Retinal FABP principally localizes to neurons and not to glial cells

The presence of fatty acid-binding protein (FABP) in the embryonic chick retina may be linked to the demand for polyunsaturated fatty acids in this developing neural tissue. There is a decline in the overall level of FABP as the retina matures, suggesting a role for FABP in cellular differentiation. However, this pattern is not present in the chick brain, indicating a unique function for FABP in the retina. Immunohistochemical staining of paraffin sections of chick retina from embryonic day 21 revealed immunopositive photoreceptor inner segments, outer nuclear layer, radial processes in the inner nuclear layer, a subpopulation of cells in the ganglion cell layer, and inner limiting membrane. This pattern suggested that FABP positive cells were photoreceptors, Müller (glial) cells, and possibly ganglion cells. Staining of sections for glutamine synthetase, an enzyme specific for Müller cells, was similar but not identical to the pattern observed with FABP; thus identification of these cells as FABP-positive was not conclusive. However, in retinal cells dissociated from day E14 embryos and cultured for one week, staining with FABP was more intense in the neurons than in the flat cells (presumed to be derived from the Müller cells). Retinal FABP thus appears to be localized predominantly in neurons, and may serve to sequester fatty acids in preparation for neurite outgrowth as the retinal cells differentiate.Abbreviations FABP Fatty Acid-Binding Protein - PUFA Polyunsaturated Fatty Acid     

Is haemoglobin Gα Philadelphia linked to α-thalassaemia?

Summary The question, Is Hb G Philadelphia linked to -thalassaemia? was first posed because the abnormal haemoglobin is found in heterozygotes at a concentration greater than 25%, the proportion predicted from a 4 -chain gene model. Globin chain biosynthesis was studied in a West Indian family in which one parent had ⁺ thalassaemia and the other was heterozygous for the G Philadelphia chain gene. The former had a globin chain production ratio / well above 1, while the latter had a ratio significantly less than 1. One child of the marriage had inherited the ⁺ thallassaemia from one parent and the G Philadelphia chain gene from the other and showed the typical picture of /-thalassaemia (/ ratio slightly above normal). It is explained in the discussion that the evidence favours a close linkage of 2 -chain genes.     

Circadian rhythms of corneal mitotic rate,retinal melatonin and immunoreactive visual pigments,and the effects of melatonin on the rhythms in the Japanese quail

We investigated circadian ocular rhythms in the Japanese quail, Coturnix coturnix japonica. The birds were placed under light-dark cycles (LD 1212), constant light (LL) and constant darkness (DD), and the retinas were dissected out at four-hour intervals throughout 24 h. Following measurements were performed. (1) Melatonin content in the retina was measured by radioimmunoassay. It was low in light and several folds higher in darkness under LD 1212. The rhythm continued in DD, but disappeared in LL. (2) Mitotic figures in the corneal epithelium were counted. Similar rhythms to the melatonin content were observed in the corneal mitotic rate with a slight phase delay. (3) The retinas were fixed at 4-h intervals and immunostained with anti-bovine rhodopsin serum and anti-chicken iodopsin monoclonal antibodies. The outer segments of photoreceptor cells were stained intensively throughout 24 h in LD 1212, LL and DD. In contrast, the stainability of the locus close to the outer limiting membrane where the Golgi apparatus exists changed diurnally. Scores showing the ratio of cells with positive staining indicated high values from 4 h after the onset of light to the beginning of dark phase under LD 1212. The values were high throughout 24 h in LL and intermediate or low in DD. (4) To investigate the effect of melatonin on the corneal mitotic rate and visual pigments at the Golgi region, melatonin was injected into one eye and saline into the contralateral eye. Melatonin induced a phase advance in the corneal mitotic rate under LD 1212, but did not induce a rhythm under LL. The ratio of photoreceptor cells with positive staining to anti-visual pigment antibodies at the Golgi region was not affected by melatonin injection.Abbreviations ANOVA analysis of variance - BSA bovine serum albumin - DD constant darkness - Io-mAb monoclonal antibodies against chicken iodospin - LD light-dark - LL constant light - mRNA messenger ribonucleic acid - PBS phosphate buffer solution - Rh-As antiserum against bovine rhodopsin - SCN suprachiasmatic nucleus - T transducin - T transducin      

