speoimens of the starfish Asterias rubens obtained in November
and March. The pieces were fixed in Carnoy's solution for 90 min,
transferred to absolute ethanol, benzene and embedded in paraffin.
Sections, 25 p thiok, were cut and spread on coverslips, deparaffinized
and hydrated with 0.01 N acetic acid* A ooverslip
was placed in an oil chamber and pieces of cytoplasm and whole
nucleoli were isolated by micromanipulation. Samples of nonnucleolar
nuclear material (nucleoplasm) were collected for
comparison. RRA was extracted from isolated parts with a buffered
ribonucleese solution. It has been demonstrated for this tissue
1) that RNA is quantitatively preserved up to the stage of ribonuclease
extraotion, 2) that free nucleotides are effioiently
removed prior to this stage, and 3) that RNA is oonpletely extraoted
during the digestion with a selectivity good enough for
the analytical procedure (Edstr6m et al., 1961). The RNA extraots
were evaporated to dryness, dissolved in 4 R hydrochloric acid
and hydrolyzed in a mioropipette. The hydrolysates were finally
analyzed by mioroeleotrophoresie in a miorosoopic oelluloee
fiber (EdstrW, 1960).
RESULTS ARD CORCLUSIORS: Data were cclleoted from one group of
four animals with young oocytes, having a diameter after fixation
of 45-55 p0 A seoond group consisted of tissue from three animals
with large oooytes of a fixed cell diameter of 80-110 v. From
eaoh animal 3 to 5 analyses were run and the mean values are
given in Table I, It can be seen that for the young oells there
is in all oases a striking similarity between the nuoleolar and
oytoplasmio RRA. For the older oells, on the other hand, the
nucleclar RIUA oompoeition differs markedly from that of the
cytoplasm, although in no case to the extent found by Vinoent
(1952). Rucleoplaemio RlfA is very unlike that of the other
speoimens of the starfish Asterias rubens obtained in Novemberand March. The pieces were fixed in Carnoy's solution for 90 min,transferred to absolute ethanol, benzene and embedded in paraffin.Sections, 25 p thiok, were cut and spread on coverslips, deparaffinizedand hydrated with 0.01 N acetic acid* A ooverslipwas placed in an oil chamber and pieces of cytoplasm and wholenucleoli were isolated by micromanipulation. Samples of nonnucleolarnuclear material (nucleoplasm) were collected forcomparison. RRA was extracted from isolated parts with a bufferedribonucleese solution. It has been demonstrated for this tissue1) that RNA is quantitatively preserved up to the stage of ribonucleaseextraotion, 2) that free nucleotides are effioientlyremoved prior to this stage, and 3) that RNA is oonpletely extraotedduring the digestion with a selectivity good enough forthe analytical procedure (Edstr6m et al., 1961). The RNA extraotswere evaporated to dryness, dissolved in 4 R hydrochloric acidand hydrolyzed in a mioropipette. The hydrolysates were finallyanalyzed by mioroeleotrophoresie in a miorosoopic oelluloeefiber (EdstrW, 1960).RESULTS ARD CORCLUSIORS: Data were cclleoted from one group offour animals with young oocytes, having a diameter after fixationof 45-55 p0 A seoond group consisted of tissue from three animalswith large oooytes of a fixed cell diameter of 80-110 v. Fromeaoh animal 3 to 5 analyses were run and the mean values aregiven in Table I, It can be seen that for the young oells thereis in all oases a striking similarity between the nuoleolar andoytoplasmio RRA. For the older oells, on the other hand, thenucleclar RIUA oompoeition differs markedly from that of thecytoplasm, although in no case to the extent found by Vinoent(1952). Rucleoplaemio RlfA is very unlike that of the other
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