Examining adaptive evolution of immune activity: opportunities provided by gastropods in the age of ‘omics’

Abstract

Parasites threaten all free-living organisms, including molluscs. Understanding the evolution of immune defence traits in natural host populations is crucial for predicting their long-term performance under continuous infection risk. Adaptive trait evolution requires that traits are subject to selection (i.e. contribute to organismal fitness) and that they are heritable. Despite broad interest in the evolutionary ecology of immune activity in animals, the understanding of selection on and evolutionary potential of immune defence traits is far from comprehensive. For instance, empirical observations are only rarely in line with theoretical predictions of immune activity being subject to stabilizing selection. This discrepancy may be because ecoimmunological studies can typically cover only a fraction of the complexity of an animal immune system. Similarly, molecular immunology/immunogenetics studies provide a mechanistic understanding of immunity, but neglect variation that arises from natural genetic differences among individuals and from environmental conditions. Here, we review the current literature on natural selection on and evolutionary potential of immune traits in animals, signal how merging ecological immunology and genomics will strengthen evolutionary ecological research on immunity, and indicate research opportunities for molluscan gastropods for which well-established ecological understanding and/or ‘immune-omics’ resources are already available. This article is part of the Theo Murphy meeting issue ‘Molluscan genomics: broad insights and future directions for a neglected phylum’.

A comparative account of coelomocyte of earthworm ecotypes with reference to its morphology, morphometry, density, phagocytosis, autofluorescence, and oxidative status

“…In recent years, ecological immunology has been the focus of comparative immunologists (Seppällä et al, 2021). Comparative analyses of the functional morphological parameters in organism inhabiting different ecological niches have been studied.…”

“…In recent years, ecological immunology has been the focus of comparative immunologists (Seppällä et al, 2021). Comparative…”

Pearls of wisdom—a Theo Murphy issue on molluscan genomics

“…In their review, Potts et al [22] specifically discuss the current state and future potential of genomic technologies to improve disease resistance in aquaculture. Similarly, Seppälä et al [23] argue that the understanding of the evolution of immune defence traits in natural host populations is crucial for predicting their long-term performance under continuous infection risk. They review the opportunities and challenges in ecoimmunology across gastropods, indicating research opportunities in gastropod molluscs for which well-established ecological understanding and/or ‘immune-omics' resources are already available.…”

Occurrence of Cruzia tentaculata Larvae in the Land Snail Megalobulimus abbreviatus—Influence of Natural Parasite Load on Snail Physiology

“…Numerous studies have focused on gastropods that are intermediate hosts of nematode parasites, due to the diseases that these parasites cause in domestic and wild animals (Collela et al, 2015; Valente et al, 2017; Penagos-Tabares et al, 2019), as well as humans (Bouthemy et al, 1972; Pavanelli et al, 2017; Valente et al, 2018). Despite the estimate that millions of domestic animals and humans are infected with snail-transmitted infections, there is a lack of precise information from the field about the relationship between the number of infected snails, dictated by immunocompatibility between parasite and snail, and ecological factors that limit infections (Adema et al, 2012; Seppälä et al, 2021).…”