December, 1954 ]
B.
S.
GILL
AND
H.
N.
RAY
241
Caspersson and his colleagues, nucleolus is an important site from which protein
(nucleolar) migrates to the nuclear membrane where it induces or participates in the
formation of cytoplasmic proteins.
Karyosome at all stages of the parasite has been shown to react strongly for
ribose-nucleic acid (RNA). The constant association of high activity of phosphatases
and similar high concentration of RNA in the karyosome naturally suggests a func-
tional correlation between these substances. Clearly it is very significant to find
abundant phosphatase in a structure rich in RNA, which is manufacturing protein
and passing it (ribonucleoprotein) to the cytoplasm. In the nucleoplasm too
the presence of a moderate degree of phosphatase activity and desoxyribose nucleic
acid (DNA), whether highly or lowly polymerised, is not without significance. The
occurrence of these enzymes and DNA in known sites of genes tempts one
to suggest that these substances may be integral parts of genes ; and that the latter
may be a specific array of enzyme molecules, whose synthetic activity is partly
defined by the nature of enzyme molecules present, and partly by the spatial orien-
tation of the enzyme. The existence of such a functional relationship between DNA
and alkaline phosphatase has been suggested by Danielli (1953). According
to him, there is another possible role which may be assigned to phosphatase in
chromosomes. They may be protecting genes from the hazardous action of vigorous
phosphorylating agents such as adenosine-tri-phosphate and acetyl phosphate, in
actual cells.
E. tenella is a very rapidly growing parasite. Schizonts and microgameto-
cytes mature within forty-eight hours. Their rate of multiplication is pretty
high. First and second generation schizonts give rise to 600-900 and 350-400
merozoites respectively. A microgametocyte produces innumberable, probably
millions of microgametes. Thus their demand for basic material, i.e. protein (es-
pecially nucleoprotein) must be very high, and that is why their karyosomes register
intense activity of phosphatases. The macrogametocyte shows a similar high RNA
content and strong activity of phosphatases in karyosome. Its peripheral globules,
which have been shown to contain RNA. too react very strongly for alkaline phos-
phatase. The macrogametocyte is undergoing maturation and is actively metabolis-
ing proteins which are so essentially required during sporulation when oocysts are
discharged and voided with faeces. When macrogamete reaches maturity physio-
logical depression sets in, which accounts for the relatively less strong reaction of
nucleus for phosphatases. In oocyst, scattered activity of alkaline phosphatase
is seen in the cytoplasm, which may be concerned with some post-fertilisation changes
in the metabolism of the zygote. The significance of strong alkaline phosphatase
activity at the micropyle of the oocyst is not understood at present, though this
area of the oocyst wall also showed intense basiphilia with toluidine blue and pyronin
suggesting high concentration of RNA ( and ribonucleoprotein) at this site.
The observations that the gradient of reactions for phosphatases is directly
proportional to the reaction for nucleic acid and the tempo of physiological activity
of E. tenella when it can reasonably be presumed that the rate of protein synthesis
is very high, leads to the conclusion that phosphatases in this protozoon are concerned
with its protein metabolism. That such a correlation can exist between alkaline
phosphatase, RNA and protein synthesis, has been accepted by Davidson [1940]