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Beneficial effects of dithiothreitol on relative levels of glutathione S‐transferase activity and thiols in oocytes, and cell number, DNA fragmentation and allocation at the blastocyst stage in the mouse
Author(s) -
Rausell Francisco,
Pertusa José F.,
GómezPiquer Vanessa,
Hermenegildo Carlos,
GarcíaPérez Miguel A.,
Cano Antonio,
Tarín Juan J.
Publication year - 2007
Publication title -
molecular reproduction and development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.745
H-Index - 105
eISSN - 1098-2795
pISSN - 1040-452X
DOI - 10.1002/mrd.20569
Subject(s) - dithiothreitol , blastocyst , biology , inner cell mass , fragmentation (computing) , propidium iodide , andrology , dna fragmentation , glutathione , microbiology and biotechnology , embryo , apoptosis , biochemistry , embryogenesis , programmed cell death , enzyme , medicine , ecology
We analyzed the effect of in vitro aging of mouse oocytes in the presence of dithiothreitol (DTT) on relative levels of glutathione S‐transferase (GST) activity and thiols in oocytes, and cell number, DNA fragmentation and cellular allocation to the inner cell mass (ICM) and trophectoderm (TE) lineage at the blastocyst stage. Ovulated oocytes from gonadotropin primed hybrid female mice of 6–8 weeks of age were aged in vitro in the presence of 0, 5, 50, or 500 µM DTT for 6 hr prior to insemination. Relative levels of GST activity and thiols in oocytes were determined by confocal laser scanning microscopy, DNA fragmentation using a single‐step TUNEL method, and cell allocation to the ICM and TE lineage by blastocyst staining with propidium iodide and Hoechst 33258. Non‐aged oocytes exhibited higher relative levels of GST activity and thiols when compared to oocytes aged in the presence of 0, 5, and 50 µM DTT. Day 5 blastocysts from the 5, 50, and 500 µM DTT groups exhibited higher total number of cells, number of ICM cells, and ICM/TE ratio, but lower percentage of number of nuclei with DNA fragmentation/number of ICM cells than blastocyst from the 0 µM DTT group. These data show that DTT counteracts the negative effects of a post‐ovulatory aging of mouse oocytes in vitro on relative levels of GST activity and thiols in oocytes, and percentage of number of nuclei with DNA fragmentation/number of ICM cells, total number of cells, number of ICM cells and ICM/TE ratio in Day 5 blastocysts. Mol. Reprod. Dev. 74: 860–869, 2007. © 2006 Wiley‐Liss, Inc.