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Cultrure and Transfer of Embryos as a Testing System for Embryo‐toxicity of Chemicals *
Author(s) -
MATSUMOTO Nobuo,
SPINDLE Akiko,
KATAYAMA Susumu,
KUBO Harumi
Publication year - 1984
Publication title -
congenital anomalies
Language(s) - English
Resource type - Journals
eISSN - 1741-4520
pISSN - 0914-3505
DOI - 10.1111/j.1741-4520.1984.tb00938.x
Subject(s) - embryo , blastocoel , biology , embryonic stem cell , sister chromatid exchange , embryogenesis , andrology , blastocyst , toxicity , embryo transfer , microbiology and biotechnology , genetics , chemistry , dna , medicine , organic chemistry , gene
Culture system of mouse embryos from 2‐cell stage to early post‐implantation stage was established. To assess the growth and development of embryos, morphological, biochemical and cytogenetical endopoints were settled as follows: 1. Blastocysts formation (Day 4 of culture) after treatment of 2‐cell, 4 to 8‐cell and morula. 2. Retention of blastocoel fluid on Day 5 of culture after treatment of blastocysts on Day 4 of culture. 3. Formation of trophblast outgrowth, discrete inner cell masses (ICMs), and ICMs differentiating into the primary endoderm and ectoderm (two‐layer ICMs) on Day 9 of culture. 4. Inhibitory effects on incorporation of 3 H‐thymidine into DNA and of L‐( 35 S) methionine into protein of embryonic cells after treatment with chemicals. 5. Induction of structural chromosome aberrations and sister chromatid exchanges (SCEs) after treatment of blastocysts. 6. Further development of the treated embryos after transfer of them into the uterine horns of foster mothers (Day 16.5). Mercuric chloride (MC), methylmercuric chloride (MMC), and 4‐Nitroquinoline 1‐oxide (4 NQO) were used for the experiment as model agents. The susceptibility of embryos to toxic effects of MMC changed as developmental stage progressed. The toxic effects of MC differed in manifestation from that of MMC. MMC was about 200 times as toxic to post‐implantation development as MC. These results were chiefly due to the difference between the compounds as regards the penetration of cell membrane and the distribution in living embryonic cells. As for the effects of 4NQO, structural chromosome aberrations and SCEs were induced at the concentration lower than the threshold value for the inhibition of morphological development. 4 NQO treated embryos which were transferred to the uterine horns of recipient mothers were implanted lower rate than control embryos. The embryos could not be implanted at all when treated with 10 ‐8 M. The fetuses originated from the treated (10 ‐10 M and 10 ‐9 M 4NQO for 24 hr) blastocysts showed a remarkable decrease in their body weights without signs of external malformations.