[Characteristics of δ-Aminolevulinic Acid Dehydratase of the Cold-Water Sponge Halisarca dujardinii].

δ-Aminolevulinic acid dehydratase (ALAD) is a key enzyme of the cytoplasmic heme biosynthesis pathway. The primary structure of the ALAD gene, the multimeric structure of the ALAD/hemB protein, and ALAD expression during the annual reproductive cycle were studied in the cold-water marine sponge Halisarca dujardinii. The results implicated the GATA-1 transcription factor and DNA methylation in regulating ALAD expression. Re-aggregation of sponge cells was accompanied by a decrease in ALAD expression and a change in the cell content of an active ALAD/hemB form. Further study of heme biosynthesis and the role of ALAD/hemB in morphogenesis of basal animals may provide new opportunities for treating pathologies in higher animals.

Post-fire insect fauna explored by crown fermental traps in forests of the European Russia.

Wildfires considerably affect forest ecosystems. However, there is a lack of data on the post-fire status of insect communities in these ecosystems. This paper presents results of a study conducted in 2019 which considered the post-fire status of the insect fauna in a Protected Area, Mordovia State Nature Reserve (Republic of Mordovia, centre of European Russia), considered as regional hotspot of insect diversity in Mordovia. We sampled insects on intact (unburned, control) and fire-damaged (burnt in 2010) sites and compared the alpha-diversity between sites. In total, we sampled and analysed 16,861 specimens belonging to 11 insect orders, 51 families and 190 species. The largest orders represented in the samples were Coleoptera (95 species), Diptera (54 species), Hymenoptera (21 species), and Neuroptera (11 species). Other insect orders were represented by between one and four species. The largest four orders (Coleoptera, Lepidoptera, Diptera and Hymenoptera) represented 96.7% of all studied specimens. We found that in the ninth year after low intensity surface fire damage, the insect diversity had returned to a similar level to that of the control (unburned) sites. Sites damaged by crown wildfire differed considerably from other sites in terms of a negative impact on both species diversity and the number of specimens. This indicates the serious effect of the crown fires on the biodiversity and consequent long-term recovery of the damaged ecosystem.

[Structure of Neuroglobin from Cold-Water Sponge Halisarca dujardinii].

The iron-containing protein neuroglobin (Ngb) involved in the transport of oxygen is generally considered the precursor of all animal globins. In this report, we studied the structure of Ngb of the cold-water sponge Halisarca dujardinii. In sponges, the oldest multicellular organisms, the Ngb gene contains three introns. In contrast to human Ngb, its promoter contains a TATA-box, rather than CG-rich motifs. In sponges, Ngb consists of 169 amino acids showing rather low similarity with its mammalian orthologues. It lacks Glu and Arg residues in positions required for prevention of hypoxia-related apoptosis. Nevertheless, Ngb contains both proximal and distal conserved heme-biding histidines. The primary structure of H. dujardinii neuroglobin predicted by sequencing was confirmed by mass-spectrometry analysis of recombinant Ngb expressed in E. coli. The high level of Ngb expression in sponge tissues suggests its possible involvement in the gas metabolism and presumably in other key metabolic processes in H. dujardinii.

The Role of Epibionts of Bacteria of the Genus Pseudoalteromonas and Cellular Proteasomes in the Adaptive Plasticity of Marine Cold-Water Sponges.

It was found that cells of different color morphs of the cold-water marine sponges Halichondria panicea (Pallas, 1766) of the class Demospongiae differ in the content of epibionts of bacteria of the genus Pseudoalteromonas. The sponge cells with elevated levels of epibionts of bacteria of the genus Pseudoalteromonas showed an increased expression of Hsp70 proteins but had a reduced level of the proteasomal catalytic beta 5 subunit, which was accompanied by a change in their activity. Probably, epibionts of bacteria of the genus Pseudoalteromonas may affect the ubiquitin-proteasome system in the cells of cold-water marine sponges and, thereby, ensure their adaptive plasticity.

Role of proteasomes in non-specific immune response of marine annelids.

We investigated functioning of proteasomes and chaperones in Arenicola marina coelomocytes in conditions of lipopolysaccharide-induced inflammation. We observed the increase of chymotrypsin-like proteasome activity in coelomocytes 1 h after induction. Amount of proteasome subunits alpha- and beta-5 types increased as well. We also detected appearance of a new form of Hsp70 chaperone in infected coelomocytes. Our results allow us to consider the changes in proteasome structure and induction of chaperones as principle mechanisms in stress adaptation and defensive reactions development in annelids.

