My area of specialization is physiology, and more specifically; the molecular, cellular and systemic physiology of growth, development and adaptation to environment. I primarily assess and evaluate the physiological status of striated muscle in the context of nutritional changes, growth promoters, and genetic variation using advanced, high-throughput molecular tools such as gene expression analyses (qRT-PCR), transcriptome analyses, proteomic, enzymatic and biochemical assays. My program is a balance between the advancement and characterization of basic science and knowledge of the mechanistic determinants of muscle growth and industry relevant applied science targeting improved performance and growth in meat producing animals in Idaho.
Selected Publications
Refereed Journals
- K. J. Thornton, C.M. Welch, L.C. Davis, M.E. Doumit, R.A. Hill, G.K. Murdoch Bovine sire selection based upon maintenance energy impacts muscle fiber type and meat color of F1 progeny J. Anim. Sci. (Accepted December 2011) Experimental design and all analyses performed in my lab.
- P. Cheguru, K.C. Chapalamadugu, M.E. Doumit, G.K. Murdoch, R.A. Hill Adipocyte differentiation-specific gene transcriptional response to C18 unsaturated fatty acids plus insulin. Pflugers Archive-European J. Physiology (Accepted December 2011 DOI pending)
- K.J.B. Martins, M. St-Louis, G.K. Murdoch, I. MacLean, W.T. Dixon, P. McDonald, C.T. Putman, R.N. Michel Nitric Oxide Synthase Inhibition Prevents Activity-Induced Calcineurin-NFATc1 Signalling and Fast-to-Slow Skeletal Muscle Fibre Type Conversions J. Physiol. (Accepted December 2011) Performed qRT-PCR design and analyses
- B.M. Murdoch, G.K. Murdoch, M. Settles, S.D. McKay; J.L. Williams; S.S. Moore Genome-wide Scan Identifies Loci Associated with Classical BSE Occurrence PLoS one 2011; 6(11):e26819. Contribution to data analyses, candidate gene interpretation and manuscript preparation.
- D.C. Julien, S. Behnke, G. Wang, G.K. Murdoch, R.A. Hill Utilization of monoclonal antibody-targeted nanomaterials in the treatment of cancer. (2011) mABs 3:5, 1-12. Contribution to qRT-PCR analyses, primer-probe design and manuscript preparation.
- K.J.B. Martins , I. MacLean , G.K. Murdoch , W.T. Dixon , C.T. Putman Nitric oxide synthase inhibition delays low-frequency stimulation-induced satellite cell activation in rat fast-twitch muscle (2011) Applied Physiology, Nutrition, and Metabolism 36:(6) 996-1000, 10.1139/h11-091 Performed qRT-PCR design and analyses.
- J.B. Ewaschuk, G.K. Murdoch, I. R. Johnson, K. L. Madsen, C. J. Field Glutamine supplementation improves intestinal barrier function in a weaned piglet model of E. coli infection (2011) British Journal of Nutrition DOI:10.1017/S0007114511001152 Experimental design, performed RNA extraction, qRT-PCR design and analyses, data analyses and manuscript preparation.
- D.C. Julien, A. Giri, M. Papasani, G.K. Murdoch, P. Hrdlicka, R.A. Hill Anti-K-ras siRNA to treat Pancreatic Cancer (2010) NSTI-Nanotech 3: 401-404. Experimental design and data analyses.
- E. B. Rosenblum, T. J. Poorten, M. Settles, G.K. Murdoch, J. Robert, N. Maddox, M.B. Eisen Genome-wide Transcriptional Response of Silurana (Xenopus) tropicalis to infection with the Deadly Chytrid Fungus (2009) PLoS ONE 4(8): e6494.
- K. C. Chapalamadugu, B. D. Robison, R. E. Drew, M. S. Powell, R. A. Hill, J. J. Amberg, K. J. Rodnick, R. W. Hardy, M. L. Hill, G.K. Murdoch Dietary carbohydrate level affects transcription factor expression that regulates skeletal muscle myogenesis in rainbow trout (2009) Comparative Biochemistry and Physiology, Part B 153 66–72.
- J. D. Allen, J. K. Ahola, M. Chahine, J. I. Szasz*, C. W. Hunt, C. S. Schneider, G.K. Murdoch and R. A. Hill Effect of pre-harvest feeding and ractopamine hydrochloride supplementation on growth performance, carcass characteristics, and end product quality in market dairy cows (2009) J. Anim. Sci. 87:2400-2408.
