Localisations of the FN1 and integrin subunits by double immunofluorescent staining on in vitro produced blastocyst. (A) Double immunofluorescent staining for ITGA3 (A, FITC), FN1 (A', Cy5) and merged signals (A"). ITGA3 was mainly expressed at the cell membranes of the TE cells. FN1 and ITGA3 were expressed adjacent to each other but no co-localisation was found (A"'). (B) Double immunofluorescent staining for ITGA5 (B, FITC) and FN1 (B', Cy5) and merged signals (B"). (C) Double immunofluorescent staining for ITGAV (C, FITC) and FN1 (C', Cy5) and merged signals (C"). ITGA5 and ITGAV were mainly expressed in the ICM. Partial co-localisation with FN1 was observed for ITGA5 (B"') as well as ITGAV (C"') by the appearance of yellow areas when signals were merged (indicated by arrows) (Original Magnification ×400).