Examinando por Autor "Maass, Alejandro"
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Ítem DNA sequencing in the classroom: complete genome sequence of two earwig (Dermaptera; Insecta) species(2023-12) Kobayashi, Sanae; E. Maldonado, Jonathan; Gaete, Alexis; Araya, Ingrid; Aguado‑Norese, Constanza; Cumplido, Nicolás; Espinoza, Alonso; Fernández, Edelmira; Gajardo, Felipe; González‑Ordenes, Felipe; Hauyon, Khantati; Maldonado, Piedad; Maldonado, Rodrigo; Pochet, Isabel; Riveros, Aníbal; Sandoval, Paula; Sepúlveda‑González, Ailynne; Stuardo, Camila; Tapia‑Reyes, Patricio; Thornton, Carolina; Undurraga, Soledad; Varas, Macarena; Valdivieso, Camilo; Earwig, School; Genome Consortium, Rodrigo A. Gutiérrez; Orellana, Ariel; Montecino, Martín; Maass, Alejandro; González, Mauricio; L. Allende, Miguel; Hodar, Christian; Irles, PaulaBackground: Despite representing the largest fraction of animal life, the number of insect species whose genome has been sequenced is barely in the hundreds. The order Dermaptera (the earwigs) suffers from a lack of genomic information despite its unique position as one of the basally derived insect groups and its importance in agroecosystems. As part of a national educational and outreach program in genomics, a plan was formulated to engage the participation of high school students in a genome sequencing project. Students from twelve schools across Chile were instructed to capture earwig specimens in their geographical area, to identify them and to provide material for genome sequencing to be carried out by themselves in their schools. Results: The school students collected specimens from two cosmopolitan earwig species: Euborellia annulipes (Fam. Anisolabididae) and Forficula auricularia (Fam. Forficulidae). Genomic DNA was extracted and, with the help of scientific teams that traveled to the schools, was sequenced using nanopore sequencers. The sequence data obtained for both species was assembled and annotated. We obtained genome sizes of 1.18 Gb (F. auricularia) and 0.94 Gb (E. annulipes) with the number of predicted protein coding genes being 31,800 and 40,000, respectively. Our analysis showed that we were able to capture a high percentage (≥ 93%) of conserved proteins indicating genomes that are useful for comparative and functional analysis. We were also able to characterize structural elements such as repetitive sequences and non-coding RNA genes. Finally, functional categories of genes that are overrepresented in each species suggest important differences in the process underlying the formation of germ cells, and modes of reproduction between them, features that are one of the distinguishing biological properties that characterize these two distant families of Dermaptera. Conclusions: This work represents an unprecedented instance where the scientific and lay community have come together to collaborate in a genome sequencing project. The versatility and accessibility of nanopore sequencers was key to the success of the initiative. We were able to obtain full genome sequences of two important and widely distributed species of insects which had not been analyzed at this level previously. The data made available by the project should illuminate future studies on the Dermaptera. © 2023, The Author(s).Ítem Genomes of the Orestias pupfish from the Andean Altiplano shed light on their evolutionary history and phylogenetic relationships within Cyprinodontiformes(BioMed Central Ltd, 2024-12) Morales, Pamela; Gajardo, Felipe; Valdivieso, Camilo; Valladares, Moisés A.; Di Genova, Alex; Orellana, Ariel; Gutiérrez, Rodrigo A.; González, Mauricio; Montecino, Martin; Maass, Alejandro; Méndez, Marco A.; Allende, Miguel L.Background: To unravel the evolutionary history of a complex group, a comprehensive reconstruction of its phylogenetic relationships is crucial. This requires meticulous taxon sampling and careful consideration of multiple characters to ensure a complete and accurate reconstruction. The phylogenetic position of the Orestias genus has been estimated partly on unavailable or incomplete information. As a consequence, it was assigned to the family Cyprindontidae, relating this Andean fish to other geographically distant genera distributed in the Mediterranean, Middle East and North and Central America. In this study, using complete genome sequencing, we aim to clarify the phylogenetic position of Orestias within the Cyprinodontiformes order. Results: We sequenced the genome of three Orestias