- K.A. Martins, G.K. Murdoch, Y. Shu, R. L. Harris, M. Gallo, W.T. Dixon, G. R. Foxcroft, T. Gordon, and C.T. Putman Satellite cell ablation attenuates short-term Fast-to-slow fibre type transformations in rat fast-twitch skeletal muscle. (2009) Pflugers Archive-European J. Physiology. 458: 325-335.
- F. Paradis, S. Novak, G.K. Murdoch, M. K. Dyck, W. T. Dixon and G. R. Foxcroft Temporal regulation of BMP2, BMP6, BMP15, GDF9, BMPR1A, BMPR1B, BMPR2 and TGFBR1 mRNA expression in the oocyte, granulosa and theca cells of developing preovulatory follicles in the pig (2009) Reproduction 138:1–18.
- J.L. Ellis, E. Kebreab, N.E. Odongo, K. Beauchemin, S. McGinn, J.D. Nkrumah, S.S. Moore, R.J. Christopherson, G.K. Murdoch, B.W. McBride, E.K. Okine and J. France Modeling methane production from beef cattle using linear and non-linear approaches. (2009) J. Anim. Sci. 87:1334-1345.
- W. Sauer, M. Cervantes, J. Yanez, B. Araiza, G.K. Murdoch, A. Morales, and R.T. Zijlstra Effect of dietary inclusion of benzoic acid on mineral balance in growing pigs (2009) Livestock Science 122: 162–168.
- R.E. Drew, K.J. Rodnick, M. Settles, J. Wacyk, E. Churchill, M.S. Powell, R.W. Hardy, G.K. Murdoch, R.A. Hill and B.D. Robison Effect of starvation on the transcriptomes of the brain and liver in adult female zebrafish. (2008) Physiological Genomics 35: 283-295.
- B.M. Sorensen, E.C. Kazala, G.K. Murdoch, A.F. Keating, C. Cruz-Hernandez, J. Wegner, J.J. Kennelly, E.O. Okine, and R.J. Weselake Effect of CLA and other C18 unsaturated fatty acids on DGAT in Bovine Milk Fat Biosynthetic Systems. (2008) Lipids, 43:903-912.
- Y. Shi, G Xu, T. Warrington, G.K. Murdoch, E. C. Kazala, C. Snyder, R. Weselake Microspore-derived cell suspension cultures of oilseed rape as a useful system for examining the effect of abiotic stress on gene expression. (2008) Plant Cell, Tissue & Organ culture. 92,131-139.
- W-Y Tse, S. Town, G.K. Murdoch, S. Novak, M. Dyck, C.T. Putman, G. Foxcroft, W. Dixon. Uterine crowding in sow affects litter sex ratio, placental development and embryonic myogenin expression in early gestation. (2008) Reproduction, Fertility and Development. 20, 497-504.
- B.D. Robison, R.E. Drew, G.K. Murdoch, M. Powell, K. J. Rodnick, M. Settles, D. Stone, E. Churchill, R.A. Hill, M. R. Papasani, S. S. Lewis, and R.W. Hardy Sexual dimorphism in hepatic gene expression and the response to dietary carbohydrate manipulation in the zebrafish (Danio rerio). (2008) Comp Bioch Physiol Part D3 141-154
ABSTRACTS
- G.K. Murdoch, R. Soofi-Siawash, E. Okine, L. Goonewardene and R. J. Christopherson Subcutaneous or oral administration of liposome-encapsulated vasoactive intestinal peptide increases dietary intake in small ruminants. International Symposium of Ruminant Physiology, September 2009, Claremont-Ferrand, France.
- G.K. Murdoch Effect of dietary carbohydrate on myogenic regulatory factor expression in rainbow trout and zebrafish AFS Annual meeting Aug 30-September 3, 2009 Nashville Tennessee.
- K.C. Chapalamadugu, B. M. Murdoch, C. Lawson, J. Griswold, P. Hunt and G.K. Murdoch Maternal Exposure to Bisphenol A Alters Expression of Genes Associated with Carbohydrate Metabolism in Developing Fetal Cardiac Tissue. ORAL 42nd Annual Meeting of SSR held in Pittsburgh, Pennsylvania, July 18-22, 2009.
