Development of the pseudothumb in frogs

Frogs have highly conserved hand and foot morphology, possessing four fingers and five toes. As an exception, two Japanese ranid frog species, the Otton frog Babina subaspera and the dagger frog Babina holsti, possess a unique thumb-like structure (the pseudothumb) in the forelimb, giving an appearance of a total of five fingers on the hand. To obtain insights into the developmental mechanisms that generate this novel character, we investigated the hand morphogenesis of the Otton frog. The unique morphological pattern of the pseudothumb was already established in juveniles. Surprisingly, the bud-like structure, which is similar to the area of inductive activity (e.g. feather buds in birds and the carapacial ridge in turtles), was detected over the site where the future prepollex develops in larvae. By contrast, this bud-like structure was not found in larvae of other ranid species. We discuss possible scenarios that would favour the evolution of this very unusual trait in frogs.     

Design,synthesis and biological evaluation of novel analgesic agents targeting both cyclooxygenase and TRPV1

Multitarget-directed ligands might offer certain advantages over traditional single-target drugs and/or drug combinations. In the present study, a series of novel analgesic agents targeting both cyclooxygenase and TRPV1 were prepared and evaluated in an effort to optimize properties of previously described lead compounds from piperazine, ethanediamine cores. These compounds were evaluated for antagonism of hTRPV1 activation by capsaicin and the ability to inhibit Ovine COX-1 and human recombinant COX-2 in vitro. The favorable potentials of these test compounds were further characterized in preliminary analgesic and side-effects tests in vivo. On the basis of comprehensive evaluations, compound 8d which showed strong TRPV1 antagonistic activity, middle COX-2 inhibition, weak ulcerogenic action and had no hyperthermia side-effect was considered as a safe candidate for the further development of analgesic drugs.     

Optimization of bio-diesel production from soybean and wastes of cooked oil: Combining dielectric microwave irradiation and a SrO catalyst

This work offers an optimized method in the transesterification of pristine (soybean) oil and cooked oil to bio-diesel, based on microwave dielectric irradiation as a driving force for the transesterification reaction and SrO as a catalyst. This combination has demonstrated excellent catalytic activity and stability. The transesterification was carried out with and without stirring. According to ¹H NMR spectroscopy and TLC results, this combination accelerates the reaction (to less than 60 s), maintaining a very high conversion (99%) and high efficiency. The catalytic activity of SrO under atmospheric pressure in the presence of air and under the argon atmosphere is demonstrated. The optimum conversion of cooked oil (99.8%) is achieved under MW irradiation of 1100 W output with magnetic stirring after only 10 s. The optimum method decreases the cost of bio-diesel production and has the potential for industrial application in the transesterification of cooked oil to bio-diesel.     

A Hoxa13:Cre mouse strain for conditional gene manipulation in developing limb,hindgut, and urogenital system

The developing limb is a useful model for studying organogenesis and developmental processes. Although Cre alleles exist for conditional loss‐ or gain‐of‐function in limbs, Cre alleles targeting specific limb subdomains are desirable. Here we report on the generation of the Hoxa13:Cre line, in which the Cre gene is inserted in the endogenous Hoxa13 gene. We provide evidence that the Cre is active in embryonic tissues/regions where the endogenous Hoxa13 gene is expressed. Our results show that cells expressing Hoxa13 in developing limb buds contribute to the entire autopod (hand/feet) skeleton and validate Hoxa13 as a distal limb marker as far as the skeleton is concerned. In contrast, in the limb musculature, Cre‐based fate mapping shows that almost all muscle masses of the zeugopod (forearm) and part of the triceps contain Hoxa13‐expressing cells and/or their descendants. Besides the limb, the activity of the Cre is detectable in the urogenital system and the hindgut, primarily in the epithelium and smooth muscles. Together our data show that the Hoxa13:Cre allele is a useful tool for conditional gene manipulation in the urogenital system, posterior digestive tract, autopod and part of the limb musculature. genesis 53:366–376, 2015. © 2015 Wiley Periodicals, Inc.     

Theropod forelimb design and evolution

We examined the relationship between forelimb design and function across the 230-million-year history of theropod evolution. Forelimb disparity was assessed by plotting the relative contributions of the three main limb elements on a ternary diagram. Theropods were divided into five functional groups: predatory, reduced, flying, wing-propelled diving, and flighdess. Forelimbs which maintained their primitive function, predation, are similarly proportioned, but non-avian theropods with highly reduced forelimbs have relatively longer humeri. Despite the dramatically different forces imparted by the evolution of flight, forelimb proportions of basal birds are only slighdy different from those of their non-avian relatives. An increase in disparity accompanied the subsequent radiation of birds. Each transition to flightlessness has been accompanied by an increase in relative humeral length, which results from relatively short distal limb elements. We introduce theoretical predictions based on five biomechanical and developmental factors that may have influenced the evolution of theropod limb proportions.     

Identification of yrrU as the methylthioadenosine nucleosidase gene in Bacillus subtilis.

Taking trimethoprim as the selective agent in the presence of thymine, we adapted to Bacillus subtilis a selection procedure depending on the peculiar organisation of the one-carbon metabolism. The corresponding pathways couple synthesis of thymine to tetrahydrofolate consumption as a substrate of the reaction mediated by thymidylate synthase, instead of being a co-enzyme as in the other reactions transferring one-carbon groups. Mutants obtained are thymidylate synthase deficient, and therefore auxotrophic for thymine. This provides positive selection in a first step for gene replacement by a thymidylate synthase cassette, and subsequently against its presence. For systematic recombination of mutations constructed in vitro, we used the property of B. subtilis to grow at high temperature, noting that the thyB gene product is inactive at 46 degrees C, while the product of thyA remains active at this temperature. As the first step, we built up a recipient thyA- background, deleting the gene by in situ recombination. This method was used to investigate the function of the yrrU gene, which is presumably involved in a sulfur recycling pathway associated with polyamine biosynthesis. We showed that yrrU codes for a protein recycling methylthioadenosine, probably a nucleosidase. In addition we observed that B. subtilis can use methylthioribose as a sulfur source, and that it is an efficient sulfur scavenger.     

Regeneration inducers in limb regeneration

Limb regeneration ability, which can be observed in amphibians, has been investigated as a representative phenomenon of organ regeneration. Recently, an alternative experimental system called the accessory limb model was developed to investigate early regulation of amphibian limb regeneration. The accessory limb model contributed to identification of limb regeneration inducers in urodele amphibians. Furthermore, the accessory limb model may be applied to other species to explore universality of regeneration mechanisms. This review aims to connect the insights recently gained to emboss universality of regeneration mechanisms among species. The defined molecules (BMP7 (or2) + FGF2 + FGF8) can transform skin wound healing to organ (limb) regeneration responses. The same molecules can initiate regeneration responses in some species.     

Mechanical feedback defines organizing centers to drive digit emergence

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Facile synthesis of glycosylated Fmoc amino acid building blocks assisted by microwave irradiation

The synthesis of glycosylated Fmoc amino acids by reaction of mono- and disaccharide peracetates with Fmoc amino acids having free carboxyl groups was rapidly promoted by Lewis acids (SnCl₄, BF₃·Et₂O) under microwave irradiation. The products are useful building blocks for the synthesis of glycopeptides.