Comparison of the hemolysis machinery in two evolutionarily distant blood-feeding arthropod vectors of human diseases

PLoS Negl Trop Dis. 2021 Feb 4;15(2):e0009151. doi: 10.1371/journal.pntd.0009151. eCollection 2021 Feb.


Host blood protein digestion plays a pivotal role in the ontogeny and reproduction of hematophagous vectors. The gut of hematophagous arthropods stores and slowly digests host blood and represents the primary gateway for transmitted pathogens. The initial step in blood degradation is induced lysis of host red blood cells (hemolysis), which releases hemoglobin for subsequent processing by digestive proteolytic enzymes. The activity cycles and characteristics of hemolysis in vectors are poorly understood. Hence, we investigated hemolysis in two evolutionarily distant blood-feeding arthropods: The mosquito Culex pipiens and the soft tick Argas persicus, both of which are important human and veterinary disease vectors. Hemolysis in both species was cyclical after blood meal ingestion. Maximum digestion occurs under slightly alkaline conditions in females. Hemolytic activity appears to be of lipoid origin in C. pipiens and enzymatic activity (proteolytic) in A. persicus. We have assessed the effect of pH, incubation time, and temperature on hemolytic activity and the hemolysin. The susceptibility of red blood cells from different hosts to the hemolysin and the effect of metabolic inhibition of hemolytic activity were assessed. We conclude that in C. pipiens and A. persicus midgut hemolysins control the amplitude of blood lysis step to guarantee an efficient blood digestion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arthropod Vectors / physiology*
  • Arthropods
  • Culex
  • Culicidae
  • Digestive System
  • Erythrocytes
  • Feeding Behavior / physiology*
  • Female
  • Hematologic Tests
  • Hemolysin Proteins
  • Hemolysis*
  • Humans
  • Mosquito Vectors / physiology


  • Hemolysin Proteins

Grant support

This study was financed by the Grant Agency of the Czech Republic (grant19-382 07247S to MK) and by ERD Funds, project CePaVip OPVVV (No. 384 CZ.02.1.01/0.0/0.0/16_019/0000759 to MK). The study was supported by the European Union within ESIF in the context of Operational Programme Research, Development and Education (project no. CZ.02.2.69/0.0/0.0/20_079/0017809 to CB). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.