Exploring South Africa’s southern frontier: A 20-year vision for polar research through the South African National Antarctic Programme

Antarctica, the sub-Antarctic islands and surrounding Southern Ocean are regarded as one of the planet’s last remaining wildernesses, ‘insulated from threat by [their] remoteness and protection under the Antarctic Treaty System’1 . Antarctica encompasses some of the coldest, windiest and driest habitats on earth. Within the Southern Ocean, sub-Antarctic islands are found between the Sub-Antarctic Front to the north and the Polar Front to the south. Lying in a transition zone between warmer subtropical and cooler Antarctic waters, these islands are important sentinels from which to study climate change.2 A growing body of evidence3,4 now suggests that climatically driven changes in the latitudinal boundaries of these two fronts define the islands’ short- and long-term atmospheric and oceanic circulation patterns. Consequently, sub-Antarctic islands and their associated terrestrial and marine ecosystems offer ideal natural laboratories for studying ecosystem response to change.5 For example, a recent study6 indicates that the shift in the geographical position of the oceanic fronts has disrupted inshore marine ecosystems, with a possible impact on top predators. Importantly, biotic responses are variable as indicated by different population trends of these top predators.7,8 When studied collectively, these variations in species’ demographic patterns point to complex spatial and temporal changes within the broader sub-Antarctic ecosystem, and invite further examination of the interplay between extrinsic and intrinsic drivers

Influence of two sports vision training techniques on visual skills performance of university students

Vision is an essential sense and crucial throughout a student’s academic career. Reading and writing during formal studies require a basic level of visual skills. Training of visual skills to students may improve the way visual stimuli are processed, and subsequently lead to visual skill-, motor- and cognitive performance enhancement. The visual system processes information by way of ‘hardware’- skills (physical, mechanical properties) and the more trainable ‘software’-skills (perceptual, cognitive abilities). Sports vision skills training in athletes indicated faster response to visual information and ultimately improved performance, particularly in fast-ball sports. The efficiency of two sports vision training programmes were tested and compared in undergraduate physiology students of various ethnicities (aged 18-25 years), during a 6-week training period. Three groups were used. One control group and two experimental groups were used. Two programmes were used for the experimental groups (a vision laboratory executed battery of repeated visual skills vs. ‘Eyedrills’ an available webbased training programme). Both comprised ‘hardware’ and ‘software’ skills, and include: visual acuity, focusing, tracking, vergence, sequencing, eye-hand coordination and visualisation. For pretest/ post-test evaluations of all students the repeated laboratory training programme was executed. The control group was only exposed to the pre- and post-test. Individuals trained in the laboratory indicated the highest improvement in all visual skills, except vergence. The ‘Eyedrills’ group displayed significant improvements in focusing, tracking and eye-hand coordination, with the control group indicating the least improvement in visual skills - ruling out the notion of improvement occurring only due to test familiarity. Visual training was verified an essential method of improving visual skills, and fundamental in the expansion of basic visual abilities of university students for enhanced performance.http://www.journals.co.za/content/journal/ajpherd1am2017Biokinetics, Sport and Leisure SciencesPhysiologyPsychologySports MedicineStatistic

Genome assembly of the medicinal plant Voacanga thouarsii

International audienceAbstract The Apocynaceae tree Voacanga thouarsii, native to southern Africa and Madagascar, produces monoterpene indole alkaloids (MIA), which are specialized metabolites with a wide range of bioactive properties. Voacanga species mainly accumulates tabersonine in seeds making these species valuable medicinal plants currently used for industrial MIA production. Despite their importance, the MIA biosynthesis in Voacanga species remains poorly studied. Here, we report the first genome assembly and annotation of a Voacanga species. The combined assembly of Oxford Nanopore Technologies long-reads and Illumina short-reads resulted in 3,406 scaffolds with a total length of 1,354.26 Mb and an N50 of 3.04 Mb. A total of 33,300 protein coding genes were predicted and functionally annotated. These genes were then used to establish gene families and to investigate gene family expansion and contraction across the phylogenetic tree. A transposable element (TE) analysis showed the highest proportion of TE in V. thouarsii compared to all other MIA-producing plants. In a nutshell, this first reference genome of V. thouarsii will thus contribute to strengthen future comparative and evolutionary studies in MIA-producing plants leading to a better understanding of MIA pathway evolution. This will also allow the potential identification of new MIA biosynthetic genes for metabolic engineering purposes

An updated version of the Madagascar periwinkle genome

This work was supported by EU Horizon 2020 research and innovation program [MIAMi project, grant number 814645; MKJ, SEO, VC]; ARD CVL Biopharmaceutical program of the Région Centre-Val de Loire [ETOPOCentre project, VC]; and ANR [project MIACYC – ANR-20-CE43-0010, VC].International audienceThe Madagascar periwinkle, Catharanthus roseus, belongs to the Apocynaceae family. This medicinal plant, endemic to Madagascar, produces many important drugs including the monoterpene indole alkaloids (MIA) vincristine and vinblastine used to treat cancer worldwide. Here, we provide a new version of the C. roseus genome sequence obtained through the combination of Oxford Nanopore Technologies long-reads and Illumina short-reads. This more contiguous assembly consists of 173 scaffolds with a total length of 581.128 Mb and an N50 of 12.241 Mb. Using publicly available RNAseq data, 21,061 protein coding genes were predicted and functionally annotated. A total of 42.87% of the genome was annotated as transposable elements, most of them being long-terminal repeats. Together with the increasing access to MIA-producing plant genomes, this updated version should ease evolutionary studies leading to a better understanding of MIA biosynthetic pathway evolutio

