Location: Cool and Cold Water Aquaculture ResearchTitle: Cloning and characterization of a novel oocyte-specific gene encoding an F-Box protein in rainbow trout (Oncorhynchus mykiss)) Author
Submitted to: Reproductive Biology and Endocrinology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/23/2013
Publication Date: 9/4/2013
Citation: Wang, L., Tripurani, S.K., Wanna, W., Rexroad III, C.E., Yao, J. 2013. Cloning and characterization of a novel oocyte-specific gene encoding an F-Box protein in rainbow trout (Oncorhynchus mykiss). Reproductive Biology and Endocrinology. 11:86.DOI: 10.1186/1477-7827-11-86. Interpretive Summary: We report a previously unidentified gene (named Fbxoo) in rainbow trout, observed its presence during egg development and identified its interactions with several other proteins known to be important factors in development. Our results suggest that Fbxoo may play a distinct and important role in the early development of eggs in rainbow trout, with the potential to affect egg quality.
Technical Abstract: Oocyte-specific genes play critical roles in oogenesis, folliculogenesis and early embryonic development. Through analysis of expressed sequence tags (ESTs) from a rainbow trout oocyte cDNA library, we identified a novel transcript which is represented by ESTs only from the oocyte library. The novel transcript is specifically expressed in ovary as shown by RT-PCR analysis. The cDNA sequence for the novel gene was obtained by assembly of the cDNA sequence from the longest EST clone and a 5'end sequence from a 5'RACE product. The complete cDNA is 1,996 bp in length containing an open reading frame which encodes a predicted protein of 514 amino acids. The amino acid sequence does not share homology with any known proteins in the NCBI databases. However, a search of the Pfam protein database revealed that the protein contains an F-box motif at the N-terminus, indicating that this novel oocyte-specific protein (named Fbxoo) is a member of the rapidly expanding family of F-box proteins. Real time PCR and Western blot analysis revealed that expression of Fbxoo mRNA and protein is high during early previtellogensis. Further analyses by in situ hybridization and immunohistochemistry revealed that Fbxoo is predominantly expressed in early previtellogenic oocytes. Analysis by yeast two-hybrid system demonstrated that Fbxoo interacts with several proteins including Tissue Inhibitor of Metalloproteinase 2 (TIMP2), a known important factor for oocyte development. These results suggest that the novel oocyte-specific gene may play an important role in early oocyte development by regulating other critical proteins involved in oogenesis in rainbow trout.