Figure 1

Figure 1

The effect of RTOF treatment on the oocyte viability and the early development of zebrafish embryos. (a) RTOF preserves zebrafish oocyte viability for at least 4 h. Oocytes were harvested by squeezing the abdomen of a competent female and incubated in RTOF or control solution (E3 water) for 4 h. Oocytes were imaged at 0, 30 and 60 min, and at 4 h. Oocytes kept in RTOF were alive and had attached chorions as a sign of preserved competence for fertilization, throughout the experiment. In contrast, control oocytes exhibited expanded chorions immediately after collection and started dying at 30 min post collection. (b,c) 30–60 min treatment with RTOF causes minor defects in the morphology and the survival of zebrafish embryos, while 90–120 min treatment causes substantially increased malformation and mortality. Fertilized zebrafish eggs were incubated in RTOF for 30, 60, 90 and 120 min after which they were moved to E3 water. The survival and well-being of the embryos was followed for 48 h and compared to E3 treated group. n(Control) = 348, n(RTOF 30 min) = 296, n(RTOF 60 min) = 202, n(RTOF 90 min) = 196, n(RTOF 120 min) = 240. (d) The comparative developmental stages of the control (E3 treated) and the RTOF treated embryos at indicated time points post fertilization. Newly fertilized eggs were kept in RTOF and their development was followed by time-lapse imaging. (e) The times for the first, the second and the third cell division in RTOF treated and control (E3 treated) embryos. Error bars represent SD, *p < 0.05, **p < 0.01, ***p < 0.001.