The effect of partial removal of yolk on the chilling sensitivity of zebrafish (Danio rerio) embryos
Authors: Liu, X.H., Zhang, T. and Rawson, D.M.
Journal: Cryobiology
Volume: 39
Issue: 3
Pages: 236-242
ISSN: 0011-2240
DOI: 10.1006/cryo.1999.2206
Abstract:The effect of partial removal of yolk on the survival of zebrafish embryos and the chilling sensitivity of yolk-reduced embryos were investigated at several stages of embryo development. Dechorionated embryos were punctured with a sharp microneedle and approximately 50 to 75% of yolk content was released following multiple punctures. The survival of yolk- reduced embryos was found to he stage dependent. Only 7.9% of 26-somite (24 h) embryos survived, whereas 56.7% of prim-6 (27 h), 62.4% of prim-15 (34 h), and 81.3% of high-pec (49 h) embryos survived after partial removal of yolk. For chilling sensitivity studies the yolk-reduced embryos at high-pec stage were cultured in embryo medium for 2, 6, or 24 h to allow embryo recovery before they were chilled at 0°C for 6 h. No significant differences (P > 0.05) were seen in normalized survivals between control and yolk-reduced embryos following a 2- or 6-h recovery period. However, when the recovery period was extended to 24 h, the yolk-reduced embryos showed significant (P < 0.05) higher survival than that of chilled controls and the significance was more pronounced (P < 0.01) after a longer period (10 h) of chilling. Similar results were also obtained with embryos at prim-6 stage. These results indicated that after partial removal of yolk, zebrafish embryos at post-prim- 6 stage can survive well and their sensitivity to chilling can he reduced. This may have significant implications in alleviating certain difficulties confronting the cryopreservation of fish embryos.
Source: Scopus