia ainda carece de estudos. No presente trabalho, apresentamos um levantamento de plantas frutíferas nativas do estado do Rio Grande do Sul com base em consultas bibliográficas e experimentação de campo. Dados adicionais de cada espécie, como nome popular, forma biológica, distribuição geográfica, hábitat, fenologia, tamanho da fruta e forma de uso também são apresentados. Reportamos 213 espécies frutíferas nativas distribuídas em 48 famílias e 102 gêneros, sendo Myrtaceae a família com o maior número de espécies. A maioria das espécies é constituída por árvores que ocorrem em ambientes florestais, distribuídas ao longo de todo território do estado. Mais de 90% das frutas são para consumo in natura ou derivados, enquanto uma pequena parte é utilizada após processamento, e outra parte é utilizada como condimento. Cerca de 20% das espécies são apresentadas de maneira inédita como frutíferas. Ressalta-se a elevada riqueza de espécies frutíferas encontrada no estado e a importância da valorização da flora nativa alimentícia com potencial de uso sustentável, incrementando a fruticultura local e agregando valor à produção agrícola.

The family Cactaceae comprises a diverse group of typically succulent plants that are native to the American continent but have been introduced to nearly all other continents, predominantly for ornamental purposes. Despite their economic, cultural, and ecological importance, very little research has been conducted on the viral community that infects them. We previously identified a highly divergent geminivirus that is the first known to infect cacti. Recent research efforts in non-cultivated and asymptomatic plants have shown that the diversity of this viral family has been under-sampled. As a consequence, little is known about the effects and interactions of geminiviruses in many plants, such as cacti. With the objective to expand knowledge on the diversity of geminiviruses infecting cacti, we used previously acquired high-throughput sequencing results to search for viral sequences using BLASTx against a viral RefSeq protein database. We identified two additional sequences with similarity to geminiviruses, for which we designed abutting primers and recovered full-length genomes. From 42 cacti and five scale insects, we derived 42 complete genome sequences of a novel geminivirus species that we have tentatively named Opuntia virus 2 (OpV2) and 32 genomes of an Opuntia-infecting becurtovirus (which is a new strain of the spinach curly top Arizona virus species). Interspecies recombination analysis of the OpV2 group revealed several recombinant regions, in some cases spanning half of the genome. Phylogenetic analysis demonstrated that OpV2 is a novel geminivirus more closely related to viruses of the genus Curtovirus, which was further supported by the detection of three recombination events between curtoviruses and OpV2. Both OpV2 and Opuntia becurtoviruses were identified in mixed infections, which also included the previously characterized Opuntia virus 1. Viral quantification of the co-infected cactus plants compared with single infections did not show any clear trend in viral dynamics that might be associated with the mixed infections. Using experimental Rhizobium-mediated inoculations, we found that the initial accumulation of OpV2 is facilitated by co-infection with OpV1. This study shows that the diversity of geminiviruses that infect cacti is under-sampled and that cacti harbor diverse geminiviruses. The detection of the Opuntia becurtoviruses suggests spill-over events between viruses of cultivated species and native vegetation. The threat this poses to cacti needs to be further investigated.