Localization and expression of LHβmRNA in the brain and Hatschek's pit of amphioxus, Branchiostoma belcheri

To determine whether gonadotropin-like substance in the brain and Hatschek' s pit of amphioxus issynthesized by the tissue in situ or transported from other tissue, a histochemical study was carried out by in situ hy- bridization using digoxigenin (DIG)-labelled LHβRNAprobes. The results showed that LHβmRNA expressed in the nerve cells of brain and the epithelial cells of Hatschek' s pit, thus providing new evidence for the homology of pituitary of ver- tebrates with Hatschek' s pit and the functional evolution of gonadotropin.