Systematic Identification of Rhythmic Genes Reveals camk1gb as a New Element in the Circadian Clockwork

A wide variety of biochemical, physiological, and molecular processes are known to have daily rhythms driven by an endogenous circadian clock. While extensive research has greatly improved our understanding of the molecular mechanisms that constitute the circadian clock, the links between this clock and dependent processes have remained elusive. To address this gap in our knowledge, we have used RNA sequencing (RNA–seq) and DNA microarrays to systematically identify clock-controlled genes in the zebrafish pineal gland. In addition to a comprehensive view of the expression pattern of known clock components within this master clock tissue, this approach has revealed novel potential elements of the circadian timing system. We have implicated one rhythmically expressed gene, camk1gb, in connecting the clock with downstream physiology of the pineal gland. Remarkably, knockdown of camk1gb disrupts locomotor activity in the whole larva, even though it is predominantly expressed within the pineal gland. Therefore, it appears that camk1gb plays a role in linking the pineal master clock with the periphery.     

Identification of the endostyle as a stem cell niche in a colonial chordate

Stem cell populations exist in "niches" that hold them and regulate their fate decisions. Identification and characterization of these niches is essential for understanding stem cell maintenance and tissue regeneration. Here we report on the identification of a novel stem cell niche in Botryllus schlosseri, a colonial urochordate with high stem cell-mediated developmental activities. Using in vivo cell labeling, engraftment, confocal microscopy, and time-lapse imaging, we have identified cells with stemness capabilities in the anterior ventral region of the Botryllus' endostyle. These cells proliferate and migrate to regenerating organs in developing buds and buds of chimeric partners but do not contribute to the germ line. When cells are transplanted from the endostyle region, they contribute to tissue development and induce long-term chimerism in allogeneic tissues. In contrast, cells from other Botryllus' regions do not show comparable stemness capabilities. Cumulatively, these results define the Botryllus' endostyle region as an adult somatic stem cell niche.     

Chlorella sorokiniana UTEX 2805, a heat and intense, sunlight-tolerant microalga with potential for removing ammonium from wastewater

In the summer of 2003, a microalga strain was isolated from a massive green microalgae bloom in wastewater stabilization ponds at the treatment facility of La Paz, B.C.S., Mexico. Prevailing environmental conditions were air temperatures over 40 degrees C, water temperature of 37 degrees C, and insolation of up to 2400 micromol m2 s(-1) at midday for several hours at the water surface for four months. The microalga was identified as Chlorella sorokiniana Shih. et Krauss, based on sequencing its entire 18S rRNA gene. In a controlled photo-bioreactor, this strain can grow to high population densities in synthetic wastewater at temperatures of 40-42 degrees C and light intensity of 2500 micromol m2 s(-1) for 5h daily and efficiently remove ammonium from the wastewater under these conditions better than under normal lower temperature (28 degrees C) and lower light intensity (60 micromol m2 s(-1)). When co-immobilized with the bacterium Azospirillum brasilense that promotes growth of microalgae, the population of microalga grew faster and removed even more ammonium. Under exposure to extreme growth conditions, the quantity of four photosynthetic pigments increased in the co-immobilized cultures. This strain of microalga has potential as a wastewater treatment agent under extreme conditions of temperature and light intensity.     

Constitutive activation of G-proteins by polycystin-1 is antagonized by polycystin-2.

Polycystin-1 (PC1), a 4,303-amino acid integral membrane protein of unknown function, interacts with polycystin-2 (PC2), a 968-amino acid alpha-type channel subunit. Mutations in their respective genes cause autosomal dominant polycystic kidney disease. Using a novel heterologous expression system and Ca(2+) and K(+) channels as functional biosensors, we found that full-length PC1 functioned as a constitutive activator of G(i/o)-type but not G(q)-type G-proteins and modulated the activity of Ca(2+) and K(+) channels via the release of Gbetagamma subunits. PC1 lacking the N-terminal 1811 residues replicated the effects of full-length PC1. These effects were independent of regulators of G-protein signaling proteins and were lost in PC1 mutants lacking a putative G-protein binding site. Co-expression with full-length PC2, but not a C-terminal truncation mutant, abrogated the effects of PC1. Our data provide the first experimental evidence that full-length PC1 acts as an untraditional G-protein-coupled receptor, activity of which is physically regulated by PC2. Thus, our study strongly suggests that mutations in PC1 or PC2 that distort the polycystin complex would initiate abnormal G-protein signaling in autosomal dominant polycystic kidney disease.     

Monitoring of black mangrove restoration with nursery-reared seedlings on an arid coastal lagoon

Black mangrove (Avicennia germinans) seedlings (n=555) were grown from field-collected propagules for 3 months in a new type of terrestrial nursery. They were grown in clusters of five plants, and then they were transplanted to a clear-cut zone in a lagoon fringed by a mangrove forest at Laguna de Balandra, Baja California Sur, Mexico. Survival and plant development of transplants were monitored at 6-monthly intervals for 2 years. After 1 month, the survival of seedlings was 96%, later stabilizing at approximately 77%. After 24 months, 74% of the plants were still alive. The best cluster, showing maximum growth under mangrove swamp conditions in this arid zone, was a two-plant cluster. The lagoon has a low natural regeneration rate of 48 plants per 350 m² per 6 years of monitoring. This study shows the feasibility of restoring destroyed arid-coast lagoons with black mangroves.     

Immunological structure of the populations of the upper and middle Volga River regions in relation to the causative agent of yersiniosis and its determining factors

The study of the immunological structure of the population in respect of intestinal yersiniosis at territories with different hydrothermal conditions has revealed the presence of a greater immune stratum (23.9% with the average agglutination titer being 1.8 +/- 0.09 log D) in humid areas, such as the region of the Upper Volga, in comparison with dry areas, such as the region of the Middle Volga, where the level of the immune stratum has proved to be twice as low (10.6% with the average agglutination titer being 0.8 +/- 0.1 log D). At both territories no essential differences in the risk of infection between the inhabitants of rural and urban areas, as well as between different professional and age groups have been revealed, with the exception of persons over 51 years of age, among whom the occurrence of seroconversions has proved to be lower.     

Photochronographic method for studying the expansion of plasma clouds

A novel method for studying the expansion of plasma clouds is developed. The method makes use of electron-optical cameras operating in the streak and frame-by-frame modes and provides a time resolution of 0.01–1 μs and spatial resolution of 1 mm. The experimental results obtained with this method are presented. Original Russian Text ? A.G. Kravchenko, D.N. Litvin, V.V. Mis’ko, V.M. Murugov, A.V. Senik, V.A. Starodubtsev, 2006, published in Fizika Plazmy, 2006, Vol. 32, No. 2, pp. 166–169.     

Dynamics of the biosynthesis of native chlorophyll forms from initial stages to the completion of the greening process in etiolated leaves]

The succession of the formation of the native chlorophill forms and the development of the energy migration between them was studied by means of the comparison of three spectrum types: absorption, fluorescence and fluorescence excitation, and of their second derivatives. Quantitatively the chlorophyll accumulation in 9 native forms was followed by means of mathematical disintegration of the spectra using computer.