What’S A Botanical Chimera?

A chimera is a plant or plant part that is a mixture of two or more genetically different types of cells. It can be a “graft hybrid”, a bud that appears at the junction of the scion and stock and contains tissues of both plants. In botany, a chimera is an organism that possesses genetically distinct types of cells. Heterogenomicity is a powerful tool for uncovering core principles of a plant.

A chimera is a meristem with different genetics in one or more of the layers of the meristem. Types of chimeras include periclinal, mericlinal, and mericlinal. A chimera is an individual whose body is composed of cells that are genetically distinct, as if they are from different individuals. When a mutation occurs within a single cell of a clone, it initially produces an island of mutant cells, and the plant becomes a mixture of two.

In genetics, a chimera is an organism or tissue that contains at least two different sets of DNA, most often originating from the fusion of as many different different DNA sets. In plant biology, a chimera is often used to denote a specific case of visible variegation called Genetic mosaicism, which is a phenomenon where cells of different genotypes are present in the same plant.

In summary, a chimera is a plant or plant part that is a mixture of two or more genetically different types of cells. Heterogenomicity is a powerful tool for understanding the origin, structure, and properties of chimeric organisms in plants.

What is meant by chimera?

An imaginary monster composed of incongruous parts is an illusion or fabrication of the mind, particularly an unrealizable dream. In Greek mythology, the fire-breathing she-monster with a lion’s head, goat’s body, and serpent’s tail serves as a prime example. A fanciful or chimera-like conception in the mind can impede the efficacy of prayer, as John Donne once observed.

What is a leaf chimera?

A Norway maple tree with typical green leaves was observed with a small cluster of variegated leaves at the end of one branch. These variegated leaves were an example of a chimera, a situation where cells of multiple genotypes grow adjacent to each other in the plant’s tissues. This chimera likely developed following a spontaneous mutation of a cell within the plant’s meristem. The cells derived from the mutation were unable to produce chlorophyll, giving normal leaves their green appearance.

There are three types of chimeras: Periclinal, Mericlinal, and Sectorial. Periclinal chimeras affect one entire layer in the meristem and are relatively stable, leading to many variegated plant cultivars, such as the variegated Tatarian Dogwood.

What does chimera mean in horticulture?

A chimera is a plant with multiple genotypes growing adjacent in its tissues. Variegated plants are the most common types of chimeras. This article explores the origins and development of chimeral plants, introduces precautions for propagation, and discusses horticulturally significant chimeras. The apical meristem of a shoot is where most cells produce the plant body. Cell division occurs rapidly in an actively growing shoot, resulting in cell elongation or expansion, leading to growth in the length of the shoot.

Secondary meristems in woody and certain herbaceous plants result in increased growth or caliper, but this is not considered in this article. Leaf primordia arise on the sides of the apical dome, and lateral buds develop in the axils of young leaves.

What does 100% chimerism mean?

The presence of a majority of donor T cells in a patient’s haematopoietic system is a significant predictor of acute GVHD, highlighting the role of alloantigen-specific donor T cells in GVHD induction. Chimerism analyses can quantify the descent of the reconstituting haematopoietic system after allo-HSCT. Complete donor chimerism, defined as 100 of haematopoietic cells derived from the donor, increases rapidly during acute GVHD, and complete chimerism significantly correlates with acute GVHD. Although acute GVHD can develop in a state of mixed chimerism, the risk of GVHD is increased in patients with complete chimerism.

The effect of potential donor T-cell epitopes on GVHD development is likely most profound during complete chimerism. The correlation between PIRCHE, being potential donor T-cell epitopes, and GVHD may be most prominent in patients with complete chimerism after allo-HSCT. A retrospective study showed a correlation between the presence of HLA-DPB1-derived PIRCHE and acute GVHD, with patients with complete chimerism developing grade II-IV acute GVHD having significantly higher numbers of PIRCHE-I and –II compared to those with grade 0-I acute GVHD. In patients with mixed chimerism, PIRCHE numbers did not differ between patients with grade II-IV acute GVHD vs.

What is a chimera in biology?

Chimera is an organism or tissue that contains at least two different sets of DNA, often originating from the fusion of multiple fertilized eggs. It is distinguished from mosaics, which contain genetically different populations of cells from a single zygote, and hybrids, which contain genetically identical populations of cells from a cross of two different species. There are different types of animal chimeras, including dispermic and twin chimeras, microchimeras, and parthenogenetic and androgenetic chimeras.

In dispermic chimeras, two fertilized eggs fuse together, producing a tetragametic individual, which is an individual originating from four gametes or sex cells. Indications of tetragametic chimerism include differing eyes, patchwork skin coloration, and ambiguous external genitalia, which is a sign of hermaphroditism. The condition is detected through extensive genetic analysis when standard tests, such as histocompatibility testing for tissue matching prior to organ transplantation, turn up unusual results.

