To address this question, we first investigated the sequence similarity between the corresponding 5ʹ genomic regions of B. mori and D. melanogaster. No sequence conservation was detected (Fig. 3A). Nevertheless, some studies have suggested that the same genomic position exhibits similar expression patterns across species even when the sequences are not conserved (Cande et al., 2009; Kalay and Wittkopp, 2010). To rule out this possibility, we conducted reciprocal tests for the hair‐specific CRE of both B. mori and D. melanogaster. The hair‐specific CRE of B. mori was not active in the developing embryo of D. melanogaster (Fig. 3B, C). Similarly, the hair‐specific CREs in D. melanogaster drove no reporter expression in B. mori. These results suggest that the trans‐regulatory landscape of B. mori hair‐specific CREs differs significantly from that of D. melanogaster.