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1.
A. V. Sidorov 《Journal of Evolutionary Biochemistry and Physiology》2009,45(3):365-371
Neuronal correlates of temperature dependence of alimentary behavior were studied in experiments on molluscs. It was found that a decrease of temperature led to suppression of food-procuring activity of the animals: to a decrease of the consumed food amount and of the number of food holes on the substrate. These behavioral changes are associated with a fall of impulsation frequency of the motoneuron alimentary network and with decrease of efficiency of synaptic transmission within the limits of central generator of the Lymnaea stagnalis alimentary rhythm. It is suggested that change of character of intercellular interactions within the CNS limits underlies the temperature dependence of the mollusc food-procuring activity. 相似文献
2.
Sidorov AV 《Zhurnal evoliutsionno? biokhimii i fiziologii》2012,48(3):238-244
Pulmonary respiration of molluscs (spontaneous and mediated by intracavital injection of monoamines) was studied at different environmental temperatures (5, 15, and 25 degrees C). It was established that monoamines (dopamine, serotonin, adrenalin) did not enlarge the temperature diapason, in which the respiratory behavior was realized. Microelectrode studies of spontaneous electrical activity of neurons from the respiratory network of Lymnaea stagnalis (RPeD1, VD4, cells of the Vi cluster) have shown that the respiratory program, both spontaneous and the monoamine-induced, is terminated in hypothermia. The indicated effects are suggested to be due to temperature dependence of the chemical, predominantly peptidergical, transmission of signal between neurons of the central pattern generator of respiratory pattern in Lymnaea. 相似文献
3.
We isolated the full-length cDNAs of engrailed and dpp-BMP2/4 orthologues from the pond snail Lymnaea stagnalis and examined their expression patterns during development by the whole mount in situ hybridization. At the gastrula and trochophore
stages, engrailed is expressed in the peripheral ectoderm of the presumptive and invaginating shell gland, corroborating its role in the shell
formation that is widely conserved among molluscs. At the same stages, dpp-BMP2/4 is expressed in the right-hand side ectoderm of the shell gland and in the invaginating stomodaeum. Unlike in the gastropod
Patella vulgata, our results suggested that dpp-BMP2/4 has a role in the shell formation, rather than in the regional specification and that it could be involved in the specification
pathway of the left–right asymmetry of the developing shell in L. stagnalis. 相似文献
4.
V. V. Zhukov 《Journal of Evolutionary Biochemistry and Physiology》2007,43(5):524-532
Retrograde staining of retina of Lymnaea stagnalis with neurobiotin demonstrated that most photoreceptor cells send axons to the optic nerve directly, without intermediate contacts. Some of the photoreceptors are glutamate-immunoreactive suggesting that glutamate can provide the synaptic transmission of visual signal to the central neurons. Other photoreceptors stained via optic nerve seem to have other transmitter systems. Some of the retinal cells, but not the optic nerve fibers are pigment-dispersing hormone-immunoreactive. There are many serotonin-containing fibers in the tissue surrounding the optic cup with some of them penetrating the basal lamina of retina. Some of them belong to central neurons providing efferent innervation of the pond snail eye. Serotonergic innervation as well as pigment-dispersing hormone-containing cells are supposed to be involved in mechanism of the photosensitivity regulation of the molluscan eye. 相似文献
5.
M. V. Karanova E. N. Gakhova 《Journal of Evolutionary Biochemistry and Physiology》2007,43(3):310-317
Effect of an autumn-winter decrease of the environmental temperature on changes of the content of free amino acids and reducing sugars was studied in tissues fluids of the freshwater mollusc L. stagnalis. At a decrease of the temperature to 4 and 0°C at the autumn period, concentration of free alanine rose several times; an increase of histidine, glutamate, glycine, and serine concentrations was less pronounced. Accumulation of methionine, leucine, isoleucine, tyrosine, and phenylalanine was revealed at 0°C. In the state of long hypobiosis (at 4°C), pools of all amino acids fell 4–8 times; essential amino acids, except for lysine, were not detected at all. Both at the summer and at the autumn periods, high concentrations of free fructose and glucose were revealed. In the process of hypobiosis the fructose pool decreased almost 35, while the glucose pool—12 times. Maltose that was absent in summer was found at 4 and 0°C as well as after 2.5 months of hypobiosis. The changes of the studied parameters in L. stagnalis in response to hypothermia are compared with the corresponding parameters of changes in cryoresistant animals in response to negative temperatures. 相似文献
6.
