Vegetative cell fusion and a new stage in the life cycle of the Aphelida (Opisthosporidia)

The aphelids, intracellular parasitoids of algae, represent a large cluster of species sister to Fungi in molecular phylogenetic trees. Sharing a common ancestor with Fungi, they are very important in terms of evolution of these groups of Holomycota. Aphelid life cycle being superficially similar to that of Chytridiomycetes is understudied. We have found in the aphelids a new stage-big multiflagellar and amoeboid cells, formed from a plasmodium that has two sorts of nuclei after trophic stage fusion. The families of protein-coding genes involved in the vegetative cell fusion in Opisthokonta were also discussed.

Extreme Genome and Nervous System Streamlining in the Invertebrate Parasite Intoshia variabili

Orthonectida is a small, rare, and in many aspects enigmatic group of organisms with a unique life cycle and a highly simplified adult free-living stage parasitizing various marine invertebrates [1, 2]. Phylogenetic relationships of Orthonectida have remained controversial for a long time. According to recent data, they are close to Annelida, specifically to Clitellata [3-5]. Several studies have shown that parasitism can not only lead to a dramatic reduction of the body plan and morphological structures but also affect organisms at the genomic level [6, 7]. Comparative studies of parasites and closely related non-parasitic species could clarify the genome reduction degree and evolution of parasitism. Here, we report on the morphology, genome structure, and content of the smallest known Orthonectida species Intoshia variabili, inhabiting the flatworm Graffiellus croceus. This orthonectid with an extremely simplified nervous system demonstrates the smallest known genome (15.3 Mbp) and one of the lowest reported so far gene numbers (5,120 protein-coding genes) among metazoans. The genome is extremely compact, due to a significant reduction of gene number, intergenic regions, intron length, and repetitive elements. The small genome size is probably a result of extreme genome reduction due to their parasitic lifestyle, as well as of simplification and miniaturization of the free-living stages. Our data could provide further insights into the evolution of parasitism and could help to define a minimal bilaterian gene set.

[Expirience introduction of quantitative analysis of chimerism after allogenic stem cell transplantation by real-time PCR with InDel polymorphism.]

Using data obtained from domestic and foreign sources, we formed a set of primers and fluorogenic probes for analyzing twentysix specific sequence polymorphisms and one reference gene. In the course of evaluating the effectiveness of real-time PCR, using the example of one of the markers (S01a), we obtained the optimal amount of DNA per reaction (70 ng), providing a resolution of at least 0.1% of the method with the ability to estimate linear chimerism. Formed panel of primers for genetic polymorphisms - InDel has a high degree of informational content for donor-recipient pairs of Russia. From January 2018 to June 2019, a quantitative assessment of the level of linear (CD3 +, CD34 +) and general chimerism was carried out for 28 patients of the clinic of the Institution. Finally, we analyzed patients who received allografts and present 4 different clinical situations that illustrate the informativity level of this method.

[Clinical and neuroimaging heterogeneity of dementia with Lewy bodies]

AIM

To study clinical characteristics of dementia with Lewy bodies (DLB) depending on neuropsychological, neuroimaging and concomitant cerebrovascular changes as well as on the character of disease onset.

MATERIAL AND METHODS

Forty-five patients with DLB (25 men and 20 women, men age 72.9±7.2 years, illness duration 2.9±2.2) were studied. The diagnosis was made according to international criteria (McKeith, et al, 2017). MRI, clinical/neurological examination and psychometric scales were used.

RESULTS AND CONCLUSION

Clinical, neuropsychological and neuroimaging results reveal the heterogeneity of DLB, which remains poorly investigated. An analysis of the clinical picture, cognitive profile, neuropsychiatric changes and MRI results identified three subtypes of DLB course: 1) typical; 2) with early psychotic manifestation; 3) atypical (mixed). This approach may improve the diagnosis of DLB, prognosis of disease course and treatment effectiveness.