The reliability of parasitic water-mites (Hydracarina) as indicators of physiological age in mosquitoes (Diptera: Culicidae)

The reliability of parasitic water-mites as criteria of a nulliparous condition has been investigated in ten species of mosquito in Uganda. Larvae of two kinds of hygrobatid-type mites, when alive, were found only on nulliparous mosquitoes; but living larvae of two other hygrobatids occurred on a small proportion of pars also. Larvae of thyasid-type mites occurred at least as often on pars as on nullipars. Different types of scars caused by mites can provide information concerning the original infestation rate of a population and also the likelihood that an individual female is parous.In the species of mosquito studied, the infestation rate of nullipars sometimes exceeded 80%, but was usually less than 20%.

---

Zusammenfassung An 10 Mückenarten von Uganda wurde untersucht, inwieweit schmarotzende Wassermilben zuverlässig sind zur Unterscheidung alter Mücken (d.h. solcher, die Eier gelegt haben) von jungen Mücken (d.h. solchen, die noch keine Eier gelegt haben). Untersuchung der Ovarien ermöglichte es, weibliche Mücken in alte und junge Individuen einzuteilen. Zu diesem Zweck wurden mehr als 20.000 Mücken seziert.Der Lebenszyklus der an Mücken schmarotzenden Wassermilben wird besprochen. Die Larven zweier Arten von hygrobatischen Wassermilben wurden lebend nur an jungen Mücken gefunden; lebende Larven von zwei anderen hygrobatischen Milbenarten kamen auch an einem kleinen Teil von alten Mücken vor. Larven von thyasischen Milben wurden mindestens ebenso oft an alten wie an jungen Mücken gefunden. Deshalb war es wichtig, den Milbentypus festzustellen und zu erkennen, ob die Milben lebendig oder tot waren.Die Infektion der Mücken durch fünf der gewöhnlichen Wassermilben-Species wird beschrieben. Es hängt von der Milben- und von der Wirts-Art ab, welche Stelle die Milben zum Anheften wählen. Verschiedene Typen der durch die Milben verursachten Narben informieren über die ursprüngliche Befallsrate einer Bevölkerung und auch über die Wahrscheinlichkeit, dass die Mücke alt ist. Die Stärke der Infektion ändert sich bei einer einzigen Mückenart von Monat zu Monat beträchtlich. Manchmal sind über 80% der jungen Mücken befallen, im allgemeinen aber weniger als 20%.Bei Culex annulioris, bei dem die hygrobatischen Larven sich auf die jungen Mücken beschränken, ist der Stechzyklus eines befallenen Weibchens derselbe wie dem aller jungen Weibchen. Deshalb kann der Stechzyklus der jungen Mücken, nicht aber der der alten, direkt von den untersuchten milbentragenden Weibchen abgeleitet werden.Es wird gefolgert, dass bestimmte Wassermilben des hygrobatischen Typus für eine schnelle Diagnose von jungen Mücken nützlich sind; vorher muss jedoch in ausgedehnten Versuchen der Grad ihrer Zuverlässigkeit für jede Wirtsart festgelegt werden.

     

Improved rate of callus induction from rice anther culture following microscopic staging of microspores in iron alum-haematoxylin

Summary High frequencies of callusing were obtained in indica rice from the microspores which were staged in acetic acid iron alum-haematoxylin stain prior to culture on G5 medium. Two local varieties, Khonorullo and Namyi, and two advance pre-release cultures, PK 1-1-3 and PK 12-22, were used in this investigation. All the cultures exhibited a wide adaptation to varying medium; however, the frequency of callusing was highest (45.5%) in PK 1-1-3 followed by PK 12-22 (32.4%) and Khonorullo (31.6%). Cold shock (10 °C) for 11 days enhanced the frequency of callusing by 200% in Khonorullo.     

