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131.
Mirella Pirovino Michael Heistermann Nina Zimmermann Robert Zingg Marcus Clauss Daryl Codron Franz-Josef Kaup Hanspeter W. Steinmetz 《International journal of primatology》2011,32(5):1161-1178
Pileated gibbons (Hylobates pileatus) are rated as endangered according to the International Union of Conservation of Nature (IUCN) Red List. The captive population
suffers from poor breeding success and is threatened to become overaged. Although several factors are likely to contribute
to the poor breeding success, one in particular may be chronic stress associated with prolonged periods of high glucocorticoid
(GC) output. We investigated fecal GC levels of pileated gibbons (Hylobates pileatus) and their relationship to specific life-history variables and environmental factors. After validation of an enzyme immunoassay
for the measurement of 5-reduced 3α,11β-dihydroxy cortisol metabolites to assess GC output reliably in pileated gibbons, we
collected fecal samples over several days from all 36 European adult pileated gibbons located in 11 institutions and compared
GC levels to intrinsic individual parameters, husbandry, behavior, and breeding history. Age, sex, and origin (wild vs. captive
born) had no effect on GC levels. However, unnaturally reared gibbons had higher GC levels and showed more behavioral abnormalities
than parent-reared individuals. Further, nonreproducing gibbons living in a pair without infants had higher GC concentrations
than gibbons living in a family, bachelor group, or as singletons. With respect to environmental factors, a large size of
the inside enclosure and the existence of visual protection from visitors was associated with lower fecal GC output. The data
indicate that rearing and housing conditions appear to correlate to GC levels in pileated gibbons housed under captive conditions.
It is hoped this knowledge will support the future management of the species in captivity and thus lead to a more successful
breeding of this endangered primate. 相似文献
132.
Dynamic changes in the copy number of pluripotency and cell proliferation genes in human ESCs and iPSCs during reprogramming and time in culture 总被引:2,自引:0,他引:2
Laurent LC Ulitsky I Slavin I Tran H Schork A Morey R Lynch C Harness JV Lee S Barrero MJ Ku S Martynova M Semechkin R Galat V Gottesfeld J Izpisua Belmonte JC Murry C Keirstead HS Park HS Schmidt U Laslett AL Muller FJ Nievergelt CM Shamir R Loring JF 《Cell Stem Cell》2011,8(1):106-118
Genomic stability is critical for the clinical use of human embryonic and induced pluripotent stem cells. We performed high-resolution SNP (single-nucleotide polymorphism) analysis on 186 pluripotent and 119 nonpluripotent samples. We report a higher frequency of subchromosomal copy number variations in pluripotent samples compared to nonpluripotent samples, with variations enriched in specific genomic regions. The distribution of these variations differed between hESCs and hiPSCs, characterized by large numbers of duplications found in a few hESC samples and moderate numbers of deletions distributed across many hiPSC samples. For hiPSCs, the reprogramming process was associated with deletions of tumor-suppressor genes, whereas time in culture was associated with duplications of oncogenic genes. We also observed duplications that arose during a differentiation protocol. Our results illustrate the dynamic nature of genomic abnormalities in pluripotent stem cells and the need for frequent genomic monitoring to assure phenotypic stability and clinical safety. 相似文献
133.
134.
Müller FJ Schuldt BM Williams R Mason D Altun G Papapetrou EP Danner S Goldmann JE Herbst A Schmidt NO Aldenhoff JB Laurent LC Loring JF 《Nature methods》2011,8(4):315-317
Pluripotent stem cells (PSCs) are defined by their potential to generate all cell types of an organism. The standard assay for pluripotency of mouse PSCs is cell transmission through the germline, but for human PSCs researchers depend on indirect methods such as differentiation into teratomas in immunodeficient mice. Here we report PluriTest, a robust open-access bioinformatic assay of pluripotency in human cells based on their gene expression profiles. 相似文献
135.
