Zeredo, J. | bioRxiv Science

bioRxiv2023

Evolution of threat response-related polymorphisms at the SLC6A4 locus in callitrichid primates

Variation in an upstream repetitive region at the SLC6A4 locus, which encodes a serotonin transporter, is associated with anxiety-related behaviour in a few primate species, including humans and rhesus macaques. In this study we investigate evolution of SLC6A4 polymorphisms associated with anxiety-related behaviour in common marmosets (Callithrix jacchus). Assaying variation in the SLC6A4 repeat region across 14 species in 8 genera of callitrichid primates (marmosets and tamarins) we find large interspecific variation in the number of repeats present (24-43). The black tufted-ear marmoset (C. penicillata) has sequence polymorphisms similar to those found in the common marmoset, which is its sister species, and no other species has intraspecific variation at these sites. We conclude that, similar to humans and rhesus macaques, the functional polymorphism at SLC6A4 in common marmosets has a recent evolutionary origin, and that the anxiety-related allele is evolutionarily derived. Common/black tufted-ear marmosets and rhesus macaques share high ecological adaptability and behavioural flexibility that we propose may be related to the maintenance of the polymorphism.

evolutionary biology↗

bioRxiv2018

Characterization of oral microbiota in marmosets: feasibility of using the marmoset as a human oral disease model

As the worlds population is aging, there is an increasing demand for research regarding aging and aging-related disorders, to achieve better understanding of aging. Ideally, such research would be performed with human subjects. However, due to ethical considerations, animals such as rodents and monkeys are used as alternatives. Among these alternative models, non-human primates are preferred because they share common traits with humans. The small South American common marmoset (Callithrix jacchus) may offer a number of advantages over other non-human primates in terms of its relatively small size, short life span, and identical dental anatomy, compared with humans. The purpose of this study was to clarify the viability of using the marmoset as a human oral disease model.\n\nWe collected saliva samples from eight common marmosets and eight human subjects. Prokaryotic DNA was extracted from the saliva samples, and 16S bacterial rRNA gene sequencing was performed on each of the samples. Our results indicated that the types of oral microbiomes detected among human and marmoset samples were nearly identical. In contrast, the oral microbiomes of our human and marmoset subjects were distinctly different from those of rat and dogs, which are popular animal models. The oral microbiomes of marmosets showed greater diversity than those of humans. With respect to individual variation, marmosets exhibited less variation in their oral flora, compared with humans. This difference in variation might be attributed to the fact that marmoset subjects were kept in a controlled environment with identical lifestyles.\n\nThe characteristics of its oral microbiota, combined with other technical advantages, suggest that the marmoset may provide the best animal model thus far for the study of oral health. This study characterized the oral microbes of the marmoset, thereby providing information to support future application of the marmoset as a model for age-related oral disease.

microbiology↗