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OCT4
Oct-4 (octamer-binding transcription factor 4), also known as POU5F1 ( POU domain, class 5, transcription factor 1), is a protein that in humans is encoded by the ''POU5F1'' gene. Oct-4 is a homeodomain transcription factor of the POU family. It is critically involved in the self-renewal of undifferentiated embryonic stem cells. As such, it is frequently used as a marker for undifferentiated cells. Oct-4 expression must be closely regulated; too much or too little will cause differentiation of the cells. Octamer-binding transcription factor 4, OCT-4, is a transcription factor protein that is encoded by the ''POU5F1'' gene and is part of the POU (Pit-Oct-Unc) family. OCT-4 consists of an octamer motif, a particular DNA sequence of AGTCAAAT that binds to their target genes and activates or deactivates certain expressions. These gene expressions then lead to phenotypic changes in stem cell differentiation during the development of a mammalian embryo. It plays a vital role in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inner Cell Mass
The inner cell mass (ICM) or embryoblast (known as the pluriblast in marsupials) is a structure in the early development of an embryo. It is the mass of cells inside the blastocyst that will eventually give rise to the definitive structures of the fetus. The inner cell mass forms in the earliest stages of embryonic development, before implantation into the endometrium of the uterus. The ICM is entirely surrounded by the single layer of trophoblast cells of the trophectoderm. Further development The physical and functional separation of the inner cell mass from the trophectoderm (TE) is a special feature of mammalian development and is the first cell lineage specification in these embryos. Following fertilization in the oviduct, the mammalian embryo undergoes a relatively slow round of cleavages to produce an eight-cell morula. Each cell of the morula, called a blastomere, increases surface contact with its neighbors in a process called compaction. This results in a polari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Induced Pluripotent Stem Cell
Induced pluripotent stem cells (also known as iPS cells or iPSCs) are a type of pluripotent stem cell that can be generated directly from a somatic cell. The iPSC technology was pioneered by Shinya Yamanaka and Kazutoshi Takahashi in Kyoto, Japan, who together showed in 2006 that the introduction of four specific genes (named Myc, Oct-4, Oct3/4, Sox2 and Klf4), collectively known as Yamanaka factors, encoding transcription factors could convert somatic cells into pluripotent stem cells. Shinya Yamanaka was awarded the 2012 Nobel Prize along with Sir John Gurdon "for the discovery that mature cells can be reprogrammed to become pluripotent." Pluripotent stem cells hold promise in the field of regenerative medicine. Because they can propagate indefinitely, as well as give rise to every other cell type in the body (such as neurons, heart, pancreatic, and liver cells), they represent a single source of cells that could be used to replace those lost to damage or disease. The most we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellular Differentiation
Cellular differentiation is the process in which a stem cell changes from one type to a differentiated one. Usually, the cell changes to a more specialized type. Differentiation happens multiple times during the development of a multicellular organism as it changes from a simple zygote to a complex system of tissues and cell types. Differentiation continues in adulthood as adult stem cells divide and create fully differentiated daughter cells during tissue repair and during normal cell turnover. Some differentiation occurs in response to antigen exposure. Differentiation dramatically changes a cell's size, shape, membrane potential, metabolic activity, and responsiveness to signals. These changes are largely due to highly controlled modifications in gene expression and are the study of epigenetics. With a few exceptions, cellular differentiation almost never involves a change in the DNA sequence itself. Metabolic composition, however, gets dramatically altered where st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pluripotency
Cell potency is a cell's ability to differentiate into other cell types. The more cell types a cell can differentiate into, the greater its potency. Potency is also described as the gene activation potential within a cell, which like a continuum, begins with totipotency to designate a cell with the most differentiation potential, pluripotency, multipotency, oligopotency, and finally unipotency. Totipotency Totipotency () is the ability of a single cell to divide and produce all of the differentiated cells in an organism. Spores and zygotes are examples of totipotent cells. In the spectrum of cell potency, totipotency represents the cell with the greatest differentiation potential, being able to differentiate into any embryonic cell, as well as any extraembryonic tissue cell. In contrast, pluripotent cells can only differentiate into embryonic cells. A fully differentiated cell can return to a state of totipotency. The conversion to totipotency is complex and not fully ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yamanaka Factors
is a Japanese stem cell researcher and a Nobel Prize laureate. He is a professor and the director emeritus of Center for iPS Cell ( induced Pluripotent Stem Cell) Research and Application, Kyoto University; as a senior investigator at the UCSF-affiliated Gladstone Institutes in San Francisco, California; and as a professor of anatomy at University of California, San Francisco (UCSF). Yamanaka is also a past president of the International Society for Stem Cell Research (ISSCR). He received the 2010 BBVA Foundation Frontiers of Knowledge Award in the biomedicine category, the 2011 Wolf Prize in Medicine with Rudolf Jaenisch, and the 2012 Millennium Technology Prize together with Linus Torvalds. In 2012, he and John Gurdon were awarded the Nobel Prize for Physiology or Medicine for the discovery that mature cells can be converted to stem cells. In 2013, he was awarded the $3 million Breakthrough Prize in Life Sciences for his work. Education Yamanaka was born in H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stem Cell Self-renewal
