Project description:The Chinese sturgeon (Acipenser sinensis) is anadromous fish distributed in Yangtze River and East China Sea. In this study, we reported cleft-palate Chinese sturgeons in artificial population for the first time. In order to explore the genetic basis of palate malformation in A. sinensis, Illumina RNA-seq technology was used to analyze the transcriptome data of normal and cleft-palate individuals in farmed Chinese sturgeons. Raw reads were obtained and assembled into 808,612 unigenes, with an average length of 509.33 bp and an N50 of 574 bp. Sequence similarity analyses against four public databases (Nr, Uniprot, KEGG and COGs) found 158,642 unigenes that can be annotated. GABAergic synapse and TGF-β signal pathway were the most two enriched pathways with high Richfactor in the analyses of different expressed genes. In these two signal pathways, six genes (GABRA4, GS, GNS, S6K, PITX2, and BMP8) were found as cleft-palate genes in Chinese sturgeon. These findings contribute to our understanding of the genetic basis of cleft palate in sturgeon, while simultaneously adding to our knowledge about craniofacial development.
Project description:Sturgeons, producers of black caviar, are one of the most valuable wildlife commodities on earth (Pikitch et al., 2005). They appeared approximately 200 million years ago, and are known as living fossils (Bemis et al., 1997). Sturgeon populations dramatically declined as a result of overfishing, poaching and habitat destruction (Birstein, 1993; Billard and Lecointre, 2001; Vidotto et al., 2013). International Union for Conservation of Nature and Natural Resources (IUCN) classified over 85% of sturgeon species as at risk of extinction, more than any other group of species. Therefore, artificial reproduction techniques have been developed for sturgeons to meet the demands of aquaculture and restocking programs. Basic knowledge regarding biology of reproduction such as egg activation and fertilization can help improving the efficiency of artificial reproduction. Fertilization happens when gametes, spermatozoon and egg, are fused together. Egg activation refers to a series of morphological and molecular changes that occur in the egg during and after fertilization. Egg activation is believed to prevent polyspermy, and may also establish a micro-environment to support embryo development (Wong and Wessel, 2006; Niksirat et al., 2015a). Although, earlier researchers have illustrated egg structure and its morphological changes during egg fertilization and activation in sturgeons (Cherr and Clark, 1982, 1985a; Linhart and Kudo, 1997; Debus et al., 2008; Zelazowska, 2010), there is still a lack of molecular knowledge to improve our understanding of this stage of reproduction in these animals. Eggs of sturgeon are released to aqueous environment, where they are fertilized, activated and develop an adhesive layer after contact with freshwater (Cherr and Clark, 1984; Vorobeva and Markov, 1999). Although, egg stickiness is necessary for eggs in nature to help them find a stable position by attaching to substrates such as gravel and stone and increase chance of survival until hatching (Riehl and Patzner, 1998), but can cause high rate of mortality during artificial incubation as a result of attachment of eggs together and subsequent suffocation in limited space of incubators. Using clay suspension in water as an activation medium has been proven to be effective to block egg stickiness in sturgeon eggs (Dettlaff et al., 1993). In recent years, label-free protein quantification techniques have been developed based on the presumption of linear proportionality between peptide mass peak signal intensity and concentration of a given peptide. This approach avoids the limitations and multiple preparation steps of methods such as those based on two-dimensional gel electrophoresis (Niksirat et al., 2015b). The aim of present study was to identify and quantify proteome changes of sterlet eggs during activation in different activation media, water and clay suspension, using label-free protein quantification technique.