Common marmoset (Callithrix jacchus) in biomedical research
Ricki J. Colman
Overview
Common marmosets, or white-tufted-ear marmosets (Callithrix jacchus), have been subjects in biomedical research since the 1960’s1. In recent years, their popularity as a research model has increased dramatically, prompted to a large degree by their realized utility for neuroscience and aging research2,3 as well as their potential as a nonhuman primate transgenic model4,5. Many factors make the marmoset an attractive model system including their genetic and physiological similarity to humans, relatively short lifespan, high fertility, rapid development, small size and human-like social structure.
Common marmosets are diurnal, arboreal Neotropical primates within the family Cebidae and subfamily Callithrichinae which is comprised of over 40 species including marmosets, tamarins and Goeldi’s monkey6. They are endemic to northeastern Brazil where they live in environments ranging from the humid Atlantic Forest to the dry scrub forest of the Caatinga7. They remain abundant in Northeastern Brazil and are classified as “Least Concern” by the IUCN Red List of Threatened Species8.
Common marmosets are small-bodied and lack sexual dimorphism. The marmosets small body size (~300-500 grams in captivity) is a derived trait of declining body size and is therefore considered a case of phyletic dwarfism9. Common marmosets are considered infants until 3-4 months of age, juveniles from 4-5 months to 10 months of age, sub-adults from 11 months of age until they reach sexual maturity and are considered adults at approximately 13-15 months of age. Common marmosets are considered aged by approximately 8 years, and in captivity they have a median lifespan of approximately 10 years and a maximum lifespan of approximately 16-20 years10. Little is known about marmoset lifespan in the wild given the inherent difficulties in acquiring such data. Common marmosets become reproductively competent by 1.5 years of age and then go on to regularly produce fraternal twins or triplets (and occasionally quadruplets) every five to six months making them among the most fecund of the anthropoid primates. Their small body size along with routine twining results in an overall high litter weight compared to the dam’s weight. Marmosets have been known to be hematopoietic chimeras since the 1960’s11. Early in gestation, the placentas fuse allowing for exchange of genetically distinct stem cells which results in naturally occurring chimeric animals12. Whether chimerism in marmosets extends beyond hematopoietic cells in still a matter of debate12–14.
Marmosets have several adaptations specific for their diet and arboreal habitat. Their long tail helps them maintain balance while moving along tree branches and they have claw-like nails (tegulae) on all but their big toe that allow them to effectively cling vertically to trees, run quadrupedally across branches and leap between trees. Their claws, along with their enlarged chisel-shaped incisors, also allow marmosets to gouge trees in search of the exudates that form the basis of their diet15. To digest these exudates, marmosets have a large and complex cecum16. In addition to tree exudates, common marmosets consume an omnivorous diet including fruit (preferred when available), insects, seeds, flowers, and small amphibians, reptiles and mammals17.
Common marmosets live in cooperative breeding groups of approximately 3-17 individuals generally consisting of a breeding pair, other adults, sub-adults juveniles and infants6. Generally, only the dominant male and female breed, while other group members assist in raising offspring forming a cooperative breeding system comparable to that of humans18. To facilitate this arrangement, subordinate females in the group are reproductively suppressed19. In the wild, breeding strategies may be more flexible20,21.
Research Contributions/Biomedical models
Though similar in size to rodents, marmosets share physiological, behavioral, and cognitive characteristics that distinguish primates from all other animals. This along with their small body size, rapid development, high fecundity and 93% sequence identity with the human genome22,23 represents a unique opportunity to study biomedical processes that are not feasible to model in other nonhuman primates. Tools that further enhance the value of this species include complete sequencing, assembly, and annotation of the marmoset genome24, generation of induced pluripotent stem cells, and production of transgenic marmosets – the first successful production of a transgenic nonhuman primate with germline transmission25. Common marmosets are particularly interesting for longitudinal and lifespan studies and provide advantages for studies involving modern molecular gene-editing technologies. They have been particularly useful in neuroscience studies given similarities between marmosets and humans in behavior, cognition, and communication as well as shared brain architecture and a smooth cortex that facilities certain types of experiments. The small body size of marmosets is particularly attractive for early-stage pharmaceutical testing where smaller amounts of the substance would need to be produced than if using a larger bodied model.