species from the Andean Altiplano. Our analysis revealed that the small genome size in this genus (~ 0.7 Gb) was caused by a contraction in transposable element (TE) content, particularly in DNA elements and short interspersed nuclear elements (SINEs). Using predicted gene sequences, we generated a phylogenetic tree of Cyprinodontiformes using 902 orthologs extracted from all 32 available genomes as well as three outgroup species. We complemented this analysis with a phylogenetic reconstruction and time calibration considering 12 molecular markers (eight nuclear and four mitochondrial genes) and a stratified taxon sampling to consider 198 species of nearly all families and genera of this order. Overall, our results show that phylogenetic closeness is directly related to geographical distance. Importantly, we found that Orestias is not part of the Cyprinodontidae family, and that it is more closely related to the South American fish fauna, being the Fluviphylacidae the closest sister group. Conclusions: The evolutionary history of the Orestias genus is linked to the South American ichthyofauna and it should no longer be considered a member of the Cyprinodontidae family. Instead, we submit that Orestias belongs to the Orestiidae family, as suggested by Freyhof et al. (2017), and that it is the sister group of the Fluviphylacidae family, distributed in the Amazonian and Orinoco basins. These two groups likely diverged during the Late Eocene concomitant with hydrogeological changes in the South American landscape. © The Author(s) 2024.Ítem The genome sequence of the soft-rot fungus Penicillium purpurogenum reveals a high gene dosage for lignocellulolytic enzymes(Taylor and Francis Ltd., 2018-01) Mardones, Wladimir; Di Genova, Alex; Cortés, María Paz; Travisany, Dante; Maass, Alejandro; Eyzaguirre, JaimeThe high lignocellulolytic activity displayed by the soft-rot fungus Penicillium purpurogenum has made it a target for the study of novel lignocellulolytic enzymes. We have obtained a reference genome of 36.2 Mb of non-redundant sequence (11,057 protein-coding genes). The 49 largest scaffolds cover 90% of the assembly, and Core Eukaryotic Genes Mapping Approach (CEGMA) analysis reveals that our assembly captures almost all protein-coding genes. RNA-seq was performed and 93.1% of the reads aligned to the assembled genome. These data, plus the independent sequencing of a set of genes of lignocellulose-degrading enzymes, validate the quality of the genome sequence. P. purpurogenum shows a higher number of proteins with CAZy motifs, transcription factors and transporters as compared to other sequenced Penicillia. These results demonstrate the great potential for lignocellulolytic activity of this fungus and the possible use of its enzymes in related industrial applications. © 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.Ítem Transcriptome profiling of grapevine seedless segregants during berry development reveals candidate genes associated with berry weight(BIOMED CENTRAL, 2016-04) Muñoz-Espinoza, Claudia; Di Genova, Alex; Correa, José; Silva, Romina; Maass, Alejandro; González-Agüero, Mauricio; Orellana, Ariel; Hinrichsen, PatricioBackground Berry size is considered as one of the main selection criteria in table grape breeding programs. However, this is a quantitative and polygenic trait, and its genetic determination is still poorly understood. Considering its economic importance, it is relevant to determine its genetic architecture and elucidate the mechanisms involved in its expression. To approach this issue, an RNA-Seq experiment based on Illumina platform was performed (14 libraries), including seedless segregants with contrasting phenotypes for berry weight at fruit setting (FST) and 6–8 mm berries (B68) phenological stages. Results A group of 526 differentially expressed (DE) genes were identified, by comparing seedless segregants with contrasting phenotypes for berry weight: 101 genes from the FST stage and 463 from the B68 stage. Also, we integrated differential expression, principal components analysis (PCA), correlations and network co-expression analyses to characterize the transcriptome profiling observed in segregants with contrasting phenotypes for berry weight. After this, 68 DE genes were selected as candidate genes, and seven candidate genes were validated by real time-PCR, confirming their expression profiles. Conclusions We have carried out the first transcriptome analysis focused on table grape seedless segregants with contrasting phenotypes for berry weight. Our findings contributed to the understanding of the mechanisms involved in berry weight determination. Also, this comparative transcriptome profiling revealed candidate genes for berry weight which could be evaluated as selection tools in table grape breeding programs.