The nature of Martian fluids based on mobile element studies in salt-assemblages from Martian meteorites

2008 ◽  
Vol 113 (E6) ◽  
Author(s):  
M. N. Rao ◽  
L. E. Nyquist ◽  
S. J. Wentworth ◽  
S. R. Sutton ◽  
D. H. Garrison
Keyword(s):  
Mobile Element ◽  
Martian Meteorites

scholarly journals Evidence for Past Life on Early Mars: How the Evidence Stands

2004 ◽  
Vol 213 ◽  
pp. 203-208 ◽  
Author(s):  
Everett K. Gibson ◽  
Kathie L. Thomas-Keprta ◽  
Simon J. Clemett ◽  
David S. Mckay ◽  
Christopher Romanek ◽  
...  
Keyword(s):  
Scientific Community ◽  
Current Status ◽  
Martian Meteorite ◽  
Martian Meteorites ◽  
Past Life ◽  
Early Mars ◽  
World’S Scientific Community

Martian Meteorite ALH84001 contains four unusual features which have been interpreted as possible signatures of relic biogenic activity. After six years of intense study by the world's scientific community, the current status of the biogenic hypothesis is reviewed and shown to still be valid. Furthermore additional features have been observed in two younger Martian meteorites. The strongest argument for possible evidence of biogenic activity within the ALH84001 meteorite is the presence of truncated hexa-octahedral magnetite crystals which are only known on Earth to be the products of biology.

scholarly journals Isolating an active and inactive CACTA transposon from lettuce color mutants and characterizing their family

2021 ◽  
Author(s):  
Csanad Gurdon ◽  
Alexander Kozik ◽  
Rong Tao ◽  
Alexander Poulev ◽  
Isabel Armas ◽  
...  
Keyword(s):  
Anthocyanin Biosynthesis ◽  
Mobile Element ◽  
Bioinformatic Analysis ◽  
Relative Expression Level ◽  
Gene Coding ◽  
Genes Encoding ◽  
Key Enzyme ◽  
Natural Derivative ◽  
Dark Green ◽  
Transposon Insertions

Abstract Dietary flavonoids play an important role in human nutrition and health. Flavonoid biosynthesis genes have recently been identified in lettuce (Lactuca sativa); however, few mutants have been characterized. We now report the causative mutations in Green Super Lettuce (GSL), a natural light green mutant derived from red cultivar NAR; and GSL-Dark Green (GSL-DG), an olive-green natural derivative of GSL. GSL harbors CACTA 1 (LsC1), a 3.9-kb active nonautonomous CACTA superfamily transposon inserted in the 5′ untranslated region of anthocyanidin synthase (ANS), a gene coding for a key enzyme in anthocyanin biosynthesis. Both terminal inverted repeats (TIRs) of this transposon were intact, enabling somatic excision of the mobile element, which led to the restoration of ANS expression and the accumulation of red anthocyanins in sectors on otherwise green leaves. GSL-DG harbors CACTA 2 (LsC2), a 1.1-kb truncated copy of LsC1 that lacks one of the TIRs, rendering the transposon inactive. RNA-sequencing and reverse transcription quantitative PCR of NAR, GSL, and GSL-DG indicated the relative expression level of ANS was strongly influenced by the transposon insertions. Analysis of flavonoid content indicated leaf cyanidin levels correlated positively with ANS expression. Bioinformatic analysis of the cv Salinas lettuce reference genome led to the discovery and characterization of an LsC1 transposon family with a putative transposon copy number greater than 1,700. Homologs of tnpA and tnpD, the genes encoding two proteins necessary for activation of transposition of CACTA elements, were also identified in the lettuce genome.

kangaroo, a Mobile Element From Volvox carteri, Is a Member of a Newly Recognized Third Class of Retrotransposons

Genetics ◽  
2002 ◽  
Vol 162 (4) ◽  
pp. 1617-1630
Author(s):  
Leonard Duncan ◽  
Kristine Bouckaert ◽  
Fay Yeh ◽  
David L Kirk
Keyword(s):  
Genomic Structure ◽  
Mobile Element ◽  
Direct Repeat ◽  
Structural Features ◽  
Volvox Carteri ◽  
Developmentally Regulated ◽  
Closed Circle ◽  
Integration Mechanisms ◽  
And Function

