Equus roundworms (Parascaris spp.) are undergoing divergence due to natural and anthropogenic factors

Abstract

The evolution of parasites is often directly affected by the host's environment or behavior. Studies on the evolution of the same parasites in different hosts are extremely attractive and highly relevant to our understanding of divergence and speciation. Here we presented the first molecular evidence of divergence of Equus roundworms in different hosts (horses, zebras and donkeys). At the genetic level, Equus roundworms were mainly separated into two clades (Horse-derived and Zebra & Donkey-derived). This divergence began at 600–1500 years ago, which interestingly coincided with the domestication history of horses. We found that most of the key enzymes related to glycolysis were under strong positive selection in zebra & donkey-derived roundworms, indicating that the evolution of the metabolic level was one of the main reasons for the divergence. In addition, we conducted a selective scan of resistance-related genes and found that the three populations were under different degrees of selection. This prompted us to pay attention to the possible impact of drugs on divergence, not just the drug resistance. This work supports that divergence or speciation is a continuous and dynamic process, and continuous monitoring of environmental factors is conducive to further understanding the adaptive evolution of roundworms.

Reactive oxygen species: Multidimensional regulators of plant adaptation to abiotic stress and development

“…For instance, mutation of the atypical kinase ACTIVITY OF BC1 COMPLEX KINASE (ABC1K) resulted in lower CAT2 expression under saline conditions and thus hypersensitivity to salt stress in Arabidopsis (Qin et al, 2020). An Arabidopsis mutant lacking function of the melatonin receptor PHYTOMELATONIN RECEPTOR 1 (pmtr1) is sensitive to salt stress due to repressed salt-induced expression of CAT1, CAT2, CAT3, and SOD1, leading to the overaccumulation of H 2 O 2 (Wang et al, 2021).…”

“…MdHSFA8a promotes the expression of flavonoid biosynthetic genes and the accumulation of flavonoids in apple (Malus domestica) for scavenging ROS under drought stress, thus enhancing drought stress tolerance (Wang et al, 2020) (Figure 6). Melatonin, a natural antioxidant and signaling molecule, also positively regulates the drought stress response; exogenous overexpression of the maize melatonin receptor gene ZmPMTR1 in Arabidopsis conferred enhanced drought stress tolerance by repressing ROS overaccumulation (Wang et al, 2021).…”