- François Paradis, Jason Grant, G. K. Murdoch, Michael K. Dyck, George R. Foxcroft and Walter T. Dixon Global Transcriptome Analysis of Porcine Oocyte, Granulosa, and Theca Cells to Identify Potential Secreted Factors and Receptors Involved in Cell-to-cell Interactions During Pre-Ovulatory Follicle Development 42nd Annual Meeting of SSR held in Pittsburgh, Pennsylvania, July 18-22, 2009
- M. Hill, K. Chapalamadugu, C. Schneider, R. Hill, G. Gaylord, J. K. Ahola, C. Hunt, J. Szasz and G.K. Murdoch Effect of time of ractopamine feeding on growth, carcass characteristics, and muscle biology of steers. 2009 Joint ADSA®-CSAS-ASAS Meeting July 12-16, 2009, Montreal, Quebec, Canada
- K.J.B Martins, P. McDonald, W.T. Dixon, G.K. Murdoch, and C.T. Putman Nitric Oxide: Immediate Satellite Cell Activator and key regulator of skeletal muscle adaptation to activity 2009 IBEC Conference Guelph Ontario, Canada
- J. J. Amberg, G.K. Murdoch, B.D. Robison, M.S. Powell, K.J. Rodnick, R. A. Hill & R.W. Hardy Dietary Carbohydrate Level Affects Expression of Hepatic Glucose Transporters in Rainbow Trout (Oncorhynchus mykiss): Is Rainbow Trout GLUT2 Different From Mammalian GLUT2? 2009 WAS Seattle Washington
- J. Wacyk, M. Powell, K. Rodnick, G.K. Murdoch, B. Robison, R. Hill and R. Hardy Dietary Carbohydrate level affects the expression of genes regulating the production of reductive power in Rainbow trout Oncorhynchus mykiss liver. 2009 Aquaculture America
- M.S. Powell, G.K. Murdoch, F.T. Barrows, J.M. Wacyk, M.T. Casten, W.M. Sealey, D.A.J. Stone, R.W. Hardy Determining size Effects on Phosphorous uptake, growth and phosphorous metabolism in rainbow trout fry, fingerling and post juvenile stages 2009 Aquaculture America
- W. Dixon, S. Novak, W-Y. Tse, S. Town, G.K. Murdoch, M. Dyck, C.T Putman and G. Foxcroft Uterine Crowding in the Sow Affects Litter Sex Ratio, Placental Development and Embryonic Myogenin mRNA Expression in Early Gestation (presented at World Congress on Reproductive Biology Hawaii, 2008)
- François Paradis, Susan Novak, G.K. Murdoch, Michael K. Dyck, George R. Foxcroft and Walter T. Dixon Spatial and temporal regulation of BMPR1A, -1B, -2 and TGFβR1 mRNA expression in developing porcine ovarian follicles SSR 2008
- Solange S. Lewis, Barrie D. Robison, Madison Powell, Kenneth Rodnick, Ronald Hardy, G.K. Murdoch and Rodney A. Hill 2008 Chronic dietary carbohydrate composition affects gene expression of some key regulators of metabolism and growth: a study using the zebrafish model (The Endocrine Society's 90th Annual Meeting, San Francisco)
- M. S. Powell, G.K. Murdoch, J.M. Wacyk, M.T. Casten, W. M. Sealey, D.A.J. Stone and R.W. Hardy Determining size effects on phosphorus uptake, growth and phosphorus metabolism in rainbow trout fry, fingerling and post juvenile stages (WAS 2008 Busan, Korea)
- J. Wacyk, M. Powell, K.Rodnick, G.K Murdoch, B. Robison, R. Hill and R. Hardy Dietary carbohydrate level affects expression of genes regulating the production of reductive power in rainbow trout Oncorhynchus mykiss, liver (WAS 2008 Busan, Korea)
- J. J. Amberg, G.K. Murdoch, B. D. Robison, M. S. Powell, K. J. Rodnick, R. A. Hill and R. W. Hardy. Dietary carbohydrate level affects expression of the intestinal nutrient transporters and amino acid catabolism in rainbow trout (Oncorhynchus mykiss). (Aquaculture America, Colorado Springs)
- J. Wacyk, M. Powell, K. Rodnick, G.K. Murdoch, B. Robison, R. Hill and R. Hardy. Increasing levels of dietary carbohydrates are able to differentially modify the expression levels of transaminases in rainbow trout Oncorhynchus mykiss, liver. (WAS 2008)
- J. J. Amberg, G.K. Murdoch, B.D. Robison, M.S. Powell, K. J. Rodnick, R. A. Hill and R.W. Hardy. Dietary Carbohydrate level affects expression of hepatic glucose transporters in rainbow triut (oncorhynchus mykiss): Is rainbow trout glut2 different from mammalian glut2? (Presented at World Aquaculture meeting)
- G.K. Murdoch, H. Klooster, B.T Li, J. Moibi, J. Galbraith, R. Mosenthin & R.J. Christopherson Effects of diet, feeding level and environment on digestion and energy metabolism in beef steers. (Lithuania, October 2007)
- M.S. Powell, B.D. Robison, R.E. Drew, D.A. Stone, G.K. Murdoch, K.J. Rodnick, R.A. Hill, and R.W. Hardy Hepatic Gene Expression and growth among Rainbow Trout Oncorhynchus mykiss in response to Carbohydrate manipulation of the diet. Aquaculture America 2007
- B.D. Robison, R.E. Drew, M.Powell, D. Stone, G.K. Murdoch, M. Settles, E. Churchill, K. Rodnick, R. Hill, and R. Hardy.Sex specific effects of chronic dietary carbohydrate manipulation on hepatic gene expression in the zebrafish (Danio rerio). (Plant and Animal Genome 2008)
- Powell, M.S., Wacyk J., Plant, K., Stone, D.A.J., Rodnick K.J., Robison, B.D., Drew, R.E., Murdoch G.K., Hill, R.A., and Hardy, R.W. Expression of glycolytic and gluconeogenic enzymes show intraspecific variation among selected and non-selected strains of rainbow trout fed high levels of dietary carbohydrate (International Congress for Biology of Fish 2008)
