Peggy Biga headshot.

Peggy Biga

Assistant Professor
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Campbell Hall 173A
(205) 934-9684

Research and Teaching Interests: Comparative Growth Biology, Developmental Physiology, Diet-Epigenetic Interactions, Skeletal Muscle Growth Regulation, Science Community Outreach, k-12 Science Engagement

Office Hours: By appointment

Education:

  • B.A., Angelo State University, Animal Science
  • M.A., Angelo State University, Nutrition
  • Ph.D., University of Idaho, Nutritional Physiology
  • Post-doctoral Training: Marine Biological Laboratory, Woods Hole, MA, Comparative Physiology

Dr. Peggy Biga is a broadly trained comparative endocrine physiologist, with primary research interests focusing on the mechanisms regulating growth patterns in animals. Her research questions revolve around what molecular and epigenetic mechanisms regulate skeletal muscle proliferation, differentiation, and atrophy. She uses comparative biology to understand the plasticity of regulatory mechanisms and how they translate to variability in overall organismal growth.

For example, most, and arguably all, terrestrial mammals reach a growth plateau around the time they reach sexual maturity which is characterized by a lack of nascent (or new) muscle fiber development post-embryonic growth. Alternatively, many aquatic vertebrates exhibit an opposing growth paradigm where no true growth plateau is reached, and skeletal muscle continues to growth through the addition of nascent muscle fibers throughout their life. The main focus of Dr. Biga’s lab for many years has been to identify molecular pathways and mechanisms that regulate the ability of some animals to continually grow (by adding NEW muscle fibers) throughout their lives. As a post-doctoral scientist, Dr. Biga identified and verified a comparative model system that can be used to ask these questions. She demonstrated that two closely related fish species, the zebrafish and giant danio, exhibit differential growth paradigms. The zebrafish, a commonly used model organism, exhibits a growth pattern that closely mirrors what is seen in human muscle growth, where muscle growth is accomplished post-birth/hatch with little to no addition of new muscle fibers, but instead through the enlargement of pre-existing fibers. Alternatively, a close relative to the zebrafish, the giant danio, exhibit continual addition of nascent muscle fibers throughout their lives. By juxtaposing the growth of these two fish species, Dr. Biga has identified transcription factors and myogenic regulatory factors that are differentially regulated between the growth types.

Research Opportunities
Dr. Biga is currently recruiting a Ph.D. graduate student to focus their graduate research on investigating the role of dietary amino acids on the epigenetic control of growth physiology. This Ph.D. position is funded through a GRA provided by the USDA and would start in Fall 2018. Students interested in joining Dr. Biga’s laboratory should send Dr. Biga an email at This email address is being protected from spambots. You need JavaScript enabled to view it. containing an outline of your research interests and your curriculum vitae.

Dr. Biga’s research interests also focus on the endocrine regulation of growth biology, with particular focus on the GH-IGF system in relation to myostatin control of cell proliferation, cell differentiation, and energy metabolism. Myostatin is a negative regulator of muscle growth, and is known to be sensitive to GH and IGF signaling in muscle tissue. In addition, Dr. Biga has shown that myostatin is also responsive to stress hormones, like cortisol, which is likely to be involved in stress-induced muscle atrophy. Also, Dr. Biga is interested in the direct action GH might have on muscle cells in relation to cell proliferation and differentiation, and cellular respiration. This work is primarily conducted using the rainbow trout as a model, as this fish species is an important species for the US aquaculture industry.

In addition, Dr. Biga’s research also focuses on how diet influences the mechanisms that regulation growth and metabolism. Her lab researches questions related to how individual nutrients influence growth and metabolic physiology, and how these nutrients alter the epigenome to regulate changes in physiology. Within this area of research, Dr. Biga has demonstrated that amino acid (ex., methionine) restriction alters muscle cell proliferation and induces autophagy in vitro. In addition, Dr. Biga’s lab has also demonstrated that methionine restriction affects glucose metabolism that is likely regulated through changes in miRNA expression in a tissue-specific manner. On the other side of the diet-epigenetic interaction research focus, Dr. Biga is interested in evaluating how methyl-donor amino acid supplementation can affect growth physiology through maternal imprinting.

