RT-PCR of the five V-ATPase subunits in embryos at different developmental stages and in organs from adult fish. (A) RT-PCR from WT embryos at different developmental stages using oligonucleotides that amplify five different V-ATPase subunits. All subunits are consistently expressed throughout all developmental stages, however subunit V1-H is expressed in lower amounts than V0-d1, V0-ac45b, V1-E1b, V1-H and V0-ca. Alpha actin expression was used as an expression control. V0-d1 is abundant in adult males than in females. (B) Semi-quantitative RT-PCR from total RNA obtained from liver, heart, eyes, skin, brain, gut, ovaries and testis from adult zebrafish. The cDNA used was diluted 1:5, 1:100 and 1:1000 and then used for the RT-PCR. V-ATPase subunits V0-ca and V0-ac45b have the higher expression levels, in contrast V0-d1 have the lower expression levels. V1-E1b and V1-H have similar expression; both are enriched in the eyes, brain and ovary.