Negative regulation of Akt activity by p38alpha MAP kinase in cardiomyocytes involves membrane localization of PP2A through interaction with caveolin-1

Cardiomyocyte-derived cell lines deficient in p38alpha are more resistant to apoptosis owing to lower expression of the pro-apoptotic proteins Bax and Fas and upregulation of the ERK survival pathway. Here, we show that increased Akt activity also contributes to the enhanced survival of p38alpha-deficient cardiomyocytes. We found that the serine/threonine phosphatase PP2A can be targeted to caveolae through interaction with caveolin-1 in a p38alpha-dependent manner. In agreement with this, PP2A activity associated with caveolin-1 was higher in wild type than in p38alpha-deficient cells. Akt was also present in caveolae and incubation of wild-type cells with the PP2A inhibitor okadaic acid increases the levels of Akt activity. Thus, p38alpha-induced re-localization of PP2A to caveolae can lead to dephosphorylation and inhibition of Akt, which in turn would contribute to the decreased survival observed in wild type cells. However, cell detachment impairs the formation of the PP2A/caveolin-1 complex and, as a consequence, phospho-Akt levels and survival are no longer regulated by p38alpha in detached wild type cardiomyocytes. Our results suggest that p38alpha can negatively modulate Akt activity, independently of PI3K, by regulating the interaction between caveolin-1 and PP2A through a mechanism dependent on cell attachment.     

Interactions of an arbuscular mycorrhizal fungus with free or co-encapsulated cells of Rhizobium trifoli and Yarowia lipolytica inoculated into a soil-plant system

Four times higher nodule number was observed when Glomus deserticola (an arbuscular mycorrhizal fungus) was introduced into a soil-plant system as compared to the control inoculated only with Rhizobium trifoli. This symbiotic parameter was further enhanced by Yarowia lipolytica together with an increase in root mycorrhizal infection of about 14%. Soil inoculation with co-encapsulated R. trifoli and Y. lipolytica provoked a 10-fold increase in root nodulation and led to 55% mycorrhization of the test plant.     

Ebola separations: trust,crisis, and ‘social distancing’ in West Africa

The Ebola outbreak in West Africa involved the introduction of new forms of social and physical separation that aimed to curtail the spread of the disease. People changed the ways they lived to avoid contact with those who might be sick. A suite of governmental instruments was introduced, ranging from by-laws and public health campaigns to the use of specialist treatment centres and military force. These events transformed social connections and affected possibilities for trust in intimate, governmental, and therapeutic relations. Drawing upon fieldwork in Sierra Leone, Liberia, and Guinea, this article explores these forms of separation and social distance ethnographically, with a focus on material objects, touch, and spaces of separation. In doing so, we contribute to discussions on the constitution of trust and distance within social relations, and the ways in which separation can enable certain kinds of closeness. Our analysis offers insights for those seeking to understand the impact of the ongoing COVID-19 pandemic on the ways that people relate to, and care for, others.     

Construction of an Expression Vector for Production and Purification of Human Somatostatin in Escherichia coli

Cassava mosaic disease, caused by cassava mosaic geminiviruses are transmitted by Bemisia tabaci. The B. tabaci adults from colonies reared on virus free cassava plant produced from apical meristem culture was studied to determine their ability to transmit Indian cassava mosaic virus (ICMV) and Sri Lankan cassava mosaic virus (SLCMV) from cassava to cassava. Virus free plants were confirmed by polymerase chain reaction (PCR) using geminivirus degenerate primers. The virus acquisition access period (AAP) of 48 h on virus infected cassava leaves and 48 h virus inoculation access periods on virus free healthy leaves were investigated. Both ICMV and SLCMV were absolutely transmitted by whiteflies reared on cassava. Virus specific primers were designed in the replicase region and used to detect virus in B. tabaci after different AAP. The PCR amplified replicase genes from virus transmitted cassava leaves were cloned the plasmid DNA was isolated from a recombinant colony of E. coli DH5α after their confirmation by colony PCR and sequenced them. The nucleotide sequences obtained from automated DNA sequencing were confirmed as ICMV and SLCMV replicase gene after homology searching by BLAST and found to be a new isolates. The nucleotide sequences of new isolates were submitted in GenBank (accession number JN652126 and JN595785).     

Climate and amphibian body size: a new perspective gained from the fossil record

In recent years several studies have been carried out to test the validity of Bergmann's rule for amphibians, and have generated varying results. Due to the lack of agreement on this topic, here we examine the relationship between climate and body size for one anuran species (Bufo calamita, commonly known as the natterjack toad) with a new methodological approach that uses the fossil record as the data source. We analysed bones from two archaeo‐paleontological sites located close to each other in the Sierra de Atapuerca (Burgos, Spain) that together encompass more than one million years from Early to Late Pleistocene. We used ordinary least squares (OLS) simple regression models to integrate body size and palaeoclimatic data (temperature and precipitation) and describe the relationship between the amphibian's body size and climate along the entire temporal gradient. We found the body size of B. calamita to be negatively related to the mean annual temperature and the mean temperature of the coldest month, and positively related to December‐to‐February precipitation. The climatic influence was stronger in females, which were smaller than males in most cases, and therefore an inverse sexual size dimorphism pattern was found. Juvenile individuals or the limited sexual size dimorphism of this species may be causes of this unusual pattern. Bufo calamita populations showed a clear Bergmann cline during the Pleistocene period, and winter stands out as the most influential season. Although this new methodology can only be used to describe patterns, we discuss several mechanisms that could explain our results. We propose that starvation resistance and delayed maturation are the main causes for this increase in size in periods with cooler winters, and a fecundity‐related hypothesis to explain why climate has a greater influence on female body size.     

Genomic organization of a UDP-glucosyltransferase gene determines differential accumulation of specific flavonoid glucosides in tepals

Glycosylation plays a major role in the chemical diversity of flavonoids. The wide diversity of the family-1 glycosyltransferase (UGT) impairs the determination of the biochemical function solely from its primary sequence. Here we combined differential expression and target metabolomic analysis in various Crocus species to identify a gene that is key in determining the flavonoid composition of Crocus species that belong to the Crocus series. UGT703B1 recognizes isorhamnetin and kaempferol as substrates in vitro. In addition, UGT703B1 expression was found to be highly correlated with the presence of kaempferol 7-O-biglucoside-3-O-β-glucoside and isorhamnetin-3,7-O-diglucoside. These flavonols were present in C. sativus and C. cartwrightianus albus, both from series Crocus but absent in Crocus species from the other series analyzed. Further, the presence of both flavonols was associated with the expression of UGT703B1, and this expression was correlated with the presence of the UGT703B1 coding gene, with the exception of C. cancellatus, whose genomic sequence was present but contained a shorter intronic sequence and promoter alterations, suggesting the presence of regulatory sequences in the deleted part of that intron and promoter important for UGT703B1 expression. Overall, the data obtained supports the involvement of UGT703B1 in the formation of specific kaempferol and isorhamnetin glucosides, while demonstrating that the integration of metabolomic and differential expression analysis is a versatile tool for understanding a multigene family of UGTs in Crocus.