scholarly journals Regulation of Transcription in a Reduced Bacterial Genome: Nutrient-Provisioning Genes of the Obligate Symbiont Buchnera aphidicola

2005 ◽  
Vol 187 (12) ◽  
pp. 4229-4237 ◽  
Author(s):  
Nancy A. Moran ◽  
Helen E. Dunbar ◽  
Jennifer L. Wilcox
Keyword(s):  
Amino Acid ◽  
Acid Content ◽  
Acyrthosiphon Pisum ◽  
Bacterial Genome ◽  
Amino Acid Content ◽  
Transcript Abundance ◽  
Regulation Of Transcription ◽  
Buchnera Aphidicola ◽  
Obligate Symbiont ◽  
Dietary Amino Acid

ABSTRACT Buchnera aphidicola, the obligate symbiont of aphids, has an extremely reduced genome, of which about 10% is devoted to the biosynthesis of essential amino acids needed by its hosts. Most regulatory genes for these pathways are absent, raising the question of whether and how transcription of these genes responds to the major shifts in dietary amino acid content encountered by aphids. Using full-genome microarrays for B. aphidicola of the host Schizaphis graminum, we examined transcriptome responses to changes in dietary amino acid content and then verified behavior of individual transcripts using quantitative reverse transcriptase PCR. The only gene showing a consistent and substantial (>twofold) response was metE, which underlies methionine biosynthesis and which is the only amino acid biosynthetic gene retaining its ancestral regulator (metR). In another aphid host, Acyrthosiphon pisum, B. aphidicola has no functional metR and shows no response in metE transcript levels to changes in amino acid concentrations. Thus, the only substantial transcriptional response involves the one gene for which an ancestral regulator is retained. This result parallels that from a previous study on heat stress, in which only the few genes retaining the global heat shock promoter showed responses in transcript abundance. The irreversible losses of transcriptional regulators constrain ability to alter gene expression in the context of environmental fluctuations affecting the symbiotic partners.

scholarly journals Edaphic controls on genome size and GC content of bacteria in soil microbial communities

2021 ◽  
Author(s):  
Peter Francis Chuckran ◽  
Cody Flagg ◽  
Jeffrey Propster ◽  
William Austin Rutherford ◽  
Ella T. Sieradzki ◽  
...  
Keyword(s):  
Amino Acid ◽  
Codon Usage ◽  
Genome Size ◽  
Acid Content ◽  
Bacterial Genome ◽  
Soil Microbial Communities ◽  
Gc Content ◽  
Amino Acid Content ◽  
The United States ◽  
Soil Bacterial

Genomic traits, such as genome size, GC content, codon usage, and amino acid content, shed insight into the evolutionary processes of bacteria and selective forces behind microbial community composition. Nutrient limitation has been shown to reduce bacterial genome size and influence nucleotide composition, yet little research has been conducted in the soil environment, and the factors which shape soil bacterial genomic traits remain largely unknown. Here we determined average genome size, GC content, codon usage, and amino acid content from 398 soil metagenomes across the United States from the National Ecological Observation Network (NEON) and observed the distribution of these traits across numerous environmental gradients. We found that genomic trait averages were most strongly related to pH, which we suggest results in both physiological constraints on growth as well as affects availability of nutrients in soil. Low pH soils had higher carbon to nitrogen ratios (C:N) and tended to have communities with larger genomes and lower GC-content, potentially a result of increased physiological stress and increased metabolic diversity. Conversely, smaller genomes with high GC content were associated with high pH and low soil carbon to nitrogen ratios, indicating potential resource driven selection against carbon-rich AT base pairs. We found that this relationship of nutrient conservation also applied to amino acid stoichiometry, where bacteria in soils with C:N ratios tended to code for amino acids with lower C:N. Together, these relationships point towards fundamental mechanisms which underpin nucleotide and amino acid selection in soil bacterial communities.

scholarly journals Influence of mild feed restriction and mild reduction in dietary amino acid content on feeding behaviour of group-housed growing pigs

2018 ◽  
Vol 198 ◽  
pp. 27-35 ◽  
Author(s):  
Giuseppe Carcò ◽  
Mirco Dalla Bona ◽  
Luca Carraro ◽  
Maria Angeles Latorre ◽  
Manuel Fondevila ◽  
...  
Keyword(s):  
Amino Acid ◽  
Acid Content ◽  
Feeding Behaviour ◽  
Amino Acid Content ◽  
Growing Pigs ◽  
Feed Restriction ◽  
Dietary Amino Acid ◽  
Mild Reduction

scholarly journals The effects of insulin and adrenaline on the amino-acid content of blood