Die Aktivit?tsperiodik bei V?geln mit und ohne dunklem Schlafkasten

Zusammenfassung In 2 Versuchsserien wurden Kohlmeisen(Parus major) und japanische Möwchen(Lonchura striata var.domestica) einzeln und schallisoliert gehalten. In der ersten Versuchsserie, in der alle Vögel einen dunklen Schlafkasten hatten, wurde der Einfluß der Beleuchtungsstärke auf die Periode () der Hüpfaktivität und auf das Verhältnis von Aktivitätszeit zu Ruhezeit ( : -Verhältnis) untersucht. Sowhol Kohlmeisen als auch japanische Möwchen folgen der Regel, daß mit wachsender Beleuchtungsstärke die Periode kürzer und das : -Verhältnis größer wird.In der 2. Serie wurde der Einfluß Ruhe im dunklen Schlafkasten auf die Periodenlänge und auf das : -Verhältnis untersucht. Es wurden die Messungen aus Bedingung 1 (der Vogel hat einen dunklen Schlafkasten zur Verfügung) mit den Messungen aus Bedingung 2 (der Vogel hat keinen oder einen hellen Schlafkasten zur Verfügung) verglichen. Das Ergebnis bei Kohlmeisen entspricht den Befunden bei konstantem Licht verschiedener Intensität. Unter Bedingung 1 ist länger und das : -Verhältnis kleiner als in Bedingung 2. Das Ausmaß der Änderung von nach Fortnahme des dunklen Kastens ist unabhängig von der Periodenlänge in Bedingung 1. Das Ausmaß der änderung von : ist unabhängig von a : in Bedingung 1, jedoch schwach negativ korreliert mit der Periodenlänge in Bedingung 1.Bei japanischen Möwchen entsprechen die Ergebnisse dieser Versuchsserie nicht der Regel für tagaktive Vögel. Mit Benützen des dunklen Schlafkastens ist kürzer als ohne den Schlafkasten. Ohne den Schlafkasten ist etwa 24 Std. Das : -Verhältnis ist in Bedingung 1 unter bestimmten Voraussetzungen kleiner als in Bedingung 2. Das Ausmaß der Änderung von nach Fortnahme des Kastens ist mit der dazugehörigen Periode in Bedingung 1 hochsignifikant korreliert (Regressionskoeffizient b=-1.01, Korrelationskoeffizient r=0.89). Ebenfalls ist das Ausmaß der Änderung von : nach Fortnahme des Kastens mit : aus Bedingung 1 korreliert; es scheint, als würde ein bevorzugtes : -Verhältnis von etwa 2.0 eingeregelt.Die Ergebnisse werden im Hinblick auf 4 Punkte diskutiert: 1) Das circadiane System arbeitet innerhalb eines engen Bereiches von - und : -Werten optimal. 2) Der Optimalbereich wird bevorzugt unter ungünstigen Bedingungen angestrebt. 3) Der Entzug des dunklen Schlafkastens belastet japanische Möwchen mehr als Kohlmeisen. 4) Bei japanischen Möwchen wird in Bedingung 1 durch fortplfanzungsphysiologischen Einfluß verkürzt.

---

Circadian activity rhythms of birds with and without a dark nest box

Summary Perch-hopping activity of Great tits(Parus major) and Bengales finches(Lonchura striata domestica), housed individually in soundproof boxes, was studied in two series of experiments. In the first series all birds had access to a dark nest box, in which they retired during their subjective night. In this experiment the effect of light intensity on the freerunning circadian activity rhythm was investigated. Both Great tits and Bengalese finches obey the circadian rule by responding to an increase in light intensity with shortening the circadian period () and with an increase of the ratio of activity time and rest time ( : ).In the second series of experiments the influence of sleeping in the dark nest box on both circadian period and : -ratio was studied. The results of two experimental conditions — without and with access to a dark nest box — were compared. In the Great tits, the results are in agreement with the effect of light intensity: when a dark nestbox is available, is longer and the : -ratio is smaller than in the absence of a nest box. The magnitude of the change in free-running period after removal of the nest box is independent of the original value of ; the amount of change : -ratio is likewise independent of the original : -ratio, but is weakly correlated to the original .InLonchura striata var. domestica, removal of the dark nest box leads to a lenghtening of the free-running period to about 24 hours; the : -ratio is smaller in the presence of a dark nestbox, if certain other conditions are fulfilled. The magnitude of the change in after removal of the nest box is highly correlated to the original free-running period (r=-0.89) in such a way that, without nest box, the period approaches a value of 24 hours. Also, the amount of change in : -ratio due to nest box removal is negatively correlated to the original : -ratio. A probably preferred : -ratio of 2.0 is adopted.These results are discussed in the view of 4 points: 1) The circadian system operates at its optimum within a narrow range of - and : -values. 2) This optimal range is especially adopted when conditions become adverse. 3) Removal of the dark nest box results in a more stressful situation for Bengalese finches than for Great tits. 4) In the Bengalese finches, is shortened in the presence of a nest box due to effects on reproductive physiology.