1. Aging
Given their rapid aging course, common marmosets are perhaps an ideal animal model for aging studies as the dynamics of the aging process can be studied longitudinally potentially throughout the entire lifespan. Importantly, their rapid life history means that within a 5-year period, three generations of offspring can be produced and during this time the founding animals will progress through old age. Furthering their utility as an aging model, common marmosets develop similar age-related conditions as humans. For example, they exhibit age-related declines in lean muscle mass, motor function, hearing, and cognition26,27 and changes in microbiome28 and the immune system29. Marmosets show a marked age-related increase in diabetes, cardiovascular disease, inflammatory conditions, cancers, amyloidosis, pathogenic tau accumulation, and renal diseases, as do humans4,30. Obesity along with dyslipidemia and altered glucose metabolism leading to hepatomegaly, hepatic steatosis, diabetes, atherosclerosis, cardiomyopathies, and stroke is becoming a more frequent finding in captive marmosets31,32. Age-related increases in insulin resistance have been detected33 and potential biomarkers of aging have been identified in the plasma metabolome34. These facts have led to interest in a marmoset aging model of obesity and metabolic syndrome.
2. Neuroscience
Marmosets have a small brain with a smooth cortex, expanded temporal lobe and a highly developed prefrontal cortex. This, along with notable similarities in their social behavior, cognition, sensory perception, and communication with humans, make common marmosets uniquely suited to explore neuroscience questions and to model neuropsychological and neurodegenerative disorders that affect humans. At the central nervous system level, efforts are ongoing to characterize age-related changes in the marmoset brain27,35 and associated changes in perception, cognition and motor function36,37. Marmosets are a popular model for neurodegenerative diseases including Parkinson’s, Alzheimer’s, Huntington’s and multiple sclerosis, due to the existence of validated behavioral, surgical and imaging techniques38 and their similarities with humans, including evidence of age-related decreases in neurogenesis that occur prior to old age39. Marmosets have been particularly useful as a neurotoxin induced model of Parkinson’s disease40 and genetic models of Parkinson’s disease have been developed5. Of particular interest, aged marmosets spontaneously develop β-amyloid deposition and tauopathies41, both implicated in the pathogenesis of Alzheimer’s disease. Because the high rate of failure in
Alzheimer’s disease clinical trials has been ascribed, in part, to the inadequacy of rodent models that recapitulate only limited aspects of Alzheimer’s disease pathology, these features of marmoset biology position them as an excellent primate model for advancing our understanding of Alzheimer’s disease.
3. Transgenics
Genetically modified rodent models have contributed significantly to our understanding of a myriad of diseases, however extrapolation from rodents to humans is challenging due to physiological and anatomical differences between the species. Genetically modified nonhuman primates could mitigate this translation issue. For transgenic production, the small size, fast maturation, and high fecundity of the marmoset provide logistical advantages, as does the marmosets amenability to modern molecular gene-editing technologies. Dr. Sasaki and colleagues first reported successful germline transmission of a transgene in marmosets in 200925. Since then, efforts to implement modern gene-editing technologies in marmosets have accelerated. These have included development of CRISPR42 and viral based approaches43 including techniques with high potential for translation to humans such as intravenous delivery of viral capsids designed to cross the blood-brain barrier44. Research has focused on developing genetically modified marmosets to model Alzheimer’s disease45, Parkinson’s disease42 and other age-related brain disorders. In addition, techniques such as optogenetics, chemogenetics, and calcium-imaging have been developed in marmosets to selectively manipulate brain circuits46,47 and better understand large populations of neurons48. As this critical line of research and technical development continues to evolve, the promise of marmosets as a primate model that can leverage genetic technologies is beginning to be realized.
1. Tardif, S. Context for the use of marmosets as animal models. in Care, Use, and Welfare of Marmosets as Animal Models for Gene Editing-Based Biomedical Research: Proceedings of a Workshop (National Academies Press, 2019).
2. Servick, K. U.S. labs clamor for marmosets. Science 362, 383–384 (2018).
3. Rodriguez-Callejas, J. D., Fuchs, E. & Perez-Cruz, C. Evidence of Tau Hyperphosphorylation and Dystrophic Microglia in the Common Marmoset. Front. Aging Neurosci. 8, 315 (2016).
4. Colman, R. J. Non-human primates as a model for aging. Biochim. Biophys. Acta Mol. Basis Dis. 1864, 2733–2741 (2018).
5. Sasaki, E. Prospects for genetically modified non-human primate models, including the common marmoset. Neurosci. Res. 93, 110–115 (2015).
6. de Fátima Arruda, M., Yamamoto, M. E., de Almeida Pessoa, D. M. & Araujo, A. Taxonomy and Natural History. in The Common Marmoset in Captivity and Biomedical Research 3–15 (Elsevier, 2019). doi:10.1016/B978-0-12-811829-0.00001-7.
