四川55种鱼生活史型的研究

四川５５种鱼生活史型的研究刁晓明,罗一兵李波（西南农业大学水产系,重庆６３０７１６）（重庆大学计算机系,６３００００）ＬｉｆｅＨｉｓｔｏｒｙＰａｔｔｅｒｎｓｏｆ５５ＦｉｓｈＳｐｅｃｉｅｓｉｎＳｉｃｈｕａｎ￥ＤｉａｏＸｉａｏｍｉｎｇ;ＬｕｏＹｉｂｉｎｇ...     

Isolation and characterization of the outer membrane of Acinetobacter calcoaceticus

A method for the separation of the outer membrane (OM) from the cytoplasmic membrane (CM) of Acinetobacter calcoaceticus 69/V grown on different carbon sources is described. The contamination of the OM with CM was less than 10%. Independent of the carbon source, five protein bands with apparent molecular weights of 47 000, 33000, 21 000, 19 000 and 12 000 were found by solubilization at 37°C and six bands at 100°C (apparent M_r 53 000, 47 000, 38 000, 26 000, 21000, 12000). Three proteins were modifiable by heat. With the periodic acid-Schiff procedure the bands with apparent M_r of 33 000 and 12 000 were made visible. After growth on d,l-carnitine an additional two non-heat-modifiable protein bands with apparent M_r between 40 000 and 45 000 were detected. By cultivation on acetate and peptone as carbon source one additional band (M_r 15 000) from OM of cells could be found.     

Changes in cytoplasmic and lysosomal enzyme activities in cultured rat heart cells: The relationship to cell differentiation and cell population in culture

Summary Postnatal rat heart cells in culture enriched with respect to muscle cells were obtained by either high density seeding or by the replating technique. [³H]Thymidine incorporation to DNA and the enzymatic pattern of cytoplasmic and lysosomal enzymes have been studied as a function of the culture’s age, of seeding density, and replating. It was shown that (a) replating maintains predominance of myocyte population for at least 2 wk in culture; (b) heavy seeding density allows homogeneous myocyte population for the 1st wk in culture; and (c) the enzyme profile of the culture may serve as an indicator for the type of cell population in culture and its state of differentiation. This study was done as partial fulfilment of the M.Sc. thesis in Biochemistry (SY). Supported by grants from The Chief Scientist, Ministry of Health, State of Israel; The Ministry of Education and Sciences, State of Niedersachssen (FRG); and The Foundation for Heart Research from Mr. and Mrs. D. Vidal-Madjar, Paris, France.     

Testicular histology of the dusky leaf monkey (presbytis obscura) as it relates to birth pattern in Peninsular Malaysia

The testicular histology of the dusky leaf monkey, Presbytis obscura,is described following a study of material from 16 adult males collected over a 13-month period in Peninsular Malaysia. The histological appearances were similar to those of the other cercopithecines studied so far. No seasonal variation in the height of the seminiferous epithelium was observed, and spermatogenesis was seen in all the adult testes. These findings suggest that males of this species are capable of breeding throughout the year. These results are discussed in relation to field observations of births of this species and to the birth patterns exhibited by other species of langur.     

Polarity and competition between megaspores in the ovule ofOenothera hybrids

New data on the development of polarity in the ovules during megasporogenesis and early stages of embryo sac development inOenothera-hybrids are presented. It is confirmed that allOe. hookeri-hybrids show a strong tendency to form heteropolar tetrads, with the micropylar megaspore developing into an embryo sac. This preference is seen in the delay of the second meiotic division on the chalazal side, the absence of callose in the lateral wall of the micropylar megaspore, and the accumulation of starch in this megaspore. However, homopolar tetrads, chalazal preference, and ovules with two developing embryo sacs are also observed with considerable frequency. Quantitative data on the frequency of the different developmental types are compared with earlier genetic results about competition in the haplophase. There is sufficiently good agreement to support the hypothesis ofRenner that there is a correlation between the developmental processes in the megaspore tetrad and the genetic phenomena of competition in the haplophase.     

Anthocyanins and their distribution in the genusEpimedium

Anthocyanins contained in plants belonging to the genusEpimedium in Japan are discussed in this study. Two kinds of anthocyanin, delphinidin 3-p-coumaroyl-sophoroside-5-glucoside (cayratinin) and cyanidin 3-p-coumaroylsophoroside, were identified, and the latter is new to the literature. Only cayratinin was found in the colored petals of theEpimedium species, but cayratinin and cyanidin glucoside were contained in the stems, young leaves and autumn leaves of all the species surveyed.     