Dr. Biga participates in several collaborations with scientists in France, Canada, and the US on research projects that focus on how endocrinology, molecular biology, epigenetics, and physiology interact to regulate growth physiology.

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Research Interests

The overall goal of my research program is to identify mechanisms regulating organismal growth potential, with specific interest on mechanisms allowing for continual growth throughout an organism’s life (indeterminate growth). My lab addresses this goal using many approaches that range from cellular to organismal: molecular biology, cell biology, endocrinology, physiology, and morphology. Generally, my lab utilizes piscine species as model organisms because they offer diverse growth potentials and serve as excellent comparative platforms. The following projects are currently active and are being primarily driven by graduate and undergraduate students in my lab:

Epigenetic regulation of myogenesis is regulated by specific nutrients, namely amino acids.

Working closely with Dr. Jean-Charles Gabillard (INRA, Rennes, France) and Dr. Iban Seiliez (INRA, St. Pee, France) we have characterized the histone methylation profile related to pax7 and myogenin expression during in vitro myogenesis in Rainbow trout, an indeterminate growing fish. We recently also demonstrated that methionine depletion specifically alters this epigenetic profile, as well as reverts myoblasts to the quiescent state, suggesting a role of histone methylation in myogenic progression regulation. This quiescence appears to be reversible with addition of methionine. We are currently investigating the role of microRNAs as part of this mechanism as well.

Nutritional state regulates atrophy/hypertrophy balance in myogenic cells in vitro.

Working closely with Dr. Jean-Charles Gabillard (INRA, Rennes, France) and Dr. Iban Seiliez (INRA, St. Pee, France) we have characterized a novel in vitro model of amino acid depletion induced autophagy using zebrafish as a model organism. Using an amino acid depleted media, we can induce autophagy without apoptosis during myogenesis in vitro. We have characterized the histone methylation profiles affected by this cell phenotype switch and identified Atg4b, p62/sqstrm1, and lc3b as tightly regulated by starvation during the onset of autophagy.

Maternal nutritional transfer regulates growth via epigenetic mechanisms.

Working closely with Dr. Beth Cleveland (USDA, ARS, Leetown, WV USA) we have demonstrated that supplementing maternal broodstock diets with choline results in enhanced offspring growth performance. Also, we recently demonstrated that choline supplemented diet intake results in increased levels of choline into the pre-fertilized eggs. We hypothesized that maternal dietary intake regulates growth performance through changes in epigenetic mechanisms regulating growth. Choline serves as a methyl donor, and we are currently evaluating the role of choline supplementation on methylome changes.

The role of paired box transcription factors (Pax) in regulating myogenic stem cell populations.

My lab has recently demonstrated that indeterminate growing fish species exhibit a unique a pax3 expression profile in adult myogenic progenitor cells (MPCs; muscle stem cells) compared to determinate growing organisms. MPCs from adult indeterminate growing danios are pax3+/+, while determinate growing danios’ MPCs are pax3-/- (similar to adult mammalian MPCs) suggesting a potential role of pax3 in regulate MPC function. We are currently working to empirically test a role of pax3 in MPC function by knocking it down (morpholino and siRNA) in isolated MPCs.

Myogenic precursor cell contribution to muscle repair across the life-course in indeterminately growing species. Question: Does repair capacity decrease with age in indeterminate growing species?

We are currently characterizing the muscle repair program in indeterminately growing fish species (trout and danios) to establish a baseline understanding of the cells, genes, and pathways that play key roles in muscle repair in juvenile, sexually mature, and aged organisms. We hypothesize that species with high pax3 expression in MPCs as adults will have an enhanced repair capacity compared to species lacking pax3 expression as adults. Additionally, we will examine the role of growth hormone, IGF-I, IGF-II, and myostatin in muscle repair related to aging decline (or lack thereof).

The role of Teneurin C-terminal Associated Peptide (TCAP) in muscle function and metabolism during aging.

