Doklady Biological Sciences最新文献

Mast cell (MC)-nerve units are one of the main elements of cooperation between the nervous and immune systems, providing a structural and functional connection between MCs and autonomic nerve fibers. Although immunoregulatory activity of acetylcholine (ACh) is well established, the exact point of its influence on MCs remains unclear. This study compared the effects of muscarinic (mAChR) versus nicotinic (nAChR) ACh receptor binding on secretory activity of HMC-1 cells. It was found that ACh activates intact MCs mainly through the M3 mAChR, but suppresses degranulation in stimulated MCs via the α7 nAChR. The findings indicate that changes in the receptor pattern within MC-nerve units underlie the dual effects of ACh and enable MCs to switch functions in inflammation from proinflammatory activity in the acute phase to anti-inflammatory activity during reparation.

The aim of this work was to summarize the data on the ecological, biological, and morphological features of Calcipostia guttulata (Polyporales, Basidiomycota) by using the original materials, revised herba-rium specimens, data on molecular barcoding of original collections, the available literature, and iconography and information stored on the GBIF portal. It was shown that C. guttulata is a widespread, but rare polypore in the Holarctic; is confined to the early stages of drying of coniferous stands, primarily spruce forests; and is a poorly studied headwood pathogen and a saprotroph that colonizes coniferous deadwood and, less often, fallen trees. The morphological diagnosis of C. guttulata was clarified. Its substrate spectrum, distribution, and relationships with insects, which are important for forest pathology, have been identified most fully to date. The conservation status of the species and the prospects for its use in biotechnology are discussed.

The formation and lifelong maintenance of memory remain one of the central unsolved problems of neuroscience. Although many experimental models have been developed to study memory, there is currently no paradigm that would enable to reliably investigate the memory mechanisms over timescales comparable to the lifespan. In this study, mice were tested for the ability to form highly stable long-term memory in a contextual fear conditioning paradigm, an adapted model of posttraumatic stress disorder (PTSD) with varying intensities of aversive stimulation. A one-trial learning model was developed by varying the intensity of aversive stimulation. The mice reliably formed long-term associative memories that persisted for at least six months. The model thus provides a promising tool for investigating the molecular and neuronal network mechanisms of lifelong memory retention.

Morphophysiological parameters of oocytes were studied in the Azov turbot (kalkan) Scophthalmus maeoticus torosus during maturation and spawning in the Sea of Azov. The fatty acid composition was additionally determined in three (cranial, middle, and caudal) regions of the gonad in each individual fish. The dynamics of the morphophysiological characteristics and the fatty acid composition of eggs was observed over the spawning period. Two physiologically significant fatty acids, oleic and docosahexaenoic, were found to dominate in eggs. Opposite trends were detected in their contents, i.e., the docosahexaenoic acid content at the beginning of spawning was higher than in the peak spawning period, when oleic acid prevailed.

Morphological features of the humerus and forearm were described for a Middle Pleistocene (Chibanian) camel, previously unknown from Western Transbaikalia. While all previous finds in Central Asia included mostly hand and foot bones, fossils from the Selenga Middle Mountains (Ust-Kiran locality, Chikoy River valley) provide a rare opportunity to most fully outline the morphosculpture of the long tubular bones of the forelimb. Morphological features indicate that the bones belonged to the camel Camelus cf. knoblochi, and their sizes indicate that the camel was significantly larger than the Pliocene and modern forms. The camel inhabited various biotopes in the middle mountains with widespread foothill trains directed towards river valleys and intermountain depressions.

Didymellaceae is one of the largest families of the order Pleosporales and includes the main genera of Phoma-like fungi, namely, Ascochyta, Didymella, Stagonosporopsis, etc. Certain wild plants of the family Convolvulaceae plants are among the most harmful weeds and act as an exceptional source of biodiversity of Phoma-like fungi, including Didymellaceae species. Reliable and correct species identification in Phoma-like fungi is only possible in the context of the Consolidated Species Concept (CSC), by combining molecular phylogenetic, micromorphologcial, and cultural features. Leaves of Convolvulaceae weeds with signs of spot diseases were collected during a long-term phytosanitary monitoring of industrial crop fields and natural and ruderal areas. More than 200 isolates of Phoma-like fungi were isolated in pure cultures. Of these, 28 strains preliminarily identified as Didymellaceae species were selected. The objective of this work was to identify the strains according to the CSC. A multilocus phylogenetic analysis was based on the nucleotide sequences of internal transcribed spacer (ITS) and large-subunit (28S) rDNA, the tub2 β-tubulin gene, and the rpb2 gene for the second-largest subunit of RNA polymerase II. The strains were assigned to 18 Didymellaceae species, including Ascochyta erotica, Didymella americana, D. bellidis, D. glomerata, D. macrostoma, D. pomorum, D. pseudomacrophylla, D. segeticola, D. sinensis, D. tanaceti, Epicoccum convolvulicola, E. pseudoplurivorum, Nothophoma brennandiae, N. gossypiicola, Phomatodes nebulosa, Stagonosporopsis caricae, S. heliopsidis, and S. inoxydabilis. All of the species were for the first time detected on plants of the Convolvulaceae family. Seven species (D. bellidis, D. segeticola, D. sinensis. D. tanaceti, N. brennandiae, P. nebulosa, and S. caricae) were for the first time detected in Russia. Stagonosporopsis heliopsidis was for the first time found in Kazakhstan. In addition to detailed phylogenetic data, detailed descriptions of the cultural and micromorphological features of the species are provided in the article.

