Red Queen revisited: Immune gene diversity and parasite load in the asexual Poecilia formosa versus its sexual host species P. mexicana

Pathogen communities can vary substantially between geographical regions due to different environmental conditions. However, little is known about how host immune systems respond to environmental variation across macro-ecological and evolutionary scales. Here, we select 37 species of songbird that inhabit diverse environments, including African and Palaearctic residents and Afro-Palaearctic migrants, to address how climate and habitat have influenced the evolution of key immune genes, the major histocompatibility complex class I (MHC-I). Resident species living in wetter regions, especially in Africa, had higher MHC-I diversity than species living in drier regions, irrespective of the habitats they occupy. By contrast, no relationship was found between MHC-I diversity and precipitation in migrants. Our results suggest that the immune system of birds has evolved greater pathogen recognition in wetter tropical regions. Furthermore, evolving transcontinental migration appears to have enabled species to escape wet, pathogen-rich areas at key periods of the year, relaxing selection for diversity in immune genes and potentially reducing immune system costs.

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Immune gene diversity in archaic and present-day humans

10.1101/348581 ◽

2018 ◽

Author(s):

David Reher ◽

Felix M. Key ◽

Aida M. Andrés ◽

Janet Kelso

Keyword(s):

Gene Diversity ◽

Innate Immune ◽

Immune Gene ◽

Similar Reduction ◽

Protein Coding ◽

Immune Genes ◽

Genome Wide ◽

Show Evidence ◽

Functional Consequences ◽

Immune Related Genes

Genome-wide analyses of two Neandertals and a Denisovan have shown that these archaic humans had lower genetic heterozygosity than present-day people. A similar reduction in genetic diversity of protein-coding genes (gene diversity) was found in exome sequences of three Neandertals. Reduced gene diversity, and particularly in genes involved in immunity, may have important functional consequences. In fact, it has been suggested that reduced diversity in immune genes may have contributed to Neandertal extinction. We therefore explored gene diversity in different human groups and at different time points on the Neandertal lineage with a particular focus on the diversity of genes involved in innate immunity and genes of the Major Histocompatibility Complex (MHC).We find that the two Neandertals and the Denisovan have similar gene diversity, both significantly lower than any present-day human. This is true across gene categories, with no gene set showing an excess decrease in diversity compared to the genome-wide average. Innate immune-related genes show a similar reduction in diversity to other genes, both in present-day and archaic humans. There is also no observable decrease in gene diversity over time in Neandertals, suggesting that there may have been no ongoing reduction in gene diversity in later Neandertals, although this needs confirmation with a larger sample size. In both archaic and present-day humans, genes with the highest levels of diversity are enriched for MHC-related functions. In fact, in archaic humans the MHC genes show evidence of having retained more diversity than genes involved only in the innate immune system.

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Chromosomal evidence for laboratory synthesis of a triploid hybrid between the gynogenetic teleost Poecilia formosa and its host species

Journal of Fish Biology ◽

10.1111/j.1095-8649.1995.tb01928.x ◽

1995 ◽

Vol 47 (4) ◽

pp. 619-623 ◽

Cited By ~ 27

Author(s):

I. Nanda ◽

M. Schartl ◽

W. Feichtinger ◽

I. Schlupp ◽

J. Parzefall ◽

...

Keyword(s):

Host Species ◽

Triploid Hybrid ◽

Poecilia Formosa ◽

Laboratory Synthesis

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Low innate immune-gene diversity in the critically endangered orange-bellied parrot (Neophema chrysogaster)

Emu - Austral Ornithology ◽

10.1080/01584197.2019.1686994 ◽

2019 ◽

Vol 120 (1) ◽

pp. 56-64 ◽

Cited By ~ 2

Author(s):

Caitlin E. Morrison ◽

Carolyn J. Hogg ◽

Rosemary Gales ◽

Rebecca N. Johnson ◽

Catherine E. Grueber

Keyword(s):

Gene Diversity ◽

Innate Immune ◽

Critically Endangered ◽

Immune Gene ◽

Innate Immune Gene

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Improving the sensitivity of gastrointestinal helminths detection using the Mini-FLOTAC technique in wild birds

10.21203/rs.3.rs-370319/v1 ◽

2021 ◽

Author(s):

Dante Lobos-Ovalle ◽

Claudio Navarrete ◽

Juan G. Navedo ◽

Miguel Peña-Espinoza ◽

Claudio Verdugo

Keyword(s):

Specific Gravity ◽

Host Species ◽

Parasite Load ◽

Gastrointestinal Parasites ◽

Wild Birds ◽

Parasitic Infections ◽

Analytical Sensitivity ◽

Gastrointestinal Helminths ◽

Fecal Samples ◽

Flotac Technique

Abstract High-performance validated tests are essential for successful epidemiological monitoring, surveillance of parasitic infections, and comparative studies in wildlife populations. The Mini-FLOTAC is a novel flotation-based technique for the sensitive detection and quantification of gastrointestinal parasites that is recently being explored for use in wildlife. A limitation of any flotation-based copromicroscopic method is the selection of the flotation solution (FS), which might influence the performance of the test. However, no study has compared the influence of using different FS in the Mini-FLOTAC technique for parasite detection in wild birds. Here, we evaluated the diagnostic performance of the Mini-FLOTAC in three waterbird host species using two widely used FS: saturated salt (NaCl; specific gravity 1.20) and saturated zinc sulfate (ZnSO4; specific gravity 1.35). One hundred fresh fecal samples were analyzed for parasite fecal egg counts (FEC). Regardless of the host species, fecal samples evaluated with the Mini-FLOTAC method using ZnSO4 resulted in a significantly higher detection rate and higher FEC of strongylid, capillarid, cestode, and trematode parasites, than samples analyzed with the NaCl solution. Our concise study demonstrated the importance of using an appropriate FS for the identification of parasite eggs in wildlife species, especially in hosts with an expected aggregated distribution and low parasite load such as waterbird hosts. The higher analytical sensitivity of the Mini-FLOTAC technique achieved with ZnSO4, and its applicability to fieldwork, highlights this method as a promising tool for the quantitative surveillance of parasite infections in wild bird populations.

