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Peggy Biga, PhD

Peggy R. Biga PhD
Assistant Professor
Department of Biology
Campbell Hall 464D
Phone: 205-934-9684
Research Profile

My research questions focus on the mechanisms regulating differential growth paradigms. In other words, we are interested in learning how some organisms have the ability to continually grow new muscle fibers throughout life, while other organisms cannot.

Specifically, we aim to identify novel regulators of muscle cell growth and to determine how myogenic progenitor cells contribute to regeneration/repair in response to several common stimuli, including injury or stress, nutritional alterations, and environmental contamination. The following are primary questions we are working to answer:

  1. What mechanisms regulate muscle cell growth and myogenic precursor cell fate choice?
    • To address this question, we utilize several fish models using comparative approaches. Two closely-related fish species that exhibit opposing growth paradigms, giant danio:indeterminate and zebrafish:determinate-like, appear to regulate growth in different ways. We are using these species in a parallel manner to understand why some satellite cells become new muscle cells, while others join pre-existing cells. We are using normal growth, enhanced growth, and injury-induced scenarios to identify these parameters. 
    • Using indeterminate growing models-giant danio and rainbow trout-we are investigating how quiescent satellite cells are activated following various different stressors (injury, increased lipid signaling and deposition, and infection).
    • Using recently validated primary myoblast cultures, we are investigating the presence of embryonic-like myogenic precursor cells in adult organisms that exhibit indeterminate growth potential. We have identified specific pathways in adult indeterminate growing organisms that are present only during embryonic myogenesis in determinate growing organisms. We aim to demonstrate that these pathways ensure increased myofiber number potential in indeterminate growth models.
  2. What role does myostatin play outside of muscle growth regulation?
    • We are focusing on the role myostatin plays in lipid metabolism, insulin signaling, and cellular growth. We are interesting in identifying the role of the extracellular matrix in regulating mstn signaling.
    • We are also analyzing the co-regulation of the stress and growth axes in relation to myostatin in Salmonids.

Recent Publications:

  • Meyer, B.M., J.M. Froehlich, N.J. Galt and P.R. Biga. Inbred strains of zebrafish exhibit variation in growth performance and myostatin expression following fasting. Accepted for publication, Comparative Biochemistry and Physiology. 
  • Rosauer, D.R., P.R. Biga, S. Lindell, F.P. Binkowski, B. Shepherd, C. Simchick, F.W. Goetz. 2011. Development of yellow perch (Perca flavescens) broodstocks: physical characteristics after grow-out of different strains of yellow perch. Aquaculture. 317:58-66.
  • Lyons, J.A., Haring, J.S., and Biga, P.R. 2010. Myostatin expression, lymphocyte population, and potential cytokine production correlate with predisposition to high-fat diet induced obesity in mice. PLoS One. 5(9): e12928. doi: 10.1371/journal.pone.0012928.
  • Biga, P.R. and J. L. Meyer. 2009. Growth hormone differentially regulates growth and growth-related gene expression in closely related fish species. Comp Biochem Phys. A. 154:465-473.
  • Biga, P.R. and F.W. Goetz. 2006. Zebrafish and giant danio as models for muscle growth: Determinate versus indeterminate growth as determined by morphometric analysis. Am J Physiol: Reg Integ Comp Physiol. 291:R1327-R1337.
  • Biga, P.R., Roberts S.R., Iliev D.B., McCauley L.A.R., and Goetz F.W. 2005. The isolation, characterization, and expression of a novel GDF11 gene and a second myostatin form in zebrafish, Danio rerio. Comp Biochem Phys. B. 141:218-230.
  • Biga, P.R., Peterson B.C., Schelling G.T., Hardy R.W., Cain K.D., Overturf K., and Ott T.L. 2005. Serum somatotropin, insulin-like growth factor-I, and antibody production in rainbow trout (Oncorhynchus mykiss) treated with sustained-release bovine somatotropin (rbST). Aquaculture. 246:437-445.
  • Ettensohn K.M., Biga P., Romano C., Devlin R.H., Roberts S.B. 2004. Genes differentially expressed in growth hormone transgenic salmon. Biol Bull. Oct; 207(2):168.
  • Biga, P.R., K.D. Cain, R.W. Hardy, G.T. Schelling, K. Overturf, S.B. Roberts, F.W. Goetz, and T.L. Ott. 2004. Growth hormone differentially regulates myostatin-I and –II and increases circulating cortisol in rainbow trout (Oncorhynchus mykiss). Gen Comp Endocrinol. 138(1):32-41.
  • Congleton, J.L., P.R. Biga, and B.C. Peterson.  2004. Plasma insulin-like growth factor-I in yearling Chinook salmon (Oncorhynchus tshawytscha) migrating from the Snake River Basin, USA. Fish Physiol Biochem. 29:57-66
  • Biga, P.R., K.D. Cain, R.W. Hardy, K. Overturf, G.T. Schelling, and T.L. Ott. 2004. The effects of recombinant bovine somatotropin (rbST) on tissue IGF-I, IGF-I receptor, and GH mRNA levels in rainbow trout (Oncorhynchus mykiss). Gen Comp Endocrinol. 135(3):324-333.
  • Peterson, B.C., P.R. Simpson, K.D. Cain, R.W. Hardy, G.T. Schelling, and T.L. Ott. 2003. Immunoneutralization of SS in rainbow trout administration of somatostatin-14 and immunoneutralization of somatostatin in rainbow trout (Oncorhynchus mykiss).  J Fish Biol. 63:506-522.