Figure 2

ha gene encodes a polyketide synthase. (A) Positional cloning of the ha mutation in linkage group (LG) 20. The number of recombinants at each marker is shown. Sequencing of ha revealed a 9-nucleotide deletion. ORF: open reading frame. (B) Architecture of OlPKS (2051 amino acid-length) predicted by a Pfam search. Each domain is shown by abbreviation. An arrow indicates mutation site of ha, which is located at 279–281 (K, P and S). (C) Whole-mount in situ hybridization with an antisense RNA probe for olpks at otolith forming developmental stages. A representative picture is shown at st. 21 (Upper; dorsal view; dotted line indicates embryonic body). olpks transcripts detected in various stages are shown at high magnification (Lower; dorsal views of left and right OVs). Scale bars: 50 μm. (D) Period of the expression of olpks in the context of otolith growth. Purple area shows the period of olpks expression. Line graphs show the sizes (longest linear dimensions) of otoliths at some developmental stages. Data are the means and standard deviations of measurements taken of at least 7 specimens each. Some observable changes in the OV during otolith development are described with arrows. Red curcle: anterior otolith; Blue triangle: posterior otolith; hpf: hours post fertilization.