GLYCOGEN AND ITS PROBABLE SIGNIFICANCE IN
            EIMERIA TENELLA RAILLIET AND LUCET, 1891

      By B. S. GILL and H. N. RAY,* Indian Veterinary Research. Institute,
                                 Mukteswar, Kumaon, U. P.

                     (Received for publication on 29 July 1954)

                                          (With Plate XI)

GLYCOGEN and paraglycogen are the most widely distributed carbohydrates
in parasites, the latter so far has, however, been reported only from protozoa
[von Brand, 1952].

Giovannola [1934] found glycogen occurring in insignificant amount in
sporozoites within the oocysts; in schizonts, microgametocytes and young macro-
gametocytes of Eimeria falciformis and E. steidae; its concentration rising high
in older macrogametes and oocysts. Lillie [1947] demonstrated as pinkish matrix
of glycogen in E. steidae occurring in hepatic cells and lying in bile ducts.

Edgar, et al., [1944] employing iodine staining technique demonstrated some
glycogen lying centrally in sporozoites of E. tenella, also in macrogametes which
on growth increasingly accumulated larger quantities of it. Unsporulated oocysts
were full of glycogen which was exhausted on sporulation but they failed to demon-
strate the polysaccharide from schizonts, merozoites, microgametocytes and micro-
gametes.

                              MATERIAL AND METHODS

White Leghorn chicks, 1-2 weeks old, reared coccidia-free were employed in
these studies. The infective brew of oocysts was raised by feeding a single typical
oocyst of E. tenella [Barber's technique, Barber, 1914 ; Chambers, 1923]. Oocysts
were sporulated and preserved in 2.5 per cent solution (aqueous), of potassium
dichromate. Chicks were heavily infected per os. They were destroyed at four-hour
intervals, from 24 hours to eighth day (inclusive) of infection. Their caeca were
harvested with minimum loss of time after death (within a couple of minutes),
to avoid intracellular degeneration of the polysaccharide. Two to three mm. long
pieces of caeca were promptly fixed in alcohol-formalin mixture (9 : 1) for 24 hours
and the procedure as detailed by Glick [1949] was adopted to prepare the material
and staining the sections with Bauer-Feulgen technique (after Bensley); which
depends upon hydrolysing the polysaccharide into aldehyde, the latter group being
visualised as reddish-violet on. treatment with leucobasic-fuchsin. At each stage of
infection portion of caecum was longitudinally split open, mucosa scraped and this
material smeared over clean glass slides, which were immediately dropped in
Coplin jar containing alcohol-formalin fixative (10-15 minutes), washed in 95 per
cent alcohol and by running through descending grades of alcohol brought down
to water. They were, subsequently, treated in the same way as the sections. This

         * At present Professor of Protozoology, School of Tropical Medicine, Calcutta.

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