Genetic diversity of carotenoid-rich bananas evaluated by Diversity Arrays Technology (DArT)

The aim of this work was to evaluate the carotenoid content and genetic variability of banana accessions from the Musa germplasm collection held at Embrapa Cassava and Tropical Fruits, Brazil. Forty-two samples were analyzed, including 21 diploids, 19 triploids and two tetraploids. The carotenoid content was analyzed spectrophotometrically and genetic variability was estimated using 653 DArT markers. The average carotenoid content was 4.73 μg.g -1 , and ranged from 1.06 μg.g -1 for the triploid Nanica (Cavendish group) to 19.24 μg.g -1 for the triploid Saney. The diploids Modok Gier and NBA-14 and the triploid Saney had a carotenoid content that was, respectively, 7-fold, 6-fold and 9-fold greater than that of cultivars from the Cavendish group (2.19 μg.g -1). The mean similarity among the 42 accessions was 0.63 (range: 0.24 to 1.00). DArT analysis revealed extensive genetic variability in accessions from the Embrapa Musa germplasm bank

Multiancestry analysis of the HLA locus in Alzheimer’s and Parkinson’s diseases uncovers a shared adaptive immune response mediated by HLA-DRB1*04 subtypes

Across multiancestry groups, we analyzed Human Leukocyte Antigen (HLA) associations in over 176,000 individuals with Parkinson’s disease (PD) and Alzheimer’s disease (AD) versus controls. We demonstrate that the two diseases share the same protective association at the HLA locus. HLA-specific fine-mapping showed that hierarchical protective effects of HLA-DRB1*04 subtypes best accounted for the association, strongest with HLA-DRB1*04:04 and HLA-DRB1*04:07, and intermediary with HLA-DRB1*04:01 and HLA-DRB1*04:03. The same signal was associated with decreased neurofibrillary tangles in postmortem brains and was associated with reduced tau levels in cerebrospinal fluid and to a lower extent with increased Aβ42. Protective HLA-DRB1*04 subtypes strongly bound the aggregation-prone tau PHF6 sequence, however only when acetylated at a lysine (K311), a common posttranslational modification central to tau aggregation. An HLA-DRB1*04-mediated adaptive immune response decreases PD and AD risks, potentially by acting against tau, offering the possibility of therapeutic avenues

Morphoagronomic characteristics display high genetic diversity in Murupi chili pepper landraces

Murupi chili pepper is a hot Amazonian pepper that has been used as flavoring in the region, yet its diversity is unknown. This paper aims to assess the diversity in 20 landraces from Peruvian, Colombian, and Brazilian Amazon. The experiment was installed in Manaus-AM, using a randomized complete block design with three replicates and five plants per plot. Analyses of variance showed significant differences for all nine descriptors. Fruit yield showed, in average, to be 208.08 fruits per plant, tantamount to 381.44 g per plant. Given 50% of relative distances estimated by generalized Mahalanobis distances and, nearest neighbor clustering, they displayed six groups. Cluster I comprised 50% of the landraces. Clusters IV, V and VI were represented by ‘8’ (Putumayo, Colombia), ‘27’ (Yurimaguas, Peru) and ‘24’ (Jutaí-AM, Brazil), respectively. The highest yielding landrace showed to be ‘17’ (Manicoré-AM, Brazil), bearing 685.5 fruits and 1.92 kg per plant. Our findings suggest Murupi pepper may possibly be improved by selection and/ or hybridization. © 2018, Sociedade de Olericultura do Brasil. All rights reserved