Nuclear AP4A-binding activity of sea urchin embryos changes in relation to the initiation of S phase

The AP4A-binding activity of sea urchin embryos was studied using radioactively labelled diadenosine 5',5"'-P1,P4-tetraphosphate (Ap4A). Among various subcellular components that can bind [3H]AP4A, nuclei alone showed the highly specific Ap4A-binding activity which was not influenced by the presence of AP4A, AP5A and GP4G. The addition of an excess amount of ATP only slightly reduced the binding of [3H]AP4A to the nuclei. It was found that AP4A binds to the residual proteinaceous structure of nuclei which was resistant to the extraction with 2 M NaCl. The nuclear AP4A-binding activity fluctuated cyclically during each cell cycle, with a transient increase at the beginning of S phase followed by an abrupt decrease within 10 min. When the initiation of S phase was blocked, the increase in the AP4A-binding activity was also prevented. It seems that the binding of AP4A to the nuclear structural protein is involved in the initiation of S phase.     

The Cellular and Synaptic Architecture of the Mechanosensory Dorsal Horn

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Tick-Borne Zoonotic Bacteria in Wild and Domestic Small Mammals in Northern Spain

The prevalence and diversity of tick-borne zoonotic bacteria (Borrelia spp., Anaplasma phagocytophilum, Coxiella burnetii, and spotted fever group rickettsiae) infecting 253 small mammals captured in the Basque Country (Spain) were assessed using PCR and reverse line blot hybridization. Trapping sites were selected around sheep farms (study 1, 2000 to 2002) and recreational parks (study 2, 2003 to 2005). The majority of the studied mammals (162) were wood mice (Apodemus sylvaticus), but six other different species were also analyzed: yellow-necked mice (Apodemus flavicollis), shrews (Crocidura russula and Sorex coronatus), bank voles (Clethrionomys glareolus), domestic mice (Mus domesticus), and moles (Talpa europaea). The results showed an infection rate ranging from 10.7% to 68.8%, depending on the small mammal species. One C. russula shrew and one A. sylvaticus mouse gave positive reactions for A. phagocytophilum, and C. burnetii was detected in two domestic mice and one A. sylvaticus mouse in a farm. The DNA of Borrelia spp. was detected in 67 animals (26.5%), most of them presenting positive hybridization with the probe for Borrelia sp. strain R57, the new Borrelia species previously detected in small mammals in our region. Furthermore, a second PCR and reverse line blot hybridization specific for B. burgdorferi sensu lato revealed the presence of Borrelia afzelii in 6.3% of C. glareolus voles and 14.3% of S. coronatus shrews. All small mammals were negative for spotted fever group rickettsiae. These results highlight the relevance of small mammals as reservoirs of some zoonotic bacteria.     

Iron and copper homeostasis and intestinal absorption using the Caco2 cell model

Whole body homeostasis can be viewed as the balance between absorption and excretion, which can be regulated independently. Present evidence suggests that for iron, intestinal absorption is the main site for homeostatic regulation, while for copper it is biliary excretion. There are connections between iron and copper in intestinal absorption and transport. The blue copper plasma protein, ceruloplasmin, and its intracellular homologue, hephaestin, play a role in cellular iron release. The studies reviewed here compare effects of Fe(II) and Cu(II) on their uptake and overall transport by monolayers of polarized Caco2 cells, which model intestinal mucosa. In the physiological range of concentrations, depletion of cellular iron or copper (by half) increased uptake of both metal ions. Depletion of iron or copper also enhanced overall transport of iron from the apical to the basal chamber. Copper depletion enhanced overall copper transport, but iron depletion did not. Pretreatment with excess copper also stimulated copper absorption. Plasma ceruloplasmin (added to the basal chamber) failed to enhance basolateral iron release, and Zn(II) failed to compete with Cu(II) for uptake. Neither copper nor iron deficiency altered expression of IREG1 or DMT1 (-IRE form) at the mRNA level. Thus, in the low-normal range of iron and copper availability, intestinal absorption of both metals appears to be positively related to the need for these elements by the whole organism. The two metal ions also influenced each other's transport; but with copper excess, other mechanisms come into play.     

