Identification of Myosin XI Receptors in Arabidopsis Defines a Distinct Class of Transport Vesicles

To characterize the mechanism through which myosin XI-K attaches to its principal endomembrane cargo, a yeast two-hybrid library of Arabidopsis thaliana cDNAs was screened using the myosin cargo binding domain as bait. This screen identified two previously uncharacterized transmembrane proteins (hereinafter myosin binding proteins or MyoB1/2) that share a myosin binding, conserved domain of unknown function 593 (DUF593). Additional screens revealed that MyoB1/2 also bind myosin XI-1, whereas myosin XI-I interacts with the distantly related MyoB7. The in vivo interactions of MyoB1/2 with myosin XI-K were confirmed by immunoprecipitation and colocalization analyses. In epidermal cells, the yellow fluorescent protein–tagged MyoB1/2 localize to vesicles that traffic in a myosin XI–dependent manner. Similar to myosin XI-K, MyoB1/2 accumulate in the tip-growing domain of elongating root hairs. Gene knockout analysis demonstrated that functional cooperation between myosin XI-K and MyoB proteins is required for proper plant development. Unexpectedly, the MyoB1-containing vesicles did not correspond to brefeldin A–sensitive Golgi and post-Golgi or prevacuolar compartments and did not colocalize with known exocytic or endosomal compartments. Phylogenomic analysis suggests that DUF593 emerged in primitive land plants and founded a multigene family that is conserved in all flowering plants. Collectively, these findings indicate that MyoB are membrane-anchored myosin receptors that define a distinct, plant-specific transport vesicle compartment.     

Natural cavity restoration as an alternative to nest box supplementation

Nest box supplementation is widely used to increase nest‐site availability for cavity nesting animals but the analysis of its effects on individuals breeding in natural cavities is often neglected. This study offers a novel restoration technique to revert abandonment of natural breeding sites by a secondary cavity avian bird, the European roller (Coracias garrulus), and other ecologically similar species. We found that, after a program of nest box supplementation with ensuing monitoring, rollers gradually abandon nesting in natural and seminatural cavities in favor of nest boxes because the latter are of higher quality. We examine whether reducing the entrance size of natural and seminatural cavities improves their suitability for rollers. A 6‐year program reduced the diameter of the entrance of sandstone cavities and cavities in bridges. This led to a high occupancy (59%) of manipulated nest‐sites. Manipulated sites were most frequently occupied by rollers and little owls (Athene noctua) (31 and 18% of sites, respectively). Manipulation did not affect clutch size or fledgling success. We suggest that nest‐site diversity and nesting in natural cavities should be preserved to reduce nest box dependence. Our study illustrates the value of nest boxes when used alongside restoration of natural breeding sites and provides insights for the management of natural cavities.     

Growth hormone and ghrelin secretion in severely obese women before and after bariatric surgery

Objective: The objective was to evaluate ghrelin and growth hormone (GH) interactions and responses to a growth hormone‐releasing hormone (GHRH)/arginine test in severe obesity before and after surgically‐induced weight loss. Research Methods and Procedures: Our study population included 11 severely obese women 39 ± 12 years of age, with a mean BMI of 48.6 ± 2.4 kg/m², re‐studied in a phase of stabilized body weight, with a BMI of 33.4 ± 1.2 kg/m², 18 months after having successfully undergone biliopancreatic diversion (BPD). A GHRH/arginine test was performed before and 18 months after BPD to evaluate ghrelin and GH interactions. Active ghrelin, measured by radioimmunoassay (RIA), and GH, measured by chemiluminescence assay, were assayed before and after the GHRH/arginine test. Results: Fasting serum GH levels and GH area under the curve (AUC) significantly increased from 0.2 ± 0.05 ng/mL to 1 ± 0.3 ng/mL (p < 0.05) and from 514.76 ± 98.7 ng/mL for 120 minutes to 1957.3 ± 665.1 ng/mL for 120 minutes after bariatric surgery (p < 0.05), respectively. Although no significant change in fasting ghrelin levels was observed (573 ± 77.9 before BPD vs. 574.1 ± 32.7 after BPD), ghrelin AUC significantly increased from ?3253.9 ± 2180.9 pg/mL for 120 minutes to 1142.3 ± 916.4 pg/mL for 120 minutes after BPD (p < 0.05). Fasting serum insulin‐like growth factor (IGF)‐1 concentration did not change significantly (133.6 ± 9.9 ng/mL before vs. 153.3 ± 25.2 ng/mL after BPD). Discussion: Our study demonstrates that the mechanisms involved in ghrelin and GH secretion after the secretagogue stimulus (GHRH/arginine) are consistent with patterns observed in other populations.     

Species of Malassezia associated with various dermatoses and healthy skin in the Mexican population

At the present, eight Malassezia species have been described and their distribution in normal skin and in several skin diseases appears variable. The aim of the present study was to determine the frequency and distribution of Malassezia species in patients with psoriasis, seborrhoeic dermatitis and pityriasis versicolor attended in a Hospital from Mexico City, in addition to a healthy individual group. Scales of abnormal and healthy skin were grown in modified Dixon agar and the species identification was performed by macroscopic and microscopic features; by catalase and urease reaction; growth at 32, 37 and 40 degrees C; and Tween 20, 40, 60 and 80 assimilation. The cultures from 63 persons were included: forty six patients (20 psoriasis, 15 seborrhoeic dermatitis, 11 pityriasis versicolor) and 17 healthy individuals (external auditory canal). A total of 96 isolates were obtained. The more frequently isolated species were: M. sympodialis (38.2%) and M. furfur (26.5%) in psoriasis; M. sympodialis (38.5%) and M. slooffiae (34.6%) in seborrhoeic dermatitis; M. globosa (46.7%) and M. sympodialis (26.7%) in pityriasis versicolor; and M. restricta (47.6%) and M. globosa (23.8%) in normal skin. The number of isolates, the species diversity and association were higher in the patients group than in the healthy individuals group.     

