Recent achievements and doors opened for coccidian parasite research and development through transcriptomics of enteric sexual stages

Mol Biochem Parasitol. 2021 May:243:111373. doi: 10.1016/j.molbiopara.2021.111373. Epub 2021 May 4.

Abstract

The Coccidia is the largest group of parasites within the Apicomplexa, a phylum of unicellular, obligate parasites characterized by the possession of an apical complex of organelles and structures in the asexual stages of their life cycles, as well as by a sexual reproductive phase that occurs enterically in host animals. Coccidian sexual reproduction involves morphologically distinct microgametes and macrogametes that combine to form a diploid zygote and, ultimately, following meiosis and mitosis, haploid, infectious sporozoites, inside sporocysts within an oocyst. Recent transcriptomic analyses have identified genes involved in coccidian sexual stage development and reproduction, including genes encoding for microgamete- and macrogamete-specific proteins with roles in gamete motility, fusion and fertilization, and in the formation of the resilient oocyst wall that allows coccidians to persist for long periods in the environment. Transcriptomics has also provided important clues about the regulation of gene expression in the transformation of parasites from one developmental stage to the next, a complex sequence of events that may involve transcription factors such as the apicomplexan Apetala2 (ApiAP2) family, alternative splicing, regulatory RNAs and MORC (a microrchida homologue and regulator of sexual stage development in Toxoplasma gondii). The molecular dissection of coccidian sexual development and reproduction by transcriptomic analyses may lead to the development of novel transmission-blocking strategies.

Keywords: Coccidia; Eimeria; Gametocytes; Merozoites; Toxoplasma; Transcriptomics.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Alternative Splicing
  • Coccidia / isolation & purification
  • Coccidia / pathogenicity
  • Coccidia / physiology*
  • Gene Expression Profiling
  • Gene Expression Regulation*
  • Life Cycle Stages
  • Merozoites / genetics
  • MicroRNAs
  • Oocysts / genetics
  • Protozoan Proteins / genetics*
  • RNA, Long Noncoding
  • RNA, Protozoan
  • Single-Cell Analysis / methods

Substances

  • MicroRNAs
  • Protozoan Proteins
  • RNA, Long Noncoding
  • RNA, Protozoan