Biomaterial Database

Preimplantation development of the mammalian embryo. 1993

E Agostoni

Département d'Embryologie et Tératologie Expérimentelles, University of Fribourg, Switzerland.

The bases for the differentiation of an adult individual are founded during the early development of the mammalian embryo before its implantation in the uterus. After the first cleavage, which is under maternal genome control, the segmentation continues under the control of the embryonic genome. At this time polarization and flattening of the blastomeres and the formation of specialized junctions among them, characterize the foundation of two different cell populations. These will give rise to the inner cell mass and the trophectoderm, which are finally segregated during cavitation. The last step of the preimplantation development is the blastocyst hatching from the zona pellucida, that prevented the implantation until now. During the preimplantation period the embryo may be exposed to environmental chemicals via mother genital fluid and teratogenic effects have been reported during this period. Even if the differentiation of the blastomeres begins very early in the development, the embryo seems to conserve its developmental plasticity, suggesting that the mechanisms of this teratogenicity are eventually to be found at DNA level.

UI	MeSH Term	Description	Entries
D008322	Mammals	Warm-blooded vertebrate animals belonging to the class Mammalia, including all that possess hair and suckle their young.	Mammalia,Mammal
D001755	Blastocyst	A post-MORULA preimplantation mammalian embryo that develops from a 32-cell stage into a fluid-filled hollow ball of over a hundred cells. A blastocyst has two distinctive tissues. The outer layer of trophoblasts gives rise to extra-embryonic tissues. The inner cell mass gives rise to the embryonic disc and eventual embryo proper.	Embryo, Preimplantation,Blastocysts,Embryos, Preimplantation,Preimplantation Embryo,Preimplantation Embryos
D004249	DNA Damage	Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.	DNA Injury,DNA Lesion,DNA Lesions,Genotoxic Stress,Stress, Genotoxic,Injury, DNA,DNA Injuries
D005314	Embryonic and Fetal Development	Morphological and physiological development of EMBRYOS or FETUSES.	Embryo and Fetal Development,Prenatal Programming,Programming, Prenatal
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000014	Abnormalities, Drug-Induced	Congenital abnormalities caused by medicinal substances or drugs of abuse given to or taken by the mother, or to which she is inadvertently exposed during the manufacture of such substances. The concept excludes abnormalities resulting from exposure to non-medicinal chemicals in the environment.	Drug-Induced Abnormalities,Abnormalities, Drug Induced,Abnormality, Drug-Induced,Drug Induced Abnormalities,Drug-Induced Abnormality
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013723	Teratogens	An agent that causes the production of physical defects in the developing embryo.	Embryotoxins,Fetotoxins,Teratogen
D015044	Zona Pellucida	A tough transparent membrane surrounding the OVUM. It is penetrated by the sperm during FERTILIZATION.
D051379	Mice	The common name for the genus Mus.	Mice, House,Mus,Mus musculus,Mice, Laboratory,Mouse,Mouse, House,Mouse, Laboratory,Mouse, Swiss,Mus domesticus,Mus musculus domesticus,Swiss Mice,House Mice,House Mouse,Laboratory Mice,Laboratory Mouse,Mice, Swiss,Swiss Mouse,domesticus, Mus musculus