В СПбГУ исследовали, как куриные гены передают информацию.

The findings of the study have been published in Nucleic Acids Research. Researchers from the Laboratory of Structure and Dynamics of the Cell Nucleus conducted a significant investigation that enhanced our understanding of gene functions on chromosomes in domestic chickens. This research was supported by the Russian Science Foundation (RSF), with complex data analysis carried out by a specialist from the Skoltech Genome Center.

The chicken genome, being one of the most studied among animals worldwide, is well-documented. Lampbrush chromosomes are unique structures that form in the oocytes of all vertebrates, except for mammals. They are named for their distinctive shape, which resembles the brushes used for cleaning kerosene lamps or test tubes, where a central axis is surrounded by numerous loops known as lateral loops. A substantial amount of RNA is produced at a very high rate on these chromosomes, making them an excellent subject for studying gene activation and information transfer within cells overall.

“We conducted extensive, multi-component research on the giant lampbrush chromosomes of chickens. We collected chicken oocytes at various developmental stages and carefully extracted nuclei using specialized tools. Then, we isolated RNA from the nuclei of oocytes and from the remaining cytoplasm. This allowed us to observe for the first time how specific genes function on the lampbrush chromosomes of birds,” said Alla Kraskova, Associate Professor of Cytology at St. Petersburg State University.

They discovered that the genes operating on lampbrush chromosomes are essential for the normal functioning of the cell. Moreover, this high gene activity is crucial for transferring a large amount of information (maternal RNA) to the new organism. Another intriguing finding was that the active functioning of genes influences the very structure of the chromosomes. Most remarkably, the gene activation processes in chickens were found to be similar to those occurring in other cells. However, due to their large size, lampbrush chromosomes are ideally suited for studying these mechanisms.

Additionally, the researchers compiled detailed information for the first time about the role of small gene regulators (miRNAs) in chicken oocytes. Small gene regulators, such as miRNAs (microRNAs), play a vital role in managing gene activity. They function as "switches," helping to control which genes will be active at any given moment and in what quantities. Furthermore, it was revealed that other short regulatory RNAs (piRNAs) regulate specific DNA regions in the chicken genome that contain repetitive sequences.

These discoveries assist scientists in gaining a better understanding of how hereditary information is passed from one generation to the next. This represents a significant advancement in the fields of genetics and molecular biology.

The work was carried out at the Laboratory of Structure and Dynamics of the Cell Nucleus at St. Petersburg State University, in collaboration with the Collective Use Center in Genomics at Skoltech, with support from the RSF grant.