An Exploration Zone in Cerberus Containing Young and Old Terrains, Including Fossae/Faults and Sher-Gottite Distal Ejecta

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The Fragmented Mitochondrial Ribosomal RNAs of Plasmodium falciparum

The mitochondrial genome in the human malaria parasite Plasmodium falciparum is most unusual. Over half the genome is composed of the genes for three classic mitochondrial proteins: cytochrome oxidase subunits I and III and apocytochrome b. The remainder encodes numerous small RNAs, ranging in size from 23 to 190 nt. Previous analysis revealed that some of these transcripts have significant sequence identity with highly conserved regions of large and small subunit rRNAs, and can form the expected secondary structures. However, these rRNA fragments are not encoded in linear order; instead, they are intermixed with one another and the protein coding genes, and are coded on both strands of the genome. This unorthodox arrangement hindered the identification of transcripts corresponding to other regions of rRNA that are highly conserved and/or are known to participate directly in protein synthesis.The identification of 14 additional small mitochondrial transcripts from P. falciparum and the assignment of 27 small RNAs (12 SSU RNAs totaling 804 nt, 15 LSU RNAs totaling 1233 nt) to specific regions of rRNA are supported by multiple lines of evidence. The regions now represented are highly similar to those of the small but contiguous mitochondrial rRNAs of Caenorhabditis elegans. The P. falciparum rRNA fragments cluster on the interfaces of the two ribosomal subunits in the three-dimensional structure of the ribosome.All of the rRNA fragments are now presumed to have been identified with experimental methods, and nearly all of these have been mapped onto the SSU and LSU rRNAs. Conversely, all regions of the rRNAs that are known to be directly associated with protein synthesis have been identified in the P. falciparum mitochondrial genome and RNA transcripts. The fragmentation of the rRNA in the P. falciparum mitochondrion is the most extreme example of any rRNA fragmentation discovered

Dietary levels of pure flavonoids improve spatial memory performance and increase hippocampal brain-derived neurotrophic factor.

Evidence suggests that flavonoid-rich foods are capable of inducing improvements in memory and cognition in animals and humans. However, there is a lack of clarity concerning whether flavonoids are the causal agents in inducing such behavioral responses. Here we show that supplementation with pure anthocyanins or pure flavanols for 6 weeks, at levels similar to that found in blueberry (2% w/w), results in an enhancement of spatial memory in 18 month old rats. Pure flavanols and pure anthocyanins were observed to induce significant improvements in spatial working memory (p = 0.002 and p = 0.006 respectively), to a similar extent to that following blueberry supplementation (p = 0.002). These behavioral changes were paralleled by increases in hippocampal brain-derived neurotrophic factor (R = 0.46, p<0.01), suggesting a common mechanism for the enhancement of memory. However, unlike protein levels of BDNF, the regional enhancement of BDNF mRNA expression in the hippocampus appeared to be predominantly enhanced by anthocyanins. Our data support the claim that flavonoids are likely causal agents in mediating the cognitive effects of flavonoid-rich foods

Mitochondrial genomes and Doubly Uniparental Inheritance: new insights from Musculista senhousia sex-linked mitochondrial DNAs (Bivalvia Mytilidae)

BACKGROUND: Doubly Uniparental Inheritance (DUI) is a fascinating exception to matrilinear inheritance of mitochondrial DNA (mtDNA). Species with DUI are characterized by two distinct mtDNAs that are inherited either through females (F-mtDNA) or through males (M-mtDNA). DUI sex-linked mitochondrial genomes share several unusual features, such as additional protein coding genes and unusual gene duplications/structures, which have been related to the functionality of DUI. Recently, new evidence for DUI was found in the mytilid bivalve Musculista senhousia. This paper describes the complete sex-linked mitochondrial genomes of this species. RESULTS: Our analysis highlights that both M and F mtDNAs share roughly the same gene content and order, but with some remarkable differences. The Musculista sex-linked mtDNAs have differently organized putative control regions (CR), which include repeats and palindromic motifs, thought to provide sites for DNA-binding proteins involved in the transcriptional machinery. Moreover, in male mtDNA, two cox2 genes were found, one (M-cox2b) 123bp longer. CONCLUSIONS: The complete mtDNA genome characterization of DUI bivalves is the first step to unravel the complex genetic signals allowing Doubly Uniparental Inheritance, and the evolutionary implications of such an unusual transmission route in mitochondrial genome evolution in Bivalvia. The observed redundancy of the palindromic motifs in Musculista M-mtDNA may have a role on the process by which sperm mtDNA becomes dominant or exclusive of the male germline of DUI species. Moreover, the duplicated M-COX2b gene may have a different, still unknown, function related to DUI, in accordance to what has been already proposed for other DUI species in which a similar cox2 extension has been hypothesized to be a tag for male mitochondria

Oxidative balance in birds: an atoms‐to‐organisms‐to‐ecology primer for ornithologists

All air-breathing organisms must face the challenge of oxidative damage, and understanding how animals cope can lend insight into their ecology. Unlike other vertebrates, birds rely primarily on fats to fuel endurance exercise such as migration, and therefore face a greater potential for damage from the reactive by-products of their own metabolism. We review the physiological ecology of migrating birds through the lens of oxidation-reduction chemistry, underscoring how oxidative balance in wild birds may affect their dietary choices and use of critical stopover habitats during migration. Recent studies reveal that migratory birds prepare for oxidative challenges either by up-regulating endogenous antioxidants or by consuming them in their diet, and they repair oxidative damage after long flights, although much remains to be discovered about how birds maintain oxidative balance over the course of migration. We conclude by describing some of the most used and useful measures of antioxidant status and oxidative damage that field ornithologists can include in their tool kit of techniques to probe the oxidative balance of wild birds

The effect of dietary glutathione and coenzyme Q10 on the prevention and treatment of inflammatory bowel disease in mice.

Because reactive oxygen species have been implicated as mediators of inflammatory bowel disease (IBD), we evaluated the potential preventive and therapeutic effects of two dietary antioxidants, glutathione (GSH) and coenzyme Q10 (CoQ10) on dextran sulfate sodium (DSS)-induced colitis in mice. Fifty female 8-wk old Swiss-Webster mice were randomly assigned to 4 groups for a pre-treatment prevention study: (1) GSH (1% of diet); (2) CoQ10 (200 mg/kg/d); (3) DSS only (3% of drinking water); (4) control (no treatment). The mice in groups 1 and 2 were fed with GSH or CoQ10 for 21 wks, and the mice in groups 1, 2 and 3 were provided DSS from wk 7 for 4 cycles (1 cycle = 1 wk DSS followed by 2-wk water). Another 50 mice were randomly assigned to 4 groups for a 21-wk treatment study where the mice in groups 1, 2, and 3 were administered DSS for 6 cycles (18 wks) to induce colitis. GSH and CoQ10 were added from wk 7 until the completion of the protocol. Loose stools and hemocult positivity were modestly but significantly reduced with GSH or CoQ10 at several periods during the intervention in both the prevention and treatment studies. In contrast, histological evaluation revealed increases in colonic dysplasia and ulceration with GSH or CoQ10. Thus, in this mouse model, GSH and CoQ10 appear to have a beneficial effect on acute signs of IBD, but may have an adverse impact on the chronic pathophysiology of the disease. Further studies using additional animal models are required to determine whether GSH or CoQ10 provide a favorable or unfavorable benefit:risk ratio in the prevention or treatment of IBD