In collaboration with Dr. David Lovejoy (University of Toronto, Canada) and his PhD student Andrea D’Aquila we are investigating the conserved function of TCAP in muscle hypertrophy and metabolic control in teleosts. In addition, we have pilot funds from the Nathan Shock Center to examine the role TCAP plays in regulating muscle function decline during aging in the short-lived killifish model. We are also examining the effects of chronic TCAP treatment on zebrafish muscle hypertrophy and metabolic regulation. We will also begin evaluating the role TCAP plays in starvation-induced autophagy in primary myotubes in vitro. This work is specifically and uniquely informative for human muscular repair/regeneration and wasting disorders.

These research projects cover the general topic of mechanisms regulating muscle growth and repair, the overarching theme of my research program. This work is translatable to human health as mammals lose their ability to adequately repair their muscle tissue with age. In some teleost species, this functional decline in muscle structure and function is not observed and we hypothesize that the mechanisms that allow for continued growth throughout the lives of these organisms plays an important role in delaying muscle senescence (or wasting). In addition, improving adult muscle repair capabilities is extremely important in wound healing. In addition, this work is translatable to production agriculture, as further understanding of mechanisms regulating fish growth, from epigenetics to endocrinology, has direct applicability to the production efficacy to several finfish industries (including rainbow trout).

Recent Courses

  • BY 429, BY 491, BY 629: Evolution
  • BY 245: Fundamentals of Scientific Investigation
  • Comparative Developmental Biology
  • Introductory Biology I
  • Non-thesis research credit (Science Mentorship in Inner City Schools)

Graduate Students

Current Students
  • Mary Latimer, Ph.D. Student
  • Ross Reid, Ph.D. Student
  • Amber Requena, M.S. Student
  • Khalid Freij, M.S. Student

