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 ?
Chromosome nondisjunction and instabilities in tapetal cells are affected by B chromosomes in maize.
It is characterized by typical clinical features in which there is golden yellow tapetal reflex over the fundus which disappears after prolonged dark adaptation.
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.
2010) studied the molecular mechanism of HMGS involved in development of tapetum-specific organelles and fertility of pollen grains, and found that the MVA pathway is essential for development of both tapetosomes and elaioplasts in tapetal cells and for pollen viability, at least during pollen tube elongation.
Large volume, dense cytoplasm and one or two large nuclei are evident in the tapetal cells at this point.
Ubisch bodies, (1) con-peito grains) are a-cellular structures of sporopollenin that might occur on the inner tangential and radial walls of tapetal cells.
Structural adaptations include modifications to dioptric elements, to photoreceptor arrangement, and to presence or absence of tapetal reflectors, while physiological adaptations may be to spectral (wavelength) sensitivity, absolute irradiance sensitivity, and temporal resolution (reviewed in Land and Nilsson, 2002).
Measurements from frontal sections rather than sagittal sections were used and the tapetal periphery was taken to represent the limits of the visual cells and therefore define the width of the retina.
Male sterility was attributed to tapetal malfunction.
Leaf removal could have led to an effect on the amount, and perhaps quality, of the secretion of the tapetal cells that nurtures the immature pollen grains, resulting in the difference in size we observed between the pollen produced by control and defoliated shoots.