Meeting Abstract
Flatfishes likely experience a different chemical environment on each side of their bodies due to their lifestyle of lying on the sediment. However, there have been no studies on potential adaptations flatfishes have to cope with this asymmetry. Since gills are essential for regulating the effects of environmental stressors such as pH regulation in fishes, we quantified the relative protein abundance between the gills facing the water column (ocular side gills) and those facing the sediment (blind side gills) of the marine flatfish: slender sole (Lyopsetta exilis). Using Western blot, we quantified the relative abundance of sodium potassium ATPase (NKA), vacuolar proton pump (VHA), and carbonic anhydrase (CA) between the ocular and blind side gills. We found that NKA does not differ between the two sides; however, VHA and CA are 103±30% and 80±40% more abundant on the ocular side compared to the blind side gills, respectively. VHA appears to be localized on the apical membrane of ocular side gills, based on immunohistochemical analysis. Taken together, these results suggest that slender soles preferentially mediate ammonia excretion or acid secretion using their ocular side gills. Our study found, for the first time, an asymmetry in cellular physiology between the two sides of gills in a fish and lays the groundwork to better understand marine flatfish gill physiology.
