蝗卵的研究Ⅳ.浸水对于蝗卵胚胎发育和死亡的影响

一、引言 东亚飞蝗常生长在湖滨、已干涸的河道、沿海边等长着禾本科杂草的低洼荒地;这些地方也就成为它们的产卵场所。蝗卵在产入土中之后须经一定时间方始孵化;夏蝗所产卵在自然情况下须经12天以上的孵育时间,秋蝗卵在越冬时在土中常长达7—8个月。蝗区每当雨季或湖、河的水位上涨时其有卵的地区常被淹没,使蝗卵在水中经过长短不一的     

THE ADSORPTION OF EGG ALBUMIN ON COLLODION MEMBRANES

An experimental study has been made of the adsorption of purified egg albumin, from aqueous solution, on collodion membranes. At protein concentrations of 4 to 7 per cent apparent saturation values were obtained which resembled closely the results obtained with gelatin, showing a maximum at pH 5.0 and lower values on either side of this region. Over large ranges of protein concentration, however, the curves for the adsorption from solutions removed in either direction from the isoelectric point exhibited a different shape from the hyperbola obtained in the neighborhood of pH 5.0. The addition of NaCl to solutions on the acid side tended to obliterate the effect of the pH difference; on the alkaline side it greatly increased the adsorption. The adsorption at 25° was about twice as great as that at 1°. The theory of the swelling of submicroscopic particles, advanced to account for the adsorption behavior of gelatin, is not sufficient to explain the results obtained with egg albumin. It is suggested that the effect is related to alterations in the forces causing the retention of the protein on the membranes.     

蝗卵的研究Ⅱ.蝗卵在孵育时的变化及其意义

一.引言 东亚飞蝗在卵階段的发育过程有许多地方是和其他种类的昆虫相类似的,但是也有许多地方可作为飞蝗种的特徵。蝗虫是陸棲的昆虫,它们的卵经常在土中孵育,因此在卵的生理和构造上有许多与此种生活习性相适应的特点。和其他昆虫的卵一样,蝗卵是一种有壳卵(cleidoic egg),但含有更为充分的营养物质。它外面的卵包膜     

THE EFFECT OF UNILATERAL ULTRAVIOLET LIGHT ON THE DEVELOPMENT OF THE FUCUS EGG

1. When Fucus eggs which have been fertilized for a sufficient length of time are irradiated unilaterally with monochromatic ultraviolet light (λ2804 Å) of adequate dosage, 97–100 per cent form rhizoids on the halves of the eggs away from the source of radiation (see Figs. 1 and 2). 2. The responsiveness of the eggs increases gradually after fertilization and does not reach a maximum until about 7 hours at 15°C. (see Fig. 3). The first rhizoids begin to form in a population at about 12 hours after fertilization. The responsiveness remains maximal until at least 11 hours after fertilization. 3. It is suggested that the low responsiveness of a population of eggs at an earlier period is due to recovery from the effects of irradiation before the rhizoids begin to form. 4. The response of eggs to λ2804 Å is proportional, over a wide range, to the logarithm of the dosage (see Fig. 1). Dosage was regulated by the duration of exposure during the period of maximum response. 5. High dosages of λ2804 Å, of the order of 10,000 ergs per mm.², cause the rhizoids to form fairly precisely away from the source of radiation (see Fig. 2). Twice this dosage inhibits rhizoid formation altogether without causing cytolysis. 6. Other wave-lengths which have also been shown to be effective are: 3660, 3130, 2654, 2537, 2482, and 2345 Å. Only exploratory measurements have been made to test the effectiveness of these wave-lengths, but they show that much greater energy is necessary to obtain a strong response with λ3130 and 3660 Å, especially the latter. The wave-lengths shorter than 2804 Å, on the other hand, show the same order of effectiveness as λ2804 Å. Some may be more effective. 7. A beam of λ2804 Å which is incident on a single layer of Fucus eggs is completely extinguished at 2, 3, 6, or 6½ hours after fertilization. About 85 per cent of a beam of λ3660 Å is extinguished. The wave-length 3660 Å is thus not so completely absorbed as λ2804 Å, but the difference in proportion absorbed by the egg is not nearly so great as the difference in effectiveness.     

A MICRO INJECTION STUDY ON THE PERMEABILITY OF THE STARFISH EGG

The experiments with the NH₄Cl are similar to, and corroborate micro injection experiments performed in connection with some work on mustard gas in which the writer collaborated. Eggs immersed in sea water containing decomposed mustard gas, at a certain low concentration are not affected. If, however, the solution be injected, the egg quickly cytolyzes owing to the free HCl present. A similar impermeability of the protoplasmic surface film to certain substances was also encountered in injection work on Amœba. Amœbœ immersed in an aqueous solution of eosin will not take the stain till after death. On the other hand, the eosin, when injected into the Amœba, quickly permeates the protoplasm, to be arrested only at the surface. The semipermeability of a living cell appears primarily to be a function of its surface film. It is immaterial whether this film be that of the original cortex of the cell, a film newly formed over a cut surface, or a film that surrounds an artificially induced vacuole within the cell. As long as such a surface film exists neither the acid group of the NH₄Cl nor the alkaline group of the NaHCO₃ can, within certain concentration limits, penetrate the protoplasm. These solutions, if injected beneath the surface film, however, will produce their characteristic effects upon the protoplasm.     