---

---

Herrn Prof. Dr. JürgenAschoff zum 60. Geburtstag gewidemt.     

One-pot enzymatic synthesis of the Galα1→3Galβ1→4GlcNAc sequence within situ UDP-Gal regeneration

The trisaccharide Gal13Gal14GlcNAc1O-(CH₂)₈COOCH₃ was enzymatically synthesized, within situ UDP-Gal regeneration. By combination in one pot of only four enzymes, namely, sucrose synthase, UDP-Glc 4-epimerase, UDP-Gal:GlcNAc 4-galactosyltransferase and UDP-Gal:Gal14GlcNAc 3-galactosyltransferase, Gal13Gal14GlcNAc1O-(CH₂)₈COOCH₃ was formed in a 2.2 µmol ml^–1 yield starting from the acceptor GlcNAc1O-(CH₂)₈COOCH₃. This is an efficient and convenient method for the synthesis of the Gal13Gal14GlcNAc epitope which plays an important role in various biological and immunological processes.     

Über den Einfluß von Gibberellinsäure auf Blüten-und Doldenbildung beim Hopfen (Humulus lupulus L.)

Zusammenfassung Die Behandlung der drei Hopfensorten Saazer, Hüller Anfang und Hallertauer mit Gibberellinsäure ergab eine Verminderung des 1000-Doldengewichtes, aber eine Zunahme der Dolden je Pflanze.Beim Hüller Anfang und beim Hallertauer nahm der Gehalt an Alpha-Säuren durch die Behandlung ab; bei der Saazer Sorte blieb er gleich bis auf die Dosierung 10 ppm, 2 x, wodurch eine Erhöhung eintrat.Bei der Handbonitierung der Dolden ergab sich eine Wertminderung besonders hinsichtlich Zapfenwuchs, Lupulingehalt und Feinheit des Aromas, wozu beim Hüller Anfang noch eine starke Doldenverlaubung hinzukommt.Die Entwicklungsdauer der ganzen Pflanze wird unter dem Einfluß von Gibberellinsäure in die Länge gezogen, so daß die Doldenreife verzögert wird. Aus frühen und mittelfrühen werden dadurch mittelfrühe bzw. späte Hopfensorten.Die weibliche Blüte wird in ihrer Ausbildung teilweise gehemmt; im Extremfall führt dies zu einer Unterdrückung aller Blütenorgane mit der Tendenz zur Rückführung des Blütenstandes in den ursprünglichen beblätterten Laubsproß. Die Kreuzungssorte Hüller Anfang reagierte außerdem mit der Bildung monözischer Blütenstände. Die Entstehung der Monözie wird diskutiert.Die unterschiedlichen Reaktionen auf die Gibberellinsäurebehandlung bei den einzelnen Sorten sind auf die verschiedenen Entwicklungszustände zum Zeitpunkt der Behandlung zurückzuführen.

---

The influence of gibberellic acid on the flower and cone development in hop (Humulus lupulus L.)

