The role of the microRNA mir-125a-5p in mouse skeletal development
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Series/Report no.:2016 Fall Undergraduate Research Student Poster Forum. 10th
In all vertebrates, the ribs and vertebrae develop from repeating tissue blocks called somites that form early in development. The regularity of somite formation depends on several genes with oscillatory expression; each oscillation corresponds to the formation of one somite. These "clock genes" include Lunatic fringe ( Lfng ), which must oscillate for normal somitogenesis. In chick, the microRNA mir-125a-5p destabilizes Lfng mRNA, allowing for its rapid clearing during the "off" phase of each oscillation. Loss of mir-125a-5p in chick results in disorganized somitogenesis; whether it plays a similar role in mammals is unknown. The purpose of this study is to determine if mir-125a-5p regulates Lfng expression during somitogenesis and axial skeleton formation in mice. To determine the role of mir-125a-5p in mouse somitogenesis, CRISPR-Cas9 mutagenesis was used to create mice lacking this miRNA. Lfng expression in mir-125a-5p mutant and wild-type mouse embryos was compared via in situ hybridization. Effects on somitogenesis were determined by in situ hybridization for Uncx4.1, a somite boundary marker, in mutant and wild-type embryos. To directly investigate the results of mir-125a-5p loss on skeletal development, older embryos were stained with tissue-specific dyes to mark bone and cartilage. Neither somitogenesis nor skeletal development was significantly altered in mir-125a-5p mutants, indicating that mir-125a-5p does not have the same vital role in mammalian somitogenesis as it does in chick. It may be that mir-125a-5p is uninvolved in mouse somitogenesis; alternatively, similar miRNAs could compensate for its loss. Interestingly, some adult male mice lacking functional mir-125a-5p appear to be less fertile; this could be due to the location of mir-125a-5p within an intron of one isoform of Spaca6, a gene involved in sperm-egg fusion.
Biological and Biomedical Sciences
Academic Major: Molecular Genetics
URO Mayers Scholarship
OSU Sigma Xi
OSU Sigma Xi
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