STUDIES ON THE FORMATION AND STATE OF DETERMINATION OF THE TRUNK ORGANIZER IN THE NEWT, CYNOPS PYRRHOGASTER

Mesoderm formation in the presumptive trunk organizer was analyzed in gastrulae of Cynops pyrrhogaster. The presumptive trunk organizer showed little or no mesodermal differentiation in the beginning gastrula (0 h embryo). But as soon as the presumptive trunk organizer came into contact with the newly invaginated cranial archenteron roof, it rapidly formed mesoderm. This suggests that this differentiation was brought about by an inductive effect of the underlying cranial archenteron roof. For investigation of this possibility, the presumptive trunk organizer of 0 h embryos (Tr-0) and the newly invaginated cranial archenteron roof (presumptive pharyngeal endoderm and prechordal plate) of successive stages were cultured in isolation and by the sandwich technique. The newly invaginated presumptive pharyngeal endoderm and prechordal plate had no effect on mesoderm formation of the presumptive trunk organizer, and mesodermal differentiation of the combinations was similar to that of the Tr-0 alone. On the other hand, results showed that the prechordal plate, which came into contact with the still uninvaginated presumptive trunk organizer, stimulated dorsalisation of the weakly mesodermized trunk organizer. Based on these results, the stepwise process of mesoderm formation in the trunk organizer is discussed.     

CHANGES OF CHROMOSOMES DURING THE EARLY NEURAL DEVELOPMENT OF A JAPANESE NEWT, CYNOPS PYRRHOGASTER

The karyotype of Cynops pyrrhogaster was determined on the mitotic chromosomes in the presumptive neural area of an early gastrula. 24 chromosomes of a diploid set consisted of 8 metacentric and 4 submetacentric pairs. Individual chromosomes were identified on the basis of their morphology and characteristic C-binding patterns. Sex chromosomes were not identified. Total length of the haploid chromosome set in the presumptive neural area decreased remarkably from morulae to gastrulae, further continued to decrease up to neurulae and thereafter remained unchanged till tail-buds. Chromosome shortening occurring from morulae to gastrulae was accompanied with a prominent decrease in chromosome volume, keeping chromosome width constant. Shortening took place evenly along the longitudinal axis of a chromosome. When gastrulae and neurulae were compared concerning their positions of the appearance of the C-bands, the basic pattern remained unchanged. In certain chromosomes, the number of C-bands decreased as the result of their fusion, as gastrulae proceeded to neurulae.     

HISTOCHEMICAL AND ELECTRON MICROSCOPIC OBSERVATIONS ON THE STEROID HORMONE-SECRETING CELLS IN THE TESTIS OF THE JAPANESE RED-BELLIED NEWT, CYNOPS PYRRHOGASTER PYRRHOGASTER

The testis of the Japanese red-bellied newt, Cynops pyrrhogaster pyrrhogaster, caught in the middle of May was investigated in order to demonstrate the presence of steroid hormone (SH)-secreting cells, by means of histochemical and electron microscopic techniques. The newt testis is divided into two main parts of spermatogenetic stages. The anterior part is immature and consists of many seminal cysts containing spermatogonia and spermatocytes. The posterior part is mature and made up of many cysts containing mature spermatozoa and glandular tissue. Histochemical studies revealed Δ⁵-3β-hydroxysteroid dehydrogenase (Δ⁵-3β-HSD) activity in the pericystic cells of the mature part, weak in those before spermiation, then gradually becoming more intense in the pericystic cells just after spermiation. Activity was most pronounced in the outer layer of cells of the glandular tissue which originate from the pericystic cells. In contrast to this, the Δ⁵-3β-HSD reaction was entirely negative in the pericystic cells of the immature part, the Sertoli cells, and the inner cells of the glandular tissue originating from the Sertoli cells. Electron microscopic observation of the pericystic cells and glandular tissue gave further information on the histochemical features. The pericystic cells in the immature part are fibroblast-like cells. The cell organelles of these cells are poorly developed except for rough-surfaced endoplasmic reticulum and rod-shaped mitochondria. In the mature part, the fibroblast-like cells are transformed into cells characteristic of SH-secreting cells. In the cytoplasm, the amount of smooth-surfaced endoplasmic reticulum increases and typical globular mitochondria with tubular cristae take the place of the rod-shaped mitochondria. In addition, a number of lipid droplets and lipofuscin granules appear. Most of the fine structures of the outer layer of the cells of the glandular tissue were found to be similar in appearance to those of the SH-secreting cells in mammals and other vertebrates. These results strongly suggest that, as in the other urodeles, the SH-secreting cells in the testis of the Japanese red-bellied newt are the pericystic cells in the mature part and in the outer layer of cells of the glandular tissue.     

