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Volume 15 (1939)
- Issue 6 Pages 301-
- Issue 5 Pages 251-
- Issue 4 Pages 183-
- Issue 3 Pages 111-
- Issue 2 Pages 47-
- Issue 1 Pages 1-
Volume 15, Issue 3
Displaying 1-10 of 10 articles from this issue
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Y. TAZIMA1939 Volume 15 Issue 3 Pages 111-117
Published: 1939
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSBy applying high temperature shock (40-41°C, one hour) to eggs of the silkworm moth immediately after being laid, the present author has obtained many mosaic eggs in respect to their coloration. In this experiment recessive red (egg color, r/r) and their normal allele (+/+) were used as markings. A crossing was made between the normal females and red males; and the eggs produced were exposed to high temperature immediately after being laid (aged 0-1 hour), namely at about the time of maturation division of the egg.
As the mother is homozygous for the dominant gene the resulting F1's are expected to be normal. In fact, the control batches which were unexposed showed normal color without exception, while exposed batches gave, besides normal eggs, many dead eggs which were unpigmented and some recessive red and mosaic eggs. Egg mosaics are divided into two categories: One is mosaics of serosa cells of dominant and recessive colors; and the other is incomplete formation of serosa cells, which is often seen in the eggs developed parthenogenetically. The term “mosaics” is applied here not to the latter but only to the former.
The red eggs and mosaics thus obtained proceeded development, but most of them died before hatching. Thus a very few caterpillers hatched out (four from the red and two from the mosaics), while three of them (one from the red and two from the mosaics) completed their life cycle.
If the characteristics of these caterpillers are referred to those their parents possessed, namely, mother [+r/+r, PsY/Py, +os] father [r/r, (Py/Py, Py/py, py/py), (os/os, os/+)] it may be known that they are too patroclinous to be expected as resultants of normal fertilization. In the case of red eggs, it may be explained by assuming as a resultant of dispermic merogony (formation of an individual by the union of two sperm nuclei in the ooplasm independently to egg nucleus) as has already been demonstrated by Hasimoto (1934) in the silkworm.
The mechanism of mosaic formation in this case is presumably explained by a slight modification of Morgan's hypothesis (1905) of dispermy in honey bees, i. e., three spermatozoa having entered, one fuses with egg nucleus and its products produce the normal part of the egg; and the remaining two fuse each other and give rise to the red part. If the invagination of the mosaic egg takes place in border regions of normal and red cells the resulting caterpillers may be mosaic.View full abstractDownload PDF (1141K) -
Takeshige Maeda1939 Volume 15 Issue 3 Pages 118-127
Published: 1939
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESS1. Meiotic prophase in the 1st spermatocyte and the 1st oöcyte of the silkworm, Bombyx mori was examined with the object of obtaining a cytological basis for the interpretation of the sex difference in crossing-over in this insect.
2. In the spermatocyte and oöcyte the meiotic prophase proceeds quite normally, except for the chiasma formation in the latter.
3. While the formation and subsequent behaviour of chiasmata are normal in the spermatocyte gemini, in the oöcyte the chiasma formation is entirely absent. In the latter case, the association of the two components of each geminus is not due to the chiasma formation; the end-to-end association is found at so early a stage of prophase as the diplotene.
4. The crossing-over value between the two genes supposed to be located at two opposite ends of a chromosome was calculated from the chiasma frequency obtained in early diakinesis after the method of Belling (1931, 1933), and it was found that there is a close coincidence between the calculated value and the highest crossing-over value ever obtained genetically in this insect.
5. From these results it is concluded that in this insect the sex difference in chiasma formation is the cause of the sex difference in crossing-over.