温度对坏鳃指环虫产卵、孵化和发育的影响

实验研究了离体条件下温度对坏鳃指环虫(Dactylogyrus vastator)产卵和孵化的影响,以及在20℃、在体条件下坏鳃指环虫的产卵和发育过程。在离体条件下,坏鳃指环虫的平均产卵量随着温度的升高而增加,在4、10、20、30和35℃时,其平均产卵量分别为0.25、5.9、9.1、9.2和13.4枚/虫;除4℃外,绝大多数虫卵是在离体后的前5h内产出;然而,在体条件下虫体的产卵是连续且稳定的,在20℃条件下平均产卵量为6.5枚/(虫d)。虫卵的孵化时间和孵化持续的时间随着温度的升高而减少,在10、20、30和35℃条件下,孵化时间和孵化持续时间分别为19d、3d、2d、36h和24d、5d、5d、3d,而最高的孵化率(65.5%)却出现在30℃。在20℃条件下,纤毛幼虫在感染7d后90%的虫体都已成熟,因此,在此温度条件下坏鳃指环虫由虫卵发育到成虫大约需要8-10d。为了有效控制指环虫病的暴发,在第一次用药1周后要进行第二次用药。       

EFFECTS OF BENZIMIDAZOLE ON CLEAVAGE OF THE SEA URCHIN EGG*

Unfertilized eggs of sea urchins were treated with benzimidazole. They were fertilized after being kept in normal sea water for a certain period. It was found that the first cleavage occurred much earlier than in the control. The eggs had a tendency to cleave directly into 3 or 4 cells. Benzimidazole induced some visible changes in unfertilized eggs, which was considered to be the result of an insufficient activation. Benzimidazole was found to have the same effect as hypertonic solution has in Loeb's “double treatment” method for artificial parthenogenesis. When eggs activated with butyric acid were treated with benzimidazole instead of hypertonic solution, they cleaved in a high percentage.     

EXPERIMENTAL STUDIES ON THE SITE OF PROPAGATION OF THE FERTILIZATION-WAVE IN THE SEA URCHIN EGG

Although the fertilization-wave in the sea urchin egg is generally considered to propagate over the egg surface, there has been no definite evidence to show the site of propagation. The possibility that the wave passes through the endoplasm, not over the egg surface, has not been denied.
A drop of paraffin was injected into an egg, so that the endoplasm was divided into 2 parts by the paraffin drop, the 2 parts being connected only by the egg cortex. When spermatozoa were added to one side of the egg, the fertilization membrane was formed first on this part of the egg and then on the opposite part. This indicates that the egg surface or the egg cortex is the site of propagation of the fertilization-wave and the endoplasm has no direct influence on the propagation.     

OBSERVATIONS ON THE MICROBIOLOGY OF RAW AND HEAT-TREATED LIQUID EGG

SUMMARY: Factors influencing the hygienic quality of raw liquid egg have been inverstigated and bacterial counts obtained during the period January–October, 1952, have been summarized. As a commercial standard of quality, it is suggested that raw liquid egg with a total bacterial count in the region of 5 × 10⁶/g. at 22°, might be regarded as reasonably satisfactory, having regard to the quality of the raw material now permitted to be used.
A study of heat-treatment of Liquid egg has shown that a time-temperature combination slightly in excess of 2 min. at 146°F. may be regarded as satisfactory, as it gives a 99·99% kill of the initial flora without significantly imparing the functional properties of the final product. The residual flora in herat-treated egg has been found to be relatively inactive.
Salmonella organisms were found in 4·2% of raw hen egg and in 67·4% of raw duck egg. Under controlled conditions of heat-treatment, destruction of Salmonella species can be accomplished.     