东方蝾螈原肠形成期瓶状细胞的结构及其对胚胎发育的影响

以１００只东方蝾螈早期胚胎为材料,用ＳＥＭ和ＴＥＭ对瓶状细胞形态结构和除去瓶状细胞的胚胎进行观察,去除瓶状细胞后,胚胎的原肠形成不会中断,外包和内卷仍能正常进行,并可以发育成幼螈,但有部分胚胎原肠前端缺失,长期培养的蝾螈胚对针刺激有反应,幼虫阶段中自由活动,我们的结论是：１）东方蝾螈原肠胚的瓶状细胞除了原肠前端存在外,还有部分瓶状细胞与原肠长轴垂直,从力学角度推断瓶状细胞在原肠形成过程中不起主要作     

ROLE OF ASYMMETRIC CELL DIVISION IN PTERIDOPHYTE DIFFERENTIATION. II. EFFECT OF CA2+ ON ASYMMETRIC CELL DIVISION,RHIZOID ELONGATION,AND ANTHERIDIUM DIFFERENTIATION IN VITTARIA GEMMAE

Gametophytes of Vittaria graminifolia reproduce vegetatively by means of gemmae. Each gemma consists of a linear array of six cells: four body cells and a knob-shaped terminal cell at each end. When gemmae are shed from the gametophyte onto Knop's mineral medium, the two terminal cells do not divide, but elongate to form primary rhizoids. The body cells undergo asymmetric cell division, and the smaller daughter cells differentiate into either secondary rhizoids or prothalli. When gibberellic acid is included in the medium, antheridia are formed as a result of asymmetric cell division instead of vegetative structures. We studied the effect of Ca²⁺ on asymmetric cell division, rhizoid elongation, and antheridium formation in gemmae cultured on Knop's mineral medium and variations of Knop's medium. Ca²⁺ inhibited the onset of cell division and rhizoid elongation, but was required for differentiation of antheridia. Treatments which lowered the Ca²⁺ content of gemmae (EGTA and dilute HCl extraction, culture on verapamil-containing and Ca²⁺-deficient medium) caused an early onset of cell division and rhizoid elongation. The stimulation of growth was most pronounced when gemmae were deprived of Ca²⁺ during the first 24 hr of culture. The proportion of cell divisions which differentiated into antheridia in response to GA was greatly reduced when the Ca²⁺ status of gemmae was lowered with verapamil and Ca²⁺-EGTA buffers.     

Galanin(甘丙肽)及其受体在成年小鼠脑内神经新生部位的表达及对神经干细胞分化的作用

Galanin(甘丙肽)是一种在中枢神经系统中广泛分布的神经肽,功能涉及摄食、睡眠和觉醒、疼痛、认知和生殖等各方面.我们在成年小鼠脑的神经细胞新生部位如SVZ,DG和RMS发现有galanin及其受体的mRNA表达,同时在SVZ来源的神经干细胞中也检测到有galanin及其受体的表达.细胞实验中,在分化后特定时间段GALKO小鼠来源的神经干细胞产生神经突的细胞比例及神经突的长度明显小于正常小鼠来源的神经干细胞.而加入galanin或受体激动剂GAL2-11后.该神经干细胞则在产生神经突的细胞比例及神经突的长度都明显上升.受体拮抗剂M35的添加可减弱galanin或GAL2-11所产生的作用.这些结果表明galanin及其受体与神经干细胞的分化及神经突的生长有着密切的联系,并可能参与了神经系统的发育.     

