TOXICITY OF CRYOPROTECTIVE AGENTS AND SIGNALING OF INSULIN-LIKE GROWTH FACTOR IN HEN CLAM (MACTRA CHINENSIS) EMBRYOS.
BACKGROUND
Signaling of Insulin-like growth factor-I (IGF-I) is involved in development, growth, reproduction and aging of organisms.


OBJECTIVE
The work investigated the toxicity of glycerol, dimethyl sulfoxide (DMSO), and ethylene glycol (EG) to hen clam (Mactra chinensis) embryos, as well as the possible role of the insulin-like growth factor-I (IGF-I) during the development and growth of embryos after freeze.


METHODS
Effects of glycerol, DMSO and EG at different concentrations were tested. The relationship between larval viability and signaling of IGF-I receptor after cryoprotective treatment and/or freezing was examined using immuno-blot analysis.


RESULTS
Glycerol had the highest toxicity, followed by DMSO or EG. No embryo survived freeze and thaw without CPAs. After freeze, the activation of the IGF-I signaling pathway, including the IGF-I receptor (IGF-IR) β-subunit, could be detected in freeze-thawed embryos. The level of IGF-IR expression was very weak in freeze-thawed embryos.


CONCLUSIONS
The survival and developmental rate of embryos was closely related to CPA concentration. IGF-IR was activated and regulated the downstream IGF-I signaling in embryos. The reduced activation of IGF-IR could be related to the death of hen clam embryos.
Youn Hee
YH
Choi
Taek Jeong
TJ
Nam
D000818:Animals; D049872:Bivalvia / Q000187:drug effects / Q000196:embryology*; D015925:Cryopreservation; D003451:Cryoprotective Agents / Q000494:pharmacology* / Q000633:toxicity; D004121:Dimethyl Sulfoxide / Q000494:pharmacology* / Q000633:toxicity; D004625:Embryo, Nonmammalian / Q000187:drug effects / Q000502:physiology; D019855:Ethylene Glycol / Q000494:pharmacology* / Q000633:toxicity; D005990:Glycerol / Q000494:pharmacology* / Q000633:toxicity; D017526:Receptor, IGF Type 1 / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects
D003451:Cryoprotective Agents; D017526:Receptor, IGF Type 1; D019855:Ethylene Glycol; D005990:Glycerol; D004121:Dimethyl Sulfoxide