The specification of metameric order in the insectCallosobruchus maculatus Fabr. (Coleoptera)

Summary Mechanically dividing an insect egg into anterior and posterior fragments results in a segment gap (Sander 1976), a loss of non-terminal segments in the constricted region. By altering the stage and duration of constriction, we produced different types of egg fragments in the pea beetleCallosobruchus. The patterns formed by these fragments suggest the existence of interactions between anterior and posterior egg regions that influence segment patterning and placement. Segments in excess of the numbers expected on the basis of permanent constrictions were produced in fragments when: (1) the constriction was released before cellularization occurred and (2) in addition the complementary fragment degenerated. Apparently the degenerating fragment induced the formation of excess segments in the developing fragment. Differences in the time and extent of excess segment formation in anterior versus posterior fragments suggest an asymmetric distribution of prerequisites for segment formation. This conclusion is consistent with our finding that a partial reversal of segment sequence (double abdomen formation) can be induced only in posterior fragments by a degenerating fragment, but not in anterior fragments (see companion paper).The formation of excess segments shows that the segment gap observed after permanent separation cannot be due to non-specific damage, caused by the process of constriction as such, to the egg or to localized putative segment precursors.     

Vascular permeability to proteins and peptides in the mouse pineal gland

Summary The permeability of fenestrated capillaries in the mouse pineal gland to proteins and peptides was demonstrated by means of ultrastructural tracers. Horseradish peroxidase (HRP) and microperoxidase (MP) were injected intravenously and allowed to circulate for approximately 30 s, 1 min, 5 min, 1 or 2h. The tissue was then fixed by vascular perfusion or by immersion with aldehydes. In all experiments a pronounced extravasation of HRP and MP occurred. Transendothelial vesicular transport seemed to have occurred across the fenestrated capillaries. The most pronounced tracer labeling of vesicles was found after 1 min of MP- or HRP-circulation. The vesicles were uncoated and more than 70 % of the HRP-and MP-containing vesicles exhibited diameters between 50 and 110 nm. Furthermore, three other transcapillary pathways taken by the tracers are suggested: 1) via intercellular junctions, 2) through fenestrae and 3) via channels formed by fusion of vesicles with the luminal and abluminal cell membranes. Based on these results, it is assumed that the capillaries in the mouse pineal gland are also permeable to peptides synthesized and secreted by the pineal gland.Part of this study was presented at the EMCELL-76 meeting, Copenhagen, 1976     

A fully coupled transient excited state model for the sodium channel

Summary The axon membrane is simulated by standard Hodgkin-Huxley leakage and potassium channels plus a coupled transient excited state kinetic scheme for the sodium channel. This scheme for the sodium channel is as proposed previously by the author. Simultations are presented showing the form of the action potential, threshold behavior, accommodation, and repetitive firing. It is seen that the form of the individual action potential, its all-or-none nature, and its refractory period are well simulated by this model, as they are by the standard Hodgkin-Huxley model. However, the model differs markedly from the Hodgkin-Huxley model with respect to repetitive firing and accommodation to stimulating currents of slowly rising intensity, in ways that are anomn to be related to those features of the sodium inactivation which are anomalous to the H-H model. The tendency for repetitive firing is highly dependent on that parameter which primarily determintes the existence of the inactivation shift in voltage clamp experiments, in such a way that the more pronounced the inactivation shift, the less the tendency for repetitive firing,. The tendency for accommodation is highly dependent on that parameter which primarily determines the “τ_c − τ_h” separation, in such a way that the greater the separation the greater the tendency for the membrane to accommodate without firing action potentials to a slowly rising current.     

Lateral enzyme topology in the rough endoplasmic reticulum of rat liver

Summary Rough microsomes were subfractionated on the basis of different properties in order to investigate the nature and extent of the enzyme heterogeneity of these vesicles. A discontinuous gradient, containing monovalent cations allowed the separation of a ribosome-poor membrane fraction which was enriched in electron transport enzymes and relatively poor in phosphatases. Zonal centrifugation on a stabilizing gradient separated 3 fractions characterized by enrichment of electron transport enzymes, glucose-6-phosphatase and adenosinetriphosphatase, respectively. An essentially similar pattern was seen when ribosomes were removed with EDTA and the denuded vesicles subfractionated on a sucrose gradient. Rough microsomes from phenobarbitaltreated rats exhibited the same pattern both qualitatively and quantitatively. It appears that electron transport enzymes and two types of phosphatases are heterogeneously distributed among rough microsomal vesicles.This work has been supported by grants from the Swedish Medical Research Council. The authors wish to thank Mrs. Ulla-Britta Torndal for her valuable technical assistance