Expression of the insulin-like growth factor-1 gene and its receptor in preimplantation mouse embryos; is it a marker of embryo viability?

• Published in: Molecular human reproduction 1999-09, Vol.5 (9), p.861-865
• Main Authors: Kowalik, A., Liu, H-C., He, Z-Y., Mele, C., Barmat, L., Rosenwaks, Z.
• Format: Article
• Language: English
• Subjects: Actins - genetics; Animals; Biological and medical sciences; Blastomeres; Culture Techniques; embryo biopsy; Embryonic Development - genetics; Female; Fetal Viability - physiology; Fundamental and applied biological sciences. Psychology; Gene expression; Gene Expression Regulation, Developmental; Genetic Markers; growth factors; IGF-I; Insulin-Like Growth Factor I - genetics; Mice; Mice, Inbred Strains; Molecular and cellular biology; Molecular genetics; Pregnancy; Receptor, IGF Type 1 - genetics; RNA, Messenger - analysis; RT–PCR
• ISSN: 1360-9947; 1460-2407
• DOI: 10.1093/molehr/5.9.861

Recent studies have demonstrated the importance of insulin-like growth factors (IGF) in mouse preimplantation development. We examined IGF-1 and IGF-1 receptor (IGF-1R) gene expression in a single blastomere of an early mouse embryo and compared it with subsequent embryo development in culture. Fertilized eggs and 2-cell embryos were obtained by tubal flushing in superovulated and mated female mice. Single cells were removed from embryos at cleavage stage between 3 and 8 cells using the standard embryo biopsy techniques. Individual blastomeres from each embryo were then assayed for the presence of IGF-1 and IGF-1R mRNA using reverse transcription–polymerase chain reaction. The biopsied embryos were washed in medium and placed in co-culture with murine endometrial cells. Embryonic development in culture was assessed and blastocyst grading was performed. IGF-1 gene expression was then examined for an association with in-vitro development. Eighty-seven embryos were biopsied. IGF-1R gene expression was detected in the majority of embryos tested and IGF-1 gene expression was detected in 34 of 81 (42%) embryos. A significant association between IGF-1 expression and blastocyst formation in vitro was found (P < 0.01). There was no association between IGF-1R expression and subsequent embryo development. We conclude that IGF-1 gene expression could potentially be used as a marker of embryo quality.