Furthermore, our transgenic fish demonstrates that the promoter of grouper tshb can direct the pituitary and kidney-specific expression of GFP in zebrafish, similar to the endogenous. Therefore, the tissue distribution L-Quisqualic acid pattern of tshb might be conserved in teleost fish. Although the significance of these expressions is unknown, the ubiquitous distribution of TSHR may suggest a divergent endocrine or paracrine TSH system in nonpituitary tissues. Kidney tubule morphogenesis and segmentation are important for kidney function, but most of the process is unknown. In proximal tubule, phosphate, glucose, amino acid and bicarbonate are reabsorbed and transported. Only one transgenic fish line that marks the proximal tubule development was reported in zebrafish. GFP is partially co-localized with proximal PCT segment marker slc20a1a, and the distribution pattern of GFP in pronephric tubule is a little extended than slc20a1a at the distal portion, which belongs to PST segment. When treated with RA, GFP signal elongates distally and almost connects at cloaca, similar with the expression of the PST segment marker trpm7 in response to RA. Therefore, gtshb promoter-driven GFP is specifically expressed in the proximal pronephric tubule, and is a valuable marker for PCT and PST segments. Pax2a is one of the earliest acting transcription factors throughout the IM, and has been identified to control the mesenchyme-to-epithelial transition of nephron progenitors. Furthermore, Pax2a and the closely related Pax8 act upstream of hnf1b genes, which initiate the gene expression programs specific to pronephric segmentation. However, the epithelialization of IM is still unaffected in Hnf1bdeficient embryos, indicating that pronephric epithelialization and segmentation are separate and the early epithelialization is Hnf1bindependent. The results suggest that both Pax2a and Hnf1b regulate the transcription of gfp through acing on gtshb promoter. Consistently, gfp message is initially detected at 16 hpf, just as the formation of pronephric tubular lumen. It is the time that the EMT is undergoing and the segmentation is initialing. Therefore, GPF driven by the gtshb promoter gives us a good marker to visualize the initial processes of pronephric development. Through tracing the GFP signal, the gtshb promoter-driven Tg can be LUF 6283 easily utilized to observe the convolution of the proximal tubules and the dynamic progression of nephron morphogenesis during the whole lifetime. Additionally, the expressed GFP can be used as a readout signal of the tubular development to detect the RA signaling alteration in response RA reagent treatment. Therefore, the transgenic line Tg provides a potential tool for understanding morphogenesis and segmentation of pronephric tubules and for genetic or chemical analysis of kidney pathology. Histamine, a major product of mast cells, regulates many vital physiological functions including vasodilation, allergic response and neurotransmission. The effects of histamine are mediated through a family of four G-protein coupled receptors, histamine H1 receptor, H2R, H3R and H4R.