6. The exceptional chiasma formation was observed in the female and its significance is considered briefly.View full abstractDownload PDF (1154K) -
Y. HOSINO1939 Volume 15 Issue 3 Pages 128-138
Published: 1939
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSIn this report two comparatively rare pattern types: F (forficula, new name proposed by Prof. T. Komai)(Fig. 1-a, b) and T (transversifascia)(Fig. 1-f, g) are dealt with. Each of these is due to a factor (PF=factor for F, PT=factor for T) which belongs to the same allelomorphic series as C (canspicua), S (spectabilis), A (axyridis, erroneously put as aulica in my last report) and s (succinea) and behaves as a dominant to s.
The heterozygotes AF(PAPF)(Fig. 1-c), SF (PSPF) (Fig. 1-d), CF (PCPF)(Fig. 1-e), AT(PAPT)(Fig. 1-h) and FT (PFPT)(Fig. 1-i) can be distinguished as such from homozygotes; ST (PSPT) and CT (PCPT), however, can not be separated from C.View full abstractDownload PDF (939K) -
Hisao Katayama1939 Volume 15 Issue 3 Pages 139-144
Published: 1939
Released on J-STAGE: May 21, 2007
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Y. NISIMURA1939 Volume 15 Issue 3 Pages 145-147
Published: 1939
Released on J-STAGE: May 21, 2007
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I. Specific differentiation in the spermato-prostatic reactionS. OMURA1939 Volume 15 Issue 3 Pages 148-152
Published: 1939
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSIn Bombyx mori, the spermatozoa remain inactive within the post-testicular male organs when not ejaculated by the copulation. On ejaculation, the spermatozoa become active by the influence of the prostatic secretion poured on them. This fact was experimentally ascertained by the writer (Omura 1938). It is at present called spermato-prostatic reaction as a matter of convenience. Similar behavior of spermatozoa is known to occur in some other Lepidopteran insects, being, however, somewhat different from the Bombycian case. The writer intended, therefore, to ascertain what physiological variation in regard to the behavior of spermatozoa is Shown by various species of Lepidopteran insects.View full abstractDownload PDF (556K) -
N. TANAKA1939 Volume 15 Issue 3 Pages 153-157
Published: 1939
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSThe maturation division and pollen development of Carex grallatoria Maxim. var. heteroclita Kükenth. ex Matsum. have been described. In the first meiotic metaphase an asynaptic chromosome pairing was observed (cf. Figs. 2-4), while in later stages pairing was found to be normal. This partial instability of the chromosomes in the first meiotic metaphase may be interpreted as having been caused by an environmental condition, namely the low temperature prevailing in the mountainous region where the materials were fixed.
Tetrad nuclei are of the same size when they are first formed, but soon one of them which is situated in the outer-most position in the PMC grows larger and the rest are pushed to an inner corner of the PMC (cf. Figs. 9, 10).
In the interstage of the prophase and metaphase of the primary pollen nuclear division, a septum is formed between the pollen nucleus and the three small nuclei which finally degenerate, and at the same time or somewhat later, septa are also formed among the three small nuclei (cf. Figs. 10, 11). The three small nuclei proved to possess the ability of dividing by themselves (cf. Figs. 11, 13).
A generative cell-plate is formed by means of the union of the phragmoplast which appears at first in the center of the telophasic spindle (Fig. 12) and then spreads parallel to the surface of the generative nucleus (Fig. 13). The generative cell-plate is not situated in the center as was reported by Piech (1928) in Heleocharis palustris, but along the wall which divides the pollen nuclei and the micronuclei in the corner (Fig. 13).View full abstractDownload PDF (571K) -
T. SHIMAMURA1939 Volume 15 Issue 3 Pages 158-159
Published: 1939
Released on J-STAGE: May 21, 2007
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S. FUJII1939 Volume 15 Issue 3 Pages 160-169
Published: 1939
Released on J-STAGE: May 21, 2007
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K. NAKAYAMA1939 Volume 15 Issue 3 Pages 170-178
Published: 1939
Released on J-STAGE: May 21, 2007
JOURNAL FREE ACCESSDownload PDF (1487K)
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