Unravelling the evolution of the Allatostatin-Type A, KISS and Galanin Peptide-Receptor gene families in Bilaterians: insights from Anopheles Mosquitoes

Allatostatin type A receptors (AST-ARs) are a group of G-protein coupled receptors activated by members of the FGL-amide (AST-A) peptide family that inhibit food intake and development in arthropods. Despite their physiological importance the evolution of the AST-A system is poorly described and relatively few receptors have been isolated and functionally characterised in insects. The present study provides a comprehensive analysis of the origin and comparative evolution of the AST-A system. To determine how evolution and feeding modified the function of AST-AR the duplicate receptors in Anopheles mosquitoes, were characterised. Phylogeny and gene synteny suggested that invertebrate AST-A receptors and peptide genes shared a common evolutionary origin with KISS/GAL receptors and ligands. AST-ARs and KISSR emerged from a common gene ancestor after the divergence of GALRs in the bilaterian genome. In arthropods, the AST-A system evolved through lineage-specific events and the maintenance of two receptors in the flies and mosquitoes (Diptera) was the result of a gene duplication event. Speciation of Anophelesmosquitoes affected receptor gene organisation and characterisation of AST-AR duplicates (GPRALS1 and 2) revealed that in common with other insects, the mosquito receptors were activated by insect AST-A peptides and the iCa(2+)-signalling pathway was stimulated. GPRALS1 and 2 were expressed mainly in mosquito midgut and ovaries and transcript abundance of both receptors was modified by feeding. A blood meal strongly up-regulated expression of both GPRALS in the midgut (p < 0.05) compared to glucose fed females. Based on the results we hypothesise that the AST-A system in insects shared a common origin with the vertebrate KISS system and may also share a common function as an integrator of metabolism and reproduction. Highlights: AST-A and KISS/GAL receptors and ligands shared common ancestry prior to the protostome-deuterostome divergence. Phylogeny and gene synteny revealed that AST-AR and KISSR emerged after GALR gene divergence. AST-AR genes were present in the hemichordates but were lost from the chordates. In protostomes, AST-ARs persisted and evolved through lineage-specific events and duplicated in the arthropod radiation. Diptera acquired and maintained functionally divergent duplicate AST-AR genes.Foundation for Science and Technology, Portugal (FCT) [PTDC/BIA-BCM/114395/2009]; European Regional Development Fund (ERDF) COMPETE - Operational Competitiveness Programme; Portuguese funds through FCT Foundation for Science and Technology [PEst-C/MAR/LA0015/2013, UID/Multi/04326/2013, PEst-OE/SAU/LA0018/2013]; FCT [SFRH/BPD/89811/2012, SFRH/BPD/80447/2011, SFRH/BPD/66742/2009]; auxiliary research contract FCT Pluriannual funds [PEst-C/MAR/LA0015/2013, UID/Multi/04326/2013]info:eu-repo/semantics/publishedVersio

Mechanical Properties of High and Very-High Strength Steel at Elevated Temperatures and After Cooling Down

High-strength steels (HSS) are produced using special chemical composition or/and manufacturing processes. Both aspects affect their mechanical properties at elevated temperatures and after cooling down, and particularly the residual strength and the ductility of the structural members. As HSS equates the design of lighter structural elements, higher temperatures are developed internally compared to the elements designed with conventional carbon steel. Therefore, the low thickness members, along with the severe effect of high temperature on the mechanical properties of the HSS, constitute to the increased vulnerability of such structures in fire. Moreover, the re-use and reinstatement of these structures are more challenging due to the lower residual mechanical properties of HSS after the cooling down period. This paper presents a review of the available experimental studies of the mechanical properties of HSS at elevated temperatures and after cooling down. The experimental results are collected and compared with the proposed material model (reduction factors) of EN1993–1-2. Based on these comparisons, modified equations describing the effect of elevated temperatures on the mechanical properties of HSS are proposed. Also, the post-fire mechanical properties of HSS are examined. A comprehensive discussion on the effect of influencing parameters, such as manufacturing process, microstructure, loading conditions, maximum temperature, and others is further explored

An analytical method for the resistance of cellular beams with sinusoidal openings

