Preprint presents whole-genome resource for over 800 US research marmosets, revealing unexpected population structure

A preprint submitted to bioRxiv describes the results of a systematic genomic census of the common marmoset (Callithrix jacchus) population used in biomedical research across the United States. Working through the NIH Marmoset Coordinating Center, the authors registered and sampled the majority of living US research marmosets — approximately 2,300 animals — and assembled pedigree and historical records for more than 10,000 individuals.

The resource includes over 800 whole-genome sequences, primarily from US research colonies. Analysis of these data revealed unexpected population structure: the marmosets do not form a single homogeneous genetic pool, as might be assumed for a captive research population, but instead show distinct substructure that the authors report predates the establishment of US colonies. The origins of this structure are explored in the preprint, with implications for how colony ancestry and genetic background are considered in the design and interpretation of biomedical studies.

Pedigree reconstruction is central to the resource, making it directly relevant to researchers working on marmoset genomics, comparative genomics, and the genetics of ageing and neurodevelopment, fields in which the marmoset is an increasingly used model organism. The dataset also serves as a reference for researchers interested in captive-population management and inbreeding avoidance.

This work is a preprint and has not yet undergone peer review.