Information about Cell Differentiation
Cellular differentiation is a concept from developmental biology describing the process by which cells acquire a "type". The morphology of a cell may change dramatically during differentiation, but the genetic material remains the same, with few exceptions.
A cell that is able to differentiate into many cell types is known as pluripotent. These cells are called stem cells in animals and meristematic cells in higher plants. A cell that is able to differentiate into all cell types is known as totipotent. In mammals, only the zygote and early embryonic cells are totipotent, while in plants, many differentiated cells can become totipotent with simple laboratory techniques.
Differentiation can involve changes in numerous aspects of cell physiology; size, shape, polarity, metabolic activity, responsiveness to signals, and gene expression profiles can all change during differentiation.
In cytopathology the level of cellular differentiation is used as a measure of cancer progression. "Grade" is a marker of how differentiated a cell in a tumor is.
Germ line cells are any line of cells that give rise to gametes—eggs and sperm—and are continuous through the generations. Stem cells, on the other hand, have the ability to divide for indefinite periods and to give rise to specialized cells. They are best described in the context of normal human development.
Development begins when a sperm fertilizes an egg and creates a single cell that has the potential to form an entire organism. In the first hours after fertilization, this cell divides into identical cells. In humans, approximately four days after fertilization and after several cycles of cell division, these cells begin to specialize, forming a hollow sphere of cells, called a blastocyst. The blastocyst has an outer layer of cells, and inside this hollow sphere, there is a cluster of cells called the inner cell mass. The cells of the inner cell mass will go on to form virtually all of the tissues of the human body. Although the cells of the inner cell mass can form virtually every type of cell found in the human body, they cannot form an organism. These cells are referred to as pluripotent.
Pluripotent stem cells undergo further specialization into multipotent progenitor cells that then give rise to functional cells. Examples of stem and progenitor cells include:
..... Click the link for more information.
..... Click the link for more information.
Gene expression is the process by which the inheritable information in a gene, such as the DNA sequence, is made into a functional gene product, such as protein or RNA.
..... Click the link for more information.
A cell that is able to differentiate into many cell types is known as pluripotent. These cells are called stem cells in animals and meristematic cells in higher plants. A cell that is able to differentiate into all cell types is known as totipotent. In mammals, only the zygote and early embryonic cells are totipotent, while in plants, many differentiated cells can become totipotent with simple laboratory techniques.
Overview
In most multicellular organisms, not all cells are alike. For example, cells that make up the human skin are different from cells that make up the inner organs. Yet, all of the different cell types in the human body are all derived from a single fertilized egg cell through differentiation. Differentiation is the process by which an unspecialized cell becomes specialized into one of the many cells that make up the body, such as a heart, liver, or muscle cell. During differentiation, certain genes are turned on, or become activated, while other genes are switched off, or inactivated. This process is intricately regulated. As a result, a differentiated cell will develop specific structures and perform certain functions.Differentiation can involve changes in numerous aspects of cell physiology; size, shape, polarity, metabolic activity, responsiveness to signals, and gene expression profiles can all change during differentiation.
In cytopathology the level of cellular differentiation is used as a measure of cancer progression. "Grade" is a marker of how differentiated a cell in a tumor is.
Mammalian cell types
Three basic categories of cells make up the mammalian body: germ cells, somatic cells, and stem cells. Each of the approximately 100,000,000,000,000 (1014) cells in an adult human has its own copy, or copies, of the genome, with the only exception being certain cell types that lack nuclei in their fully differentiated state, such as red blood cells. The majority of the cells are diploid, meaning they have two copies of each chromosome. This category of cells, called somatic cells, includes most of the cells that make up the human body, such as skin and muscle cells.Germ line cells are any line of cells that give rise to gametes—eggs and sperm—and are continuous through the generations. Stem cells, on the other hand, have the ability to divide for indefinite periods and to give rise to specialized cells. They are best described in the context of normal human development.
Development begins when a sperm fertilizes an egg and creates a single cell that has the potential to form an entire organism. In the first hours after fertilization, this cell divides into identical cells. In humans, approximately four days after fertilization and after several cycles of cell division, these cells begin to specialize, forming a hollow sphere of cells, called a blastocyst. The blastocyst has an outer layer of cells, and inside this hollow sphere, there is a cluster of cells called the inner cell mass. The cells of the inner cell mass will go on to form virtually all of the tissues of the human body. Although the cells of the inner cell mass can form virtually every type of cell found in the human body, they cannot form an organism. These cells are referred to as pluripotent.
