Bone Development in Laboratory Mammals Used in Developmental Toxicity Studies

Research Gate

September 25, 2018

Dr. John DeSesso, Principal Scientist in Exponent's Health Sciences practice, recently published a paper (co-authored by Dr. Anthony Scialli), which discusses the importance of distinguishing adverse skeletal outcomes from minor ossification delays and presents the chronologic embryology of the rodent, rabbit, and primate skeletons to assist in interpretation of skeletal findings.


Evaluation of the skeleton in laboratory animals is a standard component of developmental toxicology testing. Because the skeleton is undergoing developmental changes at the time fetuses are evaluated, transient delays in development can result in what appears to be findings of abnormal skeletal structure such as alterations in the number, shape, and size of ossification centers, and alterations in the numbers of ribs and vertebrae. Determination of whether such findings are permanent changes with adverse consequences is important in study interpretation.

The paper appeared in Birth Defects Research and can be accessed online.