Summary The treatment of the three hop-varieties Saazer, Hüller Anfang and Hallertauer with gibberellic acid caused a decrease of the 1000-cone weight, but an increase in cones of each plant.With Hüller Anfang and Hallertauer there was a decrease in -acid content, in the Saazer variety it remained equal, only when it was treated by the dosage 10 ppm, times two, an icrease in -acid content resulted.The organoleptic valuation of the cones showed a decrease in quality especially in respect to cone size, Jupulin content and delicacy of aroma. In the Huller Anfang variety a high percentage of cock hops resulted also.Under the influence of gibberellic acid the development of the hop plant is prolonged, so that the ripening of cones is retarded. Early and middle-early varieties thus become middle-early and late varieties.The female flower is somewhat retarded in development; in the extreme case this leeds to complete suppression of all flower parts and a tendency to reduce the female inflorescence to the original leaf shoot. Moreover, the hybrid variety Hüller Anfang formed monoecious plants. The origin of monoecious plants is discussed.The different reactions to treatment with gibberellic acid of the several varieties are caused by the differing stages of plant development at the time of treatment.

     

Immunocytochemical study by two photon fluorescence microscopy of the distribution of GABA<Subscript>A</Subscript> receptor subunits in rat cerebellar granule cells in culture

Summary. An immunocytochemical investigation of the expression of ₁, ₆, _2/3, ₂ and subunits was performed on rat cerebellum granule cells in culture by the two photon microscopy technique.The first four subunits appear to be expressed abundantly in these cells, whereas the one seems to be expressed at a lower level. Another major difference in the distribution of these subunits is that whereas ₆, _2/3 and ₂ appear only on plasma membranes ₁ and are present mainly in the cell bodies cytoplasm. Still another difference was found in that the presence of ₂ on neurites is polarized, preferentially labelling neurites with the appearance of dendrites. The subunits ₆ and _2/3 appear to label all types of neurites, with _2/3 being by far the most heavily expressed subunit type. A final distinct characteristic is that ₆ and, even more, ₂ appear to accumulate in the cytoplasmic domains immediately below the cone of emergence of neurites. This suggests a conspicuous transport of such subunits from the site of synthesis in the cell body to the site of final expression in the neurites (dendrites and axon terminals).     

What Limits the Number of Tītī (Puffinus griseus) Harvested by Rakiura Māori?

Mori continue a centuries old harvest of tt chicks (sooty shearwater, Puffinus griseus) on islands adjacent to Rakiura (Stewart Island). This study measured time limits on the number of Tttaken each day from Putauhinu Island. In the first period of the harvest (nanao) the chicks are extracted from the breeding burrows during daytime. In the second period of harvest (rama) the chicks are caught at night after they have emerged from their nesting burrows. Capture rate is much higher during the rama than the nanao. More time is spent processing (plucking, cutting-up, gutting, and packing) chicks during rama than the nanao because of a 1.3–1.7 increase in the number of chicks caught. Recently introduced motorized plucking machines decrease the time required to pluck each chick and make plucking less physically demanding and less painful. However, motorized pluckers did not increase the number of chicks harvested on Putauhinu. Other social limits may control harvest intensity and influence sustainability of muttonbirding.     

Ornithine decarboxylase prevents tumor necrosis factor alpha-induced apoptosis by decreasing intracellular reactive oxygen species

Ornithine decarboxylase (ODC) plays an essential role in various biological functions, including cell proliferation, differentiation and cell death. However, how it prevents the cell apoptotic mechanism is still unclear. Previous studies have demonstrated that decreasing the activity of ODC by difluoromethylornithine (DFMO), an irreversible inhibitor of ODC, causes the accumulation of intracellular reactive oxygen species (ROS) and cell arrest, thus inducing cell death. These findings might indicate how ODC exerts anti-oxidative and anti-apoptotic effects. In our study, tumor necrosis factor alpha (TNF-) induced apoptosis in HL-60 and Jurkat T cells. The kinetic studies revealed that the TNF- -induced apoptotic process included intracellular ROS generation (as early as 1 h after treatment), the activation of caspase 8 (3 h), the cleavage of Bid (3 h) and the disruption of mitochondrial membrane potential ( _m) (6 h). Furthermore, ROS scavengers, such as glutathione (GSH) and catalase, maintained _m and prevented apoptosis upon treatment. Putrescine and overexpression of ODC had similar effects as ROS scavengers in decreasing intracellular ROS and preventing the disruption of _m and apoptosis. Inhibition of ODC by DFMO in HL-60 cells only could increase ROS generation, but did not disrupt _m or induce apoptosis. However, DFMO enhanced the accumulation of ROS, disruption of _m and apoptosis when cells were treated with TNF- . ODC overexpression avoided the decline of Bcl-2, prevented cytochrome c release from mitochondria and inhibited the activation of caspase 8, 9 and 3. Overexpression of Bcl-2 maintained _m and prevented apoptosis, but could not reduce ROS until four hours after TNF- treatment. According to these data, we suggest that TNF- induces apoptosis mainly by a ROS-dependent, mitochondria-mediated pathway. Furthermore, ODC prevents TNF- -induced apoptosis by decreasing intracellular ROS to avoid Bcl-2 decline, maintain _m, prevent cytochrome c release and deactivate the caspase cascade pathway.     