Research Projects
“Basic” Research program
Mammalian species, including beef cattle and humans, lose the prenatal capacity for muscle hyperplasia shortly after birth (within 5 days, with the exception of a few unique examples) while other vertebrate species such as Salmonid species, retain this ability throughout their developmental lifespan. It is well understood that this variation is related to the capacity and modified capacity for recruitment of mesodermally-derived muscle stem cells known as ‘satellite’ cells. Not only are these stem cells important for the muscle growth capacity, rate and activation they are further pluripotent in nature and are innately involved in the development of intramuscular fat cells that are important in production livestock for ‘marbling’. One important aspect of my basic research program surrounds my endeavor to better understand the natural physiological mechanisms that regulate satellite cell number, activation, recruitment and replenishment in prenatal and postnatal mammals as well as in post-larval teleost species. In addition, I am interested in the natural interaction and cross-talk that exists in skeletal muscle between; satellite cells and myoblasts with pre-adipoblasts and adipocytes. Through improved understanding of the basic physiological regulatory mechanisms that dictate skeletal muscle growth and intramuscular fat deposition we can better and more reliably facilitate growth of muscle and marbling in livestock species that ultimately become the marketed and consumed commodity: meat. My basic research program is therefore centered on the mediation and determination of carcass and muscle phenotype, as determined and regulated through alterations in gene expression (transcriptome) and protein expression (proteome). This research is best performed through evaluation of changes in physiological systems, which has recently been described as both functional genomics and metabolomics, though in my perspective these are fancy words for adaptive physiology which is my area of expertise.
“Applied” Research programWhenever livestock production practices are altered for the purpose of improving efficiency or extent of physical growth, especially as pertaining to the lean deposition of muscle, it is critical that an assessment of the benefits versus risks are fully characterized. As one might expect a critical aspect of livestock production sustainability is associated with the ability to consistently provide a high-quality, safe, reliable and palatable consumer product. My applied research program focuses on the integration of my understanding as to how muscle tissue grows and its relationship to the end-product meat quality. This includes but is not limited to the characterization of nutrition, growth promoters, genetic selection and environmental conditions on the growth and performance of cattle. Therefore simplistically stated, I work to simultaneously increase the efficiency of muscle growth in cattle while improving meat quality traits such as; tenderness, juiciness, flavor, and consistency just to name a few. With Idaho being a “top 10” U.S. beef production state this aspect of my research program best matches my endeavor to serve the needs of the State and the mission of this ‘Land-grant’ institution.
Teaching philosophy and strategy
I enjoy teaching as well as the resulting interaction with students at both the undergraduate and graduate level, which is at least one driving force that steered me toward an academic research and teaching career. I attempt to impart a rather simple philosophy to my teaching, which can be summarized with the following statement of belief; “When students are able to observe instructor enthusiasm regarding the subject matter, they too may become enthusiastic about learning. It is expected that an enthusiastic learner not only retains more subject matter but also better assimilates such information into knowledge”. Since integrative knowledge in many areas of physiology and molecular biology are rapidly progressing, it is easy for me to maintain my enthusiasm for each step taken towards an improved understanding of the complexity and intricacies of these systems, while building on accepted fundamental principles. I believe in including a significant level of rigor in my classes and attempt to encourage the students to work diligently towards maximizing their own individual knowledge potentials. In accordance with my high expectations I make all attempts to be clear in my course syllabi, my verbal instructions and guidance to inform all students how to achieve their best performance and reach personal levels of achievement and ambition. Further, rather than having set office hours I prefer to have an open door policy and facilitate all students as best as my schedule and commitments allow for individual supplementary instruction, clarification and review.
Awards and Honors
- AVS Outstanding Academic Advisor, 2010-2011