Marine Biodiversity in South Africa: An Evaluation of Current States of Knowledge

Continental South Africa has a coastline of some 3,650 km and an Exclusive Economic Zone (EEZ) of just over 1 million km2. Waters in the EEZ extend to a depth of 5,700 m, with more than 65% deeper than 2,000 m. Despite its status as a developing nation, South Africa has a relatively strong history of marine taxonomic research and maintains comprehensive and well-curated museum collections totaling over 291,000 records. Over 3 million locality records from more than 23,000 species have been lodged in the regional AfrOBIS (African Ocean Biogeographic Information System) data center (which stores data from a wider African region). A large number of regional guides to the marine fauna and flora are also available and are listed

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Prediction of breeding values for average fruit weight in mango using a multivariate individual mixed model

Mango is an important horticultural fruit crop and breeding is a key strategy to improve ongoing sustainability. Knowledge of breeding values of potential parents is important for maximising progress from breeding. This study successfully employed a mixed linear model methods incorporating a pedigree to predict breeding values for average fruit weight from highly unbalanced data for genotypes planted over three field trials and assessed over several harvest seasons. Average fruit weight was found to be under strong additive genetic control. There was high correlation between hybrids propagated as seedlings and hybrids propagated as scions grafted onto rootstocks. Estimates of additive genetic correlation among trials ranged from 0. 69 to 0. 88 with correlations among harvest seasons within trials greater than 0. 96. These results suggest that progress from selection for broad adaptation can be achieved, particularly as no repeatable environmental factor that could be used to predict G × E could be identified. Predicted breeding values for 35 known cultivars are presented for use in ongoing breeding programs

Overexpression and self-assembly of virus-like particles in Nicotiana benthamiana by a single-vector DNA replicon system

Based on recent developments, virus-like particles (VLPs) are considered to be perfect candidates as nanoplatforms for applications in materials science and medicine. To succeed, mass production of VLPs and self-assembly into a correct form in plant systems are key factors. Here, we report expression of synthesized coat proteins of the three viruses, Brome mosaic virus, Cucumber mosaic virus, and Maize rayado fino virus, in Nicotiana benthamiana and production of self-assembled VLPs by transient expression system using agroinfiltration. Each coat protein was synthesized and cloned into a pBYR2fp single replicon vector. Target protein expression in cells containing p19 was fourfold higher than that of cells lacking p19. After agroinfiltration, protein expression was analyzed by SDS-PAGE and quantitative image analyzer. Quantitative analysis showed that BMVCP, CMVCP, and MRFVCP concentrations were 0.5, 1.0, and 0.8 mg ?? g-1 leaf fresh weight, respectively. VLPs were purified by sucrose cushion ultracentrifugation and then analyzed by transmission electron microscopy. Our results suggested that BMVCP and CMVCP proteins expressed in N. benthamiana leaves were able to correctly self-assemble into particles. Moreover, we evaluated internal cavity accessibility of VLPs to load foreign molecules. Finally, plant growth conditions after agroinfiltration are critical for increasing heterologous protein expression levels in a transient expression system.close0