Das Fettsäurespektrum des Flußkrebses Orconectes limosus und seine Beeinflussung durch die Nahrung

Zusammenfassung Das Fettsäurespektrum von männlichen Flußkrebsen Orconectes limosus wurde gaschromatographisch analysiert. Die Fettsäuren zeigen eine spezifische Verteilung auf die Lipidklassen. Das Gesamtspektrum entspricht dem Schema eines Süßwassertieres im Winter mit den größten Fraktionen: C160, C181, C202 und C204 (zusammen rund 53% der Gesamtfettsäuren). In verschiedenen Fraktionen wurden ungeradzahlige und verzweigte Fettsäuren gefunden.Durch Verfüttern von Kartoffeln und Lebertran kann das Spektrum beeinflußt werden. Die Fettsäuren in der Mitteldarmdrüse, und in weniger starkem Ausmaß im Restkörper, haben sich nach viermonatiger Fütterung mit Lebertran qualitativ und quantitativ dessen Spektrum angepaßt. Nach siebenmonatiger Fütterung mit Kartoffeln zeigen Mitteldarmdrüse und Restkörper ein Spektrum, das dem eines unbehandelten Kontrollkrebses ähnelt und sowohl C182 als auch höher ungesättigte Fettsäuren enthält. Hierfür kommen zwei Deutungen in Frage: Entweder wird das Spektrum der Fettsäuren in Strukturlipiden aufrechterhalten, oder es erfolgt de novo Synthese einer C18:2^6,9-Fettsäure und deren Verlängerung analog dem von Wirbeltieren bekannten Weg.

---

The fatty acid composition in the crayfish, orconectes limosus, and the effect of nutrition

Summary The fatty acid composition in the male crayfish, Orconectes limosus, was analysed by gas-liquid chromatography. The fatty acids were found to have a specific distribution in different lipid classes. The composition corresponds to those of a fresh water animal in winter with the most important acids: C160, C181, C202, C204 (including about 53% of the total acids). In several lipid classes oddnumbered and branched chain fatty acids could be detected.Potatoe and fish-liver oil diets influence the fatty acid composition. After four months feeding with fish-liver oil the fatty acids in the hepatopancreas and to a lesser extent in the rest body show a similar spectrum as the fed oil. After feeding for seven months with potatoes hepatopancreas and rest body exhibit a fatty acid composition representative for the untreated animal, which contains C182 as well as higher unsaturated acids. These findings support the hypotheses that either the fatty acid composition in the structure lipids was maintained or that a C182^6,9-fatty acid was de novo synthesized and elongated analogous to the known vertebrate pathway.

---

---

Herrn Prof. Dr. K. Urich bin ich für die Anregung zu der vorliegenden Arbeit und für die Durchsicht des Manuskriptes zu großem Dank verpflichtet.     

