TY - JOUR

T1 - Functional challenge affects aquaporin mRNA abundance in mouse blastocysts

AU - Offenberg, Hanne Kjær

AU - Thomsen, Preben Dybdahl

PY - 2005

Y1 - 2005

N2 - The aquaporins (AQPs) are a family of channel proteins that facilitate diffusion of water across cell membranes. Three members of the AQP family have been detected in the mouse blastocyst: AQP 3 and 8 are located in the basolateral domain and AQP 9 predominantly in the apical domain of the trophoblast cells. These are believed to be involved in facilitating the accumulation of fluid into the blastocyst cavity. We have investigated the ability of mouse embryos to regulate AQP gene expression in response to different treatments expected to affect the passage of water across the trophoblast cells using real-time PCR. In the first experiment 8-cell embryos were allowed to develop to blastocysts in media from 300 to 400 mOsm. Blastocyst formation was unaffected by media made hyperosmolar by glycerol, whereas blastocyst formation was significantly reduced in sucrose-based 350 and 400 mOsm media. AQP 8 mRNA levels were reduced when embryos were cultured in glycerol-based hyperosmolar media. The mRNA levels of AQP 3, 7, 9, and 11 were not significantly affected by hperosmolar media. In the second experiment blastocysts were punctured (0 hr) and allowed to re-expand. AQP mRNA levels were examined after 2, 6, and 10 hr. Compared to control embryos, the expression of AQP 3, 7, and 9 were upregulated after 2 hr. Upregulation was sustained only for AQP 9 and this was sustained up to 6 and 10 hr after puncture. In the third experiment we compared expression of AQPs between in vitro cultured and in vivo developed blastocysts. We found that in vitro culture resulted in lower levels of AQP 8, 9, and 11 compared to in vivo development. These experiments show that mouse embryos are capable of regulating AQP mRNA abundances in response to environmental alterations.

AB - The aquaporins (AQPs) are a family of channel proteins that facilitate diffusion of water across cell membranes. Three members of the AQP family have been detected in the mouse blastocyst: AQP 3 and 8 are located in the basolateral domain and AQP 9 predominantly in the apical domain of the trophoblast cells. These are believed to be involved in facilitating the accumulation of fluid into the blastocyst cavity. We have investigated the ability of mouse embryos to regulate AQP gene expression in response to different treatments expected to affect the passage of water across the trophoblast cells using real-time PCR. In the first experiment 8-cell embryos were allowed to develop to blastocysts in media from 300 to 400 mOsm. Blastocyst formation was unaffected by media made hyperosmolar by glycerol, whereas blastocyst formation was significantly reduced in sucrose-based 350 and 400 mOsm media. AQP 8 mRNA levels were reduced when embryos were cultured in glycerol-based hyperosmolar media. The mRNA levels of AQP 3, 7, 9, and 11 were not significantly affected by hperosmolar media. In the second experiment blastocysts were punctured (0 hr) and allowed to re-expand. AQP mRNA levels were examined after 2, 6, and 10 hr. Compared to control embryos, the expression of AQP 3, 7, and 9 were upregulated after 2 hr. Upregulation was sustained only for AQP 9 and this was sustained up to 6 and 10 hr after puncture. In the third experiment we compared expression of AQPs between in vitro cultured and in vivo developed blastocysts. We found that in vitro culture resulted in lower levels of AQP 8, 9, and 11 compared to in vivo development. These experiments show that mouse embryos are capable of regulating AQP mRNA abundances in response to environmental alterations.

KW - Former LIFE faculty

KW - gene expression

KW - real-time PCR

KW - preimplantation embryo

U2 - 10.1002/mrd.20306

DO - 10.1002/mrd.20306

M3 - Journal article

C2 - 15892044

VL - 71

SP - 422

EP - 430

JO - Molecular Reproduction and Development

JF - Molecular Reproduction and Development

SN - 1040-452X

ER -