Twin chimeras, on the other hand, are produced when two zygotes exchange cells and genetic material during development. Blood chimeras are the most widely known examples of twin chimerism, produced when blood anastomoses form between the placentas of dizygotic twins, enabling the transfer of stem cells between developing embryos. When blood chimerism involves male and female twins, female exposure to male hormones results in freemartin syndrome, which is commonly seen in cattle and rarely in humans. In human blood chimeras of the same sex, chimerism may be detected through routine blood typing when unexpected results prompt further genetic investigation.

What is chimera in plants?

A chimera is a plant or plant part that is a mixture of two or more genetically different types of cells. It can be a “graft hybrid”, a bud that appears at the junction of the scion and stock and contains tissues of both plants. These chimeras were first studied by German botanist Hans Winkler in 1907. In his experiments, he found that black nightshade was grafted on tomato, and at the nexus, all shoots were either of nightshade or tomato except one.

This shoot was called a chimera because it was partly of one species and partly of another. Winkler gave certain graft hybrids special names. Erwin Baur later provided evidence that two plants to which Winkler had given special names were built up of a core of tomato with a skin of nightshade one and two cell layers thick, respectively, and two others of a core of nightshade with skins of tomato one and two cell layers thick. Chimeras may also arise by a mutation in cells of a growing region, which may be conspicuously different from the old tissue or only evident on special investigation.

Does chimera exist today?

Chimeras are genetically modified organisms that consist of two genomes in a single body, producing two types of cells that work together to create a viable organism. They develop from two fertilized eggs that combine to form a single embryo, rather than staying separate and developing into fraternal twins. Chimerism within a species occurs naturally in nearly all animals, including humans. In 1989, scientists at the University of California, Davis created the first artificial chimera, a sheep-goat hybrid dubbed the “geep”.

In 2003, Hui Zhen Sheng at Shanghai Second Medical University created the first human-nonhuman chimera, removing genetic material from some cells in a rabbit embryo and inserting human DNA. This research inspired several subsequent studies that demonstrate the enormous potential of chimeras. By creating animals with human cells, scientists can monitor and track cell differentiation, tissue development, and organ formation without using human infants as subjects.

Chimeras can also be used to study the molecular mechanisms governing fundamental biological phenomena, such as pluripotency, reprogramming, differentiation, and imprinting. A French team led by Nicole le Douarin has replaced cells in the vertebrae of a developing cow fetus with human pluripotent stem cells to observe their differentiation and study the development of the spinal cord.

What does it mean if someone is a chimera?

A chimera, a term often associated with Greek mythology, refers to a person with cells from two different organisms, resulting in two sets of DNA. In humans, chimerism can occur when a mother is pregnant with twins, where one embryo may absorb the deceased twin’s cells. This alters the basic understanding of genetics, which states that all cells contain the same DNA. However, with a chimera, this understanding is obsolete. A chimera has two sets of cells with two distinct types of DNA.

The tissues that will be chimeric will vary depending on how the cells travel, which ones come through the placenta, and where they settle. One common outcome is blood chimerism, where blood cells from the bone marrow are strong and mobile, likely to survive while traveling through the placenta in the exchange between the chimeric twins.

What is a short description of chimera?

Chimera, a mythical female monster in Greek mythology, was a fire-breathing creature that devastated Caria and Lycia before being killed by Bellerophon. In art, Chimera is typically depicted as a lion with a goat’s head in its back and a snake’s head tail. In architecture, Chimera is loosely used for any grotesque, fantastic, or imaginary beast used in decoration. The term is now generally used to denote a fantastic idea or figment of the imagination.

What is a chimera in plants?

A chimera is a plant or plant part that is a mixture of two or more genetically different types of cells. It can be a “graft hybrid”, a bud that appears at the junction of the scion and stock and contains tissues of both plants. These chimeras were first studied by German botanist Hans Winkler in 1907. In his experiments, he found that black nightshade was grafted on tomato, and at the nexus, all shoots were either of nightshade or tomato except one.

This shoot was called a chimera because it was partly of one species and partly of another. Winkler gave certain graft hybrids special names. Erwin Baur later provided evidence that two plants to which Winkler had given special names were built up of a core of tomato with a skin of nightshade one and two cell layers thick, respectively, and two others of a core of nightshade with skins of tomato one and two cell layers thick. Chimeras may also arise by a mutation in cells of a growing region, which may be conspicuously different from the old tissue or only evident on special investigation.

What species is a chimera?

The Chimera, a monstrous hybrid creature in Greek mythology, has a long history in the fields of biology and genetics. The creature is said to have a body and head like a fire-breathing lion, a goat head on its back, and a snake’s head on its tail. The term “chimaera” has been employed in the fields of biology and genetics for centuries. Please be advised that this site uses cookies and is copyrighted by Elsevier B. V., its licensors, and contributors.