@article{SeitzRistowKlemmetal.2004, author = {Seitz, Birgit and Ristow, Michael and Klemm, Gunther and R{\"a}tzel, Stefan and Schulze, Gerhart and Hoffmann, Maik}, title = {Zur Verbreitung der Wildrosen und verwilderten Kulturrosen in Berlin und Brandenburg}, issn = {0724-3111 -}, year = {2004}, language = {de} } @article{RistowSeitz2002, author = {Ristow, Michael and Seitz, Birgit}, title = {Zur Kenntnis einiger {\"u}bersehener, wenig beachteter oder verkannter Sippen der Gattungen Vicia und Valerianella in Brandenburg}, year = {2002}, language = {de} } @article{RistowBurkartPrasse1997, author = {Ristow, Michael and Burkart, Michael and Prasse, R{\"u}diger}, title = {Zum Vorkommen der Bleichen Hainsimse, Luzula pallidula Kirschner (syn. L. pallescens auct.) in Brandenburg}, year = {1997}, language = {de} } @article{BergholzMayRistowetal.2017, author = {Bergholz, Kolja and May, Felix and Ristow, Michael and Giladi, Itamar and Ziv, Yaron and Jeltsch, Florian}, title = {Two Mediterranean annuals feature high within-population trait variability and respond differently to a precipitation gradient}, series = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie}, volume = {25}, journal = {Basic and applied ecology : Journal of the Gesellschaft f{\"u}r {\"O}kologie}, publisher = {Elsevier}, address = {Jena}, issn = {1439-1791}, doi = {10.1016/j.baae.2017.11.001}, pages = {48 -- 58}, year = {2017}, abstract = {Intraspecific trait variability plays an important role in species adaptation to climate change. However, it still remains unclear how plants in semi-arid environments respond to increasing aridity. We investigated the intraspecific trait variability of two common Mediterranean annuals (Geropogon hybridus and Crupina crupinastrum) with similar habitat preferences. They were studied along a steep precipitation gradient in Israel similar to the maximum predicted precipitation changes in the eastern Mediterranean basin (i.e. -30\% until 2100). We expected a shift from competitive ability to stress tolerance with decreasing precipitation and tested this expectation by measuring key functional traits (canopy and seed release height, specific leaf area, N-and P-leaf content, seed mass). Further, we evaluated generative bet-hedging strategies by different seed traits. Both species showed different responses along the precipitation gradient. C. crupinastrum exhibited only decreased plant height toward saridity, while G. hybridus showed strong trends of generative adaptation to aridity. Different seed trait indices suggest increased bet-hedging of G. hybridus in arid environments. However, no clear trends along the precipitation gradient were observed in leaf traits (specific leaf area and leaf N-/P-content) in both species. Moreover, variance decomposition revealed that most of the observed trait variation (>> 50\%) is found within populations. The findings of our study suggest that responses to increased aridity are highly species-specific and local environmental factors may have a stronger effect on intraspecific trait variation than shifts in annual precipitation. We therefore argue that trait-based analyses should focus on precipitation gradients that are comparable to predicted precipitation changes and compare precipitation effects to effects of local environmental factors. (C) 2017 Gesellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved.}, language = {en} } @article{ThierbachDrewesFusseretal.2010, author = {Thierbach, Ren{\´e} and Drewes, Gunnar and Fusser, Markus and Voigt, Anja and Kuhlow, Doreen and Blume, Urte and Schulz, Tim Julius and Reiche, Carina and Glatt, Hansruedi and Epe, Bernd and Steinberg, Pablo and Ristow, Michael}, title = {The Friedreich's ataxia protein frataxin modulates DNA base excision repair in prokaryotes and mammals}, issn = {0264-6021}, doi = {10.1042/Bj20101116}, year = {2010}, abstract = {DNA-repair mechanisms enable cells to maintain their genetic information by protecting it from mutations that may cause malignant growth. Recent evidence suggests that specific DNA-repair enzymes contain ISCs (iron-sulfur clusters). The nuclear-encoded protein frataxin is essential for the mitochondrial biosynthesis of ISCs. Frataxin deficiency causes a neurodegenerative disorder named Friedreich's ataxia in humans. Various types of cancer occurring at young age are associated with this disease, and hence with frataxin deficiency. Mice carrying a hepatocyte- specific disruption of the frataxin gene develop multiple liver tumours for unresolved reasons. In the present study, we show that frataxin deficiency in murine liver is associated with increased basal levels of oxidative DNA base damage. Accordingly, eukaryotic V79 fibroblasts overexpressing human frataxin show decreased basal levels of these modifications, while prokaryotic Salmonella enterica serotype Typhimurium TA 104 strains transformed with human frataxin show decreased mutation rates. The repair rates of oxidative DNA base modifications in V79 cells overexpressing frataxin were significantly higher than in control cells. Lastly, cleavage activity related to the ISC-independent repair enzyme 8-oxoguanine glycosylase was found to be unaltered by frataxin overexpression. These findings indicate that frataxin modulates DNA-repair mechanisms probably due to its impact on ISC-dependent repair proteins, linking mitochondrial dysfunction to DNA repair and tumour initiation.