In multicellular organisms, stem cells are undifferentiated or partially differentiated cells that can change into various types of cells and proliferate indefinitely to produce more of the same stem cell. They are the earliest type of cell in a cell lineage. They are found in both embryonic and adult organisms, but they have slightly different properties in each. They are usually distinguished from progenitor cells, which cannot divide indefinitely, and precursor or blast cells, which are usually committed to differentiating into one cell type. In mammals, roughly 50 to 150 cells make up the inner cell mass during the blastocyst stage of embryonic development, around days 5–14. These have stem-cell capability. ''In vivo'', they eventually differentiate into all of the body's cell types (making them pluripotent). This process starts with the differentiation into the three germ layers – the ectoderm, mesoderm and endoderm – at the gastrulation stage. However, when they ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kruppel-like Factors
In molecular genetics, the Krüppel-like family of transcription factors (KLFs) are a set of eukaryotic C2H2 zinc finger DNA-binding proteins that regulate gene expression. This family has been expanded to also include the Sp transcription factor and related proteins, forming the Sp/KLF family. Members The following human genes encode Kruppel-like factors: KLF1, KLF2, KLF3, KLF4, KLF5, KLF6, KLF7, KLF8, KLF9, KLF10, KLF11, KLF12, KLF13, KLF14, KLF15, KLF16, KLF17 The following genes are Sp factors: Sp1 transcription factor, Sp1, Sp2 transcription factor, Sp2, Sp3 transcription factor, Sp3, Sp4 transcription factor, Sp4, Sp5 transcription factor, Sp5, Sp6 transcription factor, Sp6, Sp7 transcription factor, Sp7, Sp8 transcription factor, Sp8, and Sp9 transcription factor, Sp9. Note that although KLF14 was an alias for Sp6 (), it now refers to a protein () derived from KLF16 by a retrotransposon event. Function and properties KLF/Sps are a family of transcriptio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embryonic Stem Cell
Embryonic stem cells (ESCs) are Cell potency#Pluripotency, pluripotent stem cells derived from the inner cell mass of a blastocyst, an early-stage pre-Implantation (human embryo), implantation embryo. Human embryos reach the blastocyst stage 4–5 days post Human fertilization, fertilization, at which time they consist of 50–150 cells. Isolating the inner cell mass (embryoblast) using immunosurgery results in destruction of the blastocyst, a process Stem cell controversy, which raises ethical issues, including whether or not embryos at the pre-implantation stage have the same moral considerations as embryos in the post-implantation stage of development. Researchers are currently focusing heavily on the therapeutic potential of embryonic stem cells, with clinical use being the goal for many laboratories. Potential uses include the treatment of diabetes and heart disease. The cells are being studied to be used as clinical therapies, models of genetic disorders, and cellular/DNA r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Danio Rerio
The zebrafish (''Danio rerio'') is a species of freshwater ray-finned fish belonging to the family Danionidae of the order Cypriniformes. Native to South Asia, it is a popular aquarium fish, frequently sold under the trade name zebra danio (and thus often called a " tropical fish" although it is both tropical and subtropical). The zebrafish is an important and widely used vertebrate model organism in scientific research, particularly developmental biology, but also gene function, oncology, teratology, and drug development, in particular pre-clinical development. It is also notable for its regenerative abilities, and has been modified by researchers to produce many transgenic strains. Taxonomy The zebrafish is a derived member of the genus '' Brachydanio'', of the family Cyprinidae. It has a sister-group relationship with '' Danio aesculapii''. Zebrafish are also closely related to the genus '' Devario'', as demonstrated by a phylogenetic tree of close species. Distr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Domain
In molecular biology, a protein domain is a region of a protein's Peptide, polypeptide chain that is self-stabilizing and that Protein folding, folds independently from the rest. Each domain forms a compact folded Protein tertiary structure, three-dimensional structure. Many proteins consist of several domains, and a domain may appear in a variety of different proteins. Molecular evolution uses domains as building blocks and these may be recombined in different arrangements to create proteins with different functions. In general, domains vary in length from between about 50 amino acids up to 250 amino acids in length. The shortest domains, such as zinc fingers, are stabilized by metal ions or Disulfide bond, disulfide bridges. Domains often form functional units, such as the calcium-binding EF-hand, EF hand domain of calmodulin. Because they are independently stable, domains can be "swapped" by genetic engineering between one protein and another to make chimera (protein), chimeric ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dysplastic Lesions
A dysplastic nevus or atypical mole is a nevus (mole) whose appearance is different from that of common moles. In 1992, the NIH recommended that the term "dysplastic nevus" be avoided in favor of the term "atypical mole". An atypical mole may also be referred to as an atypical melanocytic nevus, atypical nevus, B-K mole, Clark's nevus, dysplastic melanocytic nevus, or nevus with architectural disorder. Dysplastic nevi often grow to larger than ordinary moles and may have irregular and indistinct borders. Their color may not be uniform and may range from light pink to very dark brown. They usually begin flat, but parts may be raised above the skin surface. See ABCDE and "ugly duckling" characteristics below. Dysplastic nevi can be found anywhere, but are most common on the trunk in men, and on the calves in women. There is some controversy in the dermatology community as to whether or not the "dysplastic"/"atypical" nevus exists. Some have argued that the terms "dysplastic" an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homeodomain Fold
A homeobox is a DNA sequence, around 180 base pairs long, that regulates large-scale anatomical features in the early stages of embryonic development. Mutations in a homeobox may change large-scale anatomical features of the full-grown organism. Homeoboxes are found within genes that are involved in the regulation of patterns of anatomical development (morphogenesis) in animals, fungi, plants, and numerous single cell eukaryotes. Homeobox genes encode homeodomain protein products that are transcription factors sharing a characteristic protein fold structure that binds DNA to regulate expression of target genes. Homeodomain proteins regulate gene expression and cell differentiation during early embryonic development, thus mutations in homeobox genes can cause developmental disorders. Homeosis is a term coined by William Bateson to describe the outright replacement of a discrete body part with another body part, e.g. antennapedia—replacement of the antenna on the head of a fru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
