Relative expression levels in term of fold change (ΔΔCt) of a known testis-relevant marker, <i>Dmc1</i>, to those of housekeeping genes in 5 testis sample groups; wild broodstock from Andaman sea (black), wild broodstock from Gulf of Thailand (diagonal lines), 18-month-old domesticated shrimp (DS) (gray), 14-month-old DS (horizontal lines), and 10-month-old DS (diamond), were compared with four housekeeping genes (<i>18s rRNA</i>, <i>GAPDH</i>, <i>β-actin</i>, and <i>EF1-α</i>) in 4-month-old domesticated shrimp.

<p>Different letters above the bars of each graph signify statistical differences in gene expression levels within the sample group.