St Petersburg University scientists uncover how chicken genes transfer information
Biologists from St Petersburg University, in collaboration with Skoltech, have conducted a study on lampbrush chromosomes in chicken oocytes. They have uncovered the mechanisms by which the chicken genome transfers information and how gene activity influences chromosome structure.
Scientists from the Laboratory of Cell Nucleus Structure and Dynamics have conducted a significant study shedding light on how genes function on chromosomes in domestic chickens. The research was supported by the Russian Science Foundation, with the complex data analysis performed by a specialist from the Skoltech Genomics Core Facility.
The research findings are published in Nucleic Acids Research.
As one of the most common animals globally, the chicken genome is well studied. Lampbrush chromosomes are unique structures found in the oocytes of all vertebrates except mammals. They are named for their distinctive shape, which resembles a paraffin lamp glass cleaning brush or a test tube brush, with a central axis surrounded by numerous lateral loops. These loops produce large amounts of RNA at exceptionally high rates, making them an excellent model for studying gene activation and information transfer within cells.
We have conducted an extensive multi-component study of giant chicken lampbrush chromosomes. Using specialised tools, we carefully extracted the nuclei from chicken oocytes at different developmental stages. Then, we isolated RNA from the oocyte nuclei and the remaining cytoplasm. This approach made it possible, for the first time, to observe how specific genes function on the lampbrush chromosomes of birds.
Alla Krasikova, Associate Professor at the Department of Cytology and Histology of St Petersburg University
They discovered that the genes active on lampbrush chromosomes are essential for normal cellular processes. Moreover, this increased gene activity plays a crucial role in transferring a large amount of maternal RNA to the new organism. Another intriguing finding revealed that the active work of genes directly influences the structure of the chromosomes themselves. Most surprisingly, the processes of gene activation in chickens were found to be similar to those in other cells. The large size of lampbrush chromosomes makes them particularly well-suited for studying these mechanisms.
Additionally, for the first time, the scientists collected detailed information about the activity of small gene regulators (miRNAs) in chicken oocytes. Small gene regulators, such as microRNAs (miRNAs), play a crucial role in controlling gene activity. They function as "on-off switches," regulating which genes are active at specific times and at what levels. Additionally, other short regulatory RNAs (piRNAs) have been identified, which control specific regions of DNA in the chicken genome containing repetitive fragments.
The research was carried out at the Laboratory of Cell Nucleus Structure and Dynamics at St Petersburg University, with the participation of the Skoltech Genomics Core Facility.
These discoveries are helping scientists gain a deeper understanding of how genetic information is transmitted from one generation to the next. This represents a significant advancement in the fields of genetics and molecular biology.
The research is supported by the grant from the Russian Science Foundation "Topologically associated chromatin domains and A/B compartments in the chicken genome: identification and visualisation using HiC technology and ultrahigh resolution microscopy." For reference: St Petersburg University is the leader in the number of grants from the Russian Science Foundation: in 2022, St Petersburg University researchers received 112 grants, which is 5.5% of the total number of winning projects and the largest number of grants for one organisation. In 2023, the University maintained its leadership in this contest of the Russian Science Foundation: scholars from St Petersburg University received 70 grants, which is 5% of the total number of winning projects.
St Petersburg University, the oldest university in Russia, was founded on 28 January (8 February) 1724. This is the day when Peter the Great issued a decree establishing the University and the Russian Academy of Sciences. Today, St Petersburg University is an internationally recognised centre for education, research and culture. In 2024, St Petersburg University celebrates its 300th anniversary.
The plan of events during the celebration of the anniversary of the University was approved at the meeting of the Organising Committee for the celebration of St Petersburg University’s 300th anniversary. The meeting was chaired by Dmitry Chernyshenko, Deputy Prime Minister of the Russian Federation. Among the events are: the naming of a minor planet in honour of St Petersburg University; the issuance of bank cards with a special design; and the branding of the aircraft of the Rossiya Airlines to name just a few. To mark the 300th anniversary of St Petersburg University, a postage stamp depicting the Twelve Collegia building and the monument to Count Sergey Uvarov was issued. Also, a Soyuz rocket bearing the symbols of the University was launched from the Baikonur Cosmodrome.
By the decision of the Governor of St Petersburg Alexander Beglov, 2024 is a year of the 300th anniversary of St Petersburg University in St Petersburg. On the day of the University’s 300th anniversary torches were lit on the Rostral Columns on the Spit of Vasilyevsky Island. St Petersburg University flags were raised on the Palace Bridge. The city public transport was decorated with the University’s symbols. During St Petersburg’s City Day celebrations in May 2024, St Petersburg University acted as a participating venue. Additionally, the University has launched a website dedicated to the anniversary. The website contains information about outstanding University staff, students, and alumni; scientific achievements; and details of events held as part of the celebration of the 300th anniversary of the University.