Fish Study Reveals Secrets of Immune System Evolution and Adaptation

Author: University of East Anglia
Published: 2017/11/06 - Updated: 2025/04/22
Publication Details: Peer-Reviewed, Anthropology News
Category Topic: Anthropology and Disability - Academic Publications

Page Content: Synopsis - Introduction - Main - Insights, Updates

Synopsis: This research presents findings from a scholarly study published in Nature Communications that explores how fish, specifically guppies, provide valuable insight into the evolution of the immune system. By analyzing the immune genes known as Major Histocompatibility Complex (MHC) genes in guppies, scientists discovered that these fish can finely tune their immune responses to adapt to diverse and changing parasitic threats, while the core functions of these genes remain remarkably stable over tens of millions of years. This duality - rapid adaptation at the population level alongside deep evolutionary conservation - helps explain why some human immune genes are nearly identical to those found in our primate relatives, such as chimpanzees. The information is authoritative and useful because it is based on rigorous genetic analysis and comparative studies, offering a clearer understanding of how immune systems can maintain essential protective functions while also evolving to meet new environmental challenges. These insights are especially relevant for people with disabilities, seniors, and immunocompromised individuals, as they highlight the fundamental mechanisms that underpin immune resilience and adaptation, which could inform future medical research and therapies for immune-related conditions - Disabled World (DW).

Introduction

New research from the University of East Anglia (UEA), UK, and Dalhousie University, Canada, reveals how immune systems can evolve resistance to parasites.

Main Content

Scientists from UEA and Dalhousie University studied how Guppy fish (Poecilia reticulata) adapt to survive by studying their immune genes, known as the Major Histocompatibility Complex or MHC genes.

They found that guppies fine-tune these genes in each location, enabling them to adapt and survive in many different and extreme environments. Despite this adaptation, genes maintained critical function of tens of millions of years.

The discovery could improve scientists' understanding of how related species can adapt and change their immune system to cope with new threats from parasites while simultaneously sharing similar function.

Dr Jackie Lighten from UEA led the study. He said:

"Guppies are a small, colorful fish native to South America, Trinidad and Tobago. They are a fantastic model for researching the ecology and evolution of vertebrates."

"MHC genes are an important line of defense in the immune system in vertebrates, including humans. Because parasites evolve quicker than their vertebrate hosts, immune genes need to be highly diverse to keep up with parasites and prevent infections."

"MHC genes produce protein structures that are on the external surface of cells. These genes are diverse and so produce an array of proteins, each of which presents a specific part of a parasite or pathogen that has attempted to infect the body. The specific shape of the protein dictates which parasites it can recognize, and signals to the immune system to prevent infection."

The study looked at MHC genetic variation in 59 guppy populations across Trinidad, Tobago, Barbados, and Hawaii. The authors found hundreds of different immune variants, but these so called 'alleles' appear to be clustered in a smaller number of functional groups or 'supertypes'.

Prof van Oosterhout, also from UEA's School of Environmental Sciences, said:

"Each supertype protects the host against a specific group of parasites, and these supertypes were common across populations, and species, irrespective of the location."

"However, the alleles that make up a supertype track the rapid evolution of the parasites, and they too are evolving rapidly. These alleles are largely specific to each population, and they help in the 'fine-tuning' of the immune response to the specific (local) parasites that attack the host in that population."

Before this study, scientists debated how these immune genes can evolve rapidly (which is necessary to keep up with the fast-evolving parasites), whilst also showing little or no evolutionary change in their function over millions of years, as observed between humans and chimpanzees. This study resolves that debate.

Prof Bentzen from Dalhousie University said:

"Although this study focused on MHC genes in vertebrates, the evolutionary dynamics described in it likely apply to other gene families, for example resistance genes and those which prevent self-fertilization in plants (self-incompatibility loci) that are caught up in their own evolutionary races."

Dr Lighten added:

"It is an important step forward in understanding the evolutionary genetics of the immune system, and can help explain some of the puzzling observations observed in previous studies of many other organisms."

Funding Disclosure

The research was funded by the British Ecological Society, Natural Sciences and Engineering Research Council of Canada (NSERC) and the Biotechnology and Biological Sciences Research Council (BBSRC).

'Evolutionary genetics of immunological supertypes reveals two faces of the Red Queen' is published in the journal Nature Communications on November 3, 2017.

Insights, Analysis, and Developments

Attribution/Source(s): This peer reviewed publication was selected for publishing by the editors of Disabled World (DW) due to its relevance to the disability community. Originally authored by University of East Anglia and published on 2017/11/06, this content may have been edited for style, clarity, or brevity.