Zum Feinbau des Komplexauges von Stylops spec. (Insecta,Strepsiptera)

Zusammenfassung Unter den Cornealinsen des Komplexauges von Stylops befindet sich ein Kristallkegel vom pseudoconen Typ, der von zahlreichen Pigmentzellen umhüllt wird. An seinem proximalen Ende liegen 6 meist pigmentfreie Zellen (Sempersche Zellen).Das Ommatidium besteht aus etwa 60 Retinulazellen. Ihre distal kranzartig miteinander verbundenen Mikrovillisäume bilden ein einziges offenes Rhabdom, das extrazelluläres (?) granuläres Material und die Basis der Semperschen Zellen umgibt. Stellenweise wird das Rhabdom samt granulärem Material von homogen erscheinenden distalen Ausläufern einzelner Retinulazellen überlagert. Proximad zerfällt das Rhabdom zunehmend in kleinere Rhabdomteile. Im zentralen Teil des Ommatidiums liegen 1–2 auffallend große Retinulazellen, die meist weniger elektronendicht erscheinen und kleinere Pigmentgrana haben.Die einzelnen Ommatidien werden von ungemein zahlreichen, sehr pigmentarmen Stützzellen umhüllt. Diese werden — wie die basalen Teile der Retinulazellen — teilweise durch Gliazellfortsätze isoliert.Bei Stylops, einem Vertreter der Strepsipteren, handelt es sich nicht um ocelläre Komplexaugen (Strohm, 1910), auch nicht um eucone Ommatidien (Kinzelbach, 1967), sondern um Ommatidien vom pseudoconen Typ. Zumindest der Bau des Rhabdoms ähnelt dem des Larvenauges (Stemma), dessen rezeptorischer Teil entgegen den Annahmen früherer Autoren in der Imago nicht reduziert wird.

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On the fine structure of the compound eye of Stylops spec. (Insecta, Strepsiptera)

Summary In the compound eye of Stylops a crystalline cone of the pseudocone type is found beneath the corneal lens. It is enveloped by several pigment cells. At the proximal part of the cone there are 6 cells (Semper cells) mostly pigment-free.The ommatidium consists of approximately 60 retinula cells. Their rhabdomeres distally rim-like connected to another form a single open rhabdom which encircles extracellular granular material as well as the bases of the Semper cells. Here and there the rhabdom plus granular material is overlain with distal protrusions of single retinula cells which appear to be homogeneous. Towards the proximal part the rhabdom increasingly divides up into smaller rhabdomal segments. One or two conspicuous large retinula cells were found in the central part of the ommatidium, appearing to be less electron-dense and containing pigment granules of a smaller size. Each ommatidium is surrounded by numerous cells (Stützzellen) lacking in pigment. These cells are partially insulated from another—as well as the basal parts of retinula cells—by protrusions of glia cells.Our investigations show that the eyes of Stylops (as a representative of Strepsiptera) are not of the ocellar complex eye type. At least the structure of the rhabdom resembles to that of the larval eye (stemma), the receptor part of which is not reduced in the imago.

Herrn Prof. Dr. Helmcke danke ich für die freundliche Unterstützung am Raster-Elektronenmikroskop.     

Eye specialisation in waterstriders: an adaptation to life in a flat world

The angular distribution of the optical axes of the ommatidia in the eyes of waterstriders (Gerris lacustris) has been investigated using antidromic illumination.

Role ofLLD, a new locus for leaflet/pinna morphogenesis inPisum sativum

Properties of a mutant at theLLD (LEAF-LET DEVELOPMENT) locus in peaPisum sativum L. are reported in this paper. Plants homozygous for the Mendelian recessive mutationlld bear leaves in which a few to many leaflets are incompletely developed. Opposite pinnae of rachis nodes often formed fused incompletely developed leaflets. Thelld mutation was observed to abort pinna development at almost all morphogenetic stages. Thelld mutation demonstrated high penetrance and low expressivity. The phenotypes oflld plants intl, tac, tl tac, tl af andtl af tac backgrounds suggested that LLD function is involved in the separation of lateral adjacent blastozones differentiated on primary, secondary and tertiary rachides and lamina development in leaflets. The aborted development of tendrils and leaflets inlld mutants was related to deficiency in vascular tissue growth. The morphological and anatomical features of the leaflets formed on atl lld double mutant permitted a model of basipetal leaflet development. The key steps of leaflet morphogenesis include origin of the lamina by splitting of a radially symmetrical growing pinna having abaxial outer surface, opposite to the vascular cylinder, through an invaginational groove, differentiation of adaxial surface along the outer boundary of split tissue in the groove and expansion of the lamina ridges so formed into lamina spans.     

Reactive Intermediates in Cytochrome P450 Catalysis

Recently, we reported the spectroscopic and kinetic characterizations of cytochrome P450 compound I in CYP119A1, effectively closing the catalytic cycle of cytochrome P450-mediated hydroxylations. In this minireview, we focus on the developments that made this breakthrough possible. We examine the importance of enzyme purification in the quest for reactive intermediates and report the preparation of compound I in a second P450 (P450_ST). In an effort to bring clarity to the field, we also examine the validity of controversial reports claiming the production of P450 compound I through the use of peroxynitrite and laser flash photolysis.     

