Reduced expression of <i>vps11</i> causes less pigmentation in medaka, <i>Oryzias latipes</i>

<jats:title>Summary</jats:title><jats:p>In this article, we describe the medaka mutant <jats:italic>pale gray eyes</jats:italic> (<jats:italic>pge</jats:italic>) that shows reduction of black, white, and silver pigmentation and lethality approximately a week after hatching. The <jats:italic>pge</jats:italic> mutation was mapped to the tip of linkage group 14 and no recombinations were observed between the mutation and medaka <jats:italic>vps11</jats:italic> in 900 meioses. <jats:italic>Vps 11</jats:italic> is one of the evolutionarily conserved class C vacuolar protein sorting genes (c‐<jats:italic>vps</jats:italic>: <jats:italic>vps11</jats:italic>, <jats:italic>vps16</jats:italic>, <jats:italic>vps18</jats:italic>, and <jats:italic>vps33</jats:italic>), whose products physically associate to form the c‐vps protein complex required for vesicle docking and fusion in the budding yeast. Mutations in <jats:italic>vps16</jats:italic>, <jats:italic>vps18</jats:italic>, and <jats:italic>vps33</jats:italic> are known to result in decreased pigmentation in organisms such as <jats:italic>Drosophila</jats:italic>. We cloned the full‐length medaka <jats:italic>vps11</jats:italic> cDNA by rapid amplification of cDNA ends (RACE) and found no RACE products from the <jats:italic>pge</jats:italic> mutants. Similarly, no <jats:italic>vps11</jats:italic> transcripts were detected from the <jats:italic>pge</jats:italic> mutants by Northern analysis. The injection of an antisense morpholino against <jats:italic>vps11</jats:italic> phenocopied the <jats:italic>pge</jats:italic> mutant. Taken together, the results suggest that reduced expression of medaka <jats:italic>vps11</jats:italic> causes <jats:italic>pge</jats:italic> and that medaka <jats:italic>vps11</jats:italic> is indispensable for survival and normal pigmentation.</jats:p>