Ancient DNA from 120-Million-Year-Old Lycoptera Fossils Reveals Evolutionary Insights

TL;DR

This study successfully extracted and sequenced ancient DNA from 120-million-year-old Lycoptera fossils, revealing genomic insights and establishing a new protocol for ancient DNA recovery from very old fossils.

Contribution

It introduces the mega screen method for extracting ancient DNA from extremely old fossils, enabling genomic analysis from 120-million-year-old specimens.

Findings

Recovered 1,258,901 DNA sequences from fossils

Identified 243 original in situ DNA sequences

Discovered 10 transposase coding sequences

Abstract

High quality ancient DNA (aDNA) is essential for molecular paleontology. Due to DNA degradation and contamination by environmental DNA (eDNA), current research is limited to fossils less than 1 million years old. The study successfully extracted DNA from Lycoptera davidi fossils from the Early Cretaceous period, dating 120 million years ago. Using high-throughput sequencing, 1,258,901 DNA sequences were obtained. We established a rigorous protocol known as the mega screen method. Using this method, we identified 243 original in situ DNA (oriDNA) sequences, likely from the Lycoptera genome. These sequences have an average length of over 100 base pairs and show no signs of deamination. Additionally, 10 transposase coding sequences were discovered, shedding light on a unique self-renewal mechanism in the genome. This study provides valuable DNA data for understanding ancient fish evolution and advances paleontological research.