First data on plasmodial slime moulds (Myxomycetes = Myxogastrea) of Rdeysky Nature Reserve (Novgorod Region, Russia)

The results of the first study of the species diversity of myxomycetes of the Rdeysky State Nature Reserve are presented. The 201 field specimens of sporophores belonging to 56 morphospecies from 27 genera, ten families, and six orders were collected from September 30 to October 5, 2020. Fifty-two species of these were new for the Novgorod Region. The most common species at the reserve were Arcyria affinis, Hemitrichia calyculata, Lycogala epidendrum, Metatrichia vesparia, Physarum album, Trichia decipiens, and T. varia. Additionally, detailed morphological descriptions of two rare species Amaurochaete trechispora and Trichia crateriformis are given.

CHEMICAL AND PHARMACOLOGICAL EVOLUTION OF SOME SYNTHESIZED CHALCONES AND HETROCYCLIC COMPOUNDS

Pharmaceutical chemistry is focused on quality aspects of medicines and aims to assure fitness for the purpose of medicinal products. With centuries medicinal chemistry had emerged as a magnanimous field of science getting a facelift from the available natural compounds for synthesis of newer and complex molecules possessing medicinal activity while the transit from the earth to a synthetically furnished laboratory. Medicinal chemistry or pharmaceutical chemistry is a discipline at the intersection of chemistry and pharmacology involved with designing, synthesizing and developing pharmaceutical drugs. Chalconesis a generic term given to compounds bearing the 1,3-diarylprop2-en-1-one, which can be functionlized in the propane chain by the presence of olefinic, keto and/or hydroxyl group. Chalcones belongs to the flavonoid family. Chemically chalcones consisted of open chain flavonoids in which the two aromaticrings are joined by a three carbon a,ß-unsaturated carbonyl system (Dhar, 1981). Microorganisms are a heterogeneous group of several distinct classes of living beings. They were classified under third kingdom, theProstita. Based on differences in cellular organization and biochemistry, the kingdom prostita has been divided into two groups, Prokaryotes and Eukaryotes. Bacteria and blue green algae are prokaryotes while fungi, other algae, slime moulds and protozoa are eukaryotes. Anti-fungal drugs are among the most frequently prescribed preparations because of their fungal activity. They are widely used for the treatment of the fungal diseases such as Candidiasis and Apergillosis. These agents prevent from fungal infection. Anti-oxidant drugs are among the most frequently prescribed preparations prevent Oxidation.

CHEMICAL AND PHARMACOLOGICAL EVOLUTION OF SOME SYNTHESIZED CHALCONES AND HETROCYCLIC COMPOUNDS

Pharmaceutical chemistry is focused on quality aspects of medicines and aims to assure fitness for the purpose of medicinal products. With centuries medicinal chemistry had emerged as a magnanimous field of science getting a facelift from the available natural compounds for synthesis of newer and complex molecules possessing medicinal activity while the transit from the earth to a synthetically furnished laboratory. Medicinal chemistry or pharmaceutical chemistry is a discipline at the intersection of chemistry and pharmacology involved with designing, synthesizing and developing pharmaceutical drugs. Chalconesis a generic term given to compounds bearing the 1,3-diarylprop2-en-1-one, which can be functionlized in the propane chain by the presence of olefinic, keto and/or hydroxyl group. Chalcones belongs to the flavonoid family. Chemically chalcones consisted of open chain flavonoids in which the two aromaticrings are joined by a three carbon a,ß-unsaturated carbonyl system (Dhar, 1981). Microorganisms are a heterogeneous group of several distinct classes of living beings. They were classified under third kingdom, theProstita. Based on differences in cellular organization and biochemistry, the kingdom prostita has been divided into two groups, Prokaryotes and Eukaryotes. Bacteria and blue green algae are prokaryotes while fungi, other algae, slime moulds and protozoa are eukaryotes. Anti-fungal drugs are among the most frequently prescribed preparations because of their fungal activity. They are widely used for the treatment of the fungal diseases such as Candidiasis and Apergillosis. These agents prevent from fungal infection. Anti-oxidant drugs are among the most frequently prescribed preparations prevent Oxidation.

Experience shapes future foraging decisions in a brainless organism

The ability to change one’s behaviour based on past experience has obvious fitness benefits. Drawing from past experience requires some kind of information storage and retrieval. The acellular slime mould Physarum polycephalum has previously been shown to use stored information about negative stimuli. Here, we repeatedly exposed the slime mould to three stimuli with differing levels of potential risk: light, salt and lavender. We asked if the slime mould would change its foraging behaviour depending on the level of risk. In our experiment, taking risk yielded better food. We consistently selected individuals that made the same foraging decision (accepting risk or avoiding risk) over multiple trials. Hence, the same individuals were tested over a period of time, but only individuals that continued to make the same decision were allowed to continue. Regardless of selection regime, slime moulds in the light became more likely to select the food in the light over time, while those exposed to salt became more salt averse. Lavender had no effect. Our results can cautiously be interpreted as examples of non-associative learning, adding to a growing body of work showing that the absence of a central nervous system is no impediment to possessing sophisticated information processing.

