Spatiotemporal expression of the cocaine- and amphetamine-regulated transcript-like (cart-like) gene during zebrafish embryogenesis.

The cocaine- and amphetamine-regulated transcript (CART) genes are involved in the neural regulation of energy homeostasis; however, their developmental expressions and functions are not fully understood in vertebrates. We have identified a novel zebrafish cart-like gene that encodes a protein of 105 amino acids possessing sequence similarity to zebrafish and mammalian CART proteins. RT-PCR analysis revealed that the cart-like transcripts were maternally supplied and gradually decreased during the cleavage, blastula and gastrula stages; then, transcripts subsequently reaccumulated at the segmentation, pharyngula and hatching stages. Based on a whole-mount in situ hybridization analysis using an antisense cart-like RNA probe, we found that the cart-like transcript was predominantly expressed in both the Rohon-Beard neurons and trigeminal ganglia, suggesting the involvement of the cart-like gene in zebrafish neural development.