Friday, November 1, 2019

Creation Moment 11/1/2019 - Embryogenesis

For by him were all things created, that are in heaven, and that are in earth, visible and invisible...
Colossians 1:16
"Initial animal embryo cells are genetically identical and pre-packaged by the mother with maternal RNA, ribosomes, and proteins, which control the establishment of the body plan in the offspring embryo.


As the cells continue to divide over the process of embryogenesis,
--they are converted into different cell types,
--eventually resulting in skin, muscle, bone, connective tissues, nerve cells, etc, in a process called differentiation.

Embryogenesis was first experimentally investigated in the 19th century because of its fundamental importance to all of biology.

Recent reviews show that the oocyte is polarized via a complex and redundant system of interactions between the cytoskeleton, several signalling pathways, and cell-to-cell communication.

These issues are also of intense interest to assisted reproductive research and the assessment of embryo quality. Precisely when and how the cells of the mammalian embryo become committed to a specific cell type is of intense interest to stem cell researchers with evidence that it occurs as early as the 2 or 4 cell stage.

Each differentiated cell employs specific parts of its genome, namely those genes and regulatory regions that are necessary to construct each specific cell type required by the developing embryo.
Genes and regions of the genome that are not required at any stage of development are blocked by repressive chromatin states associated with DNA methylation and histone modifications.

A complex control system exists which causes the embryonic cells to differentiate so that the appropriate body parts and organs will
develop at the proper location in the developing body at the required time. This system must operate at a high level of control to ensure the zygote develops into a complete functional organism consisting of many billions of differentiated cells that develop into functional organs and organ systems.

The fates of individual cells and lineages are determined by a variety of genetic systems involving transcription factors, gene regulatory features (promoters, enhancers, and silencers), chromatin-modifying non-coding RNAs, as well as cytosine and histone modifications that accurately mark and dynamically designate its state in the developmental continuum.

Many gene products, including proteins and a diversity of non-coding RNAs, are required for the development of a specific animal body plan and its many structures and organs.
These gene products transmit information that influences how and when individual cells differentiate. These signals must interact with each other during embryological development in order to regulate both how cells and tissues are organized and assembled. The cell’s many types of signalling molecules, such as hormones and cytokines, also coordinate and influence this cellular development.

They form networks of coordinated systems that interact in ways analogous to how computer systems are designed to achieve the functional complexity of integrated circuits, hardware, and software required.

When and how cell signalling molecules are transmitted often depends both on what signals from other molecules are received, and when they are received.
This system, in turn affects the transmission of yet other signals—all of which must be properly integrated and coordinated in order to achieve the numerous specific time-critical functions required for organism development from a zygote to an adult.
Such organism and organelle specific genetic circuitry also guides the process of biomineralization resulting in skeletons and teeth as well as the generation of turtle and clam shells.
The coordination and integration of a plethora of signalling molecules ensure that the proper cellular differentiation and organization of distinct cell types occurs during the development of a specific animal body plan, such as that of a mammal or insect."
CMI