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Cloning And Expression Analysis Of Drosophila Extracellular Cu Zn Superoxide Dismutase, Michael J. Blackney, Rebecca Cox, David Shepherd, Joel D. Parker
Cloning And Expression Analysis Of Drosophila Extracellular Cu Zn Superoxide Dismutase, Michael J. Blackney, Rebecca Cox, David Shepherd, Joel D. Parker
Joel D Parker
In the present study, we cloned and sequenced the mRNAs of the Sod3 [extracellular Cu Zn SOD (superoxide dismutase)] gene in Drosophila and identified two mRNA products formed by alternative splicing. These products code for a long and short protein derived from the four transcripts found in global expression studies (Flybase numbers Dmel\CG9027, FBgn0033631). Both mRNA process variants contain an extracellular signalling sequence, a region of high homology to the Sod1 (cytoplasmic Cu Zn SOD) including a conserved AUG start, with the longer form also containing a hydrophobic tail. The two fully processed transcripts are homologous to Caenorhabditis elegans Sod3 …
Short Telomeres In Short-Lived Males: What Are The Molecular And Evolutionary Causes?, Stephanie Jemielity, Masayuki Kimura, Karen M. Parker, Joel D. Parker, Xiaojian Cao, Abraham Aviv, Laurent Keller
Short Telomeres In Short-Lived Males: What Are The Molecular And Evolutionary Causes?, Stephanie Jemielity, Masayuki Kimura, Karen M. Parker, Joel D. Parker, Xiaojian Cao, Abraham Aviv, Laurent Keller
Joel D Parker
Telomere length regulation is an important aspect of cell maintenance in eukaryotes, since shortened telomeres can lead to a number of defects, including impaired cell division. Although telomere length is correlated with lifespan in some bird species, its possible role in aging and lifespan determination is still poorly understood. Here we investigate telomere dynamics (changes in telomere length and attrition rate) and telomerase activity in the ant Lasius niger, a species in which different groups of individuals have evolved extraordinarily different lifespans. We found that somatic tissues of the short-lived males had dramatically shorter telomeres than those of the much …
Decreased Expression Of Cu–Zn Superoxide Dismutase 1 In Ants With Extreme Lifespan, Joel D. Parker, Karen M. Parker, Barbara H. Sohal, Rajindar S. Sohal, Laurent Keller
Decreased Expression Of Cu–Zn Superoxide Dismutase 1 In Ants With Extreme Lifespan, Joel D. Parker, Karen M. Parker, Barbara H. Sohal, Rajindar S. Sohal, Laurent Keller
Joel D Parker
Reactive oxygen species, the by-products of oxidative energy metabolism, are considered a main proximate cause of aging. Accordingly, overexpression of the enzyme Cu–Zn superoxide dismutase 1 (SOD1) can lengthen lifespan of Drosophila melanogaster in the laboratory. However, the role of SOD1 as a main determinant of lifespan has been challenged on the grounds that overexpression might be effective only in compromised genetic backgrounds. Moreover, interspecific comparisons show lower levels of antioxidant activities in longer-lived species, suggesting that life-span extension may evolve through less reactive oxygen species generation from the mitochondria rather than higher expression of SOD1. The tremendous variation in …
Evolutionary Genetics And Genetic Variation Of Haplodiploids And X-Linked Genes, Philip W. Hedrick, Joel D. Parker
Evolutionary Genetics And Genetic Variation Of Haplodiploids And X-Linked Genes, Philip W. Hedrick, Joel D. Parker
Joel D Parker
The evolutionary genetics of haplodiploids and X-linked genes share many features and are different from diploid (autosomal) genes in many respects. For example, the conditions for a stable polymorphism, the amount of genetic load, and the effective population size are all expected to be quite different between haplodiploids or X-linked genes and diploids. From experimental data, the genetic load for X-linked genes is much less than autosomal genes and appears less for haplodiploids than for diploids. The observed amount of molecular variation for haplodiploids is much less than that for diploids, even more so than predicted from the differences in …