Functional Specialization of Human Salivary Glands and Origins of Proteins Intrinsic to Human Saliva.
To understand the glandular origins of proteins in saliva, we performed the hitherto most comprehensive investigation of gene expression in healthy human salivary glands. Our results revealed that each mature salivary gland type contributes a distinct repertoire of proteins to saliva. We provide evidence that these unique, gland-specific secreted protein profiles emerge late in gland development. Our results suggest that the origins of salivary proteins in whole mixed saliva can be parsed out only through an integrative analysis of both protein and RNA levels.
Human and Non-Human Lineage-Specific Footprints in the Salivary Proteome.
Here, we compared the proteomes of human saliva and the saliva of our closest extant evolutionary relatives, chimpanzees and gorillas, using macaques as an outgroup, with the aim to uncover features in saliva protein composition that are unique to each species. We found that humans produce a waterier saliva, containing less than half total protein than great apes and Old World monkeys. For all major salivary proteins in humans, we could identify counterparts in chimpanzee and gorilla saliva. However, we discovered unique protein profiles in saliva of humans that were distinct from those of nonhuman primates. These findings open up the possibility that dietary differences and pathogenic pressures may have shaped a distinct salivary proteome in the human lineage.
Pajic P, Pavlidis P, Dean K, Neznanova L, Romano R-A, Garneau D, Daugherity E, Globig A, Ruhl S*, Gokcumen O*. (2019) eLife https://doi.org/10.7554/eLife.44628.001
Independent Amylase Gene Copy Number Bursts Correlate with Dietary Preferences in Mammals.
Here, we present comprehensive evidence for AMY copy number expansions that independently occurred in several mammalian species which consume diets rich in starch. We also provide correlative evidence that AMY gene duplications may be an essential first step for amylase to be expressed in saliva. Our findings underscore the overall importance of gene copy number amplification as a flexible and fast evolutionary mechanism that can independently occur in different branches of the phylogeny.
Glycan Recognition at the Saliva – Oral Microbiome Interface
Review article describing the important roles of salivary glycans in oral microbial ecology and host defense.
Archaic Hominin Introgression in Africa Contributes to Functional Salivary MUC7 Genetic Variation
Our investigation revealed a significant association of MUC7 haplotypic variation with the composition of the oral microbiome. Furthermore, we conclude that a divergent MUC7 haplotype likely originated in an unknown African hominin population and introgressed into ancestors of modern Africans.
Complete List of Publications from our Laboratory in Google Scholar
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