A possible role for embryo-derived factors during mouse preimplantation development?
A possible role for embryo-derived factors during mouse preimplantation development?
Several previous reports have suggested that development of mouse preimplantation embryos in vitro at high culture densities (i.e. number of embryos developing per unit volume of medium) is stimulatory to their development both in terms of morphology and cell proliferation. Although the mechanism(s) involved in this density-dependent stimulation of embryo development is unknown, growth factor-like molecules released by the embryo have been proposed as likely candidates.
Initially, I investigated the effects of varying embryo culture density and culture of embryos in embryo-conditioned medium (CM) on preimplantation mouse embryo development in vitro. Culture of embryos at high density or in CM from the 4-cell stage significantly decreased the mean time taken for embryos to complete compaction, initiate cavitation, and undergo successful zona hatching (see also Paria and Dey, 1990) and increased the number cells in blastocysts.
I then compared the composition of CM and non-conditioned control medium in terms of osmolarity and concentrations of glucose and pyruvate. Screening for the presence of amino acids in CM was performed by amino acids analysis and for certain growth factors (TGF-β, IGF-II and EGF-receptor ligands) by ELISA and bioassay techniques . Embryonic peptide secretion was investigated by metabolic labelling of embryos at the 8-cell/morula and blastocyst stages, fractionation of the resulting CM by reducing SDS-PAGE and fluorography. These experiments failed to identify any significant differences in the osmolarity or glucose and pyruvate concentrations of the two media and no significant concentrations of amino acids or any of the growth factors assayed for were detectable. However, metabolic labelling did reveal the presence of a number of unidentified secreted peptides which were specific to CM from 8-cell/morula and blastocyst stage embryos.
The possiblity of platelet activating factor (PAF)-like activity being responsible for some of the stimulatory effects seen in this study was investigated with the use of two structurally distinct competitive PAF-receptor antagonists, CV-3988 and SDZ 64-412.
University of Southampton
1994
Stoddart, Neil Richard
(1994)
A possible role for embryo-derived factors during mouse preimplantation development?
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
Several previous reports have suggested that development of mouse preimplantation embryos in vitro at high culture densities (i.e. number of embryos developing per unit volume of medium) is stimulatory to their development both in terms of morphology and cell proliferation. Although the mechanism(s) involved in this density-dependent stimulation of embryo development is unknown, growth factor-like molecules released by the embryo have been proposed as likely candidates.
Initially, I investigated the effects of varying embryo culture density and culture of embryos in embryo-conditioned medium (CM) on preimplantation mouse embryo development in vitro. Culture of embryos at high density or in CM from the 4-cell stage significantly decreased the mean time taken for embryos to complete compaction, initiate cavitation, and undergo successful zona hatching (see also Paria and Dey, 1990) and increased the number cells in blastocysts.
I then compared the composition of CM and non-conditioned control medium in terms of osmolarity and concentrations of glucose and pyruvate. Screening for the presence of amino acids in CM was performed by amino acids analysis and for certain growth factors (TGF-β, IGF-II and EGF-receptor ligands) by ELISA and bioassay techniques . Embryonic peptide secretion was investigated by metabolic labelling of embryos at the 8-cell/morula and blastocyst stages, fractionation of the resulting CM by reducing SDS-PAGE and fluorography. These experiments failed to identify any significant differences in the osmolarity or glucose and pyruvate concentrations of the two media and no significant concentrations of amino acids or any of the growth factors assayed for were detectable. However, metabolic labelling did reveal the presence of a number of unidentified secreted peptides which were specific to CM from 8-cell/morula and blastocyst stage embryos.
The possiblity of platelet activating factor (PAF)-like activity being responsible for some of the stimulatory effects seen in this study was investigated with the use of two structurally distinct competitive PAF-receptor antagonists, CV-3988 and SDZ 64-412.
This record has no associated files available for download.
More information
Published date: 1994
Identifiers
Local EPrints ID: 458528
URI: http://eprints.soton.ac.uk/id/eprint/458528
PURE UUID: 9d43e2c5-27a5-48b1-bb03-30a8319622cf
Catalogue record
Date deposited: 04 Jul 2022 16:50
Last modified: 04 Jul 2022 16:50
Export record
Contributors
Author:
Neil Richard Stoddart
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics