RNA content of single cells?
Troianovsk_s at MSDISK.WUSTL.EDU
Thu Nov 24 21:02:48 EST 1994
>Date: 22-NOV-1994 19:03
>From: K.M.Toellner at bham.ac.uk (Kai-M. Toellner)
>Description: RNA content of single cells?
Kai-M. Toellner wrote:
>Does anybody have an idea, what the mRNA content of a single cell is, a
>human lymphocyte for example? Depending on the activation state of the
>cell, the mRNA content will probably change. Does anybody know,
>whether there is published anything about that somewhere?
Sure there should be somewhere the numbers you are interested in. However,
this is my "two cents".
Source: Molecular Cloning a Laboratory Manual. T.Maniatis; E.F.Fritsch;
The following numbers are there:
A typical mammalian cell contains about 10 ^-5^ mcg of RNA;
80-85% of which is ribosomal RNA (28S, 18S, 5S);
10-15% is made up of a variety of a low m/w species (tRNAs, small
nuclear RNAs, and etc.);
Between 1-5% of total cellular RNA (heterogeneous in size and sequence)
is thought represent the mRNAs encoding different proteins;
In some cases (globin or ovalbumin) as much as 50-90% of the total
poly(A) cytoplasmic RNA belong to these species, so called abundant mRNAs.
A typical mammalian cell contains between 10'000 & 30'000 different
mRNA sequences (Davidson,E., 1976, Gene activity in early development.
Human fibroblast cell contains appr. 12'000 different mRNAs
(Williams,J.G., 1981, The preparation and screening of a cDNA clone bank. In
Genetic engineering, ed., R.Williamson, vol. 1, p. 2., Acad.Press;
Williams,J.G., and M.M.Lloyd, 1979, Changes in the abundance of
polyadenilated RNA during slime mold development measured using clones
molecular hybridization probes. J.Mol.Biol., 129:19). The low abundance
class of mRNAs (<14 copies/cell) comprises appr. 30% of total mRNA;
About 11'000 different mRNAs lie within this class.
I guess to have these numbers quite enough for appr. calculation. Everything
will lie in between.
Child says: "If All Fails Carefully Read the Manual"
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