The Effect of Morpholino Oligonucleotides to Gene Anxa2a on the Embryonic Development of Danio rerio

The Annexin 2 protein (ANXA2) encoded by the ANXA2 gene performs a number of biological functions that are primarily related to cellular transport. An impaired functional activity of the ANXA2 gene have been primarily detected in oncological diseases; however, we have previously shown an increased expression of the Anxa2 gene at the mRNA level in the early stages of neurodegeneration. In this regard, it is most interesting to study the effect of suppressed expression of the ANXA2 gene on nervous-system functioning in a Danio rerio model with the use of morpholino oligonucleotides (morpholino). The present study examined the effect of morpholino to the anxa2a gene on the development of Danio rerio embryo. The study was conducted with D. rerio line AB, embryos of which were injected with morpholino oligonucleotides to the anxa2a gene. The estimate of the effect of injected morpholino oligonucleotides on embryo development was examined by the changes in the phenotype on the second and fourth day post fertilization (dpf). An injection of experimental morpholino targeting the start-codon and 5'UTR region results in an increased percentage of deformations compared with the Co–In and Co–Mo–D groups at the fourth dpf. The deformations observed at the fourth dpf were evident in both control and experimental groups. In addition, we analyzed an earlier time point such as the second dpf. Phenotype changes at this time point were detected only in the experimental groups. A comparative analysis of data obtained from injected morpholino targeting start-codon and 5'UTR of the anxa2a gene evidence that both variants may be used for further research. In addition, we have shown that it is preferable to carry out analysis of expression at the second dpf. Apparently, the effects detected at the second dpf are specific, while the presence of a hindbrain ventricular deformity suggests that altered expression of the anxa2a gene may result in dysfunction of the nervous system.