A. V. Sidorov 《Journal of Evolutionary Biochemistry and Physiology》2017,53(6):493-500
Hydrogen peroxide at a concentration of 100 μM was found to exert a pronounced modulatory effect on motor (R/L cells in B1–B4 clusters) and modulatory (R/L cerebral giant cells) neurons in the feeding neural network of the mollusc Lymnaea stagnalis as manifested in changes in the firing rate, membrane potential level and spike amplitude in these cells. The observed effects were reversible, transient, and reached their peak values in 1 min since application of the preparation. Injection of hydrogen peroxide into the cavity of the cephalopedal sinus resulted in no statistically significant changes in the parameters of mollusc feeding behavior. Hydrogen peroxide is assumed to act as a rapid neuromodulator towards neurons of the central feeding rhythm generator in Lymnaea stagnalis. 相似文献
7.
8.
Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes. 相似文献
9.
E. E. Voronezhskaya M. Yu. Khabarova A. K. Chaban L. P. Nezlin 《Russian Journal of Developmental Biology》2007,38(2):66-75
We have earlier found that freshwater pond snails Helisoma trivolvis and Lymnaea stagnalis, when reared under conditions of starvation, release chemical signals that reversibly suppress larval development of conspecific embryos. Here, we report that (i) these signals are not strictly conspecific and affect also the embryos of a closely related species, which occupies a similar environmental niche; (ii) besides the development of embryos, the signals also affect the release of main motor programs, such as locomotion, feeding, and cardiac activity; (iii) action of the signals is bidirectional: they retard the development and release of motor programs at the early larval stages (trochophore to veliger) and accelerate them at later stages (late veliger to hatching). A possible adaptive significance of the described phenomena is discussed. 相似文献
10.
Noel H. Holmgren 《Brittonia》2018,70(1):115-139
A revision of Penstemon sect. Saccanthera subsect. Serrulati includes a new species (P. salmonensis), a new variety (P. triphyllus var. infernalis), and the elevation of a subspecies to species (P. curtiflorus), bringing the total number of species to eight, which are keyed and described, complete with nomenclature and type citations. 相似文献
11.
A genetic transformation system has been developed for callus cells of Crataegus
aronia using Agrobacterium
tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with
5 mg l−1 Indole-3-butyric acid (IBA) and 0.5 mg l−1 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different
types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red
colored callus was obtained on MS medium supplemented with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l−1 kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli
were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l−1 hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this
is the first time to report an Agrobacterium-mediated transformation system in Crataegus
aronia. 相似文献
12.
Studying Pneumocystis has proven to be a challenge from the perspective of propagating a significant amount of the pathogen in a facile manner.
The study of several fungal pathogens has been aided by the use of invertebrate model hosts. Our efforts to infect the invertebrate
larvae Galleria
mellonella with Pneumocystis proved futile since P. murina neither caused disease nor was able to proliferate within G. mellonella. It did, however, show that the pathogen could be rapidly cleared from the host. 相似文献
13.
The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae. 相似文献
14.
E. V. Gorbacheva V. S. Ershova M. E. Astashev C. A. Vulfius 《Biochemistry (Moscow) Supplemental Series A: Membrane and Cell Biology》2018,12(3):261-267
Giant neurons of the mollusc Lymnaea stagnalis contain heterogeneous population of nicotinic acetylcholine receptors (nAChRs) according to their relative sensitivity to antagonists. All these receptors are involved in the total response to acetylcholine (ACh). To evaluate activity of different pharmacological agents correctly it is necessary to know ionic selectivity of nAChRs which participate in transmembrane ionic current. In this work we studied the influence of ionic composition of the external and intracellular solutions on the current amplitude and current–voltage relation under the action of ACh or other nAChR agonists on the identified neurons of the left and right parietal ganglia of Lymnaea. After non-permeable cation N-methyl-D-glucamine was completely substituted for external Na+ ions there were no changes in the current characteristics. After a 10-fold decrease in Cl–concentration in the external solution there was a considerable shift of the current–voltage curve to the right, outward currents at the holding potential (Vh) up to 30 mV were not observed. On the contrary, a 10-fold decrease of Cl– concentration in the intracellular solution led to a shift of the current–voltage curve to hyperpolarizing direction, the reversal potential shift was in the average –42 mV. When ACh and nicotinic agonists with higher selectivity towards vertebrate α7 neuronal nAChR type and one of the two subtypes of Lymnaea nAChRs were compared, no differences in changes of ionic current characteristics were found. Neurons with distinct relative fraction of one or another nAChR subtype reacted to Cl– concentration change in the same way. Our results support earlier data on Cl– mechanism of Lymnaea neuron responses to ACh and evidence identical ionic selectivity of the two nAChR subtypes in identified neurons tested. 相似文献
15.
