Fig. 2.

The tre locus encodes NCX1h. (A) Schematic diagram of NCX1h protein.AGtoT transversion at codon 489 is detected in tre^tc318, which creates a premature stop codon and MseI polymorphism. (B) MseI restriction fragment-length polymorphism in wild type, tre heterozygotes, and tre homozygotes. (C) Na⁺ gradient-dependent uptake assay. HEK293 cells transfected with zebrafish NCX1h (NCX1h) showed significant ⁴⁵Ca²⁺ uptake in the presence of an outwardly directed Na⁺ gradient. ⁴⁵Ca²⁺ uptake in cells transfected with tre^tc318 (tc318) remained at basal levels similar to the vector transfected cells (control). The gray bars represent uptake activities in the absence of a Na⁺ gradient, and the white bars represent uptake in the presence of an outwardly directed Na⁺ gradient.