[Plasticity of nervous and immune systems in different species: the role of proteasomes].

Nervous and immune systems have many general features in their organization and functioning in various animal species from insects to mammals. These systems are capable to regulate effectively each other by exchange of information through rather small molecules like oligopeptides, cytokines, and neuropeptides. For many such molecules, that function as transmitters or signaling peptides, their origin and receptors are common within nervous and immune systems. Development of nervous and immune systems during ontogenesis and their functions in various species are controlled by the ubiquitous HYPERLINK "http://slovari.yandex.ru/proteolytic/en-ru/Medical/" \1 "longvo/" proteolytic ubiquitin-proteasome system (UPS). UPS regulates key biochemical processes in both systems by providing formation of synaptic connections and synaptic plasticity, and governs immune responses. In the review, the molecular mechanisms of functioning and interaction between nervous and immune systems are considered in different species of invertebrats and vertebrats. The role of UPS in these processes in the main subject of this review.

[Interspecies variability of number of bristles on dorsal surface of aedeagus in D. virilis species group and its genetic mapping with interspecies hybrids of D. virilis and D. lummei].

The results of morphologic and hybrid analyses of the feature of the male reproductive system of sibling species in the virilis group were presented. Bristles appeared on the surfaces of male genitals (aedeagus). The occurrence of a specific expression of the examined feature in the phyllades of D. virilis group, the correspondence of both the number and distribution pattern of the bristles on surfaces ofthe aedeagus and developmental temperature in D. virilis and D. lummei, as well as the link between feature and sexual behavior, have been shown. Dominance of D. lummei phenotype in the interspecies D. virilis x D. lummei was found. The interspecies hybrids D. virilis and D. lummei were used for a genetic analysis of the variability of the examined feature. The significant influence of chromosomes 2 and 6 on the number of bristles on the aedeagus in hybrid males was shown. Furthermore, the correspondence between the effects of the autosomes 2 and 6 on the variability of the examined feature and the genetic status of the other chromosomes (the effect of interaction between genetic factors, chromosomes here) was revealed. The adaptive value of the examined feature related to the involvement in the formation of isolating barriers at the copulation stage is under discussion.

[Dominance status of shape of male genitalia in interspecific crosses of some Drosophila virilis group species].

The heritability of the shape of the main species-specific morphological trait for the Drosophila virilis group--the male mating organ has been analyzed using the hybrid males D. virilis x D. lummei and D. virilis x D. novamexicana. The results suggest an increase in the share of the characters with a recessive status in the evolutionarily younger species and demonstrate the role of sex chromosomes in the implementation of a dominant or recessive status of the trait. The roles of additive and epistatic components of the total variation in the evolution of dominance status, shown in several known theoretical models and confirmed by our data, are considered. The published data on sterility of hybrid males in interspecific crosses are discussed from the standpoint of the evolution of dominance.

[Irregular evolutionary rate of the fruit fly from the Virilis group: I. Use of phylogeny-mediated Takezaki tests].

The aim of this study is to test the hypothesis about an inconsistency in time estimation of the divergence and topology of species Drosophila kanekoi, D. ezoana, and D. littoralis which is caused by the irregular accumulation rate of replacements in different DNA sequences used for analysis and in evolutionary lineages. The phylogenetic relationships based on sequences of five genes among 11 fruit fly species of virilis group are revised, and estimation of molecular clock regularity in several phylogenetic lineages of this group is given. It was shown that Drosophila kanekoi, D. ezoana, and D. littoralis assembled in a single cluster, which was most related to the subfilade montana. The irregularity of molecular clocks was shown for the high conservative sequences of mt 12S-16S.

[Morphometric analysis of male genitalia in sibling species of Drosophila virilis Sturt]. / Morfometricheskii analiz polovykh organov samtsov vidov-dvoinikov Drosophila virilis Sturt.

The structure of male genital organs in sibling species of the virilis group of Drosophila was examined using methods of multivariate statistics. The differences among these species were estimated using 33 indices and 2 angle parameters. The intraspecific and interspecific correlation structure of the examined characters and the order of their divergence were established. The key characters with respect to forming interspecific differences in the virilis species group were identified. Based on these results, the relative systematic positions of the sibling species are discussed as well as similarities and differences of the pattern of relationships among the species from that generally accepted for the virilis group.