Adaptive behaviour and learning in slime moulds: the role of oscillations

The slime mould Physarum polycephalum , an aneural organism, uses information from previous experiences to adjust its behaviour, but the mechanisms by which this is accomplished remain unknown. This article examines the possible role of oscillations in learning and memory in slime moulds. Slime moulds share surprising similarities with the network of synaptic connections in animal brains. First, their topology derives from a network of interconnected, vein-like tubes in which signalling molecules are transported. Second, network motility, which generates slime mould behaviour, is driven by distinct oscillations that organize into spatio-temporal wave patterns. Likewise, neural activity in the brain is organized in a variety of oscillations characterized by different frequencies. Interestingly, the oscillating networks of slime moulds are not precursors of nervous systems but, rather, an alternative architecture. Here, we argue that comparable information-processing operations can be realized on different architectures sharing similar oscillatory properties. After describing learning abilities and oscillatory activities of P. polycephalum , we explore the relation between network oscillations and learning, and evaluate the organism's global architecture with respect to information-processing potential. We hypothesize that, as in the brain, modulation of spontaneous oscillations may sustain learning in slime mould. This article is part of the theme issue ‘Basal cognition: conceptual tools and the view from the single cell’.

Secretive Slime Moulds

Neither plants, nor animals, nor fungi, the myxomycetes are a surprisingly diverse and fascinating group of organisms. They spend the majority of their life out of sight as single-celled amoeboid individuals in leaf litter, soil or decaying wood, foraging for bacteria and other simple life forms. However, when conditions are right, two individual cells come together to give rise to a much larger, creeping structure called a plasmodium, which produces the even more complex and often beautiful fruiting bodies. Indeed, the fruiting bodies of myxomycetes are often miniature works of art! Their small size (usually only a few millimetres tall) and fleeting fruiting phase mean that these organisms, although ubiquitous and sometimes abundant, are overlooked by most people. However, recent research by a few dedicated individuals has shown that Australia has a very diverse myxomycete biota with more than 330 species, the largest number known for any region of the Southern Hemisphere. This comprehensive monograph provides keys, descriptions and information on the known distribution for all of these species in addition to containing introductory material relating to their biology and ecology. Many species are illustrated, showing the diversity of their fruiting bodies, and greatly facilitating their identification. This book will give naturalists a new insight into an often overlooked group of organisms in addition to providing an incentive to search for the many species which have undoubtedly thus far escaped notice.

The evolution of multicellular complexity: the role of relatedness and environmental constraints

A major challenge in evolutionary biology has been to explain the variation in multicellularity across the many independently evolved multicellular lineages, from slime moulds to vertebrates. Social evolution theory has highlighted the key role of relatedness in determining multicellular complexity and obligateness; however, there is a need to extend this to a broader perspective incorporating the role of the environment. In this paper, we formally test Bonner's 1998 hypothesis that the environment is crucial in determining the course of multicellular evolution, with aggregative multicellularity evolving more frequently on land and clonal multicellularity more frequently in water. Using a combination of scaling theory and phylogenetic comparative analyses, we describe multicellular organizational complexity across 139 species spanning 14 independent transitions to multicellularity and investigate the role of the environment in determining multicellular group formation and in imposing constraints on multicellular evolution. Our results, showing that the physical environment has impacted the way in which multicellular groups form, highlight that environmental conditions might have affected the major evolutionary transition to obligate multicellularity.

Stress signalling in acellular slime moulds and its detection by conspecifics

Unicellular organisms live in unpredictable environments. Therefore, they need to continuously assess environmental conditions and respond appropriately to survive and thrive. When subjected to rapid changes in their environment or to cellular damages, unicellular organisms such as bacteria exhibit strong physiological reactions called stress responses that can be sensed by conspecifics. The ability to detect and use stress-related cues released by conspecifics to acquire information about the environment constitutes an adaptive survival response by prompting the organism to avoid potential dangers. Here, we investigate stress signalling and its detection by conspecifics in a unicellular organism, Physarum polycephalum . Slime moulds were subjected to either biotic (i.e. nutritional) or abiotic (i.e. chemical and light) stressors or left undisturbed while they were exploring a homogeneous environment. Then, we observed the responses of slime moulds facing a choice between cues released by stressed clone mates and cues released by undisturbed ones. We found that slime moulds actively avoided environments previously explored by stressed clone mates. These results suggest that slime moulds, like bacteria or social amoeba, exhibit physiological responses to biotic and abiotic stresses that can be sensed by conspecifics. Our results establish slime moulds as a promising new model to investigate the use of social information in unicellular organisms. This article is part of the theme issue ‘Signal detection theory in recognition systems: from evolving models to experimental tests’.