An updated version of the Madagascar periwinkle genome

This work was supported by EU Horizon 2020 research and innovation program [MIAMi project, grant number 814645; MKJ, SEO, VC]; ARD CVL Biopharmaceutical program of the Région Centre-Val de Loire [ETOPOCentre project, VC]; and ANR [project MIACYC – ANR-20-CE43-0010, VC].International audienceThe Madagascar periwinkle, Catharanthus roseus, belongs to the Apocynaceae family. This medicinal plant, endemic to Madagascar, produces many important drugs including the monoterpene indole alkaloids (MIA) vincristine and vinblastine used to treat cancer worldwide. Here, we provide a new version of the C. roseus genome sequence obtained through the combination of Oxford Nanopore Technologies long-reads and Illumina short-reads. This more contiguous assembly consists of 173 scaffolds with a total length of 581.128 Mb and an N50 of 12.241 Mb. Using publicly available RNAseq data, 21,061 protein coding genes were predicted and functionally annotated. A total of 42.87% of the genome was annotated as transposable elements, most of them being long-terminal repeats. Together with the increasing access to MIA-producing plant genomes, this updated version should ease evolutionary studies leading to a better understanding of MIA biosynthetic pathway evolutio

The Vinca minor genome highlights conserved evolutionary traits in monoterpene indole alkaloid synthesis

International audienceAbstract Vinca minor, also known as the lesser periwinkle, is a well-known species from the Apocynaceae, native to central and southern Europe. This plant synthesizes monoterpene indole alkaloids (MIAs), which are a class of specialized metabolites displaying a wide range of bioactive- and pharmacologically important properties. Within the almost 50 MIAs it produces, V. minor mainly accumulates vincamine, which is commercially used as a nootropic. Using a combination of Oxford Nanopore Technologies long read- and Illumina short-read sequencing, a 679,098 Mb V. minor genome was assembled into 296 scaffolds with an N50 scaffold length of 6 Mb, and encoding 29,624 genes. These genes were functionally annotated and used in a comparative genomic analysis to establish gene families and to investigate gene family expansion and contraction across the phylogenetic tree. Furthermore, homology-based MIA gene predictions together with a metabolic analysis across four different V. minor tissue types guided the identification of candidate MIA genes. These candidates were finally used to identify MIA gene clusters, which combined with synteny analysis allowed for the discovery of a functionally validated vincadifformine-16-hydroxylase, reinforcing the potential of this dataset for MIA gene discovery. It is expected that access to these resources will facilitate the elucidation of unknown MIA biosynthetic routes with the potential of transferring these pathways to heterologous expression systems for large-scale MIA production

The Rauvolfia tetraphylla genome suggests multiple distinct biosynthetic routes for yohimbane monoterpene indole alkaloids

Abstract Monoterpene indole alkaloids (MIAs) are a structurally diverse family of specialized metabolites mainly produced in Gentianales to cope with environmental challenges. Due to their pharmacological properties, the biosynthetic modalities of several MIA types have been elucidated but not that of the yohimbanes. Here, we combine metabolomics, proteomics, transcriptomics and genome sequencing of Rauvolfia tetraphylla with machine learning to discover the unexpected multiple actors of this natural product synthesis. We identify a medium chain dehydrogenase/reductase (MDR) that produces a mixture of four diastereomers of yohimbanes including the well-known yohimbine and rauwolscine. In addition to this multifunctional yohimbane synthase (YOS), an MDR synthesizing mainly heteroyohimbanes and the short chain dehydrogenase vitrosamine synthase also display a yohimbane synthase side activity. Lastly, we establish that the combination of geissoschizine synthase with at least three other MDRs also produces a yohimbane mixture thus shedding light on the complex mechanisms evolved for the synthesis of these plant bioactives

The Rauvolfia tetraphylla genome suggests multiple distinct biosynthetic routes for yohimbane monoterpene indole alkaloids

Monoterpene indole alkaloids (MIAs) are a structurally diverse family of specialized metabolites mainly produced in Gentianales to cope with environmental challenges. Due to their pharmacological properties, the biosynthetic modalities of several MIA types have been elucidated but not that of the yohimbanes. Here, we combine metabolomics, proteomics, transcriptomics and genome sequencing of Rauvolfia tetraphylla with machine learning to discover the unexpected multiple actors of this natural product synthesis. We identify a medium chain dehydrogenase/reductase (MDR) that produces a mixture of four diastereomers of yohimbanes including the well-known yohimbine and rauwolscine. In addition to this multifunctional yohimbane synthase (YOS), an MDR synthesizing mainly heteroyohimbanes and the short chain dehydrogenase vitrosamine synthase also display a yohimbane synthase side activity. Lastly, we establish that the combination of geissoschizine synthase with at least three other MDRs also produces a yohimbane mixture thus shedding light on the complex mechanisms evolved for the synthesis of these plant bioactives.</p