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Evidence for reduced immune gene diversity and activity during the evolution of termites

10.1101/2020.07.09.192013 ◽

2020 ◽

Author(s):

Shulin He ◽

Thorben Sieksmeyer ◽

Yanli Che ◽

M. Alejandra Esparza Mora ◽

Petr Stiblik ◽

...

Keyword(s):

Gene Family ◽

Gene Diversity ◽

Immune Gene ◽

Gene Repertoire ◽

Individual Level ◽

Social Defense ◽

Major Transition ◽

Species Comparisons ◽

Organismal Complexity ◽

Multicellular Organisms

AbstractThe evolution of biological complexity is associated with the emergence of bespoke immune systems that maintain and protect organism integrity. Unlike the well studied immunity at the cell and individual level, little is known about the origins of immunity during the transition to eusociality, a major evolutionary transition comparable to the evolution of multicellular organisms from single-celled ancestors. We tackle this by characterizing the immune gene repertoire of 18 cockroach and termite species, spanning the spectrum of solitary, subsocial and eusocial lifestyles. We identified five significant immune gene family contractions and one immune gene family expansion along the spine of a time-calibrated phylogeny, correlating with key transitions in termite sociality. In cross-species comparisons of immune gene expression, we find that termites appear to have evolved a caste-specific social defense system at the expense of individual immune protection. Our study indicates that a major transition in organismal complexity entailed a fundamental reshaping of the immune system optimized for group over individual defense.

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Evidence for reduced immune gene diversity and activity during the evolution of termites

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2020.3168 ◽

2021 ◽

Vol 288 (1945) ◽

pp. 20203168

Author(s):

Shulin He ◽

Thorben Sieksmeyer ◽

Yanli Che ◽

M. Alejandra Esparza Mora ◽

Petr Stiblik ◽

...

Keyword(s):

Gene Diversity ◽

Immune Gene ◽

Gene Repertoire ◽

Evolutionary Transition ◽

Immune Systems ◽

Immune Gene Expression ◽

Major Transition ◽

Species Comparisons ◽

Organismal Complexity ◽

Multicellular Organisms

The evolution of biological complexity is associated with the emergence of bespoke immune systems that maintain and protect organism integrity. Unlike the well-studied immune systems of cells and individuals, little is known about the origins of immunity during the transition to eusociality, a major evolutionary transition comparable to the evolution of multicellular organisms from single-celled ancestors. We aimed to tackle this by characterizing the immune gene repertoire of 18 cockroach and termite species, spanning the spectrum of solitary, subsocial and eusocial lifestyles. We find that key transitions in termite sociality are correlated with immune gene family contractions. In cross-species comparisons of immune gene expression, we find evidence for a caste-specific social defence system in termites, which appears to operate at the expense of individual immune protection. Our study indicates that a major transition in organismal complexity may have entailed a fundamental reshaping of the immune system optimized for group over individual defence.

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Allelic diversity of DQA2 exon 2 gene in Egyptian goat populations

Indian Journal of Animal Research ◽

10.18805/ijar.v0iof.7660 ◽

2017 ◽

Author(s):

Sahar S. Ahmed ◽

Salah M. Abdel-Rahman ◽

Paul J. Grobler ◽

Antoinette Kotzé

Keyword(s):

Genetic Diversity ◽

Gene Diversity ◽

Allelic Diversity ◽

Single Strand Conformation Polymorphism ◽

Immune Gene ◽

Exon 2 ◽

Goat Population ◽

Allele Composition ◽

The Difference ◽

Conformation Polymorphism

The study aimed to assess the genetic diversity of 2-decyl-4-quinazolinyl amine exon2 (DQA2 exon2) gene among the Egyptian goat populations from different agro-climatic areas. Data of diseases distribution as well as blood samples were collected. The data collected for diseases distribution showed differences in the types of diseases between the agro-climatic areas. The Single Strand Conformation Polymorphism technique (SSCP) was used to assess the genetic diversity of DQA2 exon2 gene among the goat populations. The results showed that the DQA2 exon2 gene locus displayed 21 alleles with different frequencies in each of goat population. The gene diversity values among the populations ranged from 0.950± 0.022 to 0.887± 0.033. The difference between the most southern population (Aswan) and the remaining populations translate to significant (P less than 0.05) differentiation for only one population pair (Aswan – Baladi, with FST= 0.055; P= 0.001). Scrutiny of allele composition in these two goat populations showed unique alleles in each population (six in Aswan and four in Baladi). The results of the study suggested that the allelic numbers and allelic composition for the DQA2 exon2 gene among the Egyptian goat populations showed diversity in the immune gene due to the different pathogens exposure.

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