7. Schiel, N. & Souto, A. The common marmoset: An overview of its natural history, ecology and behavior. Dev. Neurobiol. 77, 244–262 (2017).
8. Miranda, J. M. D. et al. IUCN Red List of Threatened Species: Callithrix jacchus. IUCN Red List Threat. Species (2015).
9. Montgomery, S. H. & Mundy, N. I. Parallel episodes of phyletic dwarfism in callitrichid and cheirogaleid primates. J. Evol. Biol. 26, 810–819 (2013).
10. Ross, C. N. Marmosets in Aging Research. in The Common Marmoset in Captivity and Biomedical Research 355–376 (Elsevier, 2019). doi:10.1016/B978-0-12-811829-0.00021-2.
11. Benirschke, K., Anderson, J. M. & Brownhill, L. E. Marrow Chimerism in Marmosets. Science 138, 513–515 (1962).
12. Sweeney, C., Ward, J. & Vallender, E. J. Naturally occurring, physiologically normal, primate chimeras. Chimerism 3, 43–44 (2012).
13. Ross, C. N., French, J. A. & Orti, G. Germ-line chimerism and paternal care in marmosets (Callithrix kuhlii). Proc Natl Acad Sci U A 104, 6278–82 (2007).
14. Wedi, E. et al. Detection of cross-sex chimerism in the common marmoset monkey (Callithrix jacchus) in interphase cells using fluorescence in situ hybridisation probes specific for the marmoset X and Y chromosomes. Reprod. Fertil. Dev. (2016) doi:10.1071/RD15321.
15. Garber, P. A. Vertical clinging, small body size, and the evolution of feeding adaptations in the Callitrichinae. Am. J. Phys. Anthropol. 88, 469 (1992).
16. Kramer, J. A. Chapter 13 - Diseases of the Gastrointestinal System. in The Common Marmoset in Captivity and Biomedical Research (eds. Marini, R., Wachtman, L., Tardif, S., Mansfield, K. & Fox, J.) 213–230 (Academic Press, 2019). doi:10.1016/B978-0-12-811829-0.00013-3.
17. Power, M. L. & Koutsos, L. Marmoset nutrition and dietary husbandry. in The Common Marmoset in Captivity and Biomedical Research (eds. Marini, R., Wachtman, L., Tardif, S., Mansfield, K. & Fox, J.) 570 (Academic Press, 2019).
18. Saito, A. The marmoset as a model for the study of primate parental behavior. Neurosci. Res. 93, (2015).
19. Abbott, D. H., Barnett, D. K., Colman, R. J., Yamamoto, M. E. & Schultz-Darken, N. J. Aspects of common marmoset basic biology and life history important for biomedical research. Comp. Med. 53, 339–350 (2003).
20. Arruda, M. F. et al. Two breeding females within free-living groups may not always indicate polygyny: alternative subordinate female strategies in common marmosets (Callithrix jacchus). Folia Primatol. Int. J. Primatol. 76, 10–20 (2005).
21. Digby, L. J. Sexual behavior and extragroup copulations in a wild population of common marmosets (Callithrix jacchus). Folia Primatol. Int. J. Primatol. 70, 136–145 (1999).
22. Marmoset Genome, S. & Analysis, C. The common marmoset genome provides insight into primate biology and evolution. Nat Genet 46, 850–7 (2014).
23. Warren, W. C. et al. Sequence diversity analyses of an improved rhesus macaque genome enhance its biomedical utility. Science 370, (2020).
24. Jayakumar, V. et al. An improved de novo genome assembly of the common marmoset genome yields improved contiguity and increased mapping rates of sequence data. BMC Genomics 21, 243 (2020).
25. Sasaki, E. et al. Generation of transgenic non-human primates with germline transmission. Nature 459, 523–527 (2009).
26. Ross, C. N. et al. Cross-sectional comparison of health-span phenotypes in young versus geriatric marmosets. Am J Primatol 81, e22952 (2019).
27. Workman, K. P., Healey, B., Carlotto, A. & Lacreuse, A. One-year change in cognitive flexibility and fine motor function in middle-aged male and female marmosets (Callithrix jacchus). Am. J. Primatol. 81, e22924 (2019).
28. Reveles, K. R., Patel, S., Forney, L. & Ross, C. N. Age-related changes in the marmoset gut microbiome: REVELES ET AL. Am. J. Primatol. 81, e22960 (2019).
