Faculty Profile

• Health Professions Advisor
• President, Merrimack College Chapter of Sigma Xi, the Scientific Research Society

Courses Taught: Principles I Laboratory, Genetics, Embryonic Development, Molecular Biology and Biotechnology, Directed Research and Senior Thesis Research

Research Interests

Members of the 18 different classes of myosin molecular motors have been found in all eukaryotes where they perform various cell motility functions such as cytokinesis and growth cone migration in of axons. During embryonic development, several examples of the roles myosin can play have come from studying various model systems such as Drosophila.  An important role in development has been revealed for Myo1d.  The Drosophila homologue of vertebrate myo1d, DmMyo31DF, is the first actin based motor shown to play a role in left-right asymmetry determination.  Mutants exhibit complete situs inversus of gut and testes.

We are investigating the roles that this same myosin isoform, XlMyo1d, can play during frog embryonic development.  XlMyo1d is a member of the myosin I, subclass 4.  Members of the myosin I class are single headed, bind calmodulin light chains and have lipid binding domains in their tails. The rat Myo1d homologue has been implicated in endosome vesicle recycling in epithelial cells. Our laboratory has cloned the  Xenopus Myo1d cDNA and determined that the derived amino acid sequence is 80% identical to the rat and human homologue.  Western blot analysis using a polyclonal antibody raised against an isoform specific peptide showed that the protein is present in eggs and levels increase at early neurula through tadpole stages.  Whole mount in situ hybridization using a probe containing the 5’UTR (untranslated region) showed that XlMyo1d mRNA is expressed in neural tube, pre-somitic mesoderm, somites and all three segments of cranial neural crest cells during their migration. 

Sections of the in situ hybridizations revealed that during somitogenesis, XlMyo1d mRNA was localized to a stripe overlapping the nuclear region of somites during early tadpole stages.  Preliminary data indicates that elimination of this myosin isoform causes profound perturbation in development including the failure to hatch, greatly reduced twitching response, inhibition of somite formation, and other anatomical abnormalities.  These continue to be investigated.

My research laboratory is maintained to provide undergraduate students with a quality research experience while making meaningful contributions to the scientific literature. Students who have participated in the research projects in my lab have gone on to acquire Ph.D.s in biochemistry, pathology, molecular biology, and completed M.D./Ph.D. and nurse practitioner programs. Several others are technicians in the biotech industry and at medical schools.