Two Developmentally Regulated Isoenzymes of Calmodulin-Stimulated Protein Kinase II in Rat Forebrain

Soluble calmodulin-stimulated protein kinase II has been purified from adult and 10-day-old rat forebrain. By autoradiography, the alpha/beta subunit ratios of the 10-day and adult enzymes were 0.67 +/- 0.03 and 2.20 +/- 0.15, respectively. By silver staining, the alpha/beta subunit ratios were 1.02 +/- 0.06 and 2.36 +/- 0.10, respectively. The apparent holoenzyme molecular masses of the purified 10-day and adult enzymes were 500,000 daltons and 700,000 daltons. However, varying the purification conditions revealed higher and lower molecular mass forms at both ages and suggested that the form of the kinase that is usually purified is merely that which has the highest affinity for calmodulin-Sepharose and may not be the form of the kinase that exists in vivo. The subunits of the adult and 10-day enzymes were indistinguishable by one- and two-dimensional electrophoresis and one-dimensional proteolytic peptide maps. These results are consistent with the suggestion that at least two developmentally regulated isoenzymes of this kinase exist in rat forebrain.     

The relationship among egg size,density and food level on larval development in the wood frog (Rana sylvatica)

Summary Although inter- and intraspecific variation in egg size among amphibians has been well documented, the relationship between egg size and fitness remains unclear. Recent attempts to correlate egg size intraspecifically with larval developmental patterns have been equivocal. In this study the development of larvae derived from large eggs and small eggs, from a single population in Maryland were compared under a range of food levels and larval population densities. Both food level and density had significant effects on the length of the larval period and size at metamorphosis. However, the response among larvae derived from different egg sizes was not additive. At low densities and high food levels, larvae from small eggs had longer larval periods and a larger size at metamorphosis than larvae derived from large eggs. In contrast, at high densities larvae from small eggs had longer developmental periods but were smaller at metamorphosis than larvae from large eggs. In addition, larvae from small eggs were more sensitive to density irrespective of food level. These results suggest that optimal egg size is correlated with environmental factors, which may explain the maintenance of both geographic and within population variation in egg size commonly observed in amphibians.     

Development of tool use in a macaque and a gorilla

The development of the capacity to use a stick as a tool was tested in a macaque (Macaca fuscata) and a gorilla (Gorilla gorilla gorilla) infants that had previously shown to be able to use strings and supports as dragging tools. Subjects were tested between 15 and 38 months of age. Different levels of competence between the subjects emerged over testing. The macaque developed a stereotyped strategy to cope with the problem, only getting random successes, whilst the gorilla developed a flexible strategy and revealed to be able to mentally represent the solution of the problem. In fact, when not successful using the stick, the gorilla thought out an alternative strategy, choosing and adapting a new object to use it as a tool.     

坛紫菜原生质体的发育研究

用2％的海螺酶和1％的纤维素酶混合,将坛紫菜叶状体的4种不同细胞类型即:营养细胞、根丝细胞、精子囊和果孢子囊,分别解离成原生质体,并研究了这些不同部位和不同生长时期。细胞的生长、发育途径。由根丝细胞分离的原生质体能长成新的叶状体;由早期中部营养细胞分离的原生质体,有70％长成新的叶状体,其余的发育成精子囊和果孢子囊。再生叶状体在室内培养,能正常成熟。由精子囊和果孢子囊分离的原生质体,即精子细胞和果孢子细胞不能再生叶状体。前者形成新的精子囊放散精子,后者形成新的果孢子囊,放散果孢子发育成丝状体。晚期紫菜与早期紫菜比较,再生叶状体的数量显著减少,而发育成精子囊和果孢子囊的数量则大大增多。     

长吻鮠精巢发育的分期及精子的发生和形成

长吻鮠精巢的发育分为精原细胞增殖期、精母细胞生长期、精母细胞成熟期、精子细胞出现期,精子完全成熟期和精子退化吸收期。精巢的后1/3不产生也不贮存精子,精子的发生和形成经过精原细胞、精母细胞、精子细胞到精子的一系列过程。精原细胞有两种类型。精子无顶体,有中心粒帽,中片长,核凹窝和线粒体发达,鞭毛具侧鳍。     

Bromodeoxyuridine-immunohistochemistry on cellular differentiation and migration in the fundic gland of Xenopus laevis during development