16.
New combinations are proposed in anticipation of the Polygonaceae treatment in the forthcoming volume of Intermountain Flora:
Polygonum kelloggii var. esotericum, P. kelloggii var. watsonii
,
Rumex densiflorus var. pycnanthus
,
R. salicifolius var. utahensis, and R. occidentalis var. tomentellus. Typifications are proposed to facilitate ongoing studies in Polygonaceae and to maintain current usage. 相似文献
17.
Notocactus scopa cv. Soonjung was subjected to in planta Agrobacterium tumefaciens-mediated transformation with vacuum infiltration, pin-pricking, and a combination of the two methods. The pin-pricking combined with vacuum infiltration (20-30 cmHg for 15 min) resulted in a transformation efficiency of 67-100%, and the expression of the uidA and nptII genes was detected in transformed cactus. The established in planta transformation technique generated a transgenic cactus with higher transformation efficiency, shortened selection process, and stable gene expression via asexual reproduction. All of the results showed that the in planta transformation method utilized in the current study provided an efficient and time-saving procedure for the delivery of genes into the cactus genome, and that this technique can be applied to other asexually reproducing succulent plant species. 相似文献
18.
Stefanie Kimbacher Ingrid Gerstl Branko Velimirov Sylvia Hagemann 《Molecular genetics and genomics : MGG》2009,282(2):165-172
P transposons belong to the eukaryotic DNA transposons, which are transposed by a cut and paste mechanism using a P-element-coded transposase. They have been detected in Drosophila, and reside as single copies and stable homologous sequences in many vertebrate species. We present the P elements Pcin1, Pcin2 and Pcin3 from Ciona intestinalis, a species of the most primitive chordates, and compare them with those from Ciona savignyi. They showed typical DNA transposon structures, namely terminal inverted repeats and target site duplications. The coding
region of Pcin1 consisted of 13 small exons that could be translated into a P-transposon-homologous protein. C. intestinalis and C. savignyi displayed nearly the same phenotype. However, their P elements were highly divergent and the assumed P transposase from C. intestinalis was more closely related to the transposase from Drosophila melanogaster than to the transposase of C. savignyi. The present study showed that P elements with typical features of transposable DNA elements may be found already at the base of the chordate lineage.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
19.
Tropilaelaps
mercedesae is a serious ectoparasite of Apis
mellifera in China. The aim of this study was to investigate the infestation rates and intensity of T. mercedesae in A. mellifera in China, and to explore the relative importance of climate, district, management practices and beekeeper characteristics
that are assumed to be associated with the intensity of T. mercedesae. Of the 410 participating apiaries, 379 apiaries were included in analyses of seasonal infestation rates and 352 apiaries
were included in multivariable regression analysis. The highest infestation rate (86.3%) of T. mercedesae was encountered in autumn, followed by summer (66.5%), spring (17.2%) and winter (14.8%). In autumn, 28.9% (93) of the infested
apiaries were in the north (including the northeast and northwest of China), 71.1% (229) were in the central and south (including
east, southeast and southwest China), and 306 apiaries (82.9%) were co-infested by both T. mercedesae and Varroa. Multivariable regression analysis showed that geographical location, season, royal jelly collection and Varroa infestation were the factors that influence the intensity of T. mercedesae. The influence of beekeeper’s education, time of beekeeping, operation size, and hive migration on the intensity of T. mercedesa was not statistically significant. This study provided information about the establishment of the linkage of the environment
and the parasite and could lead to better timing and methods of control. 相似文献
20.
E. I. Samarova V. V. Zhukov K. A. Sudoplatov 《Journal of Evolutionary Biochemistry and Physiology》2005,41(2):169-175
The study was performed on effects of serotonin and its antagonists (mianserin, propranolol, and metergoline) on efferent electrical activity in nerves cervicalis superior, cervicalis inferior, and columellaris innervating muscles withdrawing body of Lymnaea stagnalis into the shell. Serotonin had a dual effect on the off-reactions caused by rhythmical light stimulation of mollusc skin. The number of responses to series of stimuli increased at serotonin concentrations of about 10−8-10−7 M and decreased at its higher concentrations. In many cases, serotonin antagonists also had a dual effect depending on their concentration. All studied substances slightly affected duration and latent period of individual off-responses. Serotoninergic regulation is suggested to participate in central chains of the pond snail defensive shadow reflex.__________Translated from Zhurnal Evolyutsionnoi Biokhimii i Fiziologii, Vol. 41, No. 2, 2005, pp. 134–138.Original Russian Text Copyright © 2005 by Samarova, Zhukov, Sudoplatov. 相似文献