| dc.description.abstract | Producers are constantly looking for ways to improve muscle growth in cattle such that both the quantity and quality of beef can be increased. One approach is to examine expression of microRNAs as a potential selection tool. MicroRNAs are small RNA molecules that have regulatory functions in all metazoans. MiR-133b and miR-27a are known to affect muscle development through the IGF-1 pathway and their effect on the myostatin gene, respectively. Current research in humans has investigated microRNAs as biomarkers for diagnostic purposes. In the current experiment, we quantified the expression of miR-27a and miR-133b in order to evaluate their potential association with muscle growth traits. At approximately 12 month of age, 44 crossbred steers received hormone implants and 44 were not given implants. Plasma was collected from the steers starting from day 0 and in 28 day intervals for 5 months. From the original collection, the plasma samples from 51 steers (28 implanted steers, and 21 control steers) were used for expression analyses. Hemolyzed samples were discarded from the experiment. MicroRNAs were extracted from the plasma, and the expression of the microRNAs was measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR) on the Fluidigm Biomark HD platform. The amount of weight gained from Day 0 until harvest was determined for each steer, and then evenly separated into groups (high-gain and low-gain). The expression of miR-27a and miR-133b was compared between high gain steers and low gain steers. A difference in miR-133b and miR-27a expression was observed in the months of April and August, where an increase in miR-133b and miR-27a expression was observed in the low-gain groups. | en |