MESENCHYME CELLS IN STARFISH DEVELOPMENT: EFFECT OF TUNICAMYCIN ON THEIR DIFFERENTIATION, MIGRATION AND FUNCTION

The effect of tunicamycin, an inhibitor of protein glycosylation, on starfish development was investigated. Specific developmental events such as 1) bulging of the archenteron tip, 2) migration of mesenchyme cells, 3) formation of coelomic pouches and 4) mouth formation, are inhibited in the presence of this drug. These events are discussed in connection with differentiation, migration and function of mesenchyme cells. The possibility is discussed that tunicamycin exerts its effect by interfering with de novo synthesis of a cell surface factor(s) supporting dynamic cell surface activities.     

睾丸酮对离体培养人蜕膜细胞形态的影响

实验选用早孕人工流产蜕膜组织进行体外培养,观察睾丸酮对蜕膜细胞形态的影响并与RU 486加以比较。研究结果提示:(1)睾丸酮(6.9×10~(-5)mol/L)能抑制离体培养人蜕膜细胞的生长发育,但这种抑制作用是暂时和可恢复的且与用药剂量及持续时间有关。(2)睾丸酮对蜕膜细胞形态的影响与RU 486(4.7×10~(-4)mol/L)的作用效果相似。     

小麦籽粒发育初期土壤水分亏缺对植株各部位光合作用的影响

小麦开花后5～16天内给予不同程度的土壤干旱处理。无论轻、中或重度干旱均不同程度地释低了植株的净光合率,但不同器官或部位对干旱的反应不同,上部器官的光合受影响较小,故随着干旱的加重在全株光合中所占比例逐渐增加。恢复灌水后,曾受轻度及中度干旱的植株,中、上部器官的光合有补偿性增强,因而可能减轻产量的损失。     

THE ROLE OF LIGHT IN HISTOGENESIS AND DIFFERENTIATION IN THE SHOOT OF PISUM SATIVUM. III. THE INTERNODE

Thomson, Betty F., and Pauline Monz Miller. (Connecticut Coll., New London.) The role of light in histogenesis and differentiation in the shoot of Pisum sativum. III. The internode. Amer. Jour. Bot. 50(3): 219–227. Illus. 1963.—Seedlings of Pisum sativum were grown under constant conditions and exposed daily to red or white fluorescent light or kept in total darkness. Counts and measurements of internodal cells in both transverse and longitudinal directions show that light does not alter the sequence or pattern of tissue differentiation, including the sequence of xylem maturation within the vascular bundle. Light does accelerate the rate of a constant course of differentiation. Light advances the time of division and enlargement of cortex, xylem, phloem, and pith cells in the longitudinal direction but reduces both the final number and the final length attained in all cases. It is concluded that light accelerates all phases of shoot growth and differentiation and that cell division and elongation in the later phases of internodal growth are reduced by light because of accelerated cell maturation.     

CHANGES IN THE CAPACITY FOR CLONAL GROWTH AND DIFFERENTIATION IN VITRO OF THE VERTEBRAL CARTILAGE CELLS WITH EMBRYONIC DEVELOPMENT II. VITALIZING EFFECT OF CONDITIONED MEDIUM ON THE CELLS OF YOUNGER EMBRYOS

Most of the younger cartilage cells taken from chick embryos at the stage 35 were known to regress after the initial cell multiplication in in vitro clonal culture. A partial supplementation of conditioned medium (CM) to the standard medium was effective to permit colony formation from many of these younger cells. Most colonies thus derived from the younger cells by the aid of CM expressed differentiative traits as cartilage, as the cells from older embryos did. CM exerted multiple effects on clonal development of the younger cells. It vitalized the cells destined to regress, to promote cell multiplication and to flatten the shape of the colony. The experimental results suggested that these effects were associated with an independent factor each.     

