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Localization of rice dwarf virus in its insect vector
DISCCSSION AND PRELIMIXARY of an icosahedron, but the number of capsomeres arranged on the surface is not definitely known. REFERENCES T., SHIKATA, E., and KIXURA, I., Vi18, 192-205 (1962). 2. KIMURA, I., TOYODA, S., and SUZUKI, N., Ann. Phytopathol. Sot. Japan 28, 85 (Abstract) 1. FIXSU~HI,
rology
(1963). R., Science117,30-31 (1953). R. F., and HALL, C. E., Virology 17, 123-
3. SCHNEIDER, I. .$. BILS,
130 (1962).
T. E.
FUKUSHI SHIKATA
Botanical Institute Faculty of Agriculture Hokkaido Vniversit2/ Sapporo, Jupan Accepted August 8, 1963
Localization
of Rice Dwarf
Virus in
Its Insect Vector
It has been previously reported (1) that rice dwarf virus particles have been found in ultrathin sections of the salivary glands of infective leafhoppers, Nephotettix: cincticeps Uhl., but electron micrographs of these particles were not published. In Figs. 1 and 2 virus particles are illustrated in the salivary glands of infect,ive leafhoppers, the bodies of which were fixed for 24 hours in 1% buffered osmium tetroxide solution, dehydrated in graded dilutions of ethyl alcohol, embedded in methacrylate, and sectioned by means of a JUM-5 ultramicrotome equipped with glass knives. The virus particles are seen to be scattered or in small clusters in the cytoplasm but not in
REPORTS
503
the cell nuclei; the larger aggregates of virus particles in crystal-like arrangements that have been frequently found in the abdomens of infective leafhoppers were not encountered in the salivary glands. This may be partly attributable to the possibility that the virus does not multiply so rapidly in the salivary glands as in the abdomen. Figures 3 and 4 show the virus particles in the ovariole of an infective adult leafhopper, 13 days after the final molting. The ovarioles were quickly removed under a dissecting microscope and fixed at 4°C for 5 hours in 1% osmium tetroxide solution buffered at pH 7.4 and containing 0.1 M sucrose. After washing and dehydration the materials were embedded in methacrylate and sectioned in the same way as mentioned above. Up to the present time virus particles have not been definitely demonstrated in egg cells, notwithstanding the fact that we (9) have successfully demonstrated the presence of virus in the egg by inoculat.ing nonviruliferous leafhoppers with extracts from eggs laid by infective female leafhoppers. REFERENCES 1. FUKUSHI,
rology 2. FUKUSHI,
T., SHIKATA, E., and KIMURA, I., Vi18, 192-205 (1962). T., and KIMURA, I., Proc. Japan Acnd.
35,482-484
(1959). T. FUKUSHI
E. Botanical Institute Faculty of Agriculture Hokkaido University Sapporo, Japan Accepted August 8, 1963
SHIKATA
DISCUSSION
FIQS.
fective
3 and 4. Rice dwarf leafhopper.
virus
AND
PRELIMINARY
particles
in ultrathin
REPORTS
sections
of the ovariole
of an in-
rology
(1963). R., Science117,30-31 (1953). R. F., and HALL, C. E., Virology 17, 123-
3. SCHNEIDER, I. .$. BILS,
130 (1962).
T. E.
FUKUSHI SHIKATA
Botanical Institute Faculty of Agriculture Hokkaido Vniversit2/ Sapporo, Jupan Accepted August 8, 1963
Localization
of Rice Dwarf
Virus in
Its Insect Vector
It has been previously reported (1) that rice dwarf virus particles have been found in ultrathin sections of the salivary glands of infective leafhoppers, Nephotettix: cincticeps Uhl., but electron micrographs of these particles were not published. In Figs. 1 and 2 virus particles are illustrated in the salivary glands of infect,ive leafhoppers, the bodies of which were fixed for 24 hours in 1% buffered osmium tetroxide solution, dehydrated in graded dilutions of ethyl alcohol, embedded in methacrylate, and sectioned by means of a JUM-5 ultramicrotome equipped with glass knives. The virus particles are seen to be scattered or in small clusters in the cytoplasm but not in
REPORTS
503
the cell nuclei; the larger aggregates of virus particles in crystal-like arrangements that have been frequently found in the abdomens of infective leafhoppers were not encountered in the salivary glands. This may be partly attributable to the possibility that the virus does not multiply so rapidly in the salivary glands as in the abdomen. Figures 3 and 4 show the virus particles in the ovariole of an infective adult leafhopper, 13 days after the final molting. The ovarioles were quickly removed under a dissecting microscope and fixed at 4°C for 5 hours in 1% osmium tetroxide solution buffered at pH 7.4 and containing 0.1 M sucrose. After washing and dehydration the materials were embedded in methacrylate and sectioned in the same way as mentioned above. Up to the present time virus particles have not been definitely demonstrated in egg cells, notwithstanding the fact that we (9) have successfully demonstrated the presence of virus in the egg by inoculat.ing nonviruliferous leafhoppers with extracts from eggs laid by infective female leafhoppers. REFERENCES 1. FUKUSHI,
rology 2. FUKUSHI,
T., SHIKATA, E., and KIMURA, I., Vi18, 192-205 (1962). T., and KIMURA, I., Proc. Japan Acnd.
35,482-484
(1959). T. FUKUSHI
E. Botanical Institute Faculty of Agriculture Hokkaido University Sapporo, Japan Accepted August 8, 1963
SHIKATA
DISCUSSION
FIQS.
fective
3 and 4. Rice dwarf leafhopper.
virus
AND
PRELIMINARY
particles
in ultrathin
REPORTS
sections
of the ovariole
of an in-