}, language = {en} } @article{ThierbachSchulzIskenetal.2005, author = {Thierbach, Ren{\`e} and Schulz, Tim Julius and Isken, Frank and Voigt, Aanja and Mietzner, Brun and Drewes, Gunnar and von Kleist-Retzow, J{\"u}rgen-Christoph and Wiesner, Rudolf J. and Magnuson, Mark A. and Puccio, Helene and Pfeiffer, Andreas F. H. and Steinberg, Pablo and Ristow, Michael}, title = {Targeted disruption of hepatic frataxin expression causes impaired mitochondrial function, decreased life span and tumor growth in mice}, year = {2005}, abstract = {We have disrupted expression of the mitochondrial Friedreich ataxia protein frataxin specifically in murine hepatocytes to generate mice with impaired mitochondrial function and decreased oxidative phosphorylation. These animals have a reduced life span and develop multiple hepatic tumors. Livers also show increased oxidative stress, impaired respiration and reduced ATP levels paralleled by reduced activity of iron-sulfur cluster (Fe/S) containing proteins (ISP), which all leads to increased hepatocyte turnover by promoting both apoptosis and proliferation. Accordingly, phosphorylation of the stress-inducible p38 MAP kinase was found to be specifically impaired following disruption of frataxin. Taken together, these findings indicate that frataxin may act as a mitochondrial tumor suppressor protein in mammals}, language = {en} } @article{ThierbachSchulzVoigtetal.2004, author = {Thierbach, Rene and Schulz, Tim Julius and Voigt, Aanja and Drewes, Gunnar and Isken, F. and Pfeiffer, Andreas F. H. and Ristow, Michael and Steinberg, Pablo}, title = {Targeted disruption of frataxin in hepatocytes causes spontaneous neoplasia accompanied by increased ROS formation}, issn = {0028-1298}, year = {2004}, language = {en} } @article{UhlemannHahnRistowetal.2002, author = {Uhlemann, Ingo and Hahn, Steffen and Ristow, Michael and Sackwitz, Peter}, title = {Taraxacum Sectio Naevosa M. P. Christiansen (Taraxacum spectabile auct. germ. p. p.) in Deutschland}, year = {2002}, language = {de} } @article{GemeinholzerMayRistowetal.2012, author = {Gemeinholzer, B. and May, F. and Ristow, Michael and Batsch, C. and Lauterbach, D.}, title = {Strong genetic differentiation on a fragmentation gradient among populations of the heterocarpic annual Catananche lutea L. (Asteraceae)}, series = {Plant systematics and evolution}, volume = {298}, journal = {Plant systematics and evolution}, number = {8}, publisher = {Springer}, address = {Wien}, issn = {0378-2697}, doi = {10.1007/s00606-012-0661-1}, pages = {1585 -- 1596}, year = {2012}, abstract = {In landscapes which are predominately characterised by agriculture, natural ecosystems are often reduced to a mosaic of scattered patches of natural vegetation. Species with formerly connected distribution ranges now have restricted gene flow among populations. This has isolating effects upon population structure, because species are often confined by their limited dispersal capabilities. In this study, we test the effects of habitat fragmentation, precipitation, and isolation of populations on the genetic structure (AFLP) and fitness of the Asteraceae Catananche lutea. Our study area is an agro-dominated ecosystem in the desert-Mediterranean transition zone of the Southern Judea Lowlands in Israel. Our analysis revealed an intermediate level of intra-population genetic diversity across the study site with reduced genetic diversity on smaller scale. Although the size of the whole study area was relatively small (20 x 45 km), we found isolation by distance to be effective. We detected a high level of genetic differentiation among populations but genetic structure did not reflect spatial patterns. Population genetic diversity was correlated neither with position along the precipitation gradient nor with different seed types or other plant fitness variables in C. lutea.}, language = {en} } @article{ThierbachFlorianWolfrumetal.2012, author = {Thierbach, Rene and Florian, Simone and Wolfrum, Katharina and Voigt, Anja and Drewes, Gunnar and Blume, Urte and Bannasch, Peter and Ristow, Michael and Steinberg, Pablo}, title = {Specific alterations of carbohydrate metabolism are associated with hepatocarcinogenesis in mitochondrially impaired mice}, series = {Human molecular genetics}, volume = {21}, journal = {Human molecular genetics}, number = {3}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0964-6906}, doi = {10.1093/hmg/ddr499}, pages = {656 -- 663}, year = {2012}, abstract = {Friedreich's ataxia is an inherited neurodegenerative disease caused by the reduced expression of the mitochondrially active protein frataxin. We have previously shown that mice with a hepatocyte-specific frataxin knockout (AlbFxn(-/-)) develop multiple hepatic tumors in later life. In the present study, hepatic carbohydrate metabolism in AlbFxn(-/-) mice at an early and late life stage was analyzed. In young (5-week-old) AlbFxn(-/-) mice hepatic ATP, glucose-6-phosphate and glycogen levels were found to be reduced by similar to 74, 80 and 88\%, respectively, when compared with control animals. This pronounced ATP, G6P and glycogen depletion in the livers of young mice reverted in older animals: while half of the mice die before 30 weeks of age, the other half reaches 17 months of age and exhibits glycogen, G6P and ATP levels similar to those in age-matched controls. A key event in this respect seems to be the up-regulation of GLUT1, the predominant glucose transporter in fetal liver parenchyma, which became evident in AlbFxn(-/-) mice being 5-12 weeks of age. The most significant histological findings in animals being 17 or 22 months of age were the appearance of multiple clear cell, mixed cell and basophilic foci throughout the liver parenchyma as well as the development of hepatocellular adenomas and carcinomas. The hepatocarcinogenic process in AlbFxn 2/2 mice shows remarkable differences regarding carbohydrate metabolism alterations when compared with all other chemically and virally driven liver cancer models described up to now.}, language = {en} }