Abstract Retrotransposons play an important role in the evolution of genomic structure and function. Here we report on the characterization of a novel retrotransposon called kangaroo from the multicellular green alga, Volvox carteri. kangaroo elements are highly mobile and their expression is developmentally regulated. They probably integrate via double-stranded, closed-circle DNA intermediates through the action of an encoded recombinase related to the λ-site-specific integrase. Phylogenetic analysis indicates that kangaroo elements are closely related to other unorthodox retrotransposons including PAT (from a nematode), DIRS-1 (from Dictyostelium), and DrDIRS1 (from zebrafish). PAT and kangaroo both contain split direct repeat (SDR) termini, and here we show that DIRS-1 and DrDIRS1 elements contain terminal features structurally related to SDRs. Thus, these mobile elements appear to define a third class of retrotransposons (the DIRS1 group) that are unified by common structural features, genes, and integration mechanisms, all of which differ from those of LTR and conventional non-LTR retrotransposons.

Role of long interspersed nuclear element-1 in the regulation of chromatin landscapes and genome dynamics

2021 ◽  
pp. 153537022110312
Author(s):  
Kenneth S Ramos ◽  
Pasano Bojang ◽  
Emma Bowers
Keyword(s):  
Cancer Biology ◽  
Mobile Element ◽  
Cancer Diagnostics ◽  
Regulatory Control ◽  
Full Potential ◽  
Genome Dynamics ◽  
Human Illness ◽  
Cancer Types ◽  
Stressful Environments

LINE-1 retrotransposon, the most active mobile element of the human genome, is subject to tight regulatory control. Stressful environments and disease modify the recruitment of regulatory proteins leading to unregulated activation of LINE-1. The activation of LINE-1 influences genome dynamics through altered chromatin landscapes, insertion mutations, deletions, and modulation of cellular plasticity. To date, LINE-1 retrotransposition has been linked to various cancer types and may in fact underwrite the genetic basis of various other forms of chronic human illness. The occurrence of LINE-1 polymorphisms in the human population may define inter-individual differences in susceptibility to disease. This review is written in honor of Dr Peter Stambrook, a friend and colleague who carried out highly impactful cancer research over many years of professional practice. Dr Stambrook devoted considerable energy to helping others live up to their full potential and to navigate the complexities of professional life. He was an inspirational leader, a strong advocate, a kind mentor, a vocal supporter and cheerleader, and yes, a hard critic and tough friend when needed. His passionate stand on issues, his witty sense of humor, and his love for humanity have left a huge mark in our lives. We hope that that the knowledge summarized here will advance our understanding of the role of LINE-1 in cancer biology and expedite the development of innovative cancer diagnostics and treatments in the ways that Dr Stambrook himself had so passionately envisioned.

scholarly journals Transcription of Drosophila mobile element gypsy (mdg4) in heat-shocked cells

FEBS Letters ◽  
1993 ◽  
Vol 325 (3) ◽  
pp. 233-236 ◽  
Author(s):  
N.V. Lyubomirskaya ◽  
I.R. Arkhipova ◽  
Yu.V. Ilyin
Keyword(s):  
Mobile Element

scholarly journals What martian meteorites reveal about the interior and surface of Mars

2020 ◽  
Author(s):  
Arya Udry ◽  
Geoffrey Hamilton Howarth ◽  
Christopher Herd ◽  
James Day ◽  
Thomas John Lapen ◽  
...  
Keyword(s):  
Martian Meteorites

scholarly journals Shock-induced transformation of olivine to a new metastable (Mg,Fe)2SiO4 polymorph in Martian meteorites

2007 ◽  
Vol 261 (3-4) ◽  
pp. 469-475 ◽  
Author(s):  
Bertrand Van de Moortèle ◽  
Bruno Reynard ◽  
Paul F. McMillan ◽  
Mark Wilson ◽  
Pierre Beck ◽  
...  
Keyword(s):  
Martian Meteorites
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