Inhibition of FGF receptor impairs primitive endoderm differentiation in bovine embryos

Author(s)

Santos, Gabriel S. ; Martins, Matheus P. ; Luedke, Felipe E. ; Tanaka, Yuki ; Carreiro, Leticia E. ; Mendes, Camilla Mota ; Goissis, Marcelo Demarchi

• Document type: Journal article
• Source: REPRODUCTION IN DOMESTIC ANIMALS; v. 58, n. 2, p. 9-pg., 2022-11-14.

Abstract

The first cellular differentiation event in the pre-implantation embryo results in the trophectoderm (TE) and the inner cell mass (ICM). A second event occurs in the latter, resulting in the epiblast and the primitive endoderm (PE). This second differentiation is still not fully characterized in bovine development, although it is likely to involve FGF signalling. Thus, in this study, we tested the hypothesis that stimulation or inhibition of the FGF pathway during bovine embryo in vitro culture would only interfere with PE differentiation if maintained until later blastocyst stages. At first, we characterized the expression of PE marker SOX17 at different blastocyst stages. Then, we treated in vitro produced embryos during different windows of time: days 5.0-7.0 (D5-D7), D7-D9, and D5-D9 with 1 mu g/ml FGF4 and 1 mu g/ml heparin or 1 mM FGFR inhibitor, AZD4547. We observed that the SOX17-positive cell number only increases in late-stage blastocysts compared to early stages. Treatment of embryos with FGF4 did not change the number of SOX17-positive cells, while inhibition of FGFR signalling reduced SOX17-positive cells from D5-D7 and completely ablated SOX17 expression when kept until D9. In conclusion, FGFR inhibition repressed PE differentiation in bovine embryos at all time points, although stimulation with FGF4 did not interfere with PE cell numbers. (AU)

• FAPESP's process: 19/21303-8 - Effect of inhibition of fibroblast growth factor receptors in the differentiation of primitive endoderm in bovine embryos produced in vitro
• Grantee: Gabriel Siqueira dos Santos
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 19/22798-0 - Effect of fibroblast growth factor 4 (FGF4) in the differentiation of primitive endoderm in bovine embryos
• Grantee: Matheus Pasini Martins
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 17/09576-3 - Studies on cell differentiation mechanisms during early bovine embryo development
• Grantee: Marcelo Demarchi Goissis
• Support Opportunities: Research Grants - Young Investigators Grants