Abstract
Expression of metallothionein (MT) genes in the preimplantation rabbit blastocyst was analysed by determination of the levels of MT mRNA and relative rates of MT synthesis. MT was found to be constitutively expressed at low levels in the blastocyst. Exposure of the day-6 blastocyst to zinc ions in vitro rapidly increased the level of MT gene expression in a dose-dependent manner, with a ten-fold induction in the relative rate of synthesis at 400 microM-Zn2+. Ion-exchange chromatography of pulse-labelled blastocyst protein showed that the relative rates of synthesis of both MT-I and MT-II were markedly increased following zinc treatment, with MT-I being the predominant isometallothionein. Zinc induction of MT synthesis in the blastocyst was also detected on day 4 of gestation just after the morula-to-blastocyst transition. In contrast to the zinc effects on MT, in vitro exposure to 10 microM-Cd2+ resulted in a large induction of MT mRNA but only a modest increase in the relative rate of MT synthesis. Cadmium was found to be toxic to the day-6 blastocyst, and 10 microM-Cd2+ induced an acute stress response as indicated by a dramatic induction of heat-shock protein (HSP-70) gene expression.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