Treatment of domestic wastewater and production of commercial flowers in vertical and horizontal subsurface-flow constructed wetlands

In developing countries, the use of non-conventional plant species as emergent plants in constructed wetlands may add economic benefits besides treating wastewater. In this work, the use of four commercial-valuable ornamental species (Zantedeschia aethiopica, Strelitzia reginae, Anturium andreanum and Agapanthus africanus) was investigated in two types of subsurface wetlands for domestic wastewater treatment. Several water quality parameters were evaluated at the inlet and outlets of a pilot-scale system. Physical measurements were used to evaluate and compare the development of the ornamental plants under two patterns of flow in subsurface wetlands.The results for pollutant removal were significantly higher in the vertical subsurface-flow constructed wetlands (VFCW) for most pollutants. The average removals were more than 80% for BOD and COD; 50.6% for Org-N; 72.2% for NH₄⁺, 50% for Total-P and 96.9% for TC. Only two pollutants were removed in statistically higher percentages in the horizontal subsurface-flow constructed wetlands (HFCW) (NO₃^?, 47.7% and TSS, 82%). The pollutant removal efficiencies were similar to the results obtained in many studies with conventional macrophytes. Most ornamental plants survived the 12-month period of experimentation and their development depended on the type of constructed wetland they were planted. Z. aethiopica looked healthier and produced around 60 flowers in the HFCW. The other three species developed better in the VFCW, although A. andreanum died during the winter. S. reginae produced healthier flowers (and more) and bigger leaves and A. Agapanthus produced more leaves and more lasting flowers. This suggests that it is possible to produce commercial flowers in constructed wetlands without reducing the efficiency of the treatment system.     

Functional analysis of the honeybee (Apis mellifera L.) salivary system using proteomics

In insects, specific proteins and physiologically active molecules whose functions are related to their lifestyles are secreted from the salivary system. To investigate proteins/molecules related to the sociality of the European honeybee (Apis mellifera L.), we performed a proteomic analysis of the honeybee salivary system. The honeybee salivary system comprises two secretory glands: the postcerebral gland (PcG) and the thoracic gland (TG), both of which are connected to a common duct that opens in the mouthpart. Although most (31 out of 35) of the major proteins identified from the PcG and TG were housekeeping proteins, the spot intensities for aldolase and acetyl-CoA acyltransferase 2 were stronger in the PcG than in the TG in the 2-dimensional gel electrophoresis. Immunoblotting confirmed that the expression of these proteins was stronger in the PcG than in the TG, whereas expression was almost not detectable in the hypopharyngeal gland (HpG), suggesting that carbohydrate metabolism is enhanced in the honeybee PcG. In addition, imaginal disc growth factor 4 (IDGF4) was synthesized in the honeybee salivary system. Immunoblotting indicated IDGF4 expression was very strong in the PcG, moderate in the TG, and very weak in the HpG. A considerable amount of IDGF4 was detected in the royal jelly, while less was detected in honey, strongly suggesting that the honeybee salivary system secretes IDGF4 into the royal jelly and honey. The secreted IDGF4 might therefore affect growth and physiology of the other colony members.     

Effect of pre-composting on vermicomposting of kitchen waste

The aim of this work was to test combination of the thermocomposting and vermicomposting to improve the treatment efficiency and assess the optimum period required in each method to produce good quality compost. The results showed that pre-thermocomposting improved vermicomposting of kitchen waste. A 9-day thermocomposting prior to vermicomposting helped in mass reduction, moisture management and pathogen reduction.     

Identification of honeybee antennal proteins/genes expressed in a sex- and/or caste selective manner

We identified three candidate proteins/genes involved in caste and/or sex-specific olfactory processing in the honeybee Apis mellifera L., that are differentially expressed between the antennae of the worker, queen, and drone honeybees using SDS-polyacrylamide gel electrophoresis or the differential display method. A protein was identified, termed D-AP1, that was expressed preferentially in drone antennae when compared to those of workers. cDNA cloning revealed that D-AP1 is homologous to carboxylesterases. Enzymatic carboxylesterase activity in the drone antennae was higher than in the workers, suggesting its dominant function in the drone antennae. In contrast, two proteins encoded by genes termed W-AP1 and Amwat were expressed preferentially in worker antennae when compared to those of queens. W-AP1 is homologous to insect chemosensory protein, and Amwat encodes a novel secretory protein. W-AP1 is expressed selectively in worker antennae, while Amwat is expressed both in the antennae and legs of the workers. These findings suggest that these proteins are involved in the antennal function characteristic to drone or worker honeybees.