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1.
Andrea Streng Hans G. Wallraff 《Ethology : formerly Zeitschrift fur Tierpsychologie》1992,91(3):203-219
The role of familiar visual landmarks in pigeon homing is still unsettled. If they are involved, they must be thought to be utilized in parallel with olfactory signals. In order to recognize the effectiveness of either one of the input channels separately, vision and olfaction, it is therefore necessary to interfere with both of them. Pigeons were temporarily deprived of image vision by spectacles made of translucent white paper, producing a condition called V- as compared with the largely unimpaired condition V+. Access to olfactory signals was temporarily prohibited by charcoal filters before release and nasal anaesthesia upon release, resulting in condition O- versus unimpaired smelling of natural air in O+. Prior to the test releases, all the participating pigeons had been made familiar with the two or four test sites (and with other sites in the area) by training flights. According to decreasing levels of initial homeward orientation and homing performance, the four combinations of treatments are to be arranged in the following order: V+O+, V+O-, V-O+, V-O-. In the last type, no trace of initial homeward orientation remained, indicating that at least one of the two input channels need be functional to enable home-related orientation. Over well known terrain, either alone seems to be more or less sufficient. The results are indicative but not definitely conclusive. Effects of visual impairment on behavioural activities in general cannot clearly be separated from orientation-specific effects. Therefore, and because many pigeons refuse to fly in V- condition or fail to provide useful data, we stopped applying this method. 相似文献
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Inês Chaves Bram van der Eerden Ruben Boers Joachim Boers Astrid A. Streng Yanto Ridwan 《Chronobiology international》2019,36(5):657-671
Circadian rhythm disturbance (CRD) increases the risk of disease, e.g. metabolic syndrome, cardiovascular disease, and cancer. In the present study, we investigated later life adverse health effects triggered by repeated jet lag during gestation. Pregnant mice were subjected to a regular light-dark cycle (CTRL) or to a repeated delay (DEL) or advance (ADV) jet lag protocol. Both DEL and ADV offspring showed reduced weight gain. ADV offspring had an increased circadian period, and an altered response to a jet lag was observed in both DEL and ADV offspring. Analysis of the bones of adult male ADV offspring revealed reduced cortical bone mass and strength. Strikingly, analysis of the heart identified structural abnormalities and impaired heart function. Finally, DNA methylation analysis revealed hypermethylation of miR17-92 cluster and differential methylation within circadian clock genes, which correlated with altered gene expression. We show that developmental CRD affects the circadian system and predisposes to non-communicable disease in adult life. 相似文献
3.
von Kries R Weiss S Falkenhorst G Wirth S Kaiser P Huppertz HI Tenenbaum T Schroten H Streng A Liese J Shai S Niehues T Girschick H Kuscher E Sauerbrey A Peters J Wirsing von König CH Rückinger S Hampl W Michel D Mertens T 《PloS one》2011,6(9):e23955
Background
We determined antibodies to the pandemic influenza A (H1N1) 2009 virus in children to assess: the incidence of (H1N1) 2009 infections in the 2009/2010 season in Germany, the proportion of subclinical infections and to compare titers in vaccinated and infected children.Methodology/Principal Findings
Eight pediatric hospitals distributed over Germany prospectively provided sera from in- or outpatients aged 1 to 17 years from April 1st to July 31st 2010. Vaccination history, recall of infections and sociodemographic factors were ascertained. Antibody titers were measured with a sensitive and specific in-house hemagglutination inhibition test (HIT) and compared to age-matched sera collected during 6 months before the onset of the pandemic in Germany. We analyzed 1420 post-pandemic and 300 pre-pandemic sera. Among unvaccinated children aged 1–4 and 5–17 years the prevalence of HI titers (≥1∶10) was 27.1% (95% CI: 23.5–31.3) and 53.5% (95% CI: 50.9–56.2) compared to 1.7% and 5.5%, respectively, for pre-pandemic sera, accounting for a serologically determined incidence of influenza A (H1N1) 2009 during the season 2009/2010 of 25,4% (95% CI : 19.3–30.5) in children aged 1–4 years and 48.0% (95% CI: 42.6–52.0) in 5–17 year old children. Of children with HI titers ≥1∶10, 25.5% (95% CI: 22.5–28.8) reported no history of any infectious disease since June 2009. Among vaccinated children, 92% (95%-CI: 87.0–96.6) of the 5–17 year old but only 47.8% (95%-CI: 33.5–66.5) of the 1–4 year old children exhibited HI titers against influenza A virus (H1N1) 2009.Conclusion
Serologically determined incidence of influenza A (H1N1) 2009 infections in children indicates high infection rates with older children (5–17 years) infected twice as often as younger children. In about a quarter of the children with HI titers after the season 2009/2010 subclinical infections must be assumed. Low HI titers in young children after vaccination with the AS03B-adjuvanted split virion vaccine need further scrutiny. 相似文献4.
