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.

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.

The coronavirus disease 19 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and the outbreak has rapidly spread worldwide causing a global severe pneumonia pandemic. Several animals have been proven to be affected by the SARS-CoV-2, posing an enormous threat to humans. However, to confirm the intermediate hosts in the epidemic regions, it is unrealistic to detect its presence in each and every animal one by one. An active transmembrane serine protease 2 (TMPRSS2) which functions in priming of S-protein of SARS-CoV-2 is one of the most important prerequisites for an animal to be an intermediate host, but the utilizing capability of TMPRSS2 for non-human animals is largely unknown. Here, we systematically predicted the ability of TMPRSS2 to prime S-protein of SARS-CoV-2 in 164 vertebrates by analyzing the phylogenetic clustering and possible functional changes induced by amino acid variation in TMPRSS2. Mammals were predicted to be the most likely animals to effectively use the TMPRSS2 for priming S-protein of SARS-CoV-2. Especially, we predicted the possible effective utilizing ability of TMPRSS2 in rats and pigs, which are reported non-susceptible to SARS-CoV-2. Given the wide distribution and the close relationships among human, pig and rat, a periodic and careful monitoring is required for pigs and rats to prevent the possible SARS-CoV-2 transmission to human.