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The genera Viburnum, Sambucus and Lonicera have been investigated for chromosome number and karyomorphology including Giemsa-C-banding, fluorochrome (DAPI/CMA) banding and cold treatment. Cold-induced undercontracted chromosome regions (CIRs) are found in Viburnum and Sambucus for the first time and are apparently identical with larger hc regions, shown by Giemsa C-banding. Certain narrow C-bands are not cold-sensitive. CIRs frequently react brightly CMA-positive in Viburnum and Sambucus, while DAPI fluorescence is virtually ineffective. The occurrence of CIRs within plants is possibly linked to certain nuclear characters such as large chromosomes and continuous condensation behaviour. Cold-induction has possibly also some influence on euchromatin condensation characteristics in prophasic chromosomes. Several karyological characters point to a closer relationship between Viburnum, Sambucus and Adoxa: Relatively large chromosomes, continuous condensation behaviour, reticulate to semireticulate interphase nuclei and presence of CIRs. These genera appear isolated from Lonicera and the Caprifoliaceae s.str., which differ remarkably in karyomorphology. 相似文献
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Chathurika Henpita Rajesh Vyas Chastity L. Healy Tra L. Kieu Aditi U. Gurkar Matthew J. Yousefzadeh Yuxiang Cui Aiping Lu Luise A. Angelini Ryan D. O'Kelly Sara J. McGowan Sanjay Chandrasekhar Rebecca R. Vanderpool Danielle Hennessy-Wack Mark A. Ross Timothy N. Bachman Charles McTiernan Smitha P. S. Pillai Warren Ladiges Mitra Lavasani Johnny Huard Donna Beer-Stolz Claudette M. St. Croix Simon C. Watkins Paul D. Robbins Ana L. Mora Eric E. Kelley Yinsheng Wang Timothy D. O'Connell Laura J. Niedernhofer 《Aging cell》2023,22(4):e13782
Cardiomyopathy is a progressive disease of the myocardium leading to impaired contractility. Genotoxic cancer therapies are known to be potent drivers of cardiomyopathy, whereas causes of spontaneous disease remain unclear. To test the hypothesis that endogenous genotoxic stress contributes to cardiomyopathy, we deleted the DNA repair gene Ercc1 specifically in striated muscle using a floxed allele of Ercc1 and mice expressing Cre under control of the muscle-specific creatinine kinase (Ckmm) promoter or depleted systemically (Ercc1−/D mice). Ckmm-Cre+/−;Ercc1−/fl mice expired suddenly of heart disease by 7 months of age. As young adults, the hearts of Ckmm-Cre+/−;Ercc1−/fl mice were structurally and functionally normal, but by 6-months-of-age, there was significant ventricular dilation, wall thinning, interstitial fibrosis, and systolic dysfunction indicative of dilated cardiomyopathy. Cardiac tissue from the tissue-specific or systemic model showed increased apoptosis and cardiac myocytes from Ckmm-Cre+/-;Ercc1−/fl mice were hypersensitive to genotoxins, resulting in apoptosis. p53 levels and target gene expression, including several antioxidants, were increased in cardiac tissue from Ckmm-Cre+/−;Ercc1−/fl and Ercc1−/D mice. Despite this, cardiac tissue from older mutant mice showed evidence of increased oxidative stress. Genetic or pharmacologic inhibition of p53 attenuated apoptosis and improved disease markers. Similarly, overexpression of mitochondrial-targeted catalase improved disease markers. Together, these data support the conclusion that DNA damage produced endogenously can drive cardiac disease and does so mechanistically via chronic activation of p53 and increased oxidative stress, driving cardiac myocyte apoptosis, dilated cardiomyopathy, and sudden death. 相似文献
67.
The topography of the Sado estuary, the second largest of Portugal, comprises the outer estuary inside the entrance channel
and the inner estuary, on the inward side of which begins the tidal mudflats. The outer estuary subtidal area covers approximately
70 km2 and presents a series of longitudinal intertidal sandbanks, separating a northern and a southern channel.
A benthic survey was undertaken in the outer estuary during June 1986, in which superficial sediments and macrofauna were
sampled at 133 locations. The environmental variables measured in the superficial sediments were the temperature, the granulometric
structure, the silt, sand and the gravel content, and the total organic matter content. The primary macrofauna biological
variables studied were the species composition, abundance and biomass, calculated on wet, dry and ash-free dry weight.
The granulometry and the organic content of superficial sediments agreed with the transient and the residual currents velocity
field, simulated in a 2-D hydrodynamic model previously elaborated for the outer estuary. The northern channel superficial
sediments showed higher silt and total organic matter content, while the model also suggested lower transient and residual
velocities, water flow and shear stress in this channel.
The distribution patterns of the subtidal macrofauna were separated into two main groups of species, one comprising taxa essentially
settled near the estuarine mouth and the other inwards. Biological primary variables also showed consistent patterns, comparable
to other Portuguese estuaries. The major subtidal benthic biotopes were obtained through classification analysis and related
to the prevailing hydrophysical and sedimentary conditions in the outer estuary. 相似文献
68.
Niraj Shrestha Pallavi Chaturvedi Xiaoyun Zhu Michael J. Dee Varghese George Christopher Janney Jack O. Egan Bai Liu Mark Foster Lynne Marsala Pamela Wong Celia C. Cubitt Jennifer A. Foltz Jennifer Tran Timothy Schappe Karin Hsiao Gilles M. Leclerc Lijing You Christian Echeverri Catherine Spanoudis Ana Carvalho Leah Kanakaraj Crystal Gilkes Nicole Encalada Lin Kong Meng Wang Byron Fang Zheng Wang Jin-an Jiao Gabriela J. Muniz Emily K. Jeng Nicole Valdivieso Liying Li Richard Deth Melissa M. Berrien-Elliott Todd A. Fehniger Peter R. Rhode Hing C. Wong 《Aging cell》2023,22(5):e13806
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The hemolymph of each noctuid species successfully parasitized by Chelonus near curvimaculatus possessed a parasitism-specific protein (PSP) previously identified in host T. ni (Insect Biochem. 19:445; 21:845). Expression of PSP occurred in a stage-specific manner in the stadium during which the host undergoes precocious metamorphosis. The appearance of the protein was not due to nutritional stress associated with parasitism of hosts, since starved nonparasitized larvae did not produce the protein, or to low juvenile hormone titers occurring in precociously metamorphosing hosts, but rather was dependent on the presence of the endoparasite larva. Results of in vivo incorporation experiments with [35S]-methionine showed that synthesis and subsequent appearance of the protein in the hemolymph of parasitized hosts was abrogated by prior surgical removal of endoparasite. Immunoprecipitation analysis of proteins from C. near curvimaculatus larvae cultured in vitro using antibodies specific to PSP indicated that the source of the protein was the endoparasite. Synthesis of PSP by the endoparasitic larvae with its subsequent secretion into the hemocoel of hosts was specific to the advanced stages of parasite development prior to its egression from the host. © 1993 Wiley-Liss, Inc. 相似文献