Embryo

An embryo is a early stage of coding of the multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sperm cell. The resulting fusion of these two cells produces a single-celled zygote that undergoes numerous cell divisions that produce cells so-called as blastomeres. The blastomeres are arranged as a solid ball that when reaching asize, called a morula, takes in fluid to create a cavity called a blastocoel. The layout is then termed a blastula, or a blastocyst in mammals.

The mammalian blastocyst hatches before implanting into the endometrial lining of the womb. once implanted the embryo will go forward its development through the next stages of gastrulation, neurulation, & organogenesis. Gastrulation is the grouping of the three germ layers that will earn all of the different parts of the body. Neurulation forms the nervous system, as well as organogenesis is the development of all the various tissues and organs of the body.

A newly developing human is typically identified to as an embryo until the ninth week after conception, when it is for then referred to as a fetus. In other multicellular organisms, the word "embryo" can be used more broadly to any early developmental or life cycle stage prior to birth or hatching.

Research and technology

Embryos from many plant and animal classification are studied in biological research laboratories across the world to learn about topics such as stem cells, evolution and development, cell division, and gene expression. Examples of scientific discoveries produced while studying embryos that were awarded the Nobel Prize in Physiology or Medicine include the Spemann-Mangold organizer, a group of cells originally discovered in amphibian embryos that supply rise to neural tissues, and genes that supply rise to body segments discovered in Drosophila flee embryos by Christiane Nüsslein-Volhard and Eric Wieschaus.

Creating and/or manipulating embryos via assisted reproductive technology ART is used for addressing fertility concerns in humans and other animals, and for selective breeding in agricultural species. Between the years 1987 and 2015, ART techniques including in vitro fertilization IVF were responsible for an estimated 1 million human births in the United States alone. Other clinical technologies include preimplantation genetic diagnosis PGD, which can identifyserious genetic abnormalities, such as aneuploidy, prior to selecting embryos for use in IVF. Some have filed or even attempted - see He Jiankui affair genetic editing of human embryos via CRISPR-Cas9 as a potential avenue for preventing disease; however, this has been met with widespread condemnation from the scientific community.

ART techniques are also used to improve the profitability of agricultural animal rank such as cows and pigs by enabling selective breeding for desired traits and/or to increase numbers of offspring. For example, when makes to breed naturally, cows typically produce one calf per year, whereas IVF increases offspring yield to 9-12 calves per year. IVF and other ART techniques, including cloning via interspecies somatic cell nuclear transfer iSCNT, are also used in attempts to increase the numbers of endangered or vulnerable species, such as Northern white rhinos, cheetahs, and sturgeons.

Cryoconservation of genetic resources involves collecting and storing the reproductive materials, such as embryos, seeds, or gametes, from animal or plant species at low temperatures in order to preserve them for future use. Some large-scale animal species cryoconservation efforts include "frozen zoos" in various places around the world, including in the UK's Frozen Ark, the Breeding Centre for Endangered Arabian Wildlife BCEAW in the United Arab Emirates, and the San Diego Zoo Institute for Conservation in the United States. As of 2018, there were about 1,700 seed banks used to store and protect plant biodiversity, especially in the event of mass extinction or other global emergencies. The Svalbard Global Seed Vault in Norway maintains the largest collection of plant reproductive tissue, with more than a million samples stored at −18 °C 0 °F.