Ítem Whole genome comparison between table and wine grapes reveals a comprehensive catalog of structural variants(BioMed Central Ltd., 2014-01) Di Genova, Alex; Almeida, Andrea M.; Muñoz-Espinoza, Claudia; Vizoso, Paula; Travisany, Dante; Moraga, Carol; Pinto, Manuel; Hinrichsen, Patricio; Orellana, Ariel; Maass, AlejandroBackground: Grapevine (Vitis vinifera L.) is the most important Mediterranean fruit crop, used to produce both wine and spirits as well as table grape and raisins. Wine and table grape cultivars represent two divergent germplasm pools with different origins and domestication history, as well as differential characteristics for berry size, cluster architecture and berry chemical profile, among others. ‘Sultanina’ plays a pivotal role in modern table grape breeding providing the main source of seedlessness. This cultivar is also one of the most planted for fresh consumption and raisins production. Given its importance, we sequenced it and implemented a novel strategy for the de novo assembly of its highly heterozygous genome. Results: Our approach produced a draft genome of 466 Mb, recovering 82% of the genes present in the grapevine reference genome; in addition, we identified 240 novel genes. A large number of structural variants and SNPs were identified. Among them, 45 (21 SNPs and 24 INDELs) were experimentally confirmed in ‘Sultanina’ and six SNPs in other 23 table grape varieties. Transposable elements corresponded to ca. 80% of the repetitive sequences involved in structural variants and more than 2,000 genes were affected in their structure by these variants. Some of these genes are likely involved in embryo development, suggesting that they may contribute to seedlessness, a key trait for table grapes. Conclusions: This work produced the first structural variants and SNPs catalog for grapevine, constituting a novel and very powerful tool for genomic studies in this key fruit crop, particularly useful to support marker assisted breeding in table grapes.Ítem Whole Genome Sequence, Variant Discovery and Annotation in Mapuche-Huilliche Native South Americans(Nature Publishing Group, 2019-12) Vidal, Elena A.; Moyano, Tomás C.; Bustos, Bernabé I.; Pérez-Palma, Eduardo; Moraga, Carol; Riveras, Eleodoro; Montecinos, Alejandro; Azócar, Lorena; Soto, Daniela C.; Vidal, Mabel; Genova, Alex Di; Puschel, Klaus; Nürnberg, Peter; Buch, Stephan; Hampe, Jochen; Allende, Miguel L.; Cambiazo, Verónica; González, Mauricio; Hodar, , Christian; Montecino, Martín; Muñoz-Espinoza, Claudia; Orellana, Ariel; Reyes-Jara, Angélica; Travisany, Dante; Vizoso, Paula; Moraga, Mauricio; Eyheramendy, Susana; Maass, Alejandro; Ferrari, Giancarlo V. De; Miquel, Juan Francisco; Gutiérrez, Rodrigo A.Whole human genome sequencing initiatives help us understand population history and the basis of genetic diseases. Current data mostly focuses on Old World populations, and the information of the genomic structure of Native Americans, especially those from the Southern Cone is scant. Here we present annotation and variant discovery from high-quality complete genome sequences of a cohort of 11 Mapuche-Huilliche individuals (HUI) from Southern Chile. We found approximately 3.1 × 10 6 single nucleotide variants (SNVs) per individual and identified 403,383 (6.9%) of novel SNVs events. Analyses of large-scale genomic events detected 680 copy number variants (CNVs) and 4,514 structural variants (SVs), including 398 and 1,910 novel events, respectively. Global ancestry composition of HUI genomes revealed that the cohort represents a sample from a marginally admixed population from the Southern Cone, whose main genetic component derives from Native American ancestors. Additionally, we found that HUI genomes contain variants in genes associated with 5 of the 6 leading causes of noncommunicable diseases in Chile, which may have an impact on the risk of prevalent diseases in Chilean and Amerindian populations. Our data represents a useful resource that can contribute to population-based studies and for the design of early diagnostics or prevention tools for Native and admixed Latin American populations. © 2019, The Author(s).