c-Abl Plays an Important Role in Mouse Preimplantation Embryo Development and the Dysregulation Associated With Decreased mTERT Expression

Abstract

c-Abl encodes a cytoplasmic and nuclear protein tyrosine kinase that has been implicated in processes of cell growth, proliferation, differentiation, division, and regulation of cytoskeletal structure. mTERT is a catalytic subunit of mouse telomerase and it is very important for controlling cell proliferation and homeostasis by maintaining telomere length. We demonstrated before the interaction between c-Abl and mTERT in mouse ovary and we suggested a role for c-Abl in the regulation of telomerase function and proliferation in mouse granulosa cells. The current study aims to examine the c-Abl and mTERT expression and potential interactions through mouse preimplantation embryonic development. To assess c-Abl's function in embryonic development, siRNA-mediated silencing of the c-Abl was used in mouse preimplantation embryos. After siRNA transfection, the immunofluorescence was used to examine the c-Abl pattern at embryonic development. Next, the levels of mTERT and c-Abl mRNA were compared. The results show that c-Abl is expressed in mouse preimplantation embryos at all developmental stages, with the cytoplasmic expression all through from the 2-cell to the blastocyst. Additionally, c-Abl is presented very intense expression in blastomer-blastomer junctions. The siRNA-mediated depletion of c-Abl showed developmental abnormalities at the 8- to 16-cell and morula to blastocyst and also with significantly decreased blastocyst development rate. Moreover, expression of the mTERT telomerase catalytic subunit was significantly reduced in c-Abl-depleted embryos during preimplantation embryonic development. Finally, we demonstrate that c-Abl may play a crucial role in compaction and preimplantation embryo development, and that the relationship between c-Abl and mTERT has developmental importance in early embryogenesis.