Marcus Moldenhauer Nikolai N. Sluchanko Neslihan N. Tavraz Cornelia Junghans David Buhrke Mario Willoweit Leonardo Chiappisi Franz-Josef Schmitt Vladana Vukojević Evgeny A. Shirshin Vladimir Y. Ponomarev Vladimir Z. Paschenko Michael Gradzielski Eugene G. Maksimov Thomas Friedrich 《Photosynthesis research》2018,135(1-3):125-139
Photoprotection in cyanobacteria relies on the interplay between the orange carotenoid protein (OCP) and the fluorescence recovery protein (FRP) in a process termed non-photochemical quenching, NPQ. Illumination with blue-green light converts OCP from the basic orange state (OCPO) into the red-shifted, active state (OCPR) that quenches phycobilisome (PBs) fluorescence to avoid excessive energy flow to the photosynthetic reaction centers. Upon binding of FRP, OCPR is converted to OCPO and dissociates from PBs; however, the mode and site of OCPR/FRP interactions remain elusive. Recently, we have introduced the purple OCPW288A mutant as a competent model for the signaling state OCPR (Sluchanko et al., Biochim Biophys Acta 1858:1–11, 2017). Here, we have utilized fluorescence labeling of OCP at its native cysteine residues to generate fluorescent OCP proteins for fluorescence correlation spectroscopy (FCS). Our results show that OCPW288A has a 1.6(±0.4)-fold larger hydrodynamic radius than OCPO, supporting the hypothesis of domain separation upon OCP photoactivation. Whereas the addition of FRP did not change the diffusion behavior of OCPO, a substantial compaction of the OCPW288A mutant and of the OCP apoprotein was observed. These results show that sufficiently stable complexes between FRP and OCPW288A or the OCP apoprotein are formed to be detected by FCS. 1:1 complex formation with a micromolar apparent dissociation constant between OCP apoprotein and FRP was confirmed by size-exclusion chromatography. Beyond the established OCP/FRP interaction underlying NPQ cessation, the OCP apoprotein/FRP interaction suggests a more general role of FRP as a scaffold protein for OCP maturation. 相似文献
136.
J. Kaup 《Journal of Ornithology》1853,1(1):29-30
Ohne Zusammenfassung 相似文献
137.
Histone deacetylases are major regulators of eukaryotic gene expression. Not unexpectedly, histone deacetylases are among the most promising targets in cancer therapy. However, despite huge efforts in histone deacetylase inhibitor design, very little is known about the impact of histone deacetylase inhibitors on enzyme stability. In this study, the conformational stability of a well-established histone deacetylase homolog with high structural similarity (histone deacetylase-like amidohydrolase from Bordetella/Alcaligenes species FB188) was investigated using denaturation titrations and stopped-flow kinetics. Based on the results of these complementary approaches, we conclude that the interconversion of native histone deacetylase-like amidohydrolase into its denatured form involves several intermediates possessing different enzyme activities and conformational structures. The refolding kinetics has shown to be strongly dependent on Zn(2+) and to a lesser extent on K(+), which underlines their importance not only for catalytic function but also for maintaining the correct conformational structure of the enzyme. Two main unfolding processes of histone deacetylase-like amidohydrolase were differentiated. The unfolding occurring at submolar concentrations of the denaturant guanidine hydrochloride was not affected by inhibitor binding, whereas the unfolding at higher concentrations of guanidine hydrochloride was strongly affected. It was shown that the known inhibitors suberoylanilide hydroxamic acid and cyclopentylpropionyl hydroxamate are capable of stabilizing the conformational structure of histone deacetylase-like amidrohydrolase. Judging from the free energies of unfolding, the protein stability was increased by 9.4 and 5.4 kJ.mol(-1) upon binding of suberoylanilide hydroxamic acid and cyclopentylpropionyl hydroxamate, respectively. 相似文献
138.
T Schnieder F J Kaup W Drommer W Thiel M Rommel 《Zeitschrift für Parasitenkunde (Berlin, Germany)》1984,70(4):451-458
Isolated cysts of Sarcocystis aucheniae of the llama (Lama glama) were fed to one dog and one cat. Only the dog excreted sporocysts, measuring 13.1-15.7 (15.0 +/- 0.54) X 9.0-11.3 (10.4 +/- 0.36) micron after 11 days for 21 days. A second cat, which had ingested meat of a llama containing macrocysts of S. aucheniae as well as sarcosporidial cysts visible only under a microscope also did not excrete sporocysts. The cysts of S. aucheniae are surrounded by a folded primary cyst wall forming cauliflower-like protrusions into the muscle fibre. The protrusions contain numerous microfilaments. In addition, the primary cyst wall forms numerous tiny vesicles. The parasitized muscle fibre is located in a large cavity within the normal muscle tissue. The cyst wall of S. aucheniae is similarly structured to that of S. gigantea of the sheep. 相似文献
139.
We demonstrate that surface-plasmon microscopy allows one to monitor the specific binding of streptavidin to biotinylated lipid molecules selectively enriched in one of the two coexisting phase domains of a phospholipid monolayer transferred in its phase transition region from the water-air interface to a solid support. 相似文献
140.
Carol Morgan Henry Franz-Josef Ferdinand Rolf Knippers 《Biochemical and biophysical research communications》1973,51(3):603-611
An endonuclease has been isolated and purified from which degrades RNA hydrogen bonded to DNA and no other polynucleotide substrates, including double stranded RNA, single stranded RNA, double stranded DNA or single stranded DNA. 相似文献