Embryo rescue from seedless grapevines (Vitis vinifera L.) treated with growth retardants

The effects of two retardants (CCC and paclobutrazol) and the new compound XE 1019, applied before grapevine anthesis, were studied in order to increase the number of fertilised embryos and growing plantlets derived from in ovulo culture of seedless cultivars CG 102.011, Emperatriz and Malvinas. No significant differences were detected between treatments with CCC (400 and 800 mg . l-1, applied 2, 3 and 4 weeks before bloom), and the control in the cv. CG 102.011. The number of growing plantlets at 10 weeks after anthesis and at maturity was significantly higher than that from 8 weeks. In applications closer to bloom, CCC treatments increased the number of ovules per berry in the cultivars assayed. From all cultivars, only CG 102.011 showed a significant increase in plantlet production after CCC treatment when clusters were harvested the 10th week after bloom. It is believed that CCC would act through inhibition of endogenous gibberellin synthesis as the cause of ovule abortion. The idea is based on the fact that gibberellic acid can induce seedlessness in some seeded cultivars

Genome-wide analysis of 30 -untranslated regions supports the existence of post-transcriptional regulons controlling gene expression in trypanosomes

In eukaryotic cells, a group of messenger ribonucleic acids (mRNAs) encoding functionally interrelated proteins together with the trans-acting factors that coordinately modulate their expression is termed a post-transcriptional regulon, due to their partial analogy to a prokaryotic polycistron. This mRNA clustering is organized by sequence-specific RNA-binding proteins (RBPs) that bind cis-regulatory elements in the noncoding regions of genes, and mediates the synchronized control of their fate. These recognition motifs are often characterized by conserved sequences and/or RNA structures, and it is likely that various classes of cis-elements remain undiscovered. Current evidence suggests that RNA regulons govern gene expression in trypanosomes, unicellular parasites which mainly use post-transcriptional mechanisms to control protein synthesis. In this study, we used motif discovery tools to test whether groups of functionally related trypanosomatid genes contain a common cis-regulatory element. We obtained conserved structured RNA motifs statistically enriched in the noncoding region of 38 out of 53 groups of metabolically related transcripts in comparison with a random control. These motifs have a hairpin loop structure, a preferred sense orientation and are located in close proximity to the open reading frames. We found that 15 out of these 38 groups represent unique motifs in which most 30 -UTR signature elements were group-specific. Two extensively studied Trypanosoma cruzi RBPs, TcUBP1 and TcRBP3 were found associated with a few candidate RNA regulons. Interestingly, 13 motifs showed a strong correlation with clusters of developmentally co-expressed genes and six RNA elements were enriched in gene clusters affected after hyperosmotic stress. Here we report a systematic genome-wide in silico screen to search for novel RNA-binding sites in transcripts, and describe an organized network of several coordinately regulated cohorts of mRNAs in T. cruzi. Moreover, we found that structured RNA elements are also conserved in other human pathogens. These results support a model of regulation of gene expression by multiple post-transcriptional regulons in trypanosomes.Fil: de Gaudenzi, Javier Gerardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Carmona, Santiago Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Agüero, Fernan Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Frasch, Alberto Carlos C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentin

Genetic transformation of Vitis vinifera L. cvs Thompson Seedless and Chardonnay with the pear PGIP and GFP encoding genes

Transgenic plants of Vitis vinifera L. cvs. Chardonnay and Thompson Seedless expressing the β-glucuronidase gene (GUS) and either the pear polygalacturonase inhibiting protein gene (PGIP) or the green fluorescent protein gene (GFP) were produced via somatic embryogenesis. Various media and culture conditions were tested in order to develop an efficient transformation method. Best results were obtained when embryogenic callus was initiated from anthers cultured on PIV medium and maintained in PT medium. Embryogenic lines of the rootstocks Saint George, 110 Richter and Freedom and from inflorescence primordia of Chardonnay and 110 Richter were also established using the same media. Inoculation with 109 cells·ml-1 Agrobacterium resulted in a higher number of selected calli than cultures inoculated with 107 or 108 cells·ml-1. Plants were regenerated in a modified WP medium from up to 46 % of the selected callus. Approximately 80 % of the lines expressed GUS and either PGIP or GFP but a low correlation was found between β-glucuronidase and polygalacturonase inhibiting protein activities.

Boussinesq Solitons as Propagators of Neural Signals

We  consider  certain  approximation for determining the  equation  of motion  for nerve  signals by  using  the  model  of the  lipid  melting  of membranes.   The  nerve  pulses  are  found  to  display nonlinearity and  dispersion  during  the  melting  transition.  In this  simplified model the  nonlinear equation  early  proposed  by  Heimburg  and  coworkers  transformed to  the  well known  integrable Boussinesq  non linear  equation.   Under  specific values of the  parametric space this  system  shows the  existence  of singular  and  regular  soliton  like structures.   After  their  collisions  the  mutual creation  and annihilation (each other)  of nerve signals along the  nerve,  during  their  propagation, has been observed.Keywords: Boussinesq equation,  singular  solitons,  single neurons,  neural  code