Biomedical Research Series: Dr. Michael Butcher

Within the Department of Biological Sciences at Youngstown State University, there are many areas of research being explored by faculty and students alike. In a monthly series, we will highlight faculty research that covers various aspects of biomedical efforts from DNA to bacteria, fungi, and more.

Dr. Michael Butcher is an Associate Professor of Biological Sciences at YSU. He earned his PhD in Zoology from the University of Calgary. Afterward, he completed a two-year NSF post-doctoral fellowship at Clemson University before becoming a full-time professor at YSU.

At YSU, Dr. Butcher conducts three different types of research with assistance from multiple graduate and undergraduate students. The main focuses of his laboratory research are the mechanical properties and shape of limb bones, fiber architecture and force production in the limb muscles, and development of muscle fiber types. His most recent work involves studies of muscle form and contraction activity in tree sloths.

Every other year, Dr. Butcher has traveled to The Sloth Sanctuary in Limón, Costa Rica. This gives him the opportunity to study species of two-toed and three-toed sloths.

On his most recent trip, he and his research team visualized live muscle contractions of the sloths using implanted fine wire electrodes. They recorded muscle activity while sloths performed combinations of walking, climbing, and hanging exercises. In addition, Dr. Butcher and his team conducted very detailed dissections on cadaver sloths to learn about their muscle architecture.

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“What we do is take geometric measurements of the muscles,” Butcher said. “For example, how long is the muscle belly, how long are the muscle fibers, at what angle are the muscle fibers? Then we apply a couple basic calculations.”

They could then estimate the force, power, and torque (strength) properties of sloth muscles. Dr. Butcher considers this approach to the study of muscle form and function “simple, but elegant.”

To understand his research interests, it is important to know some of the unusual characteristics of a sloth.

“Why a sloth?” Dr. Butcher was asked. “Because they’re old and interesting mammals that do something really different from what humans are capable of doing.”

In a sloth’s body, there is only about 24% muscle mass. Dr. Butcher and his students are finding that their muscles have a high tolerance for lactic acid and rarely fatigue, unlike skeletal muscles in humans. Much to his surprise, Dr. Butcher is also learning that sloths primarily use anaerobic mechanisms to allow them to conserve energy and resist fatigue. This contributes to a sloth’s ability to hang from tree limbs for extended periods of time.

Other factors that relate to the strength and stamina of sloths are lower body temperature, lower metabolism, and slower digestion than most placental mammals.

“Sloths also have a network of blood vessels in their forearms that lowers the temperature of the muscles,” Butcher said. “This allows the muscles to remain strongly contracted for gripping branches while using energy at a slower rate.”

With these distinctive characteristics, sloths can conserve a tremendous amount of energy. For this very reason, Dr. Butcher finds sloth research remarkably insightful.

Dr. Butcher does not simply perform research to learn more about muscle structure-function in sloths, but rather to give further evidence of the performance range of muscles, in general. He wants to continue studying how muscles are put together and how they work, as functionality is diverse for animals depending on their lifestyle.

While this research has medical applications such as bioengineering artificial muscles and limbs, Dr. Butcher remains committed to fundamental science where his findings contribute towards education in the scientific community, future textbooks, and enhancement of the courses that he teaches at YSU.

Dr. Butcher stresses the immense contribution from his students. He believes that they are vital to his research efforts. To further his studies in primitive mammals Dr. Butcher plans to travel to Argentina this fall to investigate muscle properties in rare species of armadillos.

Recent Publication: Biology Student, Faculty, and Staff

Thomas DR, Chadwell BA, Walker GR, Budde JE, Vandeberg JL, Butcher MT. “Ontogeny of myosin isoform expression and prehensile function in the tail of the gray short-tailed opossum (Monodelphis domestica),” Journal of Applied Physiology, May 2017. DOI: 10.1152/japplphysiol.00651.2016

Former YSU biology student Dylan Thomas authored this paper in collaboration with faculty and staff from YSU, Ohio University, and the University of Texas Rio Grande Valley. The paper was submitted in July 2016 and was accepted and published in May 2017 by the American Physiological Society.

Abstract:

Terrestrial opossums use their semi-prehensile tail for grasping nesting materials as opposed to arboreal maneuvering. We relate the development of this adaptive behavior with ontogenetic changes in myosin heavy chain (MHC) isoform expression from 21 days to adulthood. Monodelphis domestica is expected to demonstrate a progressive ability to flex the distal tail up to age 7 months, when it should exhibit routine nest construction. We hypothesize that juvenile stages (3-7 months) will be characterized by retention of the neonatal isoform (MHC-Neo), along with predominant expression of fast MHC-2X and 2B, which will transition into greater MHC-1β and 2A isoform content as development progresses. This hypothesis was tested using Q-PCR to quantify and compare gene expression of each isoform to its protein content determined by gel electrophoresis and densitometry. These data were correlated with nesting activity in an age-matched sample of each age group studied. Shifts in regulation of MHC gene transcripts matched well with isoform expression. Notably, mRNA for MHC-Neo and 2B decrease, resulting in little-to-no isoform translation after age 7 months, whereas mRNA for MHC-1β and 2A increase, and this corresponds with subtle increases in content for these isoforms into late adulthood. Despite the tail remaining intrinsically fast-contracting, a critical growth period for isoform transition is observed between 7 and 13 months, correlating primarily with use of the tail during nesting activities. Functional transitions in MHC isoforms and fiber type properties may be associated with muscle ‘tuning’ repetitive nest remodeling tasks requiring sustained contractions of the caudal flexors.

STEM Showcase 2016

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The annual STEM Showcase was a huge success this year, with more student projects presented than ever before. On Saturday, April 23, prospective students, current students, parents, faculty, and many others filled Moser Hall to see what the students of STEM have been working on all semester (and for some, all year).

Student organizations displayed some of their annual creations, such as AIChE’s Chem-E-Car, ASCE’s Concrete Canoe, and SAE’s Baja Car. Some of the other notable projects on display were the automated snow blower, which can be controlled by a smart phone, and the digital theremin, which is an instrument that produces a very unique sound.

Sloth Research groupOne group of students won the Ohio Academy of Science Research Award for their project concerning sloth muscle research. Tyler Tsangaris-Braatz, Paije Kiraly, Amanda Svenson, and Abdel-Ruhman Yusuf, along with faculty mentor Dr. Butcher, examined the muscle fibers of sloths to determine the efficiency of their energy use when hanging from trees.

The research award grants them $100 and a publication on the Ohio Academy of Sciences website as well as in their newsletter.

Also during the showcase, guests were given tours of the Center for Innovation in Additive Manufacturing and the brand new Launch Lab.

To conclude the day’s activities, Dean Steelant congratulated all of the students on their successes and inducted new members into the STEM Leadership Society.