Influence of leaf trichome type, and density on the host plant selection by the greenhouse whitefly, Trialeurodes vaporariorum (Hemiptera: Aleyrodidae)

Host selection by adult greenhouse whitefly Trialeurodes vaporariorum (Westwood) was assessed on two pelargonium plant cultivars, Pelargonium x domesticum (regal) and P. x hortorum (zonal) using Petri dish bioassay chambers in choice and no-choice tests. Plant characteristics which could influence the oviposition preference of the whitely i.e., type and density of trichomes on the abaxial leaf surface was determined. A strong host preference was observed for the regal compared to the zonal pelargonium by the adult whiteflies. In no-choice tests, adults laid a significantly higher number of eggs on regal than on zonal leaves both at 24 and 48 hours post-exposure, respectively. After exposure to the adult whitefly, the number of 42 eggs in choice tests were similar between cultivars at 24 hours, but were higher for regal at 48 and 72 hours. The total number of trichomes (sng: straight non-glandular + sg: straight glandular) per 0.50 cm2 44 was significantly less on regal (Mean ± SE sng + sg; 43.1 ± 1.5) than on zonal leaves (60.5 ± 1.2); however, the sng trichomes were significantly higher on the zonal (49.4 ± 0.96) than the regal leaves (28.6 ± 1.00). Also, the number of sg trichomes was slightly higher for the regal cultivar leaves compared to the zonal, being 14.4 ± 1.2 and 11.2 ± 0.5, respectively. Results suggest that the trichome density, type and the ability to express glandular exudates can affect adult whitefly Pelargonium cultivar preference and plays an important role in their host plant selection for oviposition

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

The role of MYH and microsatellite instability in the development of sporadic colorectal cancer

Biallelic germline mutations in MYH are associated with colorectal neoplasms, which develop through a pathway involving somatic inactivation of APC. In this study, we investigated the incidence of the common MYH mutations in an Australian cohort of sporadic colorectal cancers, the clinicopathological features of MYH cancers, and determined whether inactivation of mismatch repair and base excision repair (BER) were mutually exclusive. The MYH gene was sequenced from lymphocyte DNA of 872 colorectal cancer patients and 478 controls. Two compound heterozygotes were identified in the cancer population and all three cancers from these individuals displayed a prominent infiltration of intraepithelial lymphocytes. In total, 11 heterozygotes were found in the cancer group and five in the control group. One tumour from an individual with biallelic germline mutation of MYH also demonstrated microsatellite instability (MSI) as a result of biallelic hypermethylation of the MLH1 promoter. Although MYH-associated cancers are rare in a sporadic colorectal population, this study shows that these tumours can develop through either a chromosomal or MSI pathway. Tumours arising in the setting of BER or mismatch repair deficiency may share a biological characteristic, which promotes lymphocytic infiltration

Floral and insect-induced volatile formation in Arabidopsis lyrata ssp. petraea, a perennial, outcrossing relative of A. thaliana

Volatile organic compounds have been reported to serve some important roles in plant communication with other organisms, but little is known about the biological functions of most of these substances. To gain insight into this problem, we have compared differences in floral and vegetative volatiles between two closely related plant species with different life histories. The self-pollinating annual, Arabidopsis thaliana, and its relative, the outcrossing perennial, Arabidopsis lyrata, have markedly divergent life cycles and breeding systems. We show that these differences are in part reflected in the formation of distinct volatile mixtures in flowers and foliage. Volatiles emitted from flowers of a German A. lyrata ssp. petraea population are dominated by benzenoid compounds in contrast to the previously described sesquiterpene-dominated emissions of A. thaliana flowers. Flowers of A. lyrata ssp. petraea release benzenoid volatiles in a diurnal rhythm with highest emission rates at midday coinciding with observed visitations of pollinating insects. Insect feeding on leaves of A. lyrata ssp. petraea causes a variable release of the volatiles methyl salicylate, C11- and C16-homoterpenes, nerolidol, plus the sesquiterpene (E)-β-caryophyllene, which in A. thaliana is emitted exclusively from flowers. An insect-induced gene (AlCarS) with high sequence similarity to the florally expressed (E)-β-caryophyllene synthase (AtTPS21) from A. thaliana was identified from individuals of a German A. lyrata ssp. petraea population. Recombinant AlCarS converts the sesquiterpene precursor, farnesyl diphosphate, into (E)-β-caryophyllene with α-humulene and α-copaene as minor products indicating its close functional relationship to the A. thaliana AtTPS21. Differential regulation of these genes in flowers and foliage is consistent with the different functions of volatiles in the two Arabidopsis species

Eosinophils in glioblastoma biology

Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults. The development of this malignant glial lesion involves a multi-faceted process that results in a loss of genetic or epigenetic gene control, un-regulated cell growth, and immune tolerance. Of interest, atopic diseases are characterized by a lack of immune tolerance and are inversely associated with glioma risk. One cell type that is an established effector cell in the pathobiology of atopic disease is the eosinophil. In response to various stimuli, the eosinophil is able to produce cytotoxic granules, neuromediators, and pro-inflammatory cytokines as well as pro-fibrotic and angiogenic factors involved in pathogen clearance and tissue remodeling and repair. These various biological properties reveal that the eosinophil is a key immunoregulatory cell capable of influencing the activity of both innate and adaptive immune responses. Of central importance to this report is the observation that eosinophil migration to the brain occurs in response to traumatic brain injury and following certain immunotherapeutic treatments for GBM. Although eosinophils have been identified in various central nervous system pathologies, and are known to operate in wound/repair and tumorstatic models, the potential roles of eosinophils in GBM development and the tumor immunological response are only beginning to be recognized and are therefore the subject of the present review

Sugarcane (Saccharum X officinarum): A Reference Study for the Regulation of Genetically Modified Cultivars in Brazil

Global interest in sugarcane has increased significantly in recent years due to its economic impact on sustainable energy production. Sugarcane breeding and better agronomic practices have contributed to a huge increase in sugarcane yield in the last 30 years. Additional increases in sugarcane yield are expected to result from the use of biotechnology tools in the near future. Genetically modified (GM) sugarcane that incorporates genes to increase resistance to biotic and abiotic stresses could play a major role in achieving this goal. However, to bring GM sugarcane to the market, it is necessary to follow a regulatory process that will evaluate the environmental and health impacts of this crop. The regulatory review process is usually accomplished through a comparison of the biology and composition of the GM cultivar and a non-GM counterpart. This review intends to provide information on non-GM sugarcane biology, genetics, breeding, agronomic management, processing, products and byproducts, as well as the current technologies used to develop GM sugarcane, with the aim of assisting regulators in the decision-making process regarding the commercial release of GM sugarcane cultivars