International audienceA new type of cellular beams fabricated from hot rolled profiles appeared recently, whose openings have a sinusoidal shape. These beams are used either for steel or composite structures and they allow rectangular ducts, even with large sizes, to pass through their openings. They can thus lead to a substantial reduction of the floor thickness and they contribute to increase the competitiveness of steel buildings. The aesthetic shape of the openings is also an advantage to improve the architectural attractiveness of steel frames. To take benefit from these possibilities, accurate design methods are required and this research project has been undertaken to establish the static behaviour of these beams with sinusoidal openings. This paper presents the results of 4 tests (on 3 steel beams and on a composite beam) and of 287 numerical simulations carried out to determine ultimate loads and failure modes under the simultaneous effects of bending and shear. A new analytical design method is then proposed for the resistance of cellular beams with sinusoidal openings taking into account the Vierendel effect. This new model can be used within the range of the geometrical and mechanical scope. Finally the comparison of the ultimate loads according to this new model and according to the reference database (experimental or numerical data) is provided to assess the safety and accuracy of the proposed expressions

Robust structures by joint ductility

peer reviewe

Specific ablation of thyroid follicle cells in adult transgenic mice.

The coding region of the herpes simplex type 1 virus thymidine kinase gene was coupled to the promoter of the bovine thyroglobulin gene and introduced into the genome of mice. The viral thymidine kinase (HSV1-TK) was expressed mainly in the thyroid glands and testis. Upon treatment of transgenic females with the antiherpetic agent Ganciclovir the thyroid regressed, while the parathyroid gland was unaffected. The number of thyroid follicle cells was greatly reduced after 3 days, and they were completely absent after 7 days of treatment. After 14 days, the levels of circulating T4 and T3 were below the limits of detection, total soluble protein recovered from the thyroid and parathyroid glands together was 10% of the control value, and the level of thyroid HSV1-TK was more than 100-fold lower than that in transgenic controls. Levels of circulating PTH and calcitonin remained normal. At the time of treatment the mice were adults. Thus, the thyroid follicle cells were selectively ablated after normal development with a functional thyroid gland. When treatment with Ganciclovir was terminated after 14 days, no circulating T4 or T3 or other indications of thyroid regeneration were detected for a subsequent period of 90 days. During this time the mice gained weight more slowly than controls, at a rate consistent with the suppression of GH synthesis by thyroid deficiency. The production of mouse major urinary protein (MUP) ceased in the treated mice and was completely restored by the administration of T4. MUP production was not restored by GH, demonstrating that the expression of the Mup genes requires T4 in addition to GH.Journal ArticleResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Molecular cloning of an orphan G-protein-coupled receptor that constitutively activates adenylate cyclase.

A human gene encoding an orphan G-protein-coupled receptor named ACCA (adenylate cyclase constitutive activator) was isolated from a genomic library using as a probe a DNA fragment obtained by low-stringency PCR. Human ACCA (hACCA) is a protein of 330 amino acids that exhibits all the structural hallmarks of the main family of G-protein-coupled receptors. Expression of hACCA resulted in a dramatic stimulation of adenylate cyclase, similar in amplitude to that obtained with other Gs-coupled receptors fully activated by their respective ligands. This stimulation was obtained in a large variety of stable cell lines derived from various organs, and originating from different mammalian species. hACCA was found to be the human homologue of a recently reported mouse orphan receptor (GPCR21). The mouse ACCA (mACCA) was therefore recloned by PCR, and expression of mACCA in Cos-7 cells demonstrated that the mouse receptor behaved similarly as a constitutive activator of adenylate cyclase. It is not known presently whether the stimulation of adenylate cyclase is the result of a true constitutive activity of the receptor or, alternatively, is the consequence of a permanent stimulation by a ubiquitous ligand. The tissue distribution of mACCA was determined by RNase protection assay. Abundant transcripts were found in the brain, whereas lower amounts were detected in testis, ovary and eye. Various hypotheses concerning the constitutive activity of ACCA and their potential biological significance are discussed

Large-scale fire test of unprotected cellular beam acting in membrane action

This paper describes a full scale fire test performed recently on a composite floor for analysing the possibility of tensile membrane action to develop when the unprotected steel beams in the central part of the floor are made of cellular beams. The natural fire was created by a wood crib fire load of 700 MJ/m² and the 9 x 15 m floor survived the fire that peaked at 1000°C and lasted for about 90 minutes. Blind predictions of the air temperature development by the software OZone and of the structural behaviour by the software SAFIR which proved quite satisfactory are also described