Ancient RNA expression profiles from the extinct woolly mammoth.

Area of Science:

• Paleogenomics
• Molecular Biology
• Evolutionary Biology

Background:

• Ancient DNA (aDNA) analysis has transformed evolutionary studies, enabling genome reconstruction of extinct species.
• Current methods analyzing aDNA do not provide insights into gene expression, tissue identity, or transcriptional regulation, which are encoded in RNA.
• Ancient RNA (aRNA) analysis offers a complementary approach to aDNA for understanding biological functions in extinct organisms.

Purpose of the Study:

• To explore the potential of ancient RNA sequencing for reconstructing gene expression and biological functions in extinct species.
• To analyze transcriptional profiles from Late Pleistocene woolly mammoths.
• To establish a framework for validating and decoding ancient RNA sequences.

Main Methods:

• Sequencing of RNA extracted from 10 woolly mammoth specimens.
• Radiocarbon dating of specimens to determine age.
• Bioinformatic analysis to identify tissue-specific regulatory mechanisms and biological functions.

Main Results:

• Successfully recovered ancient RNA sequences from 10 woolly mammoths.
• Identified the oldest ancient RNA sequences to date from a mammoth specimen dated to approximately 39,000 years old.
• Recovered tissue-specific regulatory mechanisms and biological functions related to skeletal muscle metabolism.
• Demonstrated the feasibility of studying ancient RNA beyond previous limitations.

Conclusions:

• Ancient RNA sequencing provides valuable insights into gene expression, tissue identity, and biological functions of extinct organisms.
• The developed analytical framework enables the validation and decoding of ancient RNA.
• This work paves the way for integrative paleogenomic studies combining genomics, transcriptomics, and proteomics.