Vertebrate and Invertebrate Animal Models for the Study of Down Syndrome

Down syndrome (DS) is the most common survivable chromosome trisomy, with an incidence of about 1 in 600-700 births. Consequences of chromosome 21 trisomy include developmental delays, congenital cardiac abnormalities, skeletal abnormalities, and age-related dementia of the Alzheimer's disease (AD) type. Up to 90% of individuals with DS develop dementia symptoms in their 40s or 50s. Because the biological mechanisms involved in DS-related developmental and age-related pathology are less known, animal models consisting of both lower-order and higher-order animals have been developed. We here review the most pertinent and well-studied DS animal models including models developed in C. elegans, Drosophila, zebrafish, and mice. Molecular pathways involved in DS morbidity that were discovered in animal models will also be discussed.