Oxalate Handling and Transporter Expression in Poecilia Latipinna in Response to Environmental Salinity and Antibiotic Exposure

Little is known about oxalate transport in fish, however mammalian models suggest the involvement of solute carrier family transporters (SLC), specifically SLC26A3 and SLC26A6. To study the effects of salinity and bacteria on intestinal oxalate excretion, sailfin mollies (Poecilia latipinna) were acclimated to freshwater or seawater (for either 14 or 28 days) and seawater for 14 days with broad-range antibiotic treatment. Initial acclimation to seawater increased the plasma oxalate concentration but homeostasis was recovered by 28 days. Kidney oxalate concentrations were unaffected by salinity, however the concentration in the anterior intestine increased in seawater while it decreased in the posterior intestine. SLC26A3 expression in both the anterior and posterior intestine was downregulated in response to seawater acclimation, while SLC26A6 expression was upregulated after seawater acclimation for 14 days. Antibiotics reduced the expression of SLC26A6 and SLC26A3 in both intestinal sections and altered the concentrations of oxalate along the intestine.