Avian mitochondrial genomes retrieved from museum eggshell

Avian eggshell is a bio-ceramic material with exceptional properties for preserving DNA within its crystalline structure, presenting an opportunity to retrieve genomic information from extinct or historic populations of birds. However, intracrystalline DNA has only been recovered from the large, thick eggshell of palaeognaths; members of their more-diverse sister group (neognaths) lay smaller, thinner eggs that may not exhibit the same propensity for DNA preservation. Here, we use three 40-60 year-old museum eggshell specimens of Australian neognath birds to determine the minimum mass of eggshell from which intracrystalline DNA can be retrieved, and to characterise the yield and quality of such DNA. In doing so, we describe the first protocol for successful extraction of intractrystalline DNA from neognath eggshells, with the view to unlocking the potential of vast museum egg collections for genetic research. We were able to retrieve DNA fragments over 200 bp in length from 10 mg of egg...