Developmental expression of NPY/PYY receptors zYb and zYc in zebrafish.

This study describes the developmental expression of zYb and zYc receptors in zebrafish. RT-PCR demonstrated that both mRNAs are present from 24-hour postfertilization (hpf) and that their expression increased during larval development. Whole-mount in situ hybridization showed zYb mRNA expression in the epithalamus (24 hpf), telencephalon, hypothalamus, rhombencephalon (24-96 hpf), mesencephalon (48-96 hpf), hatching gland, and otic vesicle (48-64 hpf). zYc mRNA is expressed in the epithalamus (24 and 96 hpf), telencephalon (48-96 hpf), spinal cord, notochord (64 hpf), and hatching gland (96 hpf). These results show that zYb and zYc receptors are expressed during ontogeny, suggesting a role for neuropeptide Y (NPY) and/or peptide YY (PYY) in organogenesis.