Flowering process in soybean under water deficit conditions: A review on genetic aspects

Soybean is a key crop in many countries, being used from human food to the animal industry due to its nutritional properties. Financially, the grain chain moves large sums of money into the economy of producing countries. However, like other agricultural commodities around the world, it can have its final yield seriously compromised by abiotic environmental stressors, like drought. As flowers imply in pods and in grains inside it to minimize damages caused by water restriction, researchers have focused on understanding flowering-process related genes and their interactions. Here a review dedicated to the soybean flowering process and gene network involved in it is presented, describing gene interactions and how genes act in this complex mechanism, also ruled by environmental triggers such as day-light and circadian cycle. The objective was to gather information and insights on the soybean flowering process, aiming to provide knowledge useful to assist in the development of drought-tolerant soybean lines, minimizing losses due to delays or anticipation of flowering and, consequently, restraining financial and productivity losses.     

Kinetics of plasmid segregation in Escherichia coli

Low copy-number bacterial replicons occupy specific locations in their host cells. Production of a GFP-Lac repressor hybrid protein in cells carrying F or P1 plasmids tagged with a lac operator array reveals that in smaller (younger) cells these plasmids are seen mainly as a single fluorescent focus at mid-cell, whereas larger cells tend to have two foci, one at each quarter-cell position. Duplication of the central focus is presumed to represent active partition of plasmid copies. We report here our investigation by time-lapse microscopy of the subsequent movement of these copies to the quarter positions. Following duplication of the central focus, the new foci migrated rapidly and directly to their quarter-cell destinations, where they remained until the next cell cycle. The speed of movement was about five times faster than poleward migration of oriC and 50 times faster than cell elongation. Aberrant positioning of mini-F lacking its sopC centromere demonstrated the requirement for the partition system in this localization process. From the measured number of F plasmid copies per cell it appears that each migrating focus contains two or more plasmid molecules. The molecular basis of this clustering, and evidence for phasing of the partition event in the cell cycle, are discussed.     

Structural investigation of the ligand binding domain of the zebrafish VDR in complexes with 1alpha,25(OH)2D3 and Gemini: purification, crystallization and preliminary X-ray diffraction analysis

The nuclear receptor of Vitamin D can be activated by a large number of agonist molecules with a wide spectrum in their stereochemical framework. Up to now most of our structural information related to the protein-ligand complex formation is based on an engineered ligand binding domain (LBD) of the human receptor. We now have extended our database, using a wild-type LBD from zebrafish that confirms the previously reported results and allows to investigate the binding of ligands that induce significant conformational changes at the protein level.     

Influence of the partial denture on the articulation of dental and postalveolar sounds

Dental prosthesis is a foreign body in oral cavity and thus necessarily interferes with speech articulation. The purpose of this study was to examine influence of partial denture on speech quality and to show eventual differences in pronunciation of dental sounds c[ts], z [z], s [s] and postalveolar sounds c [t], z [3] and s [integral of]. We have examined differences in pronunciation between subjects with removable partial dentures, the same group without partial dentures and a control group. The study was performed on 30 subjects with removable partial dentures and 30 subjects with complete dental arch. All subjects were recorded while reading six Croatian words containing the examined sounds. Recordings were analyzed with Multispeech Program (Kay Elemetrics Inc.). Acoustic analysis--LPC (linear prediction coding) provided formant peaks (Hz) for each examined sound, its intensity (dB) and formant bandwidths (Hz). Results showed that subjects with partial dentures had 50% less distorted variables and that prostheses did not completely restore articulation of postalveolar sounds. Groups with and without prostheses had lower formant peaks intensities and wider formant bandwidths in comparison to the control group. Partial dentures have not significantly interfered with resonance frequency. At the same time, pronunciation of the examined sounds was significantly improved. However, precision of the articulation movements has deteriorated.     

Genetic variation at nine short tandem repeat loci among islanders of the eastern Adriatic coast of Croatia

We have analyzed the extent of genetic variation at nine autosomal short tandem repeat loci (D3S1358, VWA, FGA, TH01, TPOX, CSF1PO, D5S818, D13S317, D7S820) among six populations from Croatia: five distributed in the islands of the eastern Adriatic coast and one from the mainland. The purpose is to investigate the usefulness of these loci in detecting regional genetic differentiation in the studied populations. Significant heterogeneity among the island and mainland populations is revealed in the distributions of allele frequencies; however, the absolute magnitude of the coefficient of gene differentiation is small but significant. The summary measures of genetic variation, namely, heterozygosity, number of alleles, and allele size variance, do not indicate reduced genetic variation in the island populations compared to the mainland population. In contrast to the two measures of genetic variation, allele size variance and within-locus heterozygosity, the imbalance index (beta) indicates evidence of recent expansion of population sizes in all islands and in the mainland. High mutation rates of the studied loci together with local drift effects are likely explanations for interisland genetic variation and the observed lack of reduced genetic diversity among the island populations.     

Jagged1 signals in the postnatal subventricular zone are required for neural stem cell self-renewal

Neural stem cells (NSCs) in the postnatal mammalian brain self-renew and are a source of neurons and glia. To date, little is known about the molecular and cellular mechanisms regulating the maintenance and differentiation of these multipotent progenitors. We show that Jagged1 is required by mitotic cells in the subventricular zone (SVZ) and stimulates self-renewal of multipotent epidermal growth factor-dependent NSCs. Jagged1-expressing cells line the adult SVZ and are juxtaposed to Notch1-expressing cells, some of which are putative NSCs. In vitro, endogenous Jagged1 acts through Notch1 to promote NSC maintenance and multipotency. In vivo, reducing Jagged1/Notch1 signaling decreases the number of proliferating cells in the SVZ. In addition, soluble Jagged1 promotes self-renewal and neurogenic potential of multipotent neural progenitors in vitro. Our findings suggest a central role for Jagged1 in the NSC niche in the SVZ for maintaining a population of NSCs in the postnatal brain.     

Inheritance of a recessive transgene-associated character controlling albinism in transgenic bean (Phaseolus vulgaris L.)

We identified a transgenic line exhibiting albinism during our work to introduce genes through genetic engineering in dry bean (Phaseolus vulgaris). The transgenic mother plant (R0) presented a normal phenotype and generated albino and normal green plants in the first generation (R1). The segregation ratio of the albino character in the R1 and R2 generations fitted the expected ratio for a character controlled by a single recessive gene linked to a foreign gus gene, suggesting that albinism could be a consequence of insertional mutation caused by introduction of the exogenous gene. Analysis by electron microscope revealed that the albino cells possessed no chloroplasts and a greater number of mitochondria when compared to normal green plants. This transgenic bean line may be used in understanding the genetic control of chloroplast genesis, for acquiring additional knowledge of genomic structure or in physiological studies. This is the first described transgene-associated mutant bean plant.