家蚕卵裂核第一次分裂的方位观察

卵裂在胚胎学上有一定的规律,Wilson(1892)曾从几何学的角度,说明卵裂面对于卵轴或胚轴的位置关系,裂球对于正体位置关系的卵裂类型,主要取决于成胚原形质和卵黄的分配。家蚕卵的类型属于中黄卵,在卵黄膜内几乎全是卵黄集中分配的地方,只有在动物极的漏斗状范围内,卵黄分配稀少。卵的成熟分裂、受精和卵裂都开始在卵的动物极内(图1),然后引向植物极。     

THE SURFACE EVENTS AT FERTILIZATION OF THE SEA URCHIN EGG I. EVENTS ON THE SURFACE OF THE VITELLINE COAT1

Sperm-egg interaction during normal fertilization in the sea urchins, Strongylocentrotus intermedius and Hemicentrotus pulcherrimus, was studied by scanning and transmission electron microscopy. Several seconds after insemination, acrosome-reacted spermatozoa were found attached to the surface of the vitelline coat on each egg. Soon, several bulges of the vitelline coat appeared surrounding the fertilizing spermatozoon. These bulges then spread over the surface increasing in number, while they became fewer and disappeared around the sperm head. Thin sections of the bulging areas revealed discharging cortical granules. As the bulging vitelline coat was elevated, the sperm head was incorporated into the perivitelline space, passing through a small hole in the coat that resulted from penetration of the sperm acrosomal process immediately before fusion of the gametes. When the spermatozoon disappeared beneath the fertilization membrane, a hole was left in the membrane and the cortical reaction had finished on the other hemispheric surface. Mechanical removal of the membrane at that time exposed a spermatozoon protruding perpendicularly from the egg plasma membrane surface. The anterior tip of the sperm head was smoothly connected with the egg surface, and neither microvillous projections nor cytoplasmic covering of the egg cytoplasm could be found around the spermatozoon.     

THE EFFECT OF EGG WEIGHT ON THE SUBSEQUENT GROWTH OF NESTLING GREAT TITS PARUS MAJOR

Eggs of known fresh weight were removed from Great Tit nests shortly before hatching and artificially incubated. Four to eight chicks were returned to each nest-box on their hatching day and reared by foster parents. The effect of egg weight on subsequent growth was studied for 81 nestlings (13 broods), 50 of them (8 broods) up to the 17th day.
Hatching success of 275 eggs in the incubator was 67·6% and was not correlated with egg weight.
Egg weight had a significant effect on nestling weight up to the 14th day. Young hatched from lighter eggs grew more slowly at the beginning, but recovered before fledging. Mortality after fledging seemed not to be influenced by egg weight.
Maximum weight (mean 19 g) was attained between the 12th and the 17th day and was positively correlated with egg weight.
The effect of brood-size (small in the experiments) on growth increased significantly with age. The range of egg weight for a nest had a significant effect on growth at the beginning, but a small and not significant effect after the 10th day.
The growth of each brood on any particular day was expressed as a deviation from mean growth. These growth deviations, plotted against date, were similar in all nests and were not correlated with any weather data.
The fledging success of 260 early broods was independent of egg weight, but it was positively correlated with egg weight in 78 late broods (data from 1965–71).
The ecological importance of egg weight at different times of the breeding season is discussed.     

赤眼蜂人工模拟寄主卵的研究

本文报道松毛虫赤眼蜂Trichogramma dendrolimi在人工模拟寄主卵上产卵寄生并发育至成虫羽化出蜂的研究结果。对人工卵壳制作及人工培养液作了叙述,就赤眼蜂对人工培养液、人工卵壳的要求以及影响赤眼蜂在人工卵内发育的一些因素进行了讨论。     

INDUCTION OF A FURROW-LIKE DENT ON THE SURFACE OF THE NEWT EGG BEFORE THE ONSET OF CLEAVAGE*

Sawai (2) found in the amphibian egg that furrow-inducing cytoplasmic component (FIC) was localized along the cleavage furrow, which could induce a furrow on the polar surface of cleaving egg under which FIC was injected. But this procedure failed on the surface of uncleaved fertilized egg. In the present experiments, an attempt was made to induce a cleavage furrow on the surface of uncleaved egg of the newt, Cynops pyrrhogaster. A piece of the cortex was cut from the uncleaved egg, which was transplanted to the egg just before or just after the onset of the cleavage, using a fine glass needle. After the transplantation FIC was injected beneath the graft with a capillary. The graft reacted to FIC and a furrow-like dent was induced at the position. Besides, stiffness of the graft increased during the cleavage of the host egg. In contrast to the cortical grafting, a large amount of the cytoplasm excluding FIC was injected under the cortex of an uncleaved egg. After several minutes FIC was deposited at the site. A furrow-like dent was formed there in many cases.     

棉铃虫卵内蛋白酶性质研究

在棉铃虫Helicoverpa armigera卵母细胞内检测到蛋白酶活性,其作用Ph在酸性范围,酶活性受E-64、Pepstatin和iPr₂P-F等多种抑制剂抑制。在Ph4.0时蛋白酶对牛血红蛋白有较高水解率。抗蓖麻蚕Philosamia cynthia ricini卵半胱氨酸蛋白酶血清和抗蓖麻蚕卵天冬氨酸蛋白酶血清可以识别棉铃虫卵内成分。实验结果表明;棉铃虫卵内可能存在半胱氨酸蛋白酶类、丝氨酸蛋白酶类和天冬氨酸蛋白酶类,并且与蓖麻蚕卵内蛋白酶有一定的相似性。