Pluripotent stem cells undergo further specialization into multipotent progenitor cells that then give rise to functional cells. Examples of stem and progenitor cells include:
- Hematopoietic stem cells (adult stem cells) from the bone marrow that give rise to red blood cells, white blood cells, and platelets
- Mesenchymal stem cells (adult stem cells) from the bone marrow that give rise to stromal cells, fat cells, and types of bone cells
- Epithelial stem cells (progenitor cells) that give rise to the various types of skin cells
- Muscle satellite cells (progenitor cells) that contribute to differentiated muscle tissue
See also
Sources
- What is a cell? 2004. A Science Primer: A Basic Introduction to the Science Underlying NCBI Resources. NCBI.
Stem cells |
|---|
Sources: Embryonic stem cells | Adult stem cells | Cancer stem cells Related articles: Stem cell treatments | Stem cell controversy | Stem cell line | Progenitor cell | Cell differentiation |
Developmental Biology is the official journal of the Society for Developmental Biology. It publishes research on the mechanisms of development, differentiation, and growth in animals and plants at the molecular, cellular, and genetic levels.
..... Click the link for more information.
..... Click the link for more information.
Editing of this page by unregistered or newly registered users is currently disabled due to vandalism.
If you are prevented from editing this page, and you wish to make a change, please discuss changes on the talk page, request unprotection, log in, or .
..... Click the link for more information.
If you are prevented from editing this page, and you wish to make a change, please discuss changes on the talk page, request unprotection, log in, or .
..... Click the link for more information.
A cell type is a distinct morphological or functional form of cell. When a cell switches state from one cell type to another, it undergoes cellular differentiation.
A partial list of cell types includes:
..... Click the link for more information.
A partial list of cell types includes:
Animals
- Human Cell Types- Blastomere
- Egg
..... Click the link for more information.
Genetic material is used to store the genetic information of an organic life form. For all currently known living organisms, the genetic material is almost exclusively Deoxyribonucleic Acid DNA. Some viruses use Ribonucleic Acid RNA as their genetic material.
..... Click the link for more information.
..... Click the link for more information.
Pluripotency in the broad sense refers to "having more than one potential outcome". In biological systems, this can refer either to cells or to biological compounds.
..... Click the link for more information.
Pluripotent (cell biology)
..... Click the link for more information.
Stem cells are primal cells found in all multi-cellular organisms. They retain the ability to renew themselves through mitotic cell division and can differentiate into a diverse range of specialized cell types.
..... Click the link for more information.
..... Click the link for more information.
A meristem is a tissue in all plants consisting of undifferentiated cells (meristematic cells) and found in zones of the plant where growth can take place.
Differentiated plant cells generally cannot divide or produce cells of a different type.
..... Click the link for more information.
Differentiated plant cells generally cannot divide or produce cells of a different type.
..... Click the link for more information.
A cell type is a distinct morphological or functional form of cell. When a cell switches state from one cell type to another, it undergoes cellular differentiation.
A partial list of cell types includes:
..... Click the link for more information.
A partial list of cell types includes:
Animals
- Human Cell Types- Blastomere
- Egg
..... Click the link for more information.
Totipotency is the ability of a single cell to divide and produce all the differentiated cells in an organism, including extraembryonic tissues. Totipotent cells formed during sexual and asexual reproduction include spores and zygotes.
..... Click the link for more information.
..... Click the link for more information.
- For other meanings see Zygote (disambiguation).
..... Click the link for more information.
This article or section is in need of attention from an expert on the subject.
Please help recruit one or [ improve this article] yourself. See the talk page for details.
..... Click the link for more information.
Please help recruit one or [ improve this article] yourself. See the talk page for details.
..... Click the link for more information.
Totipotency is the ability of a single cell to divide and produce all the differentiated cells in an organism, including extraembryonic tissues. Totipotent cells formed during sexual and asexual reproduction include spores and zygotes.
..... Click the link for more information.
..... Click the link for more information.
Plantae Chromalveolata Heterokontophyta Haptophyta Cryptophyta Alveolata
..... Click the link for more information.
..... Click the link for more information.
Editing of this page by unregistered or newly registered users is currently disabled due to vandalism.
If you are prevented from editing this page, and you wish to make a change, please discuss changes on the talk page, request unprotection, log in, or .
