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101.
Poulakakis N Parmakelis A Lymberakis P Mylonas M Zouros E Reese DS Glaberman S Caccone A 《Biology letters》2006,2(3):451-454
During the Pleistocene pygmy elephantids, some only a quarter of their ancestors' size, were present on Mediterranean islands until about 10,000 years ago (y.a.). Using a new methodology for ancient DNA (aDNA) studies, the whole genomic multiple displacement amplification method, we were able to retrieve cytochrome b (cytb) DNA fragments from 4200 to 800,000 y.a. specimens from island and mainland samples, including pygmy and normal-sized forms. The short DNA sequence (43 bp) retrieved from the 800,000 y.a. sample is one of the oldest DNA fragment ever retrieved. Duplication of the experiments in two laboratories, the occurrence of three diagnostic sites and the results of the phylogenetic analyses strongly support its authenticity. Our results challenge the prevailing view that pygmy elephantids of the eastern Mediterranean originated exclusively from Elephas, suggesting independent histories of dwarfism and the presence of both pygmy mammoths and elephant-like taxa on these islands. Based on our molecular data, the origin of the Tilos and Cyprus elephantids from a lineage within the genus Elephas is confirmed, while the DNA sequence from the Cretan sample falls clearly within the mammoth clade. Thus, the name Mammuthus creticus rather than Elephas creticus, seems to be justified for this form. Our findings also suggest a need to re-evaluate the evolutionary history of the Sicilian/Maltese species, traditionally included in the genus Elephas. 相似文献
102.
Endogenous viral elements in animal genomes 总被引:2,自引:0,他引:2
Integration into the nuclear genome of germ line cells can lead to vertical inheritance of retroviral genes as host alleles. For other viruses, germ line integration has only rarely been documented. Nonetheless, we identified endogenous viral elements (EVEs) derived from ten non-retroviral families by systematic in silico screening of animal genomes, including the first endogenous representatives of double-stranded RNA, reverse-transcribing DNA, and segmented RNA viruses, and the first endogenous DNA viruses in mammalian genomes. Phylogenetic and genomic analysis of EVEs across multiple host species revealed novel information about the origin and evolution of diverse virus groups. Furthermore, several of the elements identified here encode intact open reading frames or are expressed as mRNA. For one element in the primate lineage, we provide statistically robust evidence for exaptation. Our findings establish that genetic material derived from all known viral genome types and replication strategies can enter the animal germ line, greatly broadening the scope of paleovirological studies and indicating a more significant evolutionary role for gene flow from virus to animal genomes than has previously been recognized. 相似文献
103.
Carola Krause Olexandr Korchynskyi Karien de Rooij Stella E. Weidauer David J. J. de Gorter Rutger L. van Bezooijen Sarah Hatsell Aris N. Economides Thomas D. Mueller Clemens W. G. M. L?wik Peter ten Dijke 《The Journal of biological chemistry》2010,285(53):41614-41626
Sclerostin is expressed by osteocytes and has catabolic effects on bone. It has been shown to antagonize bone morphogenetic protein (BMP) and/or Wnt activity, although at present the underlying mechanisms are unclear. Consistent with previous findings, Sclerostin opposed direct Wnt3a-induced but not direct BMP7-induced responses when both ligand and antagonist were provided exogenously to cells. However, we found that when both proteins are expressed in the same cell, sclerostin can antagonize BMP signaling directly by inhibiting BMP7 secretion. Sclerostin interacts with both the BMP7 mature domain and pro-domain, leading to intracellular retention and proteasomal degradation of BMP7. Analysis of sclerostin knock-out mice revealed an inhibitory action of sclerostin on Wnt signaling in both osteoblasts and osteocytes in cortical and cancellous bones. BMP7 signaling was predominantly inhibited by sclerostin in osteocytes of the calcaneus and the cortical bone of the tibia. Our results suggest that sclerostin exerts its potent bone catabolic effects by antagonizing Wnt signaling in a paracrine and autocrine manner and antagonizing BMP signaling selectively in the osteocytes that synthesize simultaneously both sclerostin and BMP7 proteins. 相似文献
104.