1933 ◽  
Vol 27 (5) ◽  
pp. 1648-1654 ◽  
Author(s):  
James Murray Luck ◽  
Stanley Wallace Morse
Keyword(s):  
Amino Acid ◽  
Acid Content ◽  
Amino Acid Content

Evaluation of seed amino acid content and its correlation network analysis in wild soybean (Glycine soja) germplasm in Japan

2021 ◽  
Vol 19 (1) ◽  
pp. 35-43
Author(s):  
Awatsaya Chotekajorn ◽  
Takuyu Hashiguchi ◽  
Masatsugu Hashiguchi ◽  
Hidenori Tanaka ◽  
Ryo Akashi
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Acid Content ◽  
Free Amino ◽  
Glycine Soja ◽  
Wild Soybean ◽  
Amino Acid Content ◽  
Soybean Seeds ◽  
Free Amino Acid Content

AbstractWild soybean (Glycine soja) is a valuable genetic resource for soybean improvement. Seed composition profiles provide beneficial information for the effective conservation and utilization of wild soybeans. Therefore, this study aimed to assess the variation in free amino acid abundance in the seeds of wild soybean germplasm collected in Japan. The free amino acid content in the seeds from 316 accessions of wild soybean ranged from 0.965 to 5.987 mg/g seed dry weight (DW), representing a 6.2-fold difference. Three amino acids had the highest coefficient of variation (CV): asparagine (1.15), histidine (0.95) and glutamine (0.94). Arginine (0.775 mg/g DW) was the predominant amino acid in wild soybean seeds, whereas the least abundant seed amino acid was glutamine (0.008 mg/g DW). A correlation network revealed significant positive relationships among most amino acids. Wild soybean seeds from different regions of origin had significantly different levels of several amino acids. In addition, a significant correlation between latitude and longitude of the collection sites and the total free amino acid content of seeds was observed. Our study reports diverse phenotypic data on the free amino acid content in seeds of wild soybean resources collected from throughout Japan. This information will be useful in conservation programmes for Japanese wild soybean and for the selection of accessions with favourable characteristics in future legume crop improvement efforts.

scholarly journals Further evidence that mechanisms of host/symbiont integration are dissimilar in the maternal versus embryonic Acyrthosiphon pisum bacteriome

EvoDevo ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Celeste R. Banfill ◽  
Alex C. C. Wilson ◽  
Hsiao-ling Lu
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Acyrthosiphon Pisum ◽  
Essential Amino Acids ◽  
Developmental Time ◽  
Follicular Epithelium ◽  
Future Research ◽  
Buchnera Aphidicola ◽  
Bacterial Endosymbionts ◽  
Asexual Embryogenesis

Abstract Background Host/symbiont integration is a signature of evolutionarily ancient, obligate endosymbioses. However, little is known about the cellular and developmental mechanisms of host/symbiont integration at the molecular level. Many insects possess obligate bacterial endosymbionts that provide essential nutrients. To advance understanding of the developmental and metabolic integration of hosts and endosymbionts, we track the localization of a non-essential amino acid transporter, ApNEAAT1, across asexual embryogenesis in the aphid, Acyrthosiphon pisum. Previous work in adult bacteriomes revealed that ApNEAAT1 functions to exchange non-essential amino acids at the A. pisum/Buchnera aphidicola symbiotic interface. Driven by amino acid concentration gradients, ApNEAAT1 moves proline, serine, and alanine from A. pisum to Buchnera and cysteine from Buchnera to A. pisum. Here, we test the hypothesis that ApNEAAT1 is localized to the symbiotic interface during asexual embryogenesis. Results During A. pisum asexual embryogenesis, ApNEAAT1 does not localize to the symbiotic interface. We observed ApNEAAT1 localization to the maternal follicular epithelium, the germline, and, in late-stage embryos, to anterior neural structures and insect immune cells (hemocytes). We predict that ApNEAAT1 provisions non-essential amino acids to developing oocytes and embryos, as well as to the brain and related neural structures. Additionally, ApNEAAT1 may perform roles related to host immunity. Conclusions Our work provides further evidence that the embryonic and adult bacteriomes of asexual A. pisum are not equivalent. Future research is needed to elucidate the developmental time point at which the bacteriome reaches maturity.

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