Potassium Simplex Optimized Medium (KSOM) is a specialized medium primarily used for in vitro culture of mouse preimplantation embryos in research. [1] [2]
Potassium Simplex Optimized Medium (KSOM) is a specialized medium primarily used for in vitro culture of mouse preimplantation embryos in research. [1] [2]
The culture of preimplantation embryos is of paramount importance as it serves as a foundation for exploring embryo development, advancing assisted reproductive technology, and facilitating the generation of genetically modified animals. [1] The primary motivation behind the establishment of KSOM was to address the phenomenon known as the two-cell block, wherein mouse embryos encounter developmental arrest at the two-cell stage. [3] Researchers Lawitts and Biggers, in their groundbreaking work in the early 1990s, employed a sequential simplex optimization strategy to solve this issue. [4] This method involves a systematic approach to optimize multiple variables simultaneously, allowing for the fine-tuning of media components. Their efforts culminated in the formulation of the Simplex Optimized Medium (SOM). Further refinements based on the intracellular K+/Na+ ratio in the two-cell stages led to the evolution of KSOM, potassium-supplemented SOM. [4] Because KSOM uses a bicarbonate buffering mechanism, it is dependent on a CO2 incubator to maintain the right pH. The handling of embryos outside a CO2 incubator necessitates the use of HEPES buffered media, such as M2. [2]
Following the foundational success of KSOM, researchers sought to further enhance the mediums' efficacy. This led to the introduction of amino acid supplementation, resulting in the variant known as KSOM/AA. The availability of amino acids in the medium further aided in the development of mouse embryos and augmented their growth potential. [5] KSOM/AA has ever since become the most widely used medium for the culture of preimplantation mouse embryos in research. [2] [1] Ready-to-use KSOM/AA can be obtained from various commercial vendors but it can also be prepared in-house based on published protocols. [2]
Developmental biology is the study of the process by which animals and plants grow and develop. Developmental biology also encompasses the biology of regeneration, asexual reproduction, metamorphosis, and the growth and differentiation of stem cells in the adult organism.
Blastulation is the stage in early animal embryonic development that produces the blastula. In mammalian development the blastula develops into the blastocyst with a differentiated inner cell mass and an outer trophectoderm. The blastula is a hollow sphere of cells known as blastomeres surrounding an inner fluid-filled cavity called the blastocoel. Embryonic development begins with a sperm fertilizing an egg cell to become a zygote, which undergoes many cleavages to develop into a ball of cells called a morula. Only when the blastocoel is formed does the early embryo become a blastula. The blastula precedes the formation of the gastrula in which the germ layers of the embryo form.
Gastrulation is the stage in the early embryonic development of most animals, during which the blastula, or in mammals the blastocyst is reorganized into a multilayered structure known as the gastrula. Before gastrulation, the embryo is a continuous epithelial sheet of cells; by the end of gastrulation, the embryo has begun differentiation to establish distinct cell lineages, set up the basic axes of the body, and internalized one or more cell types including the prospective gut.
The blastocyst is a structure formed in the early embryonic development of mammals. It possesses an inner cell mass (ICM) also known as the embryoblast which subsequently forms the embryo, and an outer layer of trophoblast cells called the trophectoderm. This layer surrounds the inner cell mass and a fluid-filled cavity known as the blastocoel. In the late blastocyst the trophectoderm is known as the trophoblast. The trophoblast gives rise to the chorion and amnion, the two fetal membranes that surround the embryo. The placenta derives from the embryonic chorion and the underlying uterine tissue of the mother.
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Sammy Lee was an expert on fertility and in vitro fertilisation
Ralph Lawrence Brinster is an American geneticist, National Medal of Science laureate, and Richard King Mellon Professor of Reproductive Physiology at the School of Veterinary Medicine, University of Pennsylvania.
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Rosa Susan Penelope Beddington FRS was a British biologist whose career had a major impact on developmental biology.
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Magdalena Żernicka-Goetz is a Polish-British developmental biologist. She is Professor of Mammalian Development and Stem Cell Biology in the Department of Physiology, Development and Neuroscience and Fellow of Sidney Sussex College, Cambridge. She also serves as Bren Professor of Biology and Biological Engineering at California Institute of Technology (Caltech).
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