Aris Bechlioulis Konstantinos Vakalis Katerina K. Naka Christos V. Bourantas Nikolaos D. Papamichael Anna Kotsia Thomas Tzimas Konstantinos Pappas Christos S. Katsouras Lampros K. Michalis 《Obesity (Silver Spring, Md.)》2013,21(3):E314-E321
Objective:
Increased body mass index (BMI) has been paradoxically inversely associated with the presence of angiographic coronary artery disease (CAD). Central obesity measures, considered to be more appropriate for assessing obesity‐related cardiovascular risk, have been little studied in relation to the presence of CAD. The aim was to investigate the association of central obesity with the presence of angiographic CAD as well as the prognostic significance of obesity measures in CAD prediction when added to other cardiovascular risk factors.Design and Methods:
Patients with suspected stable CAD (n = 403, age 61 ± 10 years, 302 males) referred for diagnostic coronary angiography with documented anthropometric data were enrolled.Results:
Significant angiographic CAD was found in 51% of patients. Both BMI (OR = 0.64 per 1 SD increase, P = 0.001) and waist circumference (WC) (OR = 0.54 per 1 SD increase, P < 0.001) were inversely associated with the presence of CAD even after adjustment for cardiovascular risk factors. In subgroup analysis, BMI and WC were significantly inversely associated with the presence of CAD in males, non diabetics, patients >60 years old and patients with Framingham risk score (FRS) >20% (P < 0.01 for all). The addition of BMI or WC in FRS‐based regression models improved prediction of CAD (P = 0.03 and P < 0.001 for BMI and WC respectively) without a significant difference between the two models (P = 0.08).Conclusions:
Central and overall obesity were independently associated with a reduced prevalence of angiographic CAD, lending further credence to the existence of the ‘obesity paradox’. Obesity measures may further improve risk discrimination for the presence of CAD when added in an established risk score such as FRS. 相似文献105.
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109.
Honoka Kiso Katsu Takahashi Kazuyuki Saito Yumiko Togo Hiroko Tsukamoto Boyen Huang Manabu Sugai Akira Shimizu Yasuhiko Tabata Aris N. Economides Harold C. Slavkin Kazuhisa Bessho 《PloS one》2014,9(5)
Bone morphogenetic proteins (BMPs) are highly conserved signaling molecules that are part of the transforming growth factor (TGF)-beta superfamily, and function in the patterning and morphogenesis of many organs including development of the dentition. The functions of the BMPs are controlled by certain classes of molecules that are recognized as BMP antagonists that inhibit BMP binding to their cognate receptors. In this study we tested the hypothesis that USAG-1 (uterine sensitization-associated gene-1) suppresses deciduous incisors by inhibition of BMP-7 function. We learned that USAG-1 and BMP-7 were expressed within odontogenic epithelium as well as mesenchyme during the late bud and early cap stages of tooth development. USAG-1 is a BMP antagonist, and also modulates Wnt signaling. USAG-1 abrogation rescued apoptotic elimination of odontogenic mesenchymal cells. BMP signaling in the rudimentary maxillary incisor, assessed by expressions of Msx1 and Dlx2 and the phosphorylation of Smad protein, was significantly enhanced. Using explant culture and subsequent subrenal capsule transplantation of E15 USAG-1 mutant maxillary incisor tooth primordia supplemented with BMP-7 demonstrated in USAG-1+/− as well as USAG-1−/− rescue and supernumerary tooth development. Based upon these results, we conclude that USAG-1 functions as an antagonist of BMP-7 in this model system. These results further suggest that the phenotypes of USAG-1 and BMP-7 mutant mice reported provide opportunities for regenerative medicine and dentistry. 相似文献
110.
Thomas Pilgrim Martina Rothenbühler Bindu Kalesan Cédric Pulver Giulio G. Stefanini Thomas Zanchin Lorenz R?ber Stefan Stortecky Simon Jung Heinrich Mattle Aris Moschovitis Peter Wenaweser Bernhard Meier Thomas Gsponer Stephan Windecker Peter Jüni 《PloS one》2014,9(12)