Vol 9, No 4 (2019)

Abstract—The evidence for the possible impact of gene introgression on species evolution, the evolutionary fate of taxa, including reticulations in phylogenetic trees, and the consistency of the latest molecular genetic data with the main modern paradigm, Neo-Darwinism, have been considered in many studies. This study includes a comparative analysis and assessments of validity of the use of molecular markers for species identification, including an approach proposed by one of the authors for the description of biological diversity in the framework of the global DNA barcoding program. The identification of hybrids and the prevalence of genetic introgression are discussed. There are four main issues in the overview presented. (1) A combination of nDNA and mtDNA markers best suits for the hybrid identification and estimates of genetic introgression or gene flow. (2) The available facts for both nDNA and mtDNA diversity make introgression among many animal and plant taxa obvious, although, even for the wide hybrid zones of Mytilus ex. group edulis, for example, introgression may be quite restricted or asymmetric for a significant part of the area, thus holding at least the “source” taxon (taxa) intact. (3) If we accept that sexually reproducing species in marine and terrestrial areas are introgressed, as is evident for many cases, then we should recognize that the orthodox BSC, which postulates a complete lack of gene flow among species, is inadequate due to the fact that many zoological or taxonomic species have currently not yet reached the stage of biological species. However, they will eventually become definitive biological species in future. This conclusion is supported by the genetic distance, which increases with taxa rank, and by the lowest diversity at the intraspecies level as for single mtDNA genes, for complete mitogenomes, and for nDNA genes. (4) A recent study of fish-taxon divergence by means of the vast BOLD (www.boldsystem.org) database showed that the gene trees for taxa up to the family level are basically monophyletic, and interspecies reticulations are rare for most gene trees. The available data allow us to conclude that molecular evolution and, in particular, genetic divergence in the taxon hierarchy are generally in good agreement with BSC and Neo-Darwinism, forming the theoretical basis for the success of DNA barcoding in the animal world, as well as its applicability for other organisms.

Abstract—This paper reviews the use of molecular genetic methods (DNA barcoding and DNA fingerprinting) for the authentication of plant raw materials and herbal medicinal products. ITS2 is shown to be the most effective DNA barcode for plants. This marker allows researchers to identify even highly degraded DNA, which is especially important in the case of herbal preparations and biologically active additives. The main problem of traditional DNA barcoding via Sanger sequencing is that it is impossible to read a barcode without preliminary cloning of an amplificate when a plant mix includes a large amount of various adulterants and excipients of plant origin, since species-specific chromatograms are superimposed on each other. Thus, NGS sequencing of ITS2 amplicons is a preferable method for the DNA barcoding of plant materials. This method can be used to analyze highly degraded DNA in multicomponent plant mixes and can be used to identify all their ingredients. The review also covers such DNA fingerprinting techniques as RFLP, RFLP-PCR, RAPD, RAPD-SCAR, AFLP-PCR, and ISSR.

Abstract—The results of a study of the fish community and population in some Russian lakes (Lake Imandra on the Kola Peninsula, Lake Syamozero in Karelia, and Lake Vozhe in Vologda district) based on the phase-portrait method are presented. This method reveals stable-state zones for the fish community and the level of deviation from this level under the influence of various anthropogenic factors. The main factors are water pollution (Lake Imandra), eutrophication, and invasion by new species (Lake Syamozero), as well as the introduction of the sander (Lake Vozhe). The removal of negative factors leads to ecosystem stabilization.

Abstract—The paper discusses the sequence of the developmental stages in the immune system and inflammation in vertebrates: the formation of classic forms of adaptive immunity and inflammation for vertebral species, the origin of cytotoxic T lymphocytes and T cell–dependent variants of productive inflammation in fish; the appearance of new antibody classes in tetrapods, and the origin of exudative–destructive inflammation in higher vertebrates and suppurative inflammation in mammals. Each evolutionary stage in the development of immunity and inflammation was determined by the need to organize the immune system to conform to the level of the general organization of vertebrate species. At the same time, each stage predetermined the appearance of “windows of vulnerability” in the form of the possible development of autoimmune, allergic diseases, and systemic complications of the inflammatory process.