Location: Cool and Cold Water Aquaculture Research
Title: Molecular characterization and expression analysis of Zar1 and Zar1-like genes in rainbow trout Authors
Submitted to: Society for the Study of Reproduction Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: April 13, 2012
Publication Date: August 16, 2012
Citation: Lin, C., Wang, L., Hao, M., Hostuttler, M.A., Rexroad III, C.E., Yao, J. 2012. Molecular characterization and expression analysis of Zar1 and Zar1-like genes in rainbow trout. Society for the Study of Reproduction Annual Meeting. 564. Technical Abstract: Zygote arrest 1 (Zar1) is a maternal effect gene that is essential for early embryonic development. Recently, a novel gene called Zar1-like (Zar1l) was discovered. Functional studies showed that ZAR1L plays an important role in regulating oocyte-to-embryo transition in mouse. The objectives of this study were to characterize the rainbow trout Zar1 and Zar1l genes and evaluate the potential roles of these genes in controlling egg quality in rainbow trout. Through database mining, we identified the cDNAs encoding rainbow trout ZAR1 and ZAR1L. The Zar1cDNA codes for a protein of 333 aa and the Zar1l cDNA encode a protein of 323 aa. The sequences at the C terminus of the two proteins are highly conserved and contain a conserved Zinc-binding domain. Analysis of tissue distribution by RT-PCR showed Zarl is predominantly expressed in ovary and testis with minor expression in other somatic tissues, while Zar1l is exclusively expressed in ovary. In situ hybridization analysis showed strong hybridization signals of Zar1l in early previtellogenic oocytes. The expression patterns of Zar1 and Zar1l genes during early embryonic development (0h, 7.5h, 10.5h, 19.5h and 2d post fertilization) were determined by quantitative real time PCR analysis. Both genes are highly expressed in unfertilized oocytes (0h) but they show different expression patterns. While the expression of Zar1gene decreases initially from 0h to 10.5h, and then increases in 2d embryos, the Zar1l gene shows continuous reduction of expression during early embryonic development (from 0h to 2d embryos). Currently, we are analyzing the expression of these genes in eggs of various qualities (post-ovulatory aged eggs) to determine the roles of these genes in controlling egg quality in rainbow trout.