Select Publications

  • Reid, R., A. D’Aquila, and P.R. Biga. 2018. The validation of a sensitive, non-toxic in vivo metabolic assay applicable across zebrafish life stages. Comp. Biochem. Physiol. C. (E-pub ahead of print, Nov. 2017) doi: 10.1016/j.cbpc.2017.11.004 PMID: 29162498
  • Latimer, M., B.M. Cleveland, and P.R. Biga. 2018. Dietary Methionine Restriction: Effects on Glucose Tolerance, Lipid Content and micro-RNA composition in the muscle of Rainbow Trout. Comp. Biochem. Physiol. C. (E-pub ahead of print, Oct. 2017) doi: 10.1016/j.cbpc.2017.10.012 PMID: 29100953
  • Galt, N.J., J.M. Froehlich, S.D. McCormick, and P.R. Biga. 2018. A comparative evaluation of crowding stress on muscle HSP90 and myostatin expression in salmonids. Aquaculture. 483:141-148. doi: 10.1016/j.aquaculture.2017.10.019
  • Biga, P.R., M.N. Latimer, J.M. Froehlich, J.C. Gabillard, and I. Seiliez. 2017. Distribution of H3K27me3, H3K9me3, and H3K4me3 along authophagy-related genes highly expressed in starved zebrafish myotubes. Biol. Open 6(11):1720-1725. doi: 10.1242/bio.029090 PMID: 29025701
  • Latimer, M.N., N. Sabin, A. Le Cam, I. Seiliez, P. Biga, and J.C. Gabillard. 2017. miR-210 expression is associated with methionine-induced differentiation of trout satellite cells. J Exp. Biol. 220(Pt 16):2932-2938. doi:10.1242/jeb.154484 PMID: 28576820.
  • Galt, N.J., S.D. McCormick, J.M. Froehlich, and P.R. Biga. 2016. A comparative examination of cortisol effects on muscle myostatin and HSP90 gene expression in salmonids. General and Comparative Endocrinology. 237:19-26. doi:10.1016/j.gcen.2016.07.019 PMID: 27444129.
  • Seiliez, I., J.M. Froehlich, L. Marandel, J.C. Gabillard, and P.R. Biga. 2015. Evolutionary history and epigenetic regulation of the three paralogous pax7 genes in rainbow trout. Cell Tissue Research. 359(3):715-27. PMID: 25487404.
  • Allison DB, Antoine LH, Ballinger SW, Bamman MM, Biga P, Darley-Usmar VM, Fisher G, Gohlke JM, Halade GV, Hartman JL, Hunter GR, Messina JL, Nagy TR, Plaisance RP, Roth KA, Sandel MW, Schwartz TS, Smith DL, Sweatt JD, Tollefsbol TO, Watts SA, Yang Y, Zhang J, Austad, S, and Powell ML. 2014. Aging and energetics’ ‘Top 40’ future research opportunities 2010-2013 [v1; ref status: indexed http://f1000r.es/4ae] F1000Research, 3:219 doi: 10.12688/f1000research.5212.1
  • Galt, N.J., J.M. Froehlich, E.A. Remily, S.R. Romero, and P.R. Biga. 2014. The effects of exogenous cortisol on myostatin transcription in rainbow trout, Oncorhynchus mykiss. Comp. Biochem. Phsyiol. A. Mol Intergr. Physiol. 175:57-63. PMID: 24875565.
  • Picha, M.E., P.R. Biga, N. Galt, A.S. McGinty, K. Gross, V.S. Hedgepeth, T.D. Siopes, and R.J. Borski. 2014. Overcompensation of circulating and local insulin-like growth factor-I during catch-up growth in hybrid striped bass (Morone chrysops X Morone saxatilis) following temperature and feeding manipulation. Aquaculture. 428-429:174-183.
  • Froehlich, J.M., I. Seiliez, J.C. Gabillard, and P.R. Biga. 2014. Preparation of Primary Myogenic Precursor Cell/Myoblast Cultures from Basal Vertebrate Lineages. Journal of Visualized Experiments. Apr 30;(86). doi:10.3791/51354. PMID: 24835774.
  • Goetz, F.W., A. Jasonowicz, R. Johnson, P. Biga, G. Fischer, and S. Sitar. 2014. Physiological differences between siscowet and lean trout morphotypes: Are these metabolotypes? Canadian Journal of Fisheries and Aquatic Sciences. 71(3):427-435.
  • Galt, N.J., J.M. Froehlich, B.M. Meyer, F.T. Barrows, and P.R. Biga. 2014. High-fat diet reduces local myostatin-1 paralog expression and alters skeletal muscle lipid content in rainbow trout, Oncorhynchus mykiss. Fish Physiology and Biochemistry. 40(3):875-86. PMID: 24264425.
  • Gabillard, J.C., P.R. Biga, P.Y. Rescan, and I. Seiliez. 2013. Revisiting the paradigm of myostatin in vertebrates: insights from fishes. Gen. Comp. Endocrinol. 194C:45-54. PMID: 24018114.
  • Froehlich, J.M., Z.G. Fowler, N.J. Galt, D.L. Smith Jr., and P.R. Biga. 2013. Sarcopenia and piscines: the case for indeterminate-growing fish as unique genetic model organisms in aging and longevity research. Frontiers of Genetics in Aging. 4:159. PMID: 23967015.
  • Froehlich, J.M., N.J. Galt, M.J. Charging, B.M. Meyer, and P.R. Biga. 2013. In vitro indeterminate teleost myogenesis appears to be dependent on Pax3. In vitro Cellular and Developmental Biology- Animal. 49(5):371-385. PMID: 23613306.
  • Biga, P.R., J.M. Froehlich, K.J. Greenlee, N.J. Galt, B.M. Meyer, and D.J. Christensen. 2013. Gelatinases impart susceptibility to high-fat diet induced obesity in mice. Journal of Nutritional Biochemistry. 24(8):1462-8. PMID: 23465590.
  • Meyer, B.M., J.M. Froehlich, N.J. Galt and P.R. Biga. 2013. Inbred strains of zebrafish exhibit variation in growth performance and myostatin expression following fasting. Comparative Biochem. Physiol. A. 164(1):1-9. PMID: 23047051.

Underlined names represent undergraduate student co-authors.

Academic Distinctions and Professional Societies

  • Society of Integrative and Comparative Biology
  • American Fisheries Society, Physiology Chapter
  • North American Society of Comparative Endocrinology

Student Groups

I co-host the department’s annual Darwin Day. If you are interested in this celebration of science, please contact me!

I organize and manage an outreach program that focuses on science engagement and achievement in the Birmingham Public Schools. This program matches UAB (graduate) students with a local k-5 or k-8 public school, where the UAB student works with science teachers to enhance science learning and exposure. Contact me if you are interested!