Chromosome-scale assembly and whole-genome sequencing of 266 giant panda
roundworms provide insights into their evolution, adaptation and
potential drug targets
Abstract
Helminth diseases have long been a threat to the health of humans and
animals. Roundworms are important organisms for studying parasitic
mechanisms, disease transmission and prevention. The study of parasites
in the living fossil giant panda is of great significance for
understanding the adaptation mechanism of roundworms to the host. Here,
we report a high-quality chromosome-scale genome of Baylisascaris
schroederi with a genome size of 262 Mb and 19,291 predicted
protein-coding genes. We found a significant expansion of genes related
to epidermal chitin synthesis and environmental information processing
in roundworms genome. Furthermore, we demonstrated unique genes involved
in essential amino acid metabolism in the B. schroederi genome, inferred
to be essential for the adaptation to the giant panda-specific diet. In
addition, under different deworming pressures, we found that four
resistance-related genes (glc-1, nrf-6, bre-4 and ced-7) were under
strong positive selection in captive population. Finally, 23 known drug
targets and 47 potential target proteins were identified. The genome
provides a unique reference for inferring the early evolution of
roundworms and the mechanisms underlying adaptive. Population genetic
analysis and drug prediction provide insights for revealing the impact
of deworming history on population genetic structure and prevention.