Fossil avian eggshell preserves ancient DNA.

Area of Science:

• Paleogenomics
• Paleontology
• Archaeology

Background:

• Fossil avian eggshell is valuable for geochronology and palaeodietary studies due to exceptional biomolecule preservation.
• Ancient DNA (aDNA) recovery from fossilized materials is crucial for understanding past life and environments.

Purpose of the Study:

• To investigate fossil avian eggshell as a previously unrecognized source of ancient DNA (aDNA).
• To assess the quality and quantity of aDNA recoverable from fossil eggshells of various ages and geographic origins.
• To evaluate methods for maximizing DNA recovery and assess the suitability of eggshell for high-throughput sequencing.

Main Methods:

• DNA isolation and amplification from fossil eggshell samples.
• Characterization of retrieved mitochondrial and nuclear DNA.
• Confocal microscopy and quantitative PCR (qPCR) to evaluate DNA recovery methods and bacterial load.
• Analysis of eggshell from extinct moa, elephant birds, emu, and owls.

Main Results:

• Successful isolation and amplification of aDNA from fossil eggshell up to 19,000 years old.
• Characterization of both mitochondrial and nuclear DNA from diverse extinct avian species (moa, elephant birds, emu, owl).
• Moa eggshell exhibited significantly lower bacterial load compared to bone, indicating suitability for high-throughput sequencing.
• Demonstrated long-term DNA preservation in eggshell from both colder (Pleistocene) and warmer (Holocene) climates.

Conclusions:

• Fossil avian eggshell represents a significant, previously unrecognized source of ancient DNA (aDNA).
• The successful recovery of aDNA from eggshell has broad implications for palaeontology and archaeology, enhancing understanding of past biodiversity, diets, and evolution.
• Eggshell provides an excellent substrate for long-term DNA preservation, even in warmer climates, opening new avenues for ancient genomics research.