Summary Cellular differentiation and migration in the fundic glands of adult and larval Xenopus laevis have been examined using bromodeoxyuridine-immunohistochemistry. In the adult fundic gland, cumulative labeling with bromodeoxyuridine revealed a proliferative cell zone between the surface mucous cells and mucous neck cells, in what is referred to as the neck portion of the gland. The labeling-index of mucous neck cells had rapidly increased by week-5. The labeling-index of oxynticopeptic cells showed a more delayed increase until week-7, coincident with the decrease in the labeling of mucous neck cells. In the immature fundic glands of larvae, the labeled proliferating cells were randomly distributed throughout the developing gastric mucosa. During metamorphosis, the labeling-index of immature epithelial cells was highest at stage 63. Following administration of bromodeoxyurdine at this, stage, there was no significant loss of labeled epithelial cells during the metamorphosing period. Furthermore, there was no significant difference in the labeling-indices among the epithelial cells, such as surface mucous cells/generative cells, mucous neck cells, and oxynticopeptic cells, 7 days after administration. Cellular differentiation and migration pathways of epithelial cells in the fundic gland of adult X. laevis and its larvae are discussed.     

Distribution and development of the serotonin-and RFamide-like immunoreactive neurons in the arrowworm,Paraspadella gotoi (Chaetognatha)

Summary The distribution and development of serotonin-and RFamide-like immunoreactivities in the nervous system of Chaetognatha, Paraspadella gotoi, were examined in whole-mount preparations. In adults, a single serotonin-like immunoreactive (5HTLI) neuron and numerous RFamide-like immunoreactive (RFaLI) neurons were found in the central nervous system. Based on the structure of the fins, hooks, and eyes, seven postembryonic developmental stages were recognized. The most obvious features of the stages are: stage 1, newly hatched young; stage 2, elongation of a continuous lateral tail fin; stage 3, separation of the lateral and tail fins; stage 4, appearance of hooks; stage 5, pigmentation of eyes, stage 6, attachment by tail adhesive fins; stage 7, prey capture. Stage 1 did not show any immunoreactivity. The 5HTLI neuron first appeared at stage 4 and its axonal pathway became similar to the adult at stage 6. On the other hand, the RFaLI neurons appeared at stage 3 in the ventral ganglion. Some of their somata disappeared at stage 5 and the neuronal architecture resembled the adult at stage 7 although the RFaLI neurons in the cerebral ganglion were complete at the juvenile stage.We are sad to announce that Dr. M. Yoshida died on 29 October 1988     

Postembryonic development of the complex tibial organ in the foreleg of the bushcricket Ephippiger ephippiger (Orthoptera,Tettigoniidae)

Summary The postembryonic development of the morphology and anatomy of the complex tibial organ in the foreleg of the bushcricket Ephippiger ephippiger is described. All the receptor cells are present in the subgenual organ, the intermediate organ and the crista acustica in the 1st larval instar. Generally, even in the 1st instar, the arrangement of the scolopidia in the three organs resembles the adult structure. The acoustic trachea, the tympana, the tympanal covers and the acoustic spiracle develop step by step in subsequent instars. The acoustic trachea resembles the adult structure for the first time in the 4th instar, although its volume is still small. The auditory threshold curves recorded from the tympanal nerve in instars 4, 5 and 6 show the same frequency maxima as those in the adult. The overall sensitivity significantly increases after the final moult. The dimensions of structures that lie within the crista acustica and that are probably involved in stimulus transduction and in frequency tuning have been analysed. The dorsal wall of the anterior trachea, the tectorial membrane and the cap cells have similar dimensions, especially in the last three instars and in adults.     

The origin of the luteinizing hormone-releasing hormone (LHRH) neurons in newts (Cynops pyrrhogaster): the effect of olfactory placode ablation

Summary Neurons containing luteinizing hormone-releasing hormone (LHRH) are first detected in newt embryos (Cynops pyrrhogaster) in the olfactory epithelium and ventromedial portion of the olfactory nerve, after which they sequentially appear in the intracerebral course of the terminal nerve at prometamorphosis, and in the septo-preoptic area at postmetamorphosis. In adults, however, LHRH-immunoreactive cells are rarely seen in the nasal region, and their distribution shifts into the brain, suggesting their migration. In order to ascertain the origin and possible migration route of these neurons in newt larvae, the effect of unilateral or bilateral olfactory placodectomy on the LHRH neuronal system has been studied. Removal of the olfactory placode results in the absence of LHRH-immunoreactive cells in the nasal and brain regions of the operated side, whereas the subsequent growth and the LHRH-immunoreactive cellular distribution in the contralateral side are identical to those of normal larvae. Following bilateral placodectomy, no LHRH immunoreactivity is detected on either side of the olfactory-brain axis. These results suggest that LHRH neurons of the newt, Cynops pyrrhogaster, originate in the olfactory placode and then migrate into the brain during embryonic development.