Event Title

lmmunolocaization of Actin in Transgenic and Wildtype Murine Myocardium

Location

CSU Ballroom

Start Date

21-4-2008 1:00 PM

End Date

21-4-2008 3:00 PM

Student's Major

Biological Sciences

Student's College

Science, Engineering and Technology

Mentor's Name

Marilyn C. Hart

Mentor's Department

Biological Sciences

Mentor's College

Science, Engineering and Technology

Description

In myocardium, actin and myosin filaments are organized into repeating units of sarcomeres, the basic unit of muscle contraction. Actin Capping Protein (CP) binds to the barbed ends of the actin filament at the Z­line, directing and maintaining the proper organization of the thin filament in the sarcomere. CP is a heterodimer composed of an alpha (a) and a beta (P) subunit. Muscle cells contain two p subunit isoforms, β1 and β2. The β1 isoform is present at the Z line; the β2 isoform is found elsewhere including cell-cell junctions. In previous studies, transgenic mice were generated that replaced the β1 isoform with the β2 isoform. We hypothesized that a decrease in βl expression will lead to a disorganized myofibrillar structure and that the disorganization will become increasingly severe as a function of murine age. We examined the myocardium of transgenic mice ranging in age from three months to twelve months. Murine hearts were extracted and frozen sections prepared using a cryomicrotome. The tissue sections were fixed, quenched with ethanolamine, permeabilized with methanol, and washed in phosphate buffered saline. The sections were probed with mouse anti-actin-Cy3 rhodamine conjugated antibody and images captured using an Olympus fluorescent microscope and Simple PCI 6 acquisition software with deconvolution. Three month myocardium exhibited minor disorganization of the Z-lines compared to six, nine, and twelve month myocardium. The Z-lines in the twelve month myocardium were grossly disorganized with irregular breaks. In addition, the spacing between Z-lines was variable indicative of altered actin filament length.

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Apr 21st, 1:00 PM Apr 21st, 3:00 PM

lmmunolocaization of Actin in Transgenic and Wildtype Murine Myocardium

CSU Ballroom

In myocardium, actin and myosin filaments are organized into repeating units of sarcomeres, the basic unit of muscle contraction. Actin Capping Protein (CP) binds to the barbed ends of the actin filament at the Z­line, directing and maintaining the proper organization of the thin filament in the sarcomere. CP is a heterodimer composed of an alpha (a) and a beta (P) subunit. Muscle cells contain two p subunit isoforms, β1 and β2. The β1 isoform is present at the Z line; the β2 isoform is found elsewhere including cell-cell junctions. In previous studies, transgenic mice were generated that replaced the β1 isoform with the β2 isoform. We hypothesized that a decrease in βl expression will lead to a disorganized myofibrillar structure and that the disorganization will become increasingly severe as a function of murine age. We examined the myocardium of transgenic mice ranging in age from three months to twelve months. Murine hearts were extracted and frozen sections prepared using a cryomicrotome. The tissue sections were fixed, quenched with ethanolamine, permeabilized with methanol, and washed in phosphate buffered saline. The sections were probed with mouse anti-actin-Cy3 rhodamine conjugated antibody and images captured using an Olympus fluorescent microscope and Simple PCI 6 acquisition software with deconvolution. Three month myocardium exhibited minor disorganization of the Z-lines compared to six, nine, and twelve month myocardium. The Z-lines in the twelve month myocardium were grossly disorganized with irregular breaks. In addition, the spacing between Z-lines was variable indicative of altered actin filament length.

Recommended Citation

Bohland, Meghan. "lmmunolocaization of Actin in Transgenic and Wildtype Murine Myocardium." Undergraduate Research Symposium, Mankato, MN, April 21, 2008.
https://cornerstone.lib.mnsu.edu/urs/2008/poster-session-B/2