Progress 01/01/24 to 12/31/24
Outputs
Target Audience:Biologists, animal scientists, growth biologists, swine nutritionists, academicians, geneticists, and students. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?This project has provided training and professional development opportunities for seven undergraduate and three graduate students. Students gained hands-on experience that has enhanced their technical and analytical skills through conducting research, data anaylsis, and experimental design. Students have also participated in seminars and research conferences fostering professional networking opportunities. Graduate students had opportunities to lead aspects of each aim to develop their leadership and management skills. How have the results been disseminated to communities of interest?The results of this project have been disseminated to communities of interest through students presenting their research at national scientific meetings. The same opportunities will be provided during the final year of this project as well as publication of findings in peer-reviewed scientific journals. What do you plan to do during the next reporting period to accomplish the goals?Objective 1 is in the final stages of the project. The manuscript is under preparation for submission to a peer-reviewed scientific journal. The live animal portion and sample collection of objective 2 is complete. Sample analysis is underway and is on track for completion during the final year of the project. For objective 3, in vitro analysis of knockout satellite cells is in progressand is on track for completion during the final year of the project.
Impacts
What was accomplished under these goals?
The overall objective of this project is to define the role of mitochondria in muscle hypertrophy models, and as such, understand better their contribution to the efficiency of overall growth. 1)Mature DNA 600 x 241 barrows (DNA Genetics) were fed a standard commercial diet containing 16% crude protein supplemented with 0 ppm (control; n = 8) or 9 ppm ractopamine hydrochloride (BAA; n = 10) for 2 weeks. Samples were collected from the longissimus dorsi (LD, glycolytic muscle), latissimus dorsi (LAT, mixed muscle), semitendinosus (ST, mixed muscle), and masseter (MS, oxidative muscle)to investigate changes in myosin heavy chain isoforms and metabolic enzymes as well as mitochondrial utilization of pyruvate, the glycolytic end product. Although there were noBAA mediated changes at a protein level, which may be attributed todosage and duration of feeding, supplementation induced changes in mitochondrial pyruvate uitiization. 2) Pigs harbouring RyRR615C(RN) and AMPKy3R200Q(Hal) mutations were bred with wild-type pigs to generate wild-type,heteroyzous RN, heterozygous Hal, and heterozygous RN;heterozygous Hal/RN offspring. Eight pigs of each genotype were harvested at approximately 120 lbs to evaluate the role of calcium in muscle hypertrophyof pigs with inherently differentmetabolic profiles. Samples were collected from the LD, LAT, ST, and MS for evaluation of metabolic enzymes, mitochondrial function, and calcium handling. 3)Muscle stem cells support postnatal muscle hypertrophy through incorporation of DNA into skeletal muscle, which is a postmitotic tissue. It has become apparent that the metabolic regulation of postnatal myogenesis plays a role regulating this process, although the role of mitochondria in this process remains unclear. To determine the role of mitochondria in myogenesis, we isolated muscle stem cells from piglets after weaning and are in the process ofassessingthe role of mitochondrial energy production in muscle stem cell behavior.
Publications
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2025
Citation:
Munk S., L. Rimmer, E. Beyer, J. Vipham, M. Chao, J. Woodworth, T. O'Quinn, D. Gerrard, and M. Zumbaugh. Beta-adrenergic agonists alter mitochondrial metabolite utilization independent of a fiber type shift. Physiology. Accepted for presentation at the 2025 American Physiological Society Summit.
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Progress 01/01/23 to 12/31/23
Outputs
Target Audience:Biologists, animal scientists, growth biologists, swine nutritionists, academicians, geneticists, and students. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Thus far, three graduate students and five undergraduate students have been trained and educatedduring the project. The graduate students are on track to graduate at the completion of the project. How have the results been disseminated to communities of interest?Students had the opportunity to present their research at local, regional, and national scientific meetings. The same opportunities will be provided during the final year of the project. What do you plan to do during the next reporting period to accomplish the goals?For objective 1, we will finish the laboratory analysis of samples collected last year after beta-adrenergic agonist feeding. For objective 2, we will collect and analyze samples from experimental pigs that will farrow this year. For objective 3, we will finish in vitro anaylsis of knockout satellite cells. We will also beging the writing an publishing of manuscripts for each project.
Impacts
What was accomplished under these goals?
The overall objective of the proposal is to understand the role of mitochondria in efficient porcine skeletal muscle growth. 1) Although not used in commercial swine production, beta-adrenergic agonists partition nutrients from fat to muscle to support lean accretion and can be used as a model to understand metabolic changes that facilitate muscle hypertophy. We have collected samples and implemented an in vitro metabolite tracing strategy usingisolated mitochondria after beta-adrenergic agonist feeding. Laboratory analysis is currently being conducted.2) Pigs harboring RyRR615C or AMPKy3R200Q mutations result in greater muscle size or an increase in oxidative capacity, respectively. Pigs harboring both mutations exhibit an increase in muscle size and oxidative capacity.Therefore, we are employing these naturally occurring mutations to uncoverthe molecular mechanisms that drive muscle hypertrophy regardless of metabolic profile. We are in the final breeding to farrow experimental pigs this year. 3) Muscle stem cells support postnatal muscle hypertrophy through incorporation of DNA into skeletal muscle, which is a postmitotic tissue. It has become apparent that the metabolic regulation of postnatal myogenesis plays a role regulating this process, although the role of mitochondria in this process remains unclear. To determine the role of mitochondria in myogenesis, we isolated muscle stem cells frompiglets after weaning and are in the process of knocking out mitochondrial genesto assess the role of mitochondrial energy production in muscle stem cell behavior.
Publications
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Progress 01/01/22 to 12/31/22
Outputs
Target Audience:Biologists, animal scientists, growth biologists,animal nutritionists, academicians, and geneticists Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Three graduate students and four undergraduate students have been involved in this project thus far. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?We will conduct the live animal portion of objective 1 to begin data collection and analysis. We will also continue the breeding scheme to generateRyRR615C/ AMPKy3R200Qexperimental pigs outlined in objective 2. We will continue with the isolation, culture, and transfection of porcine satellite cells to conduct experiments outlines in objective 3.
Impacts
What was accomplished under these goals?
We have resurrected pigs harboring RyRR615C and AMPKy3R200Qmutations.We have begunbreeding these pigs to generate experimental pigs that will be used to complete objective 2.We have also started the optimization ofsatellite cell isolation, culture, and transfection as outlined in objective 3.The plasmids that will be used in this objective have been designed and generated. Arrangements have also been made to conduct the live animal portion of objective 1. The in vitro model that will be used in objective 1 has also been optimized. Briefly, an in vitro model that usesisolated mitochondria incubated with [4-13C] glutamate or [3-13C] pyruvate to trace metabolites in the TCA cycle has been implemented successfully.
Publications
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