Vol 43, No 3 (2016)

A comparative study of regeneration and asexual reproduction across annelids is presented. The importance and universality of early stages of the restoration morphogeneses, which, however, vary in details, is shown. Here, we concern on the conserved elements of genetic regulatory programs involved in both processes, responsible for cell fate plasticity and rapid changes of following re-establishment of positional identity along the anterior-posterior axis.

The structure of the yolk syncytial layer (YSL) of the larvae of two cyprinids, Danio rerio and Cyprinus carpio koi, has been studied by transmission electron microscopy and by the histological methods. The structure of the YSL of these taxonomically related species of Teleostei is characterized by both similarity and dissimilarity in particular features, related to the overall shape of YSL, functional regionalization, and programmed death. Original and published data on the morphofunctional structure of the YSL have been discussed for representatives of Teleostei, Myxini, Chondrichthyes, Lepisosteiformes and Cephalopoda.

It was found that pseudocyclical similarities are common in modular organisms due to the peculiarities of their morphogenesis and ontogenesis and the system specifics of the modular organization. An analysis of the structural evolution in the different groups of modular living beings according to the concept of pseudocycles is topical, as it will contribute to the further development of evolutionary morphology and theoretical biology.

High level of intraspecific polymorphism of the mtDNA cytochrome b gene in the Atlantic cod Gadus morhua L. from the northeastern part of the species range (Barents and White seas) is detected. The absence of genetic differentiation between the samples from different areas of the Norwegian and Barents seas is shown, and the fact that these samples belong to the same population of Northeast Arctic cod is confirmed. Significant differences in the frequences of mitochondrial DNA haplotypes between the cod from the Barents and White seas, as well as from the northwestern part of the range, are found. The cod Gadus morhua kildinensis Derjugin, 1920 from Mogilnoye Lake and Gadus morhua marisalbi Derjugin, 1920 from the White Sea were revealed to have common haplotypes with the cod from the Barents Sea, confirming the recent origin of these forms from the Atlantic cod G. morhua.

The effect of copper and nickel ions at concentrations of 1, 10, 25, 50, and 100 mg/L on morphometric and pigment indicators of the seedlings of narrowleaf water-plantain Alisma gramineum and seashore dock Rumex maritimus was studied. It was found that the pigment characteristics were more sensitive to nickel and copper than the morphometric characteristics. It was noted that copper started to be toxic at relatively low concentrations and lead to a significant degradation of the pigment complex compared with nickel. An inverse correlation was found in seedlings between metal concentrations in the medium and chlorophyll a (Chl a). It was shown that the synthesis of chlorophyll a was inhibited by metal salts more strongly than by chlorophyll b and carotenoids, and seedlings of seashore dock were more resistant to the action of the factors studied than seedlings of the narrowleaf water-plantain.

Our own and previous data concerning the findings of parasitic gamasid mites (Mesostigmata: Gamasina) on bats (Chiroptera), which are not a principal host for them, are analyzed. The gamasid mites under study belong to the following families: Laelapidae Berlese, 1892; Hirstionyssidae Evans, Till, 1966; and Haemogamasidae Oudemans, 1926. In total, 27 species of parasites of the analyzed groups were found on bats. Among them, two species were described for bats for the first time. The medicinal value of this exchange is considered. Possible places where bats have contact with other mammals are discussed.

The seasonal variability of the lysozyme content has been detected in the liver, kidney, and spleen of bream. It is manifested in a higher lysozyme content in cold winter months and lower values in other seasons. It is shown that the enzyme activity is absent in blood serum of the studied fish regardless of its amount in immunocompetent organs. A high content of lysozyme in organs in the cold season of the year is not the result of the immunomodulatory effect of water temperature on this parameter but can be determined by physiological factors that do not depend on seasonal variations of the environmental temperature. It has been established that the blood serum in fish does not indicate the entire dynamics of the enzyme in the organism.

The first metagenomic analysis of the microbiome of the first sample of diseased endemic sponge Lubomirskia baicalensis (Pallas, 1771) from Lake Baikal and the comparison of the results with data published earlier on the microbiome of healthy sponges were carried out. Essential changes in the composition and structure of the microbial community were detected in the diseased individual possessing an uncharacteristic pink coloring. Cyanobacteria were predominant in the community, the fraction of the representatives of Verrucomicrobia was increased. The diversity and number of eukaryotic algae, as well as of representatives of Bacteroidetes, Proteobacteria, Actinobacteria, and Planctomycetes, were decreased. A wide range of minor phyla were eliminated. The factors affecting the composition of symbiotic communities in sponges were considered. It was supposed that changes in the structure of symbiotic communities resulting in mass disease and death could be caused by an increase in the methane concentration in the water column of Lake Baikal.

Nucleotide sequences of b/c intron of the mitochondrial gene nad1 were determined for the first time and analyzed in 24 plants of Monotropa hypopitys and in three related Ericaceae species. Two mitotypes of b/c intron of the nad1 gene, differing in sequence lengths and the presence of a number of single nucleotide substitutions and indels, were revealed in M. hypopitys. For the first time, a possible pre-mRNA secondary structure of M. hypopitys b/c intron was determined and IBS/EBS binding sites and the borders of six functional domains were identified.