Cross-species comparison of mammalian saliva using an LC-MALDI based proteomic approach

Abstract

Despite the importance of saliva in the regulation of oral cavity homeostasis, few studies have been conducted to quantitatively compare the saliva of different mammal species. Aiming to define a proteome signature of mammals' saliva, an in-depth SDS-PAGE-LC coupled to MS/MS (GeLC-MS/MS) approach was used to characterize the saliva from primates (human), carnivores (dog), glires (rat and rabbit), and ungulates (sheep, cattle, horse). Despite the high variability in the number of distinct proteins identified per species, most protein families were shared by the mammals studied with the exception of cattle and horse. Alpha-amylase is an example that seems to reflect the natural selection related to digestion efficacy and food recognition. Casein protein family was identified in all species but human, suggesting an alternative to statherin in the protection of hard tissues. Overall, data suggest that different proteins might assure a similar role in the regulation of oral cavity homeostasis, potentially explaining the specific mammals' salivary proteome signature. Moreover, some protein families were identified for the first time in the saliva of some species, the presence of proline-rich proteins in rabbit's saliva being a good example.

The Saliva Proteome of Dogs: Variations Within and Between Breeds and Between Species

“…By using mass spectrometry based proteomics, ten common proteins were found across seven mammals: carbonic anhydrase, albumin, polymeric immunoglobulin receptor, prolactin‐inducible protein, lactoperoxidase, glutathione‐S‐transferase, and keratins 1, 9, and 10. De Sousa‐Pereira et al., additionally reported that histatins and statherin were not found in dogs. In the present study, we set out to quantitatively analyze the protein composition of canine saliva for the first time in two differently sized breeds, Labrador retriever (large) and Beagles (medium), and to compare these with human saliva.…”

“…In depth analysis of the protein composition of canine saliva from three mixed breed individuals has been initiated by de Sousa‐Pereira et al. (2015) . Using qualitative gel electrophoresis to compare to other mammals, including humans, they demonstrated that canine saliva contained a smaller proportion of lower molecular weight proteins.…”

Comparison of carnivore, omnivore, and herbivore mammalian genomes with a new leopard assembly

“…Specialized diets have resulted in a number of physiological, biochemical, and morphological adaptations. In carnivores, several key diet-related physiological traits have been identified, including differences in digestive enzymes [7], shortened digestive tracts [8], changes in amino acid dietary requirements [9, 10], and alterations to taste bud sensitivities (including a heightened response to amino acids and a loss of response to many mono- and di-saccharides) [11, 12], to name a few. In addition to these characteristics, the morphology of cats is highly adapted to hunting and includes flexible bodies, fast reflexes, and strong muscular limbs.…”

Production of functional human nerve growth factor from the saliva of transgenic mice by using salivary glands as bioreactors

“…Furthermore, saliva contains a smaller number and amount of endogenous proteins than milk, which may be advantageous for the purification of expressed foreign proteins. For example, the number of proteins detected in the saliva of humans and cattle is about 120013 and 90013 respectively, while the total protein concentration is 0.72 mg/ml14 and about 0.6–1.8 mg/ml15. More importantly, saliva can be collected repeatedly from various animals, including mouse, pig, cattle, sheep and goat by surgical or non-surgical methods121617181920.…”