Daniel G. Miller, MD, PhD (Pediatrics)
Dr. Miller and members of his research group utilize induced pluripotent stem cells (IPSc) made from the skin cells of individuals with Facioscapulohumeral Muscular Dystrophy (FSHD) to understand the etiology of this debilitating condition. The hypothesis is that FSHD is caused by a defect in muscle development and/or maintenance so studying differences between control and patient embryonic cells as they differentiate to form muscle may reveal key mechanisms of disease pathology. Dr. Miller is also interested in treatment strategies for genetic conditions so members of his research group use vectors based on Adeno-Associated Virus (AAV) to perform gene targeting in primary human cells. This approach is currently being applied to keratinocytes from patients affected with a skin blistering condition called Epidermolysis Bullosa. The molecular consequence of disease-causing mutations can also be studied by creating the same mutations in primary human cells, or correcting mutations in cells from affected patients.
Dr. Miller also sees patients with genetic conditions in the pediatric medical genetics clinic at Children’s Hospital.
Hannele Ruohola-Baker, PhD (Biochemistry)
This group has recently shown that Dcr-1-deficient germ line stem cells are delayed in the CDK-inhibitor We p21/p27/Dacapo-dependent G1/S transition, suggesting that miRNAs are required for stem cells to bypass the normal G1/S checkpoint (Hatfield et al., 2005, Nature). Hence, the miRNA pathway might be part of a mechanism that makes stem cells insensitive to environmental signals that normally stop the cell cycle at the G1/S transition. Since miRNAs are a novel class of genes involved in human tumorgenesis, it is tempting to speculate that miRNAs could play a similar role in cancer cells. The investigator is now moving towards analyzing micro RNA function in humans.
Billie Swalla, PhD (Biology)
We are studying stem cells in colonial ascidians. In botryllid ascidians, there are multiple stem cells which circulate in the blood. Some stem cells are necessary to form a new individual asexually, and there are also germline stem cells for gametes to develop in the ovary and testes. We are developing molecular markers to identify various stem cells circulating in the colonial ascidians, in order to understand their potential. Brown et al. (2009; Development 136: 3485-3494) has shown that there are germline precursors that are specified early, but then continue to populate gonads as they develop. We have also shown that these colonial ascidians undergo extensive regeneration, thorough activation of a piwi-positive stem cell population (Brown et al. 2009; JEZ:MDE 312B: 885-900).