Development and qualification of a novel virus removal filter for cell culture applications

Commercial bioreactors employing mammalian cell cultures to express biological or pharmaceutical products can become contaminated with adventitious viruses. The high expense of such a contamination can be reduced by passing all gases and fluids feeding the bioreactor through virus inactivation or removal steps, which act as viral barriers around the bioreactor. A novel virus barrier filter has been developed for removing viruses from serum-free cell culture media. This filter removes the 20 nm minute virus of mice by >3 log reduction value (LRV), the 28 nm bacteriophage PhiX174 by >4.5 LRV, the mycoplasma Acholeplasma laidlawii by > or =8.8 LRV, and the bacteria Brevundimonas diminuta by > or =9.2 LRV. Robust removal occurs primarily by size exclusion as demonstrated over a wide range of feedstocks and operating conditions. The filtered media are indistinguishable from unfiltered media in growth of cells to high densities, maintenance of cell viability, and productivity in expressing protein product. Insulin and transferrin show high passage through the filter. The virus barrier filter can be autoclaved. The relatively high membrane permeability enables the use of a moderate filtration area.     

Geographic variation in beak colouration in gentoo penguins <Emphasis Type="Italic">Pygoscelis papua</Emphasis>

Ornamental colouration is often due to carotenoid pigments and varies inter- and intra-specifically. This paper reports on variation in beak colour of the gentoo penguin, Pygoscelis papua, corresponding to different geographical locations along a latitudinal gradient in the Antarctic Peninsula (from King George Island (62o15′S–58o37′W) to Rongé Island (64o40′S–62o40′W). The gentoo penguin has a conspicuous red spot on both sides of the beak that indicates the presence of the carotenoid pigment, astaxanthin. Beak colouration was measured with a portable spectrophotometer for 20 individuals in three locations, along the Western coast of the Antarctic Peninsula. In the study area, marked variation can be found in terms of factors such us parasite load, human impact, variations in UV radiation and the abundance of krill; all possibly affecting carotenoid availability for signalling purposes. Colour traits were expected to be more intense, that is more vivid, saturated and pure, in places where there is diminished pressure from factors such as contamination, parasites or diseases, all of which may reduce the availability of carotenoids for other functions, such as antioxidant or immune stimulation involving physiological trade-offs. Likewise, colour traits might be predicted to be more intense where carotenoid sources, krill in the case of gentoo penguins, are more available. However, contrary to this initial expectation, our results indicate that northerly penguins’ populations, which are in the most polluted and parasitized areas, have more saturated beaks. An alternative hypothesis suggests that environmental constraints relating to the variation in abundance of krill may explain the geographical variation in colour expression found among gentoo penguins.     

Virus-derived gene expression and RNA interference vector for grapevine

The improvement of the agricultural and wine-making qualities of the grapevine (Vitis vinifera) is hampered by adherence to traditional varieties, the recalcitrance of this plant to genetic modifications, and public resistance to genetically modified organism (GMO) technologies. To address these challenges, we developed an RNA virus-based vector for the introduction of desired traits into grapevine without heritable modifications to the genome. This vector expresses recombinant proteins in the phloem tissue that is involved in sugar transport throughout the plant, from leaves to roots to berries. Furthermore, the vector provides a powerful RNA interference (RNAi) capability of regulating the expression of endogenous genes via virus-induced gene-silencing (VIGS) technology. Additional advantages of this vector include superb genetic capacity and stability, as well as the swiftness of technology implementation. The most significant applications of the viral vector include functional genomics of the grapevine and disease control via RNAi-enabled vaccination against pathogens or invertebrate pests.     

High rates of detection of respiratory viruses in tonsillar tissues from children with chronic adenotonsillar disease

Chronic tonsillar diseases are an important health problem, leading to large numbers of surgical procedures worldwide. Little is known about pathogenesis of these diseases. In order to investigate the role of respiratory viruses in chronic adenotonsillar diseases, we developed a cross-sectional study to determine the rates of viral detections of common respiratory viruses detected by TaqMan real time PCR (qPCR) in nasopharyngeal secretions, tonsillar tissues and peripheral blood from 121 children with chronic tonsillar diseases, without symptoms of acute respiratory infections. At least one respiratory virus was detected in 97.5% of patients. The viral co-infection rate was 69.5%. The most frequently detected viruses were human adenovirus in 47.1%, human enterovirus in 40.5%, human rhinovirus in 38%, human bocavirus in 29.8%, human metapneumovirus in 17.4% and human respiratory syncytial virus in 15.7%. Results of qPCR varied widely between sample sites: human adenovirus, human bocavirus and human enterovirus were predominantly detected in tissues, while human rhinovirus was more frequently detected in secretions. Rates of virus detection were remarkably high in tonsil tissues: over 85% in adenoids and close to 70% in palatine tonsils. In addition, overall virus detection rates were higher in more hypertrophic than in smaller adenoids (p = 0.05), and in the particular case of human enteroviruses, they were detected more frequently (p = 0.05) in larger palatine tonsils than in smaller ones. While persistence/latency of DNA viruses in tonsillar tissues has been documented, such is not the case of RNA viruses. Respiratory viruses are highly prevalent in adenoids and palatine tonsils of patients with chronic tonsillar diseases, and persistence of these viruses in tonsils may stimulate chronic inflammation and play a role in the pathogenesis of these diseases.