Function Of JNK In The Ontogeny Of Zebrafish

The JNK signaling pathway is one of the mitogen-activated kinase(MAPK)signaling pathway,which plays an important role in animal growth and development,apoptosis,the incidence of cancer and pathological response.Extracellular stimuli such as growth factors,cytokines and stress caused series of cell reactions within the cells via the JNK signaling pathway.To investigate the role of the JNK signaling pathway in fish ontogeny,we carried out experiments on the important model animal zebrafish by using JNK inhibitor treatment,RNA interference,combined with the histological observation,RT-PCR,western blot method,et al.The results are as follows:1.zebrafish embryos were soaked with JNK specific inhibitor SP600125,and it showed that the embryo mortality,malformations were significantly increased.Malformation in embryonic development mainly in:embryonic growth retardation,the yolk sac abnormal digestion,body axis bending,the enlargement of the pericardial cavity and abnormal differentiation of retinal cells.RNA interference vectors which can specifically interfere jnkl gene translation process were used for micro injection of zebrafish embryos and it showed that zebrafish embryo mortality and malformation rate were both greatly increased,embryonic body axis bending or even branch appeared,the tail of embryo adversely differentiated and developed.These results suggested that JNK may be involved in the zebrafish embryonic development,especially play an important role in the construction of normal body axis.2.By SP600125 treatment,some phenomenons of abnormal development such as skull missing,maxillary defect and spine asymmetric development appeared in the adult zebra fish.It revealed that JNK has a major impact on the construction of the adult tissues and organs,in particular,a Important regulatory function on normal development of the bone tissue of zebrafish.3.The treatment of SP600125 on zebrafish embryos or fry could significantly regulate the differentiation and development of the zebrafish gonad,which confirmed that JNK has an important regulatory function in fish gonadal development especially in the early differentiation and development of ovarian.4.The expression of Fox03a gene-a JNK downstream regulatory factor,both in RNA and protein levels,were higher in the zebrafish ovary than in the testis.It remains to be further studied whether the differential expression of the transcription factor fox03a genes in male and female gonads in the zebrafish associated with the regulation of fish gonadal development by JNK signaling pathway.