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Mammalia comprises a great diversity of diet types and associated adaptations. An understanding of the genomic mechanisms underlying these adaptations may offer insights for improving human health. Comparative genomic studies of diet that employ taxonomically restricted analyses or simplified diet classifications may suffer reduced power to detect molecular convergence associated with diet evolution. Here, we use a quantitative carnivory score—indicative of the amount of animal protein in the diet—for 80 mammalian species to detect significant correlations between the relative evolutionary rates of genes and changes in diet. We have identified six genes—ACADSB,CLDN16,CPB1,PNLIP,SLC13A2, andSLC14A2—that experienced significant changes in evolutionary constraint alongside changes in carnivory score, becoming less constrained in lineages evolving more herbivorous diets. We further consider the biological functions associated with diet evolution and observe that pathways related to amino acid and lipid metabolism, biological oxidation, and small molecule transport experienced reduced purifying selection as lineages became more herbivorous. Liver and kidney functions show similar patterns of constraint with dietary change. Our results indicate that these functions are important for the consumption of animal matter and become less important with the evolution of increasing herbivory. So, genes expressed in these tissues experience a relaxation of evolutionary constraint in more herbivorous lineages.
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This content will become publicly available on November 6, 2025
Evolution of g-type lysozymes in metazoa: insights into immunity and digestive adaptations
Exploring the evolutionary dynamics of lysozymes is critical for advancing our knowledge of adaptations in immune and digestive systems. Here, we characterize the distribution of a unique class of lysozymes known as g-type, which hydrolyze key components of bacterial cell walls. Notably, ctenophores, and choanoflagellates (the sister group of Metazoa), lack g-type lysozymes. We reveal a mosaic distribution of these genes, particularly within lophotrochozoans/spiralians, suggesting the horizontal gene transfer events from predatory myxobacteria played a role in their acquisition, enabling specialized dietary and defensive adaptations. We further identify two major groups of g-type lysozymes based on their widespread distribution in gastropods. Despite their sequence diversity, these lysozymes maintain conserved structural integrity that is crucial for enzymatic activity, underscoring independent evolutionary pathways where g-type lysozymes have developed functionalities typically associated with different lysozyme types in other species. Specifically, usingAplysia californicaas a reference species, we identified three distinct g-type lysozyme genes: two are expressed in organs linked to both feeding and defense, and the third exhibits broader distribution, likely associated with immune functions. These findings advance our understanding of the evolutionary dynamics shaping the recruitment and mosaic functional diversification of these enzymes across metazoans, offering new insights into ecological physiology and physiological evolution as emerging fields.
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- Award ID(s):
- 2341882
- PAR ID:
- 10621717
- Publisher / Repository:
- Frontiers
- Date Published:
- Journal Name:
- Frontiers in Cell and Developmental Biology
- Volume:
- 12
- ISSN:
- 2296-634X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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