THE EFFECT OF CELL CROWDING ON THE IN VITRO REACTIVITY OF NORMAL AND ABNORMAL HUMAN LYMPHOCYTES

The effects of cell crowding on the blastogenic response to phytohaemagglutinin in in vitro cultures of lymphocytes from both normal subjects and from patients with lymphoproliferative disorders were studied. Moderate degrees of cell crowding resulted in enhancement of blast transformation; however, further increases in the degree of crowding produced relative or absolute inhibition of blast transformation, an effect which was more marked in the normal controls than in the lymphoproliferative group. The significance of these findings is discussed.     

EFFECT OF FLORAL AGING ON THE GROWTH OF COMPATIBLE AND INCOMPATIBLE POLLEN TUBES IN LILIUM LONGIFLORUM

Compatible and incompatible pollen tube growth in detached styles of three Lilium longiflorum cultivare varies with the physiological age of the style. Before anthesis both compatible and incompatible pollen tubes grow, in 48 hr, only a fraction of the distance compatible tubes grow after anthesis. Incompatible pollen tubes are restricted to about half the distance of compatible tubes in the four days postanthesis, but thereafter increase up to or three-fourths or more the length of compatible tubes at the time of floral senescence. About 10 days after anthesis, growth of both types of pollen tubes decreases. The detached style method of pollen-tube cultivation is validated in the cultivar ‘Ace’ by seed set obtained following self-pollination in the 6- to 9-day interval and failure of seed set after either self- or cross-pollination after 9 days following anthesis. Also, in agreement with detached style data, self-pollination fails to produce seeds when attempted in bud stages or the five days following anthesis. Cross-pollinations are successful in this period. This material and technique appear well suited for study of the nature of the self-incompatibility reaction.     

辛硫磷和溴氰菊酯混剂对家蝇抗性发展的影响

以家蝇（ＭｕｓｃａｄｏｍｅｓｔｉｃａｖｉｃｉｎａＭａｃｑｕａｒｔ）为试虫,用辛硫磷溴氰菊酯单剂及不同配比的混剂进行汰选试验。所有混剂选育的家蝇抗性发展都很缓慢,而单剂抗性发展都很快。增效试验表明,辛硫磷与溴氰菊酯混配有明显增效作用,特别是对抗性品系。生化分析结果表明,对溴氰菊酯的抗性发展与酯酶的酶活升高有关。对辛硫磷抗性发展与多功能氧化酶的酶活升高和乙酰胆碱酯酶敏感性降低有关。混剂选育的家蝇其对单剂的敏感性的变化及酶系的变化,随着混剂的配比而变化     

THE EFFECT OF ULTRA-VIOLET,X-RAY,AND RADIUM RADIATION ON THE TOXICITY OF NORMAL BLOOD

While the number of experiments performed is perhaps somewhat limited the results obtained were quite definite and warrant the following conclusions. The toxicity of normal blood for living plant protoplasm as studied on the growth of Lupinus albus seedlings is definitely influenced by various radiations. Ultra-violet rays produce no effect on normal blood or may even render it slightly less toxic. Roentgen rays render normal blood more toxic. The toxicity is greater in the case of the blood plasma as compared with the blood cells and a more toxic effect is produced with the Coolidge tube as compared with the gas tube. Radium emanations in the few experiments performed produced changes very much the same as those given by the x-rays.     

