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 giant panda is of importance for understanding how roundworms
adapt to the host. Here, we report a high-quality chromosome-scale
genome of Baylisascaris schroederi with a genome size of 253.60 Mb and
19,262 predicted protein-coding genes. We found that gene families
related to epidermal chitin synthesis and environmental information
processes in the roundworm genome have expanded significantly.
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 a captive population. Finally, 23 known drug targets and 47
potential drug target proteins (essential homologues linked to lethal
phenotypes) were identified. The genome provides a unique reference for
inferring the early evolution of roundworms and their adaptation to the
host. Population genetic analysis and drug sensitivity prediction
provide insights revealing the impact of deworming history on population
genetic structure of importance for disease prevention.