Differential expression of α-amylase genes in germinating rice and barley seeds

Steady-state levels of mRNA from individual -amylase genes were measured in the embryo and aleurone tissues of rice (Oryza sativa) and two varieties of barley (Hordeum vulgare L. cv. Himalaya and cv. Klages) during germination. Each member of the -amylase multigene families of rice and barley was differentially expressed in each tissue. In rice, -amylase genes displayed tissue-specific expression in which genes RAmy3B, RAmy3C, and RAmy3E were preferentially expressed in the aleurone layer, genes RAmy1A, RAmy1B and RAmy3D were expressed in both the embryo and aleurone, and genes RAmy3A and RAmy2A were not expressed in either tissue. Whenver two or more genes were expressed in any tissue, the rate of mRNA accumulation from each gene was unique. In contrast to rice, barley -amylase gene expression was not tissue-specific. Messenger RNAs encoding low- and high-pI -amylase isozymes were detectable in both the embryo and aleurone and accumulated at different rates in each tissue. In particular, peak levels of mRNA encoding high-pI -amylases always preceded those encoding low-pI -amylases. Two distinct differences in -amylase gene expression were observed between the two barley varieties. levels of high-pI -amylase mRNA peaked two days earlier in Klages embryos than in Himalaya embryos. Throughout six days of germination, Klages produced three times as much high-pI -amylase mRNA and nearly four times as much low-pI -amylase mRNA than the slower-germinating Himalaya variety.     

Application of H(N)CA,CO-E.COSY experiments for calibrating the φ angular dependences of vicinal couplings J(C′i−1,Hi α), J(C′i−1,Ci β) and J(C′i−1,C′i) in proteins

A triple-resonance NMR technique suitable for the determination ofcarbonyl-related couplings in polypeptide systems is introduced. Theapplication of three novel pulse sequences to uniformly¹³C/¹⁵N-enriched proteins yields E.COSY-likemultiplet patterns exhibiting either one of the³J(C_i–1,H_i ), ³J(C_i–1,C_i ) and³J(C_i–1,C_i)coupling constants in the indirectly detected ¹³Cdimension, depending on the passive spin selected. The experiments aredemonstrated with oxidized flavodoxin from Desulfovibrio vulgaris. On thebasis of the J-values measured and the backbone -angles derived from ahigh-resolution X-ray structure of the protein, the three associated Karplusequations were reparametrized. The root-mean-square differences between theexperimental coupling constants and those predicted by the optimized Karpluscurves are 0.41, 0.33 and 0.32 Hz for³J(C_i–1,H_i ),³J(C_i–1,C_i ) and³J(C_i–1,C_i),respectively. The results are compared with the Karplus parameters previouslypublished for the same couplings.     

Temporal shifts in visual pigment absorbance in the retina of Pacific salmon

The visual pigments and photoreceptor types in the retinas of three species of Pacific salmon (coho, chum, and chinook) were examined using microspectrophotometry and histological sections for light microscopy. All three species had four cone visual pigments with maximum absorbance in the UV (_max: 357–382 nm), blue (_max: 431–446 nm), green (_max: 490–553 nm) and red (_max: 548–607 nm) parts of the spectrum, and a rod visual pigment with _max: 504–531 nm. The youngest fish (yolk-sac alevins) did not have blue visual pigment, but only UV pigment in the single cones. Older juveniles (smolts) had predominantly single cones with blue visual pigment. Coho and chinook smolts (>1 year old) switched from a vitamin A₁- to a vitamin A₂-dominated retina during the spring, while the retina of chum smolts and that of the younger alevin-to-parr coho did not. Adult spawners caught during the Fall had vitamin A₂-dominated retinas. The central retina of all species had three types of double cones (large, medium and small). The small double cones were situated toward the ventral retina and had lower red visual pigment _max than that of medium and large double cones, which were found more dorsally. Temperature affected visual pigment _max during smoltification.     

Molecular dynamics simulations of ribonuclease T1

Molecular dynamics simulations in vacuum and with a water sphere around the active site were performed on the 2GMP-RNase T1 complex. The presence of water led to the maintenance of the 2-GMP-RNase T1 interactions as compared to the X-ray structure, including the hydrogen bonds implicated in the enzyme-inhibitor recognition process. The sidechain of His92 in the molecular dynamics water simulation, however, hydrogen bonds directly to the phosphate of 2GMP in contrast to the X-ray structure but in support of the role of that residue in the enzyme's catalytic mechanism. Fluctuations of activesite residues are not strongly influenced by water, possibly owing to the exclusion of water by the bound 2GMP, which did show an increase in mobility. Analysis of the 2GMP-RNase T1 interactions versus time reveal an equilibrium fluctuation in the presence of water, leading to a less favorable 2GMP-RNase T1 interaction energy, suggesting a possible relationship between picosecond fluctuations and inhibitor dissociation occurring in the millisecond time domain.Abbreviations RNase T1 Ribonuclease T1 (EC.3.1.27.3) - 2GMP Guanosine-2-monophosphate - SBS Stochastic Bondary Simulation - VS Vacuum Simulation - MD Molecular Dynamics     