..... Click the link for more information.
If you are prevented from editing this page, and you wish to make a change, please discuss changes on the talk page, request unprotection, log in, or .
..... Click the link for more information.
Skin layers: epidermis, dermis, and subcutis, showing a hair follicle, sweat gland & sebaceous gland.]] In zootomy and dermatology, skin is the largest organ of the integumentary system made up of multiple layers of epithelial tissues that guard underlying muscles and organs.
..... Click the link for more information.
..... Click the link for more information.
For a non-technical introduction to the topic, see .
A gene is a locatable region of genomic sequence, corresponding to a unit of inheritance, which is associated with regulatory regions, transcribed regions and/or other functional sequence regions...... Click the link for more information.
Regulation of gene expression (or gene regulation) refers to the cellular control of the amount and timing of changes to the appearance of the functional product of a gene.
..... Click the link for more information.
..... Click the link for more information.
Metabolism is the complete set of chemical reactions that occur in living cells. These processes are the basis of life, allowing cells to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories.
..... Click the link for more information.
..... Click the link for more information.
- For vocabulary, see Glossary of gene expression terms
Gene expression is the process by which the inheritable information in a gene, such as the DNA sequence, is made into a functional gene product, such as protein or RNA.
..... Click the link for more information.
Cytopathology is a branch of pathology that studies and diagnoses diseases on the cellular level. The most common use of cytopathology is the Pap smear, used to detect cervical cancer at an early treatable stage.
..... Click the link for more information.
..... Click the link for more information.
Editing of this page by unregistered or newly registered users is currently disabled due to vandalism.
If you are prevented from editing this page, and you wish to make a change, please discuss changes on the talk page, request unprotection, log in, or .
..... Click the link for more information.
If you are prevented from editing this page, and you wish to make a change, please discuss changes on the talk page, request unprotection, log in, or .
..... Click the link for more information.
In pathology, grading is a measure of the progress of tumors and other neoplasms. Some pathology grading systems apply only to malignant neoplasms (cancer); others apply also to benign neoplasms.
..... Click the link for more information.
..... Click the link for more information.
A germ cell is part of the germline and is involved in the reproduction of organisms. Germ cells should not be confused with "germs" (pathogens).
Germ cells includes all stages of gametogenesis, i.e. gametogonia, gametocytes, gametids and gametes.
..... Click the link for more information.
Germ cells includes all stages of gametogenesis, i.e. gametogonia, gametocytes, gametids and gametes.
..... Click the link for more information.
A somatic cell is generally taken to mean any cell forming the body of an organism: the word "somatic" is derived from the Greek word sōma (σώμα), meaning "body". Somatic cells, by definition, are not germline cells.
..... Click the link for more information.
..... Click the link for more information.
Stem cells are primal cells found in all multi-cellular organisms. They retain the ability to renew themselves through mitotic cell division and can differentiate into a diverse range of specialized cell types.
..... Click the link for more information.
..... Click the link for more information.
In biology the genome of an organism is its whole hereditary information and is encoded in the DNA (or, for some viruses, RNA). This includes both the genes and the non-coding sequences of the DNA.
..... Click the link for more information.
..... Click the link for more information.
Red blood cells are the most common type of blood cell and the vertebrate body's principal means of delivering oxygen from the lungs or gills to body tissues via the blood.
..... Click the link for more information.
..... Click the link for more information.
A gamete (from Ancient Greek γαμετης; translated gamete = wife, gametes = husband) is a cell that fuses with another gamete during fertilisation (conception) in organisms that reproduce sexually.
..... Click the link for more information.
..... Click the link for more information.
sperm is derived from the word spermos (meaning "seed") and refers to the male reproductive cells. Sperm cells are the smaller gametes involved in fertilization.
..... Click the link for more information.
..... Click the link for more information.
In most birds and reptiles, an egg (Latin ovum) is the zygote, resulting from fertilization of the ovum. To enable incubation the egg is usually kept within a favourable temperature range as it nourishes and protects the growing embryo.
..... Click the link for more information.
..... Click the link for more information.
This article is copied from an article on Wikipedia.org - the free encyclopedia created and edited by online user community. The text was not checked or edited by anyone on our staff. Although the vast majority of the wikipedia encyclopedia articles provide accurate and timely information please do not assume the accuracy of any particular article. This article is distributed under the terms of GNU Free Documentation License.
Herod_Archelaus
