Issue No. 5 of the journal Transactions of the Karelian Research Centre RAS, Experimental Biology Series, was released at the end of May. The contributors are Russian scientists representing the Institute of Biology and the Forest Research Institute of the KarRC RAS, St. Petersburg State University of Veterinary Medicine, Arctic State Agrotechnological University (Republic of Sakha (Yakutia)), Petrozavodsk State University, All-Russian Research Institute of Forest Genetics, Breeding and Biotechnology (Voronezh), Don State Technical University (Rostov-on-Don), and several other research organizations.

One of the review articles explains the causes of leaf photodamage under long photoperiods. The authors of the study, Tatyana Shibaeva, Doctor of Biological Sciences, Leading Researcher at the Institute of Biology KarRC RAS, and the Institute’s Trainee Researcher Alexander Mamaev state that nearly a century of research has not yet provided the answer to the question of why 24h lighting has a positive effect on some species and a negative effect on others. They hypothesize that the first event triggering the chain of events leading to leaf chlorosis and necrosis is circadian asynchrony.

The second review article, by Marina Zaretskaya, Candidate of Biological Sciences, Researcher at the Institute of Biology KarRC RAS, reveals the genetic mechanisms that initiate flowering in plants. Among the known mechanisms regulating the expression of flowering genes, the article focuses on the details of the regulatory functions of plant microRNAs.

The histoarchitecture of the placenta in final stages of gestation in domesticated reindeer was the subject of a study by scientists from St. Petersburg State University of Veterinary Medicine and Arctic State Agrotechnological University (Republic of Sakha (Yakutia)). Doctor of Veterinary Sciences, Professor of the Department of Genetic and Reproductive Biotechnologies Vladimir Avdeenko; Candidate of Veterinary Sciences, Associate Professor of the Department of Biology, Ecology and Histology Danil Safronov; and Candidate of Veterinary Sciences, Vice Rector for Research, Associate Professor Konstantin Nifontov analyzed placental samples and noted that the results reflect the adaptive mechanisms of ruminant mammals related to successful gestation and birth of offspring in the extreme conditions of Yakutia.

A study on the level of CD73+ cells in the blood of patients with different forms of metabolism-associated fatty liver disease was conducted by Galina Zhulai, Candidate of Biological Sciences, Researcher at the Laboratory of Genetics, Institute of Biology KarRC RAS, Irina Kurbatova, Candidate of Biological Sciences, Senior Researcher at the Laboratory of Genetics, Institute of Biology KarRC RAS, and Olga Dudanova, Doctor of Medical Sciences, Head of the Department of Propaedeutics of Internal Diseases and Hygiene, Petrozavodsk State University.

An experimental article on the identification of figured wood in clones of curly birch was authored by Lydia Vetchinnikova, Doctor of Biology, Chief Researcher at the Laboratory of Forest Biotechnologies, Forest Research Institute KarRC RAS, Ksenia Gudkova, Junior Researcher at the Department of Forest Genetics, Breeding and Biotechnology, All-Russian Research Institute of Forest Genetics, Breeding and Biotechnology (Voronezh), and Alexander Titov, RAS Corresponding Fellow, Doctor of Biology, Head of the Laboratory of Plant Ecological Physiology, Institute of Biology KarRC RAS. They studied the possibility of using the molecular marker BpCW1 in in vitro cultivated curly birch clones to address various issues related to breeding of curly birch, as well as to select initial genotypes for establishing plantations to grow trees with desired traits for commercial purposes.

Another experimental article, by a team of scientists led by Irina Tkacheva, Doctor of Biology, Chief Researcher at the Center for Agrobiology, Don State Technical University, presents the results of a study aimed at optimizing the formulation of compound feeds for hybrid sturgeon species through addition of plant components and bacteriocins. The feed developed by the scientists, supplemented with the antimicrobial peptide Pediocin RA 1, has a positive effect on the general wellbeing of the fish and ensures weight gain. According to the scientists, the use of the new feed additive will expand the aquaculture feed market and reduce water treatment costs by minimizing waste.

A brief communication by Doctor of Biology, Senior Lecturer at the Department for Technical Means of Aquaculture Irina Tkacheva and Master's Student Nadezhda Nedina of Don State Technical University also deals with the prospects of using bacteriocins in aquaculture. Their application addresses a problem of relevance for many countries: replacing antibiotics with safer and more effective substances.

Another brief communication discusses the identification of genes associated with resistance to major viral diseases and late blight in potato hybrids, for the subsequent use of these hybrids in potato breeding and seed production programs. The authors of the study, Irina Gazdanova, Candidate of Agricultural Sciences, Senior Researcher at the Laboratory of Molecular Genetic Research of Agricultural Plants, Vladikavkaz Scientific Centre RAS (Republic of North Ossetia Alania), and Nino Doguzova, Researcher at the same laboratory, used molecular screening to select hybrids that will be used to develop new virus-resistant potato varieties.

The Dates and Anniversaries feature is dedicated to Doctor of Veterinary Sciences, Professor Vyacheslav Berestov. Professor Berestov was the founder and first head of the Laboratory of Fur Animal Physiology at the Institute of Biology of the Karelian Branch of the USSR Academy of Sciences (now the Laboratory of Animal Ecophysiology). Vyacheslav Berestov contributed greatly to the study of fur animals and the development of the fur industry in Karelia. This year, he would have turned 95.

Preparation of the next issue of the Transactions of the Karelian Research Centre RAS, Experimental Biology Series, has already begun. It will be published in November 2026.