Yap1-Driven Intestinal Repair Is Controlled by Group 3 Innate Lymphoid Cells

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Cadmium induces nuclear translocation of β-catenin and increases expression of <Emphasis Type="Italic">c-myc</Emphasis> and <Emphasis Type="Italic">Abcb1a</Emphasis> in kidney proximal tubule cells

Cadmium (Cd²⁺) induces renal proximal tubular (PT) damage, including disruption of the E-cadherin/β-catenin complex of adherens junctions (AJs) and apoptosis. Yet, chronic Cd²⁺ exposure causes malignant transformation of renal cells. Previously, we have demonstrated that Cd²⁺-mediated up-regulation of the multidrug transporter Abcb1 causes apoptosis resistance in PT cells. We hypothesized that Cd²⁺ activates adaptive signaling mechanisms mediated by β-catenin to evade apoptosis and increase proliferation. Here we show that 50 μM Cd²⁺, which induces cell death via apoptosis and necrosis, also causes a decrease of the trans-epithelial resistance of confluent WKPT-0293 Cl.2 cells, a rat renal PT cell model, within 45 min of Cd²⁺ exposure, as measured by electric cell-substrate impedance sensing. Immunofluorescence microscopy demonstrates Cd²⁺-induced decrease of E-cadherin at AJs and redistribution of β-catenin from the E-cadherin/β-catenin complex of AJs to cytosol and nuclei after 3 h. Immunoblotting confirms Cd²⁺-induced decrease of E-cadherin expression and translocation of β-catenin to cytosol and nuclei of PT cells. RT-PCR shows Cd²⁺-induced increase of expression of c-myc and of the isoform Abcb1a at 3 h. The data prove for the first time that Cd²⁺ induces nuclear translocation of β-catenin in PT cells. We speculate that Cd²⁺ activates β-catenin/T-cell factor signaling to trans-activate proliferation and apoptosis resistance genes and promote carcinogenesis of PT cells.     

Comparative ultrastructure of coxal glands in unfed larvae of Leptotrombidium orientale (Schluger, 1948) (Trombiculidae) and Hydryphantes ruber (de Geer, 1778) (Hydryphantidae)

Coxal glands of unfed larvae Leptotrombidium orientale (Schluger, 1948) (Trombiculidae), a terrestrial mite parasitizing vertebrates, and Hydryphantes ruber (de Geer, 1778) (Hydryphantidae), a water mite parasitizing insects were studied using transmission electron microscopy. In both species, the coxal glands are represented by a paired tubular organ extending on the sides of the brain from the mouthparts to the frontal midgut wall and are formed of the cells arranged around the central lumen. As in other Parasitengona, the coxal glands are devoid of a proximal sacculus. The excretory duct, joining with ducts of the prosomal salivary glands constitutes the common podocephalic duct, opening into the subcheliceral space. The coxal glands of L. orientale are composed of a distal tubule with a basal labyrinth, an intermediate segment without labyrinth, and a proximal tubule bearing tight microvilli on the apical cell surface and coiled around the intermediate segment. The coxal glands of H. ruber mainly consist of the uniformly organized proximal tubule with apical microvilli of the cells lacking the basal labyrinth. This tubule shows several loops running backward and forward in a vertical plane on the side of the brain. In contrast to L. orientale , larvae of H. ruber reveal a terminal cuticular sac/bladder for accumulation of secreted fluids. Organization of the coxal glands depends on the ecological conditions of mites. Larvae of terrestrial L. orientale possess distal tubule functioning in re‐absorption of ions and water. Conversely, water mite larvae H. ruber need to evacuate of the water excess, so the filtrating proximal tubule is prominent.     

The Role of Hypocotyl and Roots in Photoperiodic Floral Induction of Chenopodium rubrum

Abstract: Hypocotyls and roots of Chenopodium rubrum were tested as possible receptors of photoperiodic signals inducing flowering. The hypocotyl was found to be responsive to such a signal. Its role as the locus of synthesis andjor the transport sys tem of a florigenic stimulus is discussed. The roots respond to light/dark conditions solely by changing their growth rate but they do not seem to be involved in induction of flowering.     

Cold-resistant changes in heartbeat of the Japanese spiny lobster

Heartbeat in Panulirus japonicus acclimated to 20°C is often augmented during cooling to 15^oC. Augmented contractions of the heart coincided with increasing amplitude of electrocardiogram. In cold saline, a pericardial hormone serotonin (10⁻⁷ M) increased both the amplitude and duration of the heartbeat while another hormone octopamine (10⁻⁶ M) slightly relieved the cold depression of heart rate despite a smaller increase in beat amplitude. In contrast, the application of the cold saline containing F1 (a FMRFamide-related peptide of pericardial hormones, 10⁻⁹ M) maintained the rate and amplitude of the heartbeat around the control level during cold exposure. This suggests that in the presence of F1, the lobster heart becomes cold resistant clearly. We previously reported that the pericardial organs of spiny lobsters are activated by a small fall in body temperature. The ligamental nerves, extensions of the pericardial organs, terminate in the heart beside the ostia and their ends remain in the isolated hearts. Therefore, the ligamental nerve ends might release their hormones into the ventricle with the fall in temperature even in the isolated hearts.     

