Neurochemicals for the Investigation of GABA<Subscript>C</Subscript> Receptors

GABA_C receptors are being investigated for their role in many aspects of nervous system function including memory, myopia, pain and sleep. There is evidence for functional GABA_C receptors in many tissues such as retina, hippocampus, spinal cord, superior colliculus, pituitary and the gut. This review describes a variety of neurochemicals that have been shown to be useful in distinguishing GABA_C receptors from other receptors for the major inhibitory neurotransmitter GABA. Some selective agonists (including (+)-CAMP and 5-methyl-IAA), competitive antagonists (such as TPMPA, (±)-cis-3-ACPBPA and aza-THIP), positive (allopregnanolone) and negative modulators (epipregnanolone, loreclezole) are described. Neurochemicals that may assist in distinguishing between homomeric ρ1 and ρ2 GABA_C receptors (2-methyl-TACA and cyclothiazide) are also covered. Given their less widespread distribution, lower abundance and relative structural simplicity compared to GABA_A and GABA_B receptors, GABA_C receptors are attractive drug targets.     

Genscan for <Emphasis Type="Italic">Arabidopsis</Emphasis> is a valuable tool for predicting sponge coding sequences

Although the first sponge genome project has already started releasing completed sequences, only a very small number of annotated sponge genomic sequences has so far been published. In addition, no gene-prediction software optimised for sponges is available yet. In the present paper, we present the performance of Arabidopsis-optimised Genscan as tested on sponge genes. All genes whose genomic and complete CDS sequences are deposited in the NCBI nucleotide database were retrieved and used as the test set. The 18 test genes are composed of 114 coding exons. The sensitivity and specificity, respectively, of all exons were predicted with 83.3% and 79.2%, internal exons with 88.5% and 80.2%, donor with 93.8% and 85.7%, acceptor with 89.6% and 78.9%, initiation with 94.4% and 85%, and termination sites with 72.2% and 81.3%. The results are compared with prediction results obtained with Genscan for vertebrates and GeneMark.hmm ES-3.0 for Arabidopsis. The surprising finding is that although the animals are the source of sequences, the best results (more than 80% accuracy in predicting complete exons) were obtained by Genscan optimised for a plant A. thaliana. Although the sample is small, the results lead to the conclusion that Genscan for Arabidopsis is a valuable tool for predicting coding sequences in sponges and could be of great help in annotating sponge genes. Dedicated to Prof. Dr.Sc. Vera Gamulin, a remarkable lady who passed away too soon and suddenly.     

Tumour‐derived exosomes: Tiny envelopes for big stories

The discovery of exosomes, which are small, 30–100 nm sized extracellular vesicles that are released by virtual all cells, has initiated a rapidly expanding and vibrant research field. Current investigations are mainly directed toward the role of exosomes in intercellular communication and their potential value as biomarkers for a broad set of diseases. By horizontal transfer of molecular information such as micro RNAs, messenger RNAs or proteins, as well as by receptor–cell interactions, exosomes are capable to mediate the reprogramming of surrounding cells. Herein, we review how especially cancer cells take advantage of this mechanism to influence their microenvironment in favour of immune escape, therapy resistance, tumour growth and metastasis. Moreover, we provide a comprehensive microarray analysis (n > 1970) to study the expression patterns of genes known to be intimately involved in exosome biogenesis across 26 different cancer entities and a normal tissue atlas. Consistent with the elevated production of exosomes observed in cancer patient plasma, we found a significant overexpression especially of RAB27A, CHMP4C and SYTL4 in the corresponding cancer entities as compared to matched normal tissues. Finally, we discuss the immune‐modulatory and anti‐tumorigenic functions of exosomes as well as innovative approaches to specifically target the exosomal circuits in experimental cancer therapy.     

<i>In vitro</i> Mutagenesis for the Improvement of Agave Genus

Biotechnological techniques provide a viable alternative to help improve and increase the production of plant species of agricultural and economic importance, which have been affected over the years by climate change, increasing their susceptibility to pests and/or diseases, generating losses in production as well as a decrease in their regenerative and genetic diversity. The application of biotechnological techniques such as in vitro mutagenesis offers a viable option for the generation of crops that are resistant to the different factors caused by abiotic and biotic stress. In vitro mutagenesis has been used in an efficient way to generate genetic changes in different plant species. However, these methods have not been studied thoroughly in crops of agro-industrial interest, such as agave, which represents an economic resource of national importance and are considered as endemic species of Mexico. Therefore, this literary review aimed to focus on the studies that have been used for the genetic improvement of this species via mutagenesis techniques in plants in the agave genus. Therefore, the objective was to set a precedent for future genetic studies that aim to obtain more productive regenerants for various industries, such as food and pharmaceutical. It is also of great interest to compile information from basic research that helps understand and elucidate a model of possible defense mechanisms that are activated in the Agave genus.