Identification Of ZRAP55, A Gene Preponderantly Expressed In Ovary Of Zebrafish

This paper studies separately effect on analysis of bioinformation,gene clone, protein expression and fluorescence immunohistochemistry and carry on the genomic structure and protein structure analysis of zRAP55 cDNA.The results are as follows:Using the analysis of bioinformation,we found that the zRAP55 largest ORF was located in 116—1264bp,which encoded a protein of 382 amino acids.The zRAP55 consists of nine exons and eight intervening introns,which is located in chromosome 23. The zRAP55 is a basic protein with the isoelectric point of 10.11 and molecular weight of 26.29 kDa.The amino acid of zRAP55 both contains the hydrophilic amino acids and the hydrophobic amino acids.We also found that transmembrane protein is existed in the region of 124-142 amino acids and its N-terminal locates inside the cell membrane. Blasting the zRAP55 cDNA and the protein in databases of NCBI,DDBJ and EMBL,we found that the zRAP55 protein shares high sequence identities with the protein from other species,which including NP₀01025676 from Xenopus tropicalis(59.7%),AAH40823 from Mus musculus(57.3%),NP₆53304 from Homo sapiens(57.2%),EDL88837 from Rattus(56.7%).In all compared sequences,the Lsm domain is highly conserved.Using Prosite to screen a Glutamine-rich region that located in the zRAP55 protein but not exist in other homology protein.The paper checked the expression patterns of zRAP55 using reverse transcription PCR(RT-PCR) to determine the tissue distribution of zRAP55 mRNA.The result shows that the zRAP55 mRNA is abundantly present in ovary and the zRAP55 mRNA expression is very weak in kidney and liver,but not in brain,testis and heart.The fluorescence immunohistochemistry in different developmental stages of ovary denotes that,zRAP55 is highly expressed at early phase of stagesâ… andâ…¡oocytes and the signal is evenly distributed throughout the cytoplasm.With the progression of oocyte growth,no signal could be detected at stagesâ…¢andâ…£oocytes.Furthermore,the expression pattern in overall ovary confirmed the result.This expression pattern suggested that the zRAP55 gene is expressed in ovary,particularly expressed specially at the early stages(â… andâ…¡) of oocytes,in addition,the zRAP55 contains Lsm domain. so it can be presumed that zRAP55 may involve in the control of protein translation in ovary of zebrafish.