Kinetics of the reconstitution of hemoglobin from semihemoglobins α and β with heme

Kinetics of the reconstitution of hemoglobin from semihemoglobins and with hemin dicyanide have been investigated using three kinds of stopped-flow technique (Soret absorption, fluorescence quenching of tryptophan, and Soret CD). The semihemoglobins and are occupied by heme in the and chains, respectively, the other chain being heme-free. Based on the kinetic results, the following scheme for the reconstitution is proposed; First, hemin dicyanide enters the pocket-like site of the apo chains. Second, in semihemoglobin , the CN-ligand in the fifth coordination position of iron is replaced by the imidazole ring of the proximal His immediately after the heme insertion. In contrast, semihemoglobin changes its conformation after the heme insertion, and this is followed by the ligand replacement. Finally, the partial structure changes induced by the ligand replacement propagate onto the whole molecule and the final conformation is attained. The results indicate that semihemoglobin retains a more rigid and organized structure, and more closely approaches its final structure than does semihemoglobin . Correspondence to: Y. Kawamura-Konishi     

Liver and intestinal fatty acid binding proteins in control and TGFβ1 gene targeted deficient mice

The effect of transforming growth factor beta-1 (TGF1) expression on fatty acid binding proteins was examined in control and two strains of gene targeted TGF1-deficient mice. Homozygous TGF1-deficient 129 × CF-1, expressing multifocal inflammatory syndrome, had 25% less liver fatty acid binding protein (L-FABP) when compared to control mice. The decrease in L-FABP expression was not due to multifocal inflammatory syndrome since homozygous TGF1-deficient/immunodeficient C3H mice on a SLID background had 36% lower liver L-FABP than controls. This effect was developmentally related and specific to liver, but not the proximal intestine, where L-FABP is also expressed. Finally, the proximal intestine also expresses intestinal-FABP (1-FABP) which decreased 3-fold in the TGF1-deficient/immunodeficient C3H mice only. Thus, TGF1 appears to regulate the expression of L-FABP and I-FABP in the liver and the proximal intestine, respectively.Abbreviations L-FABP liver fatty acid binding protein - I-FABP intestinal fatty acid binding protein - TGF1 transforming growth factor beta-1 - TNF- tumor necrosis factor- - MIP- macrophage inflammatory protein- - PMSF phenylmethyl sulfonyl fluoride - PBS phosphate buffered saline     

Some observations on the visual optics of kingfishers (Aves,Coraciformes, Alcedinidae)

Summary We studied visual optics using ophthalmoscopy in six species of coraciform birds, five species from the family Alcedinidae (kingfishers) and one from the family Meropidae (bee-eaters). All six species had large angular separations between the two foveae of one eye (angle ); angle was greater than 40° in all cases, the largest separation so far reported for any group of vertebrates. In all kingfishers, but not in the bee-eater, the plane containing the projections of both foveae in one eye (angle ) was rotated from the horizontal plane so that the projection of the monocular fovea was lower than the projection of the binocular fovea.Retinal ganglion cell isodensity maps were obtained for the sacred kingfisher (Halcyon sancta) and laughing kookaburra (Dacelo gigas). These maps were constructed in the usual way for the peripheral regions of the retina. For the high-density, multi-layered, central region of the retinal ganglion cell layer, we used a combined retinal wholemount-cross-sectional technique. It was discovered that the horizontal streak, formed by the elliptically shaped contours of retinal ganglion cell isodensity, deviated inferiorly at its nasal extent from the line of the foveae. This deviation had the same sign, and slightly greater magnitude, as the rotation (angle ) observed ophthalmoscopically when the eyes were in their primary position.Our new observations provide new insights into the functional significance of the bifoveate visual organization. In particular, the relationship between angle and angle suggests one strategy which could be used by kingfishers to maximize their visual capabilities when hunting from a perch above the substrate.