神经干细胞分化过程中微管蛋白表达变化的光电镜观察

目的对神经干细胞向神经元定向分化过程中微管蛋白的表达变化进行光、电镜观察研究。方法采用细胞培养技术、免疫荧光技术以及免疫电镜技术对神经干细胞向神经元定向分化过程中微管蛋白的表达变化进行观察。结果在神经干细胞向神经元定向分化的不同时期,存在微管蛋白的表达变化,在分化初期以核周附近分布明显,随神经元的成熟散在分布于胞质中及突起内,形成细网状,构成细胞骨架,维持细胞形态。结论在神经干细胞向神经元定向分化过程中伴随有微管蛋白的表达变化,随神经元的成熟而构成细胞骨架,维持细胞形态。     

小麦远缘杂种幼胚胚状体的发生、发育及低温对愈伤组织分化能力的影响

通过普通小麦与滨麦、簇毛麦及山羊草属7个种杂交幼胚培养,获得8个体细胞胚性无性系(8个组合10个胚)及大量试管苗。愈伤组织及胚性愈伤组织诱导率分别为65.79%和26.32%。形态学及细胞学鉴定结果,均为真杂种。不同染色体组及同一染色体组不同基因型的幼胚,在组织培养中有明显差异。非整倍体细胞具有遗传的全能性,但当染色体数目严重偏离双单倍体数目时,其全能性即丧失。胚状体的发育具有与合子胚极相似的典型结构。由愈伤组织表层和深层细胞产生的胚状体,在形态结构上有明显区别。低温(4℃)处理早代胚性愈伤组织180—240天,以及严格筛选和及时转移,可使培养65—80代(5—6年)的愈伤组织植株分化率保持在77.73%以上。     

EFFECT OF ACTINOMYCIN D ON THE DIFFERENTIATION OF HATCHING GLAND CELL AND CILIA CELL IN THE FROG EMBRYO

The forehead epidermis of the stage 18–20 R. japonica embryo includes the hatching gland cell (HGC) which contains cell-specific secretory granules. The cilia cell (CC) and common epidermal cell (CEC) constitute the epidermis of the entire body surface, in addition to the forehead region.
Culture of superficial epidermal explants from various embryonic portions at various developmental stages revealed that HGCs are derived from cells localized on the neural crest in the stage 13a (early neural plate) embryo. When explants from the presumptive HGC area were treated with 1 ug/ml actinomycin D (AMD), the formation of secretory granules in HGCs was inhibited either by continuous treatment from stage 13 or by an 8-hr treatment at stage 13b. Similarly, the ciliogenesis in CCs was inhibited. The differentiation of CECs was entirely unaffected by any of the AMD treatment. After release from AMD, mucous vesicles, characteristic of the CEC, were formed in cells whose differentiation into HGC and CC had been suppressed by the antibiotic. Thread complexes and clumps of coiled strings were found in the nuclei of AMD-affected cells.
It is concluded that the DNA-dependent RNA syntheses which direct secretory granule formation in the HGC and ciliogenesis in the CC occur during a limited period at stage 13b, viz. , 20 hr before their cytodifferentiation becomes appreciable.     

高温致神经管畸形过程中神经生长因子及其受体表达变化的观察

为进一步探讨高温致神经管畸形的机制, 本文利用我们已经建立的高温致神经管畸形金黄地鼠模型, 在神经管发育的不同阶段, 用免疫组织化学法检测了高温对神经管及其周围间充质中神经生长因子（Ｎｅｒｖｅ Ｇｒｏｗ ｔｈ Ｆａｃｔｏｒ, ＮＧＦ） 和ＮＧＦ受体 （ｔｒｋＡ） 表达的影响。结果显示： ＮＧＦ及其受体广泛分布于神经管及其周围间充质内, 并随胎龄增加而呈规律性变化, 高温处理后的胚胎神经管上皮及其周围间充质中ＮＧＦ及其受体的免疫组织化学反应不同程度的减弱。结果提示, 神经管ＮＧＦ及其受体的减少, 可能是高温致神经管畸形的一个重要因素