Myoglobin expression in notothenioid ancestor Bovichtus variegatus suggests loss is not cold adaptive.
Degree GrantorUniversity of Canterbury
Degree LevelPostgraduate Certificate
Degree NamePostgraduate Certificate in Antarctic Studies
The icefish family Channichthyidae has been the focus of considerable research in myoglobin expression. It is known that none of the sixteen species studied produce myoglobin protein in their pectoral muscle, and six species do not produce myoglobin at all. This loss of expression has occurred by at least three separate events and two different mechanisms, and was thought be an adaptation to the cold waters of Antarctica. Four Bovichtus variegatus individuals were studied as the basal ancestor to the notothenioid suborder, and was compared to five notothenioids, a non-Antarctic notothenioid and an outgroup. Preliminary results suggest myoglobin expression is not cold adaptive as none of the species produced myoglobin protein in the pectoral adductor profundus muscle, including the outgroup, NZ Spotty (Notolabrus celidotus). All species had myoglobin protein present in the heart tissue ranging in size from 14kDa to 16kDa, and could only be seen by comparing the red muscle and heart tissue of each species. The RNA was better quality than the gDNA but neither cDNA (RT product) or gDNA bound well to the primers, and only very faint bands could be seen on the gels. Further analysis should be undertaken to confirm the results of this study by purifying the samples to gain brighter bands on the gel and sequencing the product to check it is myoglobin.