29. Mietsch, M., Paqué, K., Drummer, C., Stahl‐Hennig, C. & Roshani, B. The aging common marmoset’s immune system: From junior to senior. Am. J. Primatol. 82, (2020).
30. Ross, C. N., Davis, K., Dobek, G. & Tardif, S. D. Aging Phenotypes of Common Marmosets (Callithrix jacchus). Journal of Aging Research https://www.hindawi.com/journals/jar/2012/567143/ (2012) doi:10.1155/2012/567143.
31. Tardif, S. D. et al. Characterization of obese phenotypes in a small nonhuman primate, the common marmoset (Callithrix jacchus). Obes. Silver Spring Md 17, 1499–1505 (2009).
32. Wachtman, L. M. et al. Differential Contribution of Dietary Fat and Monosaccharide to Metabolic Syndrome in the Common Marmoset (Callithrix jacchus). Obesity 19, 1145–1156 (2011).
33. Tardif, S. D., Mansfield, K. G., Ratnam, R., Ross, C. N. & Ziegler, T. E. The Marmoset as a Model of Aging and Age-Related Diseases. ILAR J. Natl. Res. Counc. Inst. Lab. Anim. Resour. 52, 54–65 (2011).
34. Hoffman, J. M. et al. A longitudinal analysis of the effects of age on the blood plasma metabolome in the common marmoset, Callithrix jacchus. Exp. Gerontol. 76, 17–24 (2016).
35. Freire-Cobo, C. et al. Neuronal vulnerability to brain aging and neurodegeneration in cognitively impaired marmoset monkeys (Callithrix jacchus). Neurobiol. Aging 123, 49–62 (2023).
36. Sadoun, A., Rosito, M., Fonta, C. & Girard, P. Key periods of cognitive decline in a nonhuman primate model of cognitive aging, the common marmoset (Callithrix jacchus). Neurobiol. Aging 74, 1–14 (2019).
37. Rothwell, E. S. et al. The marmoset as an important primate model for longitudinal studies of neurocognitive aging. Am. J. Primatol. 83, (2021).
38. Yun, J.-W., Ahn, J.-B. & Kang, B.-C. Modeling Parkinson’s disease in the common marmoset (Callithrix jacchus): overview of models, methods, and animal care. Lab. Anim. Res. 31, 155–165 (2015).
39. Leuner, B., Kozorovitskiy, Y., Gross, C. G. & Gould, E. Diminished adult neurogenesis in the marmoset brain precedes old age. Proc. Natl. Acad. Sci. U. S. A. 104, 17169–17173 (2007).
40. Santana, M., Palmér, T., Simplício, H., Fuentes, R. & Petersson, P. Characterization of long-term motor deficits in the 6-OHDA model of Parkinson’s disease in the common marmoset. Behav. Brain Res. 290, 90–101 (2015).
41. Perez-Cruz, C. & Rodriguez-Callejas, J. de D. The common marmoset as a model of neurodegeneration. Trends Neurosci. S0166-2236(23)00043–7 (2023) doi:10.1016/j.tins.2023.02.002.
42. Vermilyea, S. C. et al. In Vitro CRISPR/Cas9-Directed Gene Editing to Model LRRK2 G2019S Parkinson’s Disease in Common Marmosets. Sci. Rep. 10, 3447 (2020).
43. Dimidschstein, J. et al. A viral strategy for targeting and manipulating interneurons across vertebrate species. Nat. Neurosci. 19, 1743–1749 (2016).
44. Flytzanis, N. C. et al. Broad gene expression throughout the mouse and marmoset brain after intravenous delivery of engineered AAV capsids. http://biorxiv.org/lookup/doi/10.1101/2020.06.16.152975 (2020) doi:10.1101/2020.06.16.152975.
45. Yoshimatsu, S. et al. Robust and efficient knock-in in embryonic stem cells and early-stage embryos of the common marmoset using the CRISPR-Cas9 system. Sci. Rep. 9, 1528 (2019).
46. MacDougall, M. et al. Optogenetic manipulation of neural circuits in awake marmosets. J. Neurophysiol. 116, 1286–1294 (2016).
47. Mimura, K. et al. Chemogenetic activation of nigrostriatal dopamine neurons in freely moving common marmosets. iScience 24, 103066 (2021).
48. Santisakultarm, T. P. et al. Two-photon imaging of cerebral hemodynamics and neural activity in awake and anesthetized marmosets. J. Neurosci. Methods 271, 55–64 (2016).