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Christopher Arnold, Ph.D.

Assistant Professor

Arnold Lab Website:

The Arnold Lab aims to build a better understanding of animal growth, behavior, and regeneration by studying planarian asexual reproduction.

Images of planaria before (top) and after (bottom) undergoing fission for asexual reproduction.

Planarians are are truly masters of regeneration. If you cut a piece of tissue from a planaria, it will regrow what was lost in less than a week. At the same time, that small piece of tissue will regenerate into an entirely new planaria. These flatworms are so skilled at regeneration that they use it as a form of reproduction. Planaria will undergo fission to divide their bodies into tissue fragments that regenerate into clones of the parent animal. Most recently, we have discovered novel roles for Hox genes, conserved regulators of embryonic patterning, in the regulation of multiple biological processes underlying planarian asexual reproduction. By studying fundamental biology in this accessible animal model, we aim to gain new insights into the complex biology of human health and disease.

Amputated planarian
Amputated planarian tissue (left) after 1 week (middle) or 2 weeks (right) of regeneration.

The Arnold Lab is currently interested in questions such as how growth is regulated in an animal that can perpetually regrow all of its tissues, which genes underlie the ability of an animal to asexually reproduce, and how regeneration proceeds in different contexts of tissue loss. To tackle these questions, we employ a variety of molecular biology, microscopic imaging, behavioral analysis, and bioinformatic approaches.

Fluo RNACombinatorial labelling with molecular probes reveals underlying planaria anatomy and gene expression. Fluorescent RNA probes delineate the stem cells (red), nervous system (green), gut (blue), adhesive gland cells (cyan), lateral anchor cells (magenta), and the expression of evolutionarily conserved hox genes (yellow). Image Credit: Jason Morrison and Zulin Yu of the Stowers Institute of Medical Research.

Open positions are available at the undergraduate, masters, graduate, and research technician levels. Please contact Dr. Arnold for more information.


We are currently seeking a lab technician to join our team. If you are interested, please click the link below for more details on the position.