tapetum


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ta·pe·tum

 (tə-pē′təm)
n. pl. ta·pe·ta (-tə)
1. Botany A nutritive tissue that surrounds certain developing spores, particularly the microspores within an anther.
2. Anatomy
a. A reflective membrane in the back of the eye of many animals that are active during low-light conditions.
b. A layer of fibers of the corpus callosum forming the roof of part of the lateral ventricle of the brain.

[Medieval Latin tapētum, coverlet, from Latin tapēte, *tapētum, from Greek tapēs, tapēt-; see tapestry.]

ta·pe′tal (-pēt′l) adj.

tapetum

(təˈpiːtəm)
n, pl -ta (-tə)
1. (Botany) a layer of nutritive cells in the sporangia of ferns and anthers of flowering plants that surrounds developing spore cells
2. (Zoology)
a. a membranous reflecting layer of cells in the choroid of the eye of nocturnal vertebrates
b. a similar structure in the eyes of certain nocturnal insects
3. (Anatomy) anatomy a covering layer of cells behind the retina of the eye
[C18: from New Latin, from Medieval Latin: covering, from Latin tapēte carpet, from Greek tapēs carpet]
taˈpetal adj

ta•pe•tum

(təˈpi təm)

n., pl. -ta (-tə).
1. Bot. a layer of nutritive tissue in a developing sporangium or anther that is absorbed as the spore matures.
2. Anat. any of certain membranous layers or layered coverings, as in the choroid coat in certain animals.
[1705–15; < New Latin; Medieval Latin tapētum coverlet (Latin, only pl.) < Greek tapēt-, s. of tápēs carpet]
ta•pe′tal, adj.
References in periodicals archive ?
The images were evaluated and characterized according to its breed which included a) Tapetal color b) Tapetal reflectivity c) Shape of tapetal area d) Homogenicity of tapetum e) The junction of tapetal and non tapetal border.
Also, there was no pollen formation possibly, because of anther deformity and narrow microsporangium as well as premature disintegration of tapetum in the GMS line.
From the cross section we see that the anther wall consists of layers from outer to inner: epidermis, endothecium, middle layer and layer of tapetum (Fig.
Both von Ubisch (1927) and von Kosmath (1927) have published lists of species with and without orbicules and considered orbicules to be restricted to taxa with a 'secretory' tapetum type.
This is due to the presence of a specialized reflecting layer behind the retina called the tapetum lucidum.
Plant Genetic Systems, NV (Gent, Belgium) has patented improved barstar DNAs, such as synthetic barstar DNAs, produce high amounts of barstar protein in eucaryotic cells, particularly in plant cells, and especially in stamen cells such as tapetum cells.
Light reflecting off the tapetum gives the retina a second chance to capture photons that weren't detected during their first pass through.
Each microsporangium displays four wall layers (from outside in: epidermis, endothecium, middle layer, and parietal layer), a secretory tapetum and the central male cells.
Then the wall differentiated to epidermis, endothecium, middle layer and tapetum layer (Fig1 L).
The tapetum is a specialised cell layer between the sporogeneous tissue and the anther wall, which functions as a source of nutrients for developing pollen grains (Davis, 1966; Pacini et al.
There are two major types of tapetum, the more primitive secretory type, considered to be the prevalent type in the majority of plants, and amoeboid type that extends to microspores in the anther locule [9].
In a recent overview Pacini and Franchi (1993) listed 33 species from 22 angiosperm families with secretory tapetum and orbicules (references from 1971 to 1993).