An integrative analysis of morphological, structural, and biochemical characteristics was performed for the first time in buckwheat seeds of several varieties grown in contrast conditions, namely, a monsoon climate of Primorsky Krai and a temperate continental climate of Central Russia. The intention was to develop important practical recommendations on the use of the new seed assessment method. Minor differences were observed in the color and weight of seeds and the weight and structure of seed coats. The total protein content in seeds was almost the same in all varieties, and differences in only minor components were detected in the protein composition. Total phenolic compound (TPC), phenylpropanoid (PhP), flavan (FL), and proanthocyanidin (PA) contents in seeds were similar between the varieties and were lower than in seed coats in most cases, with the exception the new-generation variety Desire. A significant accumulation of PAs (polyphenol oligomers with high antioxidant activity) was observed in buckwheat seed coats, suggesting their potential application in various industries.

Organs that can be considered as homologous to the spongy bodies of sea urchins and Tiedemann's bodies of sea stars were found in the holothuroid Chiridota laevis (O. Fabricius, 1780). The C. laevis spongy bodies occur in interradii and are formed by outgrowths of coelomic canals, which connect the water ring with the coelomic cavities of tentacles. Haemocoelic lacunae are adjacent to the coelomic outgrowths. The spongy bodies of sea urchins and Tiedemann's bodies of sea stars are also in the interradii and indicate the position of reduced tentacles. The spongy bodies were assumed to function as excretory organs (additional kidneys) in echinoderms. Because the water vascular system does not open outwards in most holothuroids, the holothuroid spongy bodies are much smaller than in other echinoderms and can be considered as rudimentary organs.

A search for new methods for activating and controlling the enzymatic activity of cellulose destructor organisms through joint cultivation is an important problem. Schizophyllum commune is a xylobiont basidiomycete from the group of white rot fungi, is known for its biotechnological versatility, but has still not found efficient application in bioconversion of agricultural wastes and, in particular, cereal straw. The strain Sc. commune EO22 was used to assess the possibility of creating artificial bacterial-fungal associations for the development of an efficient strategy to utilize straw as a by-product of crop production. Streptomyces bacteria possessing cellulolytic activity were co-cultured with S. commune EO22. The dynamics of cellulase activity was determined in Sc. commune EO22 monocultures and binary cultures with Streptomyces griseoaurantiacus Mb4-2, St. thermocarboxydus T1-3, St. hygroscopicus N27-25, and "St. ryensis" H13-3. The cultures were grown in a liquid mineral medium with straw as the only carbon source. Cellulase activity of the Sc. commune EO22 binary cultures with each of the bacterial strains reached its maximum 3-6 days earlier than in the fungal monoculture (a maximum was reached on day 7) under the same conditions. Co-culture with the strain Mb4-2 did not significantly increase the cellulase activity (122 ± 13.1 units/ml) as compared with the fungal monoculture (114.4 ± 37.1 units/ml). Maximum cellulase activities of the binary associations with the strains T1-3, N27-25, and H13-3 exceeded the maximum activity of the Sc. commune EO22 monoculture by factors of 2.3, 1.6, and 1.3, respectively. The degree of straw decomposition was inferred from the weight loss and found to increase by 10.3, 2.3, and 22.4%, respectively, as compared with the fungal monoculture. Decrease in straw weight did not correlate significantly with cellulase activity in the experiment. The results indicate that artificial bacterial-fungal associations provide a promising means for efficient destruction of straw and other cellulose-containing wastes from crop production.

Bone remains of the yellow-necked mouse (Apodemus flavicollis) were identified and described from Holocene deposits at the Starik rock shelter (River Serga, Olenyi Ruchyi Nature Park, Middle Urals). The specimens, collected during 2008 excavations, are housed in the museum collection of the Institute of Plant and Animal Ecology. The stratigraphic context dates to 200-300 years BP. Dental morphometrics match both modern and Holocene A. flavicollis populations from the Urals. The specimen is the first and only find documenting the occurrence of the species in the Middle Urals and provides important evidence for understanding the historical distribution of the species at the eastern margin of its modern range.