Uptake and distribution of calcium in rose plantlets as affected by calcium and boron concentration in culture solution

Grafted rose plantlets were grown in a controlled growth room in order to study the effect of Ca and B concentration on Ca uptake, distribution and transport to the apex. There were three Ca levels and three B levels. Root development was affected by Ca and B levels available to the roots. ⁴⁵Ca taken up was readily translocated to the scion, but accumulated in the rootstock in low-Ca plants. Translocation of Ca was increased by increasing B concentration. The relative Ca sink strength of low- and high-transpiring organs was affected by Ca and B concentrations. Increasing Ca level will increase rose growth only if B concentration is adjusted accordingly.     

Biosynthesis of α-linolenic acid by desaturation of oleic and linoleic acids in several organs of higher and lower plants and in algae

The biosynthesis of α-linolenic acid by successive desaturations of oleic and linoleic acids has been shown to occur in the leaves, roots and seeds of many higher plants. The age and the physiological state of the plant organs are extremely important. This route occurs also in several lower plants including algae. It is concluded that the desaturation pathway is the major route for the biosynthesis of α-linolenic acid in plants.     

The Immune Response of the Tasmanian Devil (Sarcophilus harrisii) and Devil Facial Tumour Disease

One of the most remarkable aspects of Devil Facial Tumour Disease (DFTD) is its infectious nature, and for successful transmission it must avoid detection by the devil’s immune system. For this to occur, the devil either is severely immunosuppressed or factors produced by the tumor contribute to its avoidance of immune detection. An analysis of the devil’s immune system revealed the presence of normal-looking lymphoid organs and lymphoid cells. At a functional level the lymphocytes proliferated in response to mitogen stimulation. Subcutaneous injection of a cellular antigen produced a strong antibody response, providing compelling evidence that the devil has a competent immune system. Tumor cell analysis demonstrated that the tumor expresses the genes of the major histocompatibility complex; however, there was a limited diversity. Therefore, the most likely explanation for devil-to-devil transmission of DFTD is that the tumor is not recognized by the devil as “non-self” because of the limited genetic diversity. With its consistent morphology and relatively stable genome, this tumor would provide a reasonable target for a vaccine approach, provided the immune system can be coaxed into recognizing the tumor as “non-self.”     

The evolution of asymmetric genitalia in spiders and insects

Asymmetries are a pervading phenomenon in otherwise bilaterally symmetric organisms and recent studies have highlighted their potential impact on our understanding of fundamental evolutionary processes like the evolution of development and the selection for morphological novelties caused by behavioural changes. One character system that is particularly promising in this respect is animal genitalia because (1) asymmetries in genitalia have evolved many times convergently, and (2) the taxonomic literature provides a tremendous amount of comparative data on these organs. This review is an attempt to focus attention on this promising but neglected topic by summarizing what we know about insect genital asymmetries, and by contrasting this with the situation in spiders, a group in which genital asymmetries are rare. In spiders, only four independent origins of genital asymmetry are known, two in Theridiidae (Tidarren/Echinotheridion, Asygyna) and two in Pholcidae (Metagonia, Kaliana). In insects, on the other hand, genital asymmetry is a widespread and common phenomenon. In some insect orders or superorders, genital asymmetry is in the groundplan (e.g. Dictyoptera, Embiidina, Phasmatodea), in others it has evolved multiple times convergently (e.g. Coleoptera, Diptera, Heteroptera, Lepidoptera). Surprisingly, the huge but widely scattered information has not been reviewed for over 70 years. We combine data from studies on taxonomy, mating behaviour, genital mechanics, and phylogeny, to explain why genital asymmetry is so common in insects but so rare in spiders. We identify further fundamental differences between spider and insect genital asymmetries: (1) in most spiders, the direction of asymmetry is random, in most insects it is fixed; (2) in most spiders, asymmetry evolved first (or only) in the female while in insects genital asymmetry is overwhelmingly limited to the male. We thus propose that sexual selection has played a crucial role in the evolution of insect genital asymmetry, via a route that is accessible to insects but not to spiders. The centerpiece in this insect route to asymmetry is changes in mating position. Available evidence strongly suggests that the plesiomorphic neopteran mating position is a female-above position. Changes to male-dominated positions have occurred frequently, and some of the resulting positions require abdominal twisting, flexing, and asymmetric contact between male and female genitalia. Insects with their median unpaired sperm transfer organ may adopt a one-sided asymmetric position and still transfer the whole amount of sperm. Spiders with their paired sperm transfer organs can only mate in symmetrical or alternating two-sided positions without foregoing transfer of half of their sperm. We propose several hypotheses regarding the evolution of genital asymmetry. One explains morphological asymmetry as a mechanical compensation for evolutionary and behavioural changes of mating position. The morphological asymmetry per se is not advantageous, but rather the newly adopted mating position is. The second hypothesis predicts a split of functions between right and left sides. In contrast to the previous hypothesis, morphological asymmetry per se is advantageous. A third hypothesis evokes internal space constraints that favour asymmetric placement and morphology of internal organs and may secondarily affect the genitalia. Further hypotheses appear supported by a few exceptional cases only.