Detection of haemocyte proteins in the integument of the developing Mediterranean fruit flyCeratitis capitata

Summary Studies of the synthesis of integumental proteins during the feeding and non-feeding stages ofCeratitis capitata demonstrated stage specificity. The synthetic profile changed dramatically, showing a maximum of protein synthesis just before the larval wandering stage, followed by an abrupt decline. The comparison between synthetic and accumulation profiles indicated that some polypeptides must be internalized into the integument from the haemolymph. The major haemolymph proteins or arylphorins have already been documented to be incorporated into the integument. In the present work, we demonstrated the interalization of some haemocyte proteins into the integument. For that purpose, polyclonal antibodies were raised against total haemocyte proteins. Immunoblot analysis of haemocyte salt extractable proteins revealed that the protein bands at 36, 54, 58, 84, 110 and 130 kDa were immunoreactive with the total haemocyte antibodies. Cell-free protein synthesis, organ culture experiments and immunoblot analysis indicated that the 36-, 54- and 58-kDa polypeptides were synthesized only in the haemocytes and were probably internalized into the integument from the serum. The 36-kDa polypeptide was also demonstrated to be internalized into the fat body of white puparia. The immunofluorescence experiments suggested that the internalization of haemocyte proteins first occurs into the epidermal cells and then into the cuticle. The presence of haemocyte proteins in the integument was also demonstrated by immunofluorescence experiments in twoC. capitata mutants. These mutations affect the darkening and stiffening of the cuticle. The demonstration of 36-, 54- and 58-kDa haemocyte polypeptides in the integument reveals a hitherto unknown function of this cell type. Moreover, the demonstration of tyrosine binding to the 54- and 58-kDa polypeptides points to their potential involvement in the sclerotization process in the cuticle.     

GEOGRAPHIC VARIATION IN THERMAL TRAITS IN DIGENEA SIMPLEX AND CHAMPIA PARVULA (RHODOPHYTA) IN RELATION TO PRESENT AND GLACIAL TEMPERATURE REGIMES

Geographic variation in temperature responses (survival and growth) was investigated in two red algae: Digenea simplex (Wulfen) C. Agardh and Champia parvula (C. Agardh) Harvey. D. simplex has a tropical to warm temperate distribution; C. parvula extends from the tropics into the cold temperate zone. Ecoclinal variation was found in both species but was much stronger in C. parvula than in D. simplex. The former species showed variation in upper and lower tolerance limits as well as in the upper and lower limits for growth. The latter species showed variation mainly in its lower tolerance limit. Ecoclinal variation was related to the amount of present and glacial selection pressure along the climate gradient. In both species, isolates from the colder localities had insufficient cold tolerance to have survived low glacial winter temperatures, so these locations must have been colonized after the end of the glaciation. Eastern Mediterranean and Atlantic populations were probably isolated during the glaciation by a thermal barrier at the entrance of the Mediterranean. In C. parvula, evidence existed for a trade-off between the performance at high and at low temperatures, which would enhance selection pressure in opposite directions at either end of the climatic range. No evidence for such a trade-off was found in D. simplex.     

Improved reliability of the urine lactate concentration under controlled hydration after maximal exercise

Context: Urine lactate may be a novel biomarker of lactate production capacity but its reliability has been unsatisfactory so far.

Objective: To compare the reliability of urine lactate between controlled hydration and no hydration after maximal exercise.

Material and methods: Athletes performed swimming exercise four times: two followed by consumption of 1?L of water and two followed by no water intake. Blood and urine lactate was measured.

Results: The reliability of urine lactate was good and similar to that in blood only after controlled hydration. Blood and urine lactate were correlated under both hydration conditions.

Discussion and conclusion: Controlled hydration after exercise provides satisfactory reliability of urine lactate.     

Silver(I) complexes with heterocyclic thiones and tertiary phosphines as ligands. Part 4. Dinuclear complexes of silver(I) bromide: the crystal structure of bis[bromo-(pyrimidine-2-thione)(triphenylphosphine)silver(I)]

Mixed-ligand complexes of the formula [Ag(PPh₃)(L)Br]₂ were obtained by treatment of various heterocyclic thiones L {L=pyridine-2-thione (py2SH), pyrimidine-2-thione (pymtH), benz-1,3-imidazoline-2-thione (bzimtH₂), benz-1,3-thiazoline-2-thione (bztztH), 1-methyl-1,3-imidazoline-2-thione (meimtH) and 5-methoxy-benz-1,3-imidazoline-2-thione (5MeObzimtH₂)} with equivalent quantities of silver(I) bromide and triphenylphosphine in dry acetone. The compounds were characterized by their IR, far-IR, UV–Vis and ¹H NMR spectroscopic data. The crystal structure of [Ag(PPh₃)(pymtH)Br]₂ was determined by single-crystal X-ray diffraction methods. The complex exhibits a planar Ag₂Br₂ moiety in which each of the doubly bromine-bridged Ag(I) centres is further bonded to one phosphine P and one thione S atom.     

Illegal trawling and induced invasive algal spread as collaborative factors in a Posidonia oceanica meadow degradation

Posidonia oceanica, a key seagrass species of the Mediterranean Sea, shows clear signs of regression throughout the Mediterranean and illegal trawling is recognized as one of the main causes. We examined the condition of a P. oceanica meadow in Alykes Bay (Zakynthos Island, western Greece), a typical Mediterranean littoral area where illegal trawling is common practice, in respect to the total area affected, and in terms of possible ecological substitution. A side scan sonar (SSS) survey of the seafloor provided an image of the condition of the meadow and biological sampling evaluated the ecological status in affected meadow areas. SSS images revealed that trawling has a serious effect on the meadow, with 11% of the vegetated area being abraded, and the affected areas were also found to be fully colonized by the invasive alga Caulerpa racemosa. Moreover, unusually high densities of the polychaete Sabella pavonina were detected in the affected areas among C. racemosa fronds. Recolonization by P. oceanica of the affected meadow areas that have been colonized by C. racemosa seems improbable considering the allelopathic interactions between the species, with the alga displaying phytotoxic properties through caulerpenyne production and deterioration of the sediment quality.     

