Using Planarian Regeneration to Engage Students in Critical Evaluation of Developmental Biology Data

This lesson focuses on elucidating the mechanisms of regeneration in the planarian, Schmidtea mediterranea. Planarians can regenerate all mature cells and complex tissues through their abundant population of pluripotent stem cells. They have a brain, eyes, peripheral nervous system, tri-branched intestine, several types of muscle, and a pharynx for feeding and waste excretion. Previous work has shown that stem cells differentiate into early progeny, late progeny, and eventually mature cell types as they lose the expression of a stem cell gene called piwi. This paper focuses on intestinal regeneration and how it is perturbed by knocking down apolipoprotein genes. Based on an article by Wong and colleagues, upper-division science majors will explore in situ hybridization (ISH), RNA interference (RNAi), and fluorescence-activated cell sorting (FACS) data with a critical lens, synthesizing their knowledge into a predicted model for the gene apolipoprotein b (apob) in intestinal regeneration. This lesson addresses the critical need for science students to apply knowledge of course concepts to scientific data and build their understanding of molecular techniques. Primary Image: Planarian regenerating a head and tail after amputation. The unpigmented tissue, called the blastema, is the new tissue formed after amputation. Newly formed eyespots can be seen in the blastema after 7 days post-amputation (far right).