Zygotic embryo

Ciemerych MA, Maro B, Kubiak JZ 1999 Control of duration of the first two mitoses in a mouse embryo. Zygote 7 293-300... 

Zeng F, Schultz RM. RNA transcript profiling dnring zygotic gene activation in the preimplantation mouse embryo. Dev Biol 2005 283 40-57. 

Arora K, Niisslein-Volhard C 1992 Altered mitotic domains reveal fate map changes in Drosophila embryos mutant for zygotic dorsoventral patterning genes. Development 114 1003-1024... 

Mailer Our original model was based on data that J. Tata published showing that bcl2 was one of the first genes transcribed by the embryo. This was a sort of default model where unless you produced zygotic Bcl2 you would apoptose. But when we made antibodies to Bcl2 we found that there was plenty of it present in the oocyte. 

Bronsema FBF, Vanuvustveen WJF, Pinsen E, Van Lammeren AAM. Distribution of [14C] dichlorophenoxyacetic acid in cultured zygotic embryos of Zea mays L. J Plant Growth Regul 1998 17 81-88. 

Schoenwaelder MEA (2002b) Physode distribution and the effects of Thallus Sunburn in Hormosira banksii (Fucales, Phaeophyceae). Bot Mar 45 262-266 Schoenwaelder MAE, Wiencke C, Clayton MN, Glombitza KW (2003) The effect of elevated UV radiation on Fucus spp. (Fucales, Phaeophyta) zygote and embryo development. Plant Biol 5 366-377... 

The term zygote refers to the immediate result of fertilisation, i.e. one cell, whereas tiie embryo contains more than one cell. The term foetus refers specifically to mammalian development but has more of a legal meaning fiian a biological one. It is defined as file embryo from the end of the eighfii week after fertilisation. Nonetheless, the term is still used in biology and biochemistry and is used in this text to describe the developing embryo (also known as the conceptus). 

Fig. 1. Dynamics of DNA methylation levels during mouse development. The methylation patterns of the oocyte and the rapidly demethylated after fertilization sperm create the combined methylation patterns in the early mouse zygote. During the first two to three cleavage divisions, the 5mC levels decrease further and stay low through the blastula stage. Post-implantation, the mouse embryo genome is methylated de novo the CpG islands remain mostly unmethylated. The primordial germ cells remain unmethylated. During gametogenesis specific parental (maternal or paternal) patterns of DNA methylation are established at imprinted loci (for further details see Refs. [13, 14]) (re-drawn from Ref [4]).

Louis Guenin in Science says, Zygotic personhood, which does collide with embryo research, is an implausible contradiction of the Catholic church s magisterium for most of its history. Until 1869, the... 

Rutledge JC, Generoso WM, Shourbaji A, Cain KT, Gans M, Oliva J (1992) Developmental anomalies derived from exposure of zygotes and first-cleavage embryos to mutagens. Mutat Res, 296 167-177. 

The embryo develops from a zygote formed by fusion of a sperm nucleus originating from the pollen and an egg cell. The fertilized egg is surrounded in the gynmosperms by a nutritive layer or endosperm which is haploid and is derived from the same game-tophyte tissue that produced the egg. In angiosperms two sperm nuclei form one of these fertilizes the egg, while the other fuses with two haploid polar nuclei derived from the female gametophyte. (The polar nuclei are formed by the same mitotic divisions that formed the egg.) From this develops a 3n triploid endosperm. 

The plant embryo is a juvenile form, the seedling. In Arabidopsis the zygote, which is surrounded by maternal diploid tissue, divides asymmetrically. The resulting apical and basal cells (Fig. 32-8B) differ in several ways. The small cytoplasm-rich apical cell is partitioned into eight proembryo cells by two rounds of vertical division and one horizontal division. The larger basal cell contains a vacuole and divides repeatedly horizontally to give 7-9 aligned cells. Only the uppermost of these becomes a part of the embryo. 

Figure 13.2 Development of the zygote to a three germ cell layered embryo.

We have found that using mature females as embryo donors is a key deviation from standard transgenic mouse production practices. The mature females typically produce fewer oocytes compared to pre-pubescent females, but the oocytes that are released tend to yield more developmentally synchronized populations of zygotes as well as zygotes of similar quality and injectibility. ... 

Schoenwaelder, M.E.A. and Clayton, M.N., Secretion of phenolic substances into the zygote wall and cell plate in embryos of Hormosira and Acrocarpia (Fucales, Phaeophyceae), J. Phycol., 34, 969,1998. 

Gamete A reproductive cell such as ovule or pollen. Female and male gametes unite to form a single cell called the zygote, which, through division, generates an embryo and ultimately a progeny individual. 

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