Effects of citronella oil (Cymbopogon winterianus Jowitt ex Bor) on Spodoptera frugiperda (J. E. Smith) midgut and fat body

The armyworm, Spodoptera frugiperda, is the principal pest of corn in Brazil. Control is achieved primarily by synthetic insecticides, which cause problems for the agro-ecosystem. Alternative methods of control are under investigation and citronella (Cymbopogon winterianus) essential oil appears to be a promising agent. We investigated the effects of citronella oil using histological, histochemical and immunohistochemical methods. The midgut of larvae treated with citronella exhibited altered epithelium including cytoplasmic protrusions, columnar cell extrusion, pyknotic nuclei, and increased periodic acid-Schiff positive granules. Regenerative cells in the epithelium of the midgut increased in number, which facilitated subsequent regeneration of this tissue. After exposure to citronella, trophocytes, the principal cell type of the fat body, possessed enlarged vacuoles and mitotic bodies, and contained reduced amounts of glycogen, lipid, and protein. Citronella oil caused morphological changes of the midgut and reduction of stored resources in the fat body, which may adversely affect insect reproduction and survival.     

Phylogenetic relationships of artiodactyls and cetaceans as deduced from the comparison of cytochrome b and 12S rRNA mitochondrial sequences

A data set of complete mitochondrial cytochrome b and 12S rDNA sequences is presented here for 17 representatives of Artiodactyla and Cetacea, together with potential outgroups (two Perissodactyla, two Carnivora, two Tethytheria, four Rodentia, and two Marsupialia). We include seven sequences not previously published from Hippopotamidae (Ancodonta) and Camelidae (Tylopoda), yielding a total of nearly 2.1 kb for both genes combined. Distance and parsimony analyses of each gene indicate that 11 clades are well supported, including the artiodactyl taxa Pecora, Ruminantia (with low 12S rRNA support), Tylopoda, Suina, and Ancodonta, as well as Cetacea, Perissodactyla, Carnivora, Tethytheria, Muridae, and Caviomorpha. Neither the cytochrome b nor the 12S rDNA genes resolve the relationships between these major clades. The combined analysis of the two genes suggests a monophyletic Cetacea +Artiodactyla clade (defined as "Cetartiodactyla"), whereas Perissodactyla, Carnivora, and Tethytheria fall outside this clade. Perissodactyla could represent the sister taxon of Cetartiodactyla, as deduced from resampling studies among outgroup lineages. Cetartiodactyla includes five major lineages: Ruminantia, Tylopoda, Suina, Ancodonta, and Cetacea, among which the phylogenetic relationships are not resolved. Thus, Suiformes do not appear to be monophyletic, justifying their split into the Suina and Ancodonta infraorders. An association between Cetacea and Hippopotamidae is supported by the cytochrome b gene but not by the 12S rRNA gene. Calculation of divergence dates suggests that the Cetartiodactyla could have diverged from other Ferungulata about 60 MYA.      

Nitrate uptake varies with tide height and nutrient availability in the intertidal seaweed Fucus vesiculosus

Intertidal seaweeds must cope with a suite of stressors imposed by aerial exposure at low tide, including nutrient limitation due to emersion. Seaweeds can access nutrients only when submerged, so individuals living higher compared to lower on the shore may have adaptations allowing them to acquire sufficient amounts of nutrients to survive and maintain growth. Using a combination of observations and experiments, we aimed to identify intraspecific variation in nitrate uptake rates across the intertidal distribution of F. vesiculosus, as well as test for acclimation in response to a change in tide height. We replicated our study at sites spanning nearly the entire Gulf of Maine coastline, to examine how local environmental variability may alter intraspecific variation in nitrate uptake. We found that average nitrate uptake rates were ~18% higher in upper compared to lower intertidal Fucus vesiculosus. Furthermore, we found evidence for both acclimation and adaptation to tide height during a transplant experiment. F. vesiculosus transplanted from the lower to the upper intertidal zone was characterized by increased nitrate uptake, but individuals transplanted from the upper to the lower intertidal zone retained high uptake rates. Our observations differed among Gulf of Maine regions and among time points of our study. Importantly, these differences may reflect associations between nitrate uptake rates and abiotic environmental conditions and seaweed nutrient status. Our study highlights the importance of long‐term variation in ambient nutrient supply in driving intraspecific variation of seaweeds across the intertidal gradient and local and seasonal variation in ambient nutrient levels in mediating intraspecific differences.     

A proteomic approach identified growth hormone-dependent nutrition markers in children with idiopathic short stature

Background  

The broad range in growth observed in short prepubertal children receiving the same growth hormone (GH) dose is due to individual variation in GH responsiveness. This study used a pharmaco-proteomic approach in order to identify novel biomarkers that discriminate between short non-GH-deficient (GHD) children who show a good or poor growth response to GH treatment.