Zhenzhong Yu Christian Streng Ramon F. Seibeld Olumuyiwa A. Igbalajobi Kai Leister Julian Ingelfinger Reinhard Fischer 《PLoS genetics》2021,17(10)
Fungi sense light of different wavelengths using blue-, green-, and red-light photoreceptors. Blue light sensing requires the “white-collar” proteins with flavin as chromophore, and red light is sensed through phytochrome. Here we analyzed genome-wide gene expression changes caused by short-term, low-light intensity illumination with blue-, red- or far-red light in Aspergillus nidulans and found that more than 1100 genes were differentially regulated. The largest number of up- and downregulated genes depended on the phytochrome FphA and the attached HOG pathway. FphA and the white-collar orthologue LreA fulfill activating but also repressing functions under all light conditions and both appear to have roles in the dark. Additionally, we found about 100 genes, which are red-light induced in the absence of phytochrome, suggesting alternative red-light sensing systems. We also found blue-light induced genes in the absence of the blue-light receptor LreA. We present evidence that cryptochrome may be part of this regulatory cue, but that phytochrome is essential for the response. In addition to in vivo data showing that FphA is involved in blue-light sensing, we performed spectroscopy of purified phytochrome and show that it responds indeed to blue light. 相似文献
5.
Christian Streng Jana Hartmann Kai Leister Norbert Krauß Tilman Lamparter Nicole FrankenbergDinkel Franco Weth Martin Bastmeyer Zhenzhong Yu Reinhard Fischer 《The EMBO journal》2021,40(17)
Mitochondria are essential organelles because of their function in energy conservation. Here, we show an involvement of mitochondria in phytochrome‐dependent light sensing in fungi. Phytochrome photoreceptors are found in plants, bacteria, and fungi and contain a linear, heme‐derived tetrapyrrole as chromophore. Linearization of heme requires heme oxygenases (HOs) which reside inside chloroplasts in planta. Despite the poor degree of conservation of HOs, we identified two candidates in the fungus Alternaria alternata. Deletion of either one phenocopied phytochrome deletion. The two enzymes had a cooperative effect and physically interacted with phytochrome, suggesting metabolon formation. The metabolon was attached to the surface of mitochondria with a C‐terminal anchor (CTA) sequence in HoxA. The CTA was necessary and sufficient for mitochondrial targeting. The affinity of phytochrome apoprotein to HoxA was 57,000‐fold higher than the affinity of the holoprotein, suggesting a “kiss‐and‐go” mechanism for chromophore loading and a function of mitochondria as assembly platforms for functional phytochrome. Hence, two alternative approaches for chromophore biosynthesis and insertion into phytochrome evolved in plants and fungi. 相似文献
6.
Richard Streng 《Ethology : formerly Zeitschrift fur Tierpsychologie》1974,35(2):157-172
Zahlreiche Insektenlarven, die sich zur Verpuppung einen Gespinstkokon herstellen, führen beim Verspinnen des Fadens eine charakteristische Instinktbewegung aus, welche die Figur einer quer zum Körper liegenden “8” nachzeichnet. Diese Bewegungsfolge wird als Achtertour bezeichnet. Es wird darauf hingewiesen, daß es nicht gleichgültig ist, in welchem Umlaufsinn die Achtertour beim Spinnvorgang durchlaufen wird. Für die beiden je nach Umlaufsinn verschiedenen Formen der Achtertour werden die Begriffe ‘positiv’ und ‘negativ’ vorgeschlagen. Die Unterschiede zwischen positiver und negativer Achtertour werden mit Hilfe einer Großrechenanlage demonstriert. Die positive Tour führt zu mehr und zu gleichmäßigeren Maschen. Zum Verschließen einer Lücke oder eines Spaltes wird eine gleiche Fadenmenge mit der positiven Tour wirkungsvoller eingesetzt als mit der negativen. Die Ergebnisse weisen darauf hin, daß die positive Achtertour gegenüber der negativen von einem höheren selektiven Wert ist. 相似文献
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A new mobergellan genus and species,Tateltella ranoculata, is described from the early Middle Cambrian (Agdzian Stage) of Morocco. The new taxon is characterized by only four pairs
of muscle scars and is furthermore distinguished from other mobergellans by its strongly concave shape and its distally rising
muscle scars. The individual specimens ofTateltella ranoculata distinctly vary in size and display different ontogenetic stages. Juvenile, intermediate, and adult stages can be distinguished
by means of the development of the muscle scars that differ in Position relative to the apex, size, and distinctness between
individual stages. The shell ofT. ranoculata is composed of a succession of thin phosphatic lamellae separated by interlamellar gaps, presumably originally filled by
organic material. The interlamellar gaps may be divided by septum-like structures producing discrete cavities. The specimens
are the youngest mobergellans known so far and correlation of their stratigraphic position suggests a correspondence with
the lower part of the Amgan stage of the Siberian Platform. In addition, they are the first reported mobergellans from the
present day continent Africa. Other mobergellan taxa and mobergellan-like species are briefly reviewed and the genusHippoklosma
Missarzhevsky, previously assigned to the Mobergellidae, is excluded from the family due to its different shell structure. An evolutionary
trend of reduction in the number of muscle scars from 14 in the early Early Cambrian to only eight in the early Middle Cambrian
is apparent among mobergellans.
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