Meeting Abstract

P2.6  Tuesday, Jan. 5  Expression Pattern of Leptin and Leptin Receptor in Developing and Adult Zebrafish LIU, Qin; CHEN, Yun; THAKKAR, Mitesh; LONDRAVILLE, Richard/L*; University of Akron; University of Akron; University of Akron; University of Akron londraville@uakron.edu

Interactions of leptin and leptin receptors play crucial roles during animal development and in regulation of appetite and energy balance. We analyzed the expression pattern of a zebrafish leptin, and leptin receptor mRNA in both developing and adult zebrafish using in situ hybridization and quantitative PCR methods. Zebrafish leptin message (lep) was detected in very early embryos (15 min.-6 hours post-fertilization) and continued through 72 hpf with an apparent spike in concentration at 24 hpf. Zebrafish leptin receptor message(lepr) was detected in all embryonic and larval stages examined, and in adult zebrafish. In embryonic zebrafish, lepr was mainly expressed in the notochord. As development proceeded, lepr expression in the notochord decreased, while its expression in several other tissues, including the trunk muscles and gut, became evident. In both larval and adult brains, large lepr expressing cells were detected in similar regions of the hindbrain. In adult zebrafish, lepr expression was also observed in several other brain regions including the hypothalamic lateral tuberal nucleus, the fish homolog of the arcuate nucleus. RT-PCR experiments confirmed lepr expression in the adult fish brain, and also showed lepr expression in a subset of adult tissues including liver, muscle and ovary tissues. Our results show that lepr expression was both spatially and temporally regulated.