Doklady Rossijskoj akademii nauk. Nauki o žizni

The work was performed on 4 groups of old Wistar rats: anesthesia only (An), noncardiac surgery (NS), extracardiac surgery (ES) with prior stress for 5 days (SNS), and intact animals used as a control. As evident from the absence of increases in proinflammatory cytokines and C-reactive protein 10 days after the surgery, the animals did not have any inflammation. The presence of stress was judged by the highest level of corticosterone in the SNS rats. These animals had myocardial injury after NS (MINS) indicated by structural and metabolic disorders, as well as an increase in the blood concentration of high-sensitive cardiac troponin I (hs-cTnI). Despite the fact that the rats in the An and NS groups had some ischemic zones in the myocardium, they did not develop MINS, since there was no oxidant-antioxidant imbalance and, most importantly, no increase in hs-cTnI. This study showed for the first time that “simple” aseptic noncardiac surgery in combination with preoperative stress can induce MINS in healthy Wistar rats. It is proposed to use a decrease in the level of superoxide dismutase as an additional biomarker of MINS.

Macrofossils of shrubby birch (Betula humilis) from boreal species group and of aven (Dryas sp.) from arcto-alpine species group, dated at ~2500 radiocarbon years ago were found on the territory of the Kazakh Uplands (Abylai site, 49°15' N, 75°07' E). These species are currently absent from the region. This reflects the existence of a refugium of these species in the Kazakh Uplands in the Holocene. These species appeared on the territory of the Kazakh Uplands at the end of the Late Pleistocene. At the beginning of the Holocene their ranges retreated to the north and a refugium was formed on the territory of the Kazakh Uplands. Sharply continental climate and favorable edaphic conditions contributed to the preservation of the refugium on the territory of the Kazakh Uplands. The disappearance of the refugium is associated with biocenotic reorganization of the vegetation in the second half of the Late Holocene caused by climatic changes.

The ascidian Styela clava is an invasive species that easily colonizes new water areas and has wide distribution. We discovered a previously undescribed typhlosole, which was studied using histological techniques, transmission electron microscopy and computer microtomography. The typhlosole is a large fold of the dorsal intestinal wall, starting in the lower quarter of the stomach and continuing to the rectum. Its shape varies greatly: from a rounded protrusion to a spirally twisted fold. The typhlosole is formed by the intestinal epithelium, a thick layer of connective tissue in which the pyloric tubules and blood vessels pass. The epithelium is formed by glandular, ciliated, and non-ciliated cells demonstrating apocrine secretion. The typhlosole intensifies cavitary digestion and absorption of nutrients. The discovered features may contribute to high digestion efficiency even in low-productive waters, determining the biological success of this species.

PCID2 protein is a subunit of the eukaryotic complex TREX-2, which is responsible for nuclear export of mRNA. PCID2 plays an important role in the complex, being responsible for the recognition and binding of the mRNA molecule. PCID2 of D. melanogaster interacts with a region of ras2 (fr4_2) mRNA and has two interaction sites located in its PCI domain: the M-PCID2 region, which non-specific binds to mRNA and the C-terminal part (C-PCID2), which specifically recognizes the ras2 fr4_2 mRNA sequence. At the same time, specific binding to C-PCID2 requires a preliminary nonspecific interaction with M-PCID2. It remains unclear how the transition from a primary nonspecific interaction to a specific interaction occurs. Whether both regions interact with RNA simultaneously or whether the nonspecific interaction is only necessary in the first step for subsequent specific binding. This study has shown that binding of M-PCID2 and C-PCID2 to ras2 fr4_2 RNA is competitive. M-PCID2 binds more efficiently and displaces C-PCID2 from the complex with the ras2 mRNA fragment. Thus, additional factors are required to replace the M-PCID2 contact by C-PCID2 during the interaction of full-length PCID2 protein with ras2 mRNA. We also show that point mutations in M-PCID2 that disrupt the interaction of full-length PCID2 with RNA result in greater association of M-PCID2 with RNA. It is likely that the increased affinity of M-PCID2 for RNA disrupts the ability to replace M-PCID2 with C-PCID2 within full-length PCID2.

The study of protein functioning in a cell cannot be performed by analyzing their content in the cell. The most commonly used method of analysis, western blotting, cannot always be used due to the impossibility of obtaining antibodies that specifically recognize the protein of interest. At the same time, western blotting is a semi-quantitative method of analysis and does not allow determining the exact content of protein in the cell. In this work, we used the protein complementation method for the qualitative and quantitative assessment of the hTERP protein content in the cell. Using genome editing, a HiBiT appendage was introduced to the C-terminus of the hTERP protein, the complementation of which with LgBiT restores active luciferase. As a result, we determined the hTERP protein content in the HEK293T cell line.

In this study, promoter sequences predicted by the MAHDS method in the Oryza sativa genome were analyzed using three genome annotations: RefSeq NCBI, Rice Genome Annotation Project, and Ensembl. A portion of the predicted promoters was found to be located near annotated genes, indicating their potential functional role. The remaining sequences, considered as potentially novel regulatory elements, were examined using YAPP for the presence of core promoter motifs and their functional combinations. All analyzed predicted promoters contain either an Inr or a TATA motif – key elements involved in transcription initiation. The identified motif combinations suggest a high likelihood of transcriptional activity in these sequences, while the consistency of the results with annotated data and CAGE-seq signals supports the reliability and applicability of the MAHDS method.