Distribution of photoperiodic receptors in the compound eyes of the bean bug, Riptortus clavatus

  The bean bug, Riptortus clavatus shows a long-day photoperiodic response with respect to the control of adult diapause. The location of photoreceptors for photoperiodism was examined in this species by complete or partial removal of photoreceptor organs. Even after one compound eye or both ocelli were removed, the insects were sensitive to photoperiod. After both compound eyes were removed, however, the insects became reproductive regardless of the photoperiod. Therefore, photoreceptors for photoperiodism were not in the ocelli but in the compound eyes. To clarify whether ommatidia in compound eyes have a regional difference in reception of photoperiod, sensitivity to photoperiod was examined after one compound eye and a part of the contralateral one were removed. Only when the central region of compound eyes was removed did the insects lose sensitivity to photoperiod. It is concluded that the ommatidia in the central region of compound eyes play a principal role in the reception of photoperiod. Accepted: 23 September 1996     

复方苦参注射液联合伊班膦酸钠治疗非小细胞肺癌骨转移癌疼痛的临床观察

目的：探讨复方苦参注射液联合伊班膦酸钠治疗非小细胞肺癌骨转移癌疼痛的临床观察。方法：选取宜昌市中心人民医院2010年3月至2012年3月收治的非小细胞肺癌骨转移患者98例,根据其治疗方式的不同,分为对照组和治疗组。对照组患者采用伊班膦酸钠进行治疗,治疗组患者采用复方苦参注射液联合伊班膦酸钠进行治疗,比较2组患者的近期疗效、疼痛缓解、KPS评分改善情况。结果：患者近期疗效比较结果显示,治疗组患者部分缓解的例数（百分比）及总有效率要明显优于对照组,且差异有统计学意义（P＜0．05）。治疗组Karnofsky评分改善的例数（百分比）要明显多余对照组,且差异有统计学意义（P＜0．05）。疼痛缓解情况比较分析显示,治疗组患者完全缓解例（百分比）及总的缓解率要明显优于对照组,且差异有统计学意义（P＜0．05）。2组患者不良反应发生情况差异无统计学意义（P＞0．05）。结论：复方苦参注射液联合伊班膦酸钠对非小细胞肺癌骨转移癌疼痛具有明显的作用,能够有效的减轻患者的疼痛,值得在临床上推广应用。     

Oxoferryl-porphyrin radical catalytic intermediate in cytochrome bd oxidases protects cells from formation of reactive oxygen species

The quinol-linked cytochrome bd oxidases are terminal oxidases in respiration. These oxidases harbor a low spin heme b(558) that donates electrons to a binuclear heme b(595)/heme d center. The reaction with O(2) and subsequent catalytic steps of the Escherichia coli cytochrome bd-I oxidase were investigated by means of ultra-fast freeze-quench trapping followed by EPR and UV-visible spectroscopy. After the initial binding of O(2), the O-O bond is heterolytically cleaved to yield a kinetically competent heme d oxoferryl porphyrin π-cation radical intermediate (compound I) magnetically interacting with heme b(595). Compound I accumulates to 0.75-0.85 per enzyme in agreement with its much higher rate of formation (~20,000 s(-1)) compared with its rate of decay (~1,900 s(-1)). Compound I is next converted to a short lived heme d oxoferryl intermediate (compound II) in a phase kinetically matched to the oxidation of heme b(558) before completion of the reaction. The results indicate that cytochrome bd oxidases like the heme-copper oxidases break the O-O bond in a single four-electron transfer without a peroxide intermediate. However, in cytochrome bd oxidases, the fourth electron is donated by the porphyrin moiety rather than by a nearby amino acid. The production of reactive oxygen species by the cytochrome bd oxidase was below the detection level of 1 per 1000 turnovers. We propose that the two classes of terminal oxidases have mechanistically converged to enzymes in which the O-O bond is broken in a single four-electron transfer reaction to safeguard the cell from the formation of reactive oxygen species.     

Physiological characterization of the compound eye in monarch butterflies with focus on the dorsal rim area

The spectral, angular and polarization sensitivities of photoreceptors in the compound eye of the monarch butterfly (Danaus plexippus) are examined using electrophysiological methods. Intracellular recordings reveal a spectrally homogenous population of UV receptors with optical axes directed upwards and ≥10° to the contralateral side. Based on optical considerations and on the opsin expression pattern (Sauman et al. 2005), we conclude that these UV receptors belong to the anatomically specialized dorsal rim area (DRA) of the eye. Photoreceptors in the main retina with optical axes <10° contralateral or ipsilateral have maximal sensitivities in the UV (λ_max≤340 nm), the blue (λ_max=435 nm) or in the long-wave range (green, λ_max=540 nm). The polarization sensitivity (PS) of the UV receptors in the DRA is much higher (PS=9.4) than in the UV cells (PS=2.9) or green cells (PS=2.8) of the main retina. The physiological properties of the photoreceptors in the DRA and in the main retina fit closely with the anatomy and the opsin expression patterns described in these eye regions. The data are discussed in the light of present knowledge about polarized skylight navigation in Lepidopterans.