Ecophysiological adaptations of two Mediterranean red algae in relation to distribution

Effects of irradiance and temperature on the Mediterranean red algae Eupogodon spinellus and Eupogodon planus were tested. Growth of both species was saturated at an irradiance of 10–20?μmol?m^?2?s^?1, which is in accordance with their sublittoral habitat. Eupogodon spinellus and E. planus survived permanently at temperatures between 8 and 30?°C. The temperature optimum for growth was 25?°C with suboptimal growth occurring at (10?)15 and 30?°C in both species. At their collection locality (Corsica), potential monthly growth yields would be highest in summer and in winter would be only about 20% of the maximum. Reproductive requirements could be determined only in E. planus. Gametophytes reproduced both in long and in short days but only at 20?°C. Tetrasporophytes reproduced at 15–20?°C but only in short days. Geographic distribution boundaries are not set by growth or survival limits. However, the reproductive requirements of E. planus did account for its restricted distribution in the Mediterranean and on the Canary Islands.     

BsdABsd2‐dependent vacuolar turnover of a misfolded version of the UapA transporter along the secretory pathway: prominent role of selective autophagy

Transmembrane proteins translocate cotranslationally in the endoplasmic reticulum (ER) membrane and traffic as vesicular cargoes, via the Golgi, in their final membrane destination. Misfolding in the ER leads to protein degradation basically through the ERAD/proteasome system. Here, we use a mutant version of the purine transporter UapA (ΔR481) to show that specific misfolded versions of plasma membrane cargoes undergo vacuolar turnover prior to localization in the plasma membrane. We show that non‐endocytic vacuolar turnover of ΔR481 is dependent on BsdA^Bsd2, an ER transmembrane adaptor of HulA^Rsp5 ubiquitin ligase. We obtain in vivo evidence that BsdA^Bsd2 interacts with HulA^Rsp5 and ΔR481, primarily in the ER. Importantly, accumulation of ΔR481 in the ER triggers delivery of the selective autophagy marker Atg8 in vacuoles along with ΔR481. Genetic block of autophagy (atg9Δ, rabO^ts) reduces, but does not abolish, sorting of ΔR481 in the vacuoles, suggesting that a fraction of the misfolded transporter might be redirected for vacuolar degradation via the Golgi. Our results support that multiple routes along the secretory pathway operate for the detoxification of Aspergillus nidulans cells from misfolded membrane proteins and that BsdA is a key factor for marking specific misfolded cargoes.     

Design and synthesis of mono- and multimeric targeted radiopharmaceuticals based on novel cyclen ligands coupled to anti-MUC1 aptamers for the diagnostic imaging and targeted radiotherapy of cancer

Targeted radiopharmaceuticals offer the possibility of improved tumor imaging and radiotherapy, with reduced side effects. A variety of monoclonal antibodies and antibody fragments have previously been successfully radiolabeled and used in diagnostic imaging and targeted radiotherapy of cancer. Many such antibodies have been shown to recognize the well-characterized MUC1 tumor marker and have recently been in clinical trials. Furthermore, a number of chelators have been synthesized and are currently used as radiopharmaceuticals for imaging and therapy. We now report the synthesis of a novel, cyclen-based ligand with a sulfur-containing arm that offers increased stability of the ligand-metal complex. We have coupled this ligand with previously selected aptamers to the MUC1 tumor marker to generate a novel targeted radiopharmaceutical with improved properties. We have tested the complex against known, commercially available chelators such as MAG3 in model breast cancer systems. To improve the pharmacokinetic properties of the aptamer-based targeted radiopharmaceutical, we have generated multi-aptamer complexes around a central chelator. Such multi-aptamer complexes have increased retention of the complex in circulation, without affecting the lack of immunogenicity of the complex or altering its superior tumor penetration properties.     

Encoding time in neural dynamic regimes with distinct computational tradeoffs

Converging evidence suggests the brain encodes time in dynamic patterns of neural activity, including neural sequences, ramping activity, and complex dynamics. Most temporal tasks, however, require more than just encoding time, and can have distinct computational requirements including the need to exhibit temporal scaling, generalize to novel contexts, or robustness to noise. It is not known how neural circuits can encode time and satisfy distinct computational requirements, nor is it known whether similar patterns of neural activity at the population level can exhibit dramatically different computational or generalization properties. To begin to answer these questions, we trained RNNs on two timing tasks based on behavioral studies. The tasks had different input structures but required producing identically timed output patterns. Using a novel framework we quantified whether RNNs encoded two intervals using either of three different timing strategies: scaling, absolute, or stimulus-specific dynamics. We found that similar neural dynamic patterns at the level of single intervals, could exhibit fundamentally different properties, including, generalization, the connectivity structure of the trained networks, and the contribution of excitatory and inhibitory neurons. Critically, depending on the task structure RNNs were better suited for generalization or robustness to noise. Further analysis revealed different connection patterns underlying the different regimes. Our results predict that apparently similar neural dynamic patterns at the population level (e.g., neural sequences) can exhibit fundamentally different computational properties in regards to their ability to generalize to novel stimuli and their robustness to noise—and that these differences are associated with differences in network connectivity and distinct contributions of excitatory and inhibitory neurons. We also predict that the task structure used in different experimental studies accounts for some of the experimentally observed variability in how networks encode time.