scholarly journals Effects of symbiotic population impairment on microbiome composition and longevity of Bactrocera dorsalis

2021 ◽  
Vol 8 (11) ◽  
Author(s):  
Mazarin Akami ◽  
Ousman Tamgue ◽  
Xueming Ren ◽  
Yaohui Wang ◽  
Xuewei Qi ◽  
...  

In order to understand the role of symbionts for their insect hosts, it is customary to treat them with antibiotics or to sterilize eggs (treatments), resulting in aposymbiotic and axenic insects, respectively. Such axenic insects can then be compared with untreated controls. Fruit flies often bear complex communities which are greatly reduced by such treatments. However, the bacterial community is not completely eliminated. Here, we examine the effect of these procedures on the structure of the remaining bacterial communities in Bactrocera dorsalis (Diptera: Tephritidae) and on the insect longevity. The antibiotics (Norfloxacin and Ceftazedime) were administered to 1-day-old adult flies through sugar meal for 7 days, and eggs were surface sterilized and dechorionated to produce axenic lines. The flies were starved of protein before they were offered full diets or diets containing non-essential amino acids only. Antibiotic and egg disinfection treatments resulted in a significant reduction of the vast majority of gut bacterial populations, especially Proteobacteria, Firmicutes and Bacteroidetes. On the other hand, antibiotic allowed the persistence of Actinobacteria, Cyanobacteria and Acidobacteria populations. In untreated control flies, longevity was extended irrespective of diet quality in comparison to treated flies. Conversely, when gut bacteria were largely reduced (aposymbiotic and axenic flies), longevity was reduced in the non-essential amino acids diet treatment versus slightly improved in the presence of a protein diet. We discuss these results in an ecological–life-history perspective.

1993 ◽  
Vol 265 (5) ◽  
pp. F605-F623 ◽  
Author(s):  
R. Garza-Quintero ◽  
J. M. Weinberg ◽  
J. Ortega-Lopez ◽  
J. A. Davis ◽  
M. A. Venkatachalam

Increases of intracellular free Ca2+ (Caf) may mediate phospholipid hydrolysis and disintegration in energy-compromised cells; on the other hand, glycine and related amino acids preserve structure. We have examined the effects of increased Caf on phospholipids and structure in ATP-depleted cells, as well as how these actions may be modified by glycine. Incubation of isolated proximal tubules with antimycin A led to ATP depletion, delayed increases of Caf to micromolar levels, polyphosphoinositide (PPI) hydrolysis by phospholipase C, and generalized disintegration of cell structure. Glycine inhibited PPI hydrolysis and preserved cell structure in entirety but did not apparently modify the Caf increases. When overwhelming increases of Caf were induced by the additional presence of a Ca2+ ionophore, glycine did not inhibit either the hydrolysis of PPI or disruption of mitochondria and microvilli. However, the cells remained integrated and unbroken. Incubation in low-Ca2+ medium prevented Caf increases, inhibited PPI hydrolysis, and preserved the structure of mitochondria and microvilli. Nevertheless, there was lethal damage by disintegration of all other membranes. This damage was prevented specifically and completely by glycine. Thus compartments of cells were shown to be differentially susceptible to injury from increased Caf or lack of glycine. Although damage by either factor occurs by distinct mechanisms, glycine also appears to have effects that suppress the deleterious effects of Ca2+ so long as Caf increases are not overwhelming. Our results also suggest that the PPI have a major structural role, which may be compromised by Caf increase during ATP depletion.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kai Kamm ◽  
Hans-Jürgen Osigus ◽  
Peter F. Stadler ◽  
Rob DeSalle ◽  
Bernd Schierwater

AbstractSymbiotic relationships between eukaryotic hosts and bacteria range from parasitism to mutualism and may deeply influence both partners’ fitness. The presence of intracellular bacteria in the metazoan phylum Placozoa has been reported several times, but without any knowledge about the nature of this relationship and possible implications for the placozoan holobiont. This information may be of crucial significance since little is known about placozoan ecology and how different species adapt to different environmental conditions, despite being almost invariable at the morphological level. We here report on the novel genome of the rickettsial endosymbiont of Trichoplax sp. H2 (strain “Panama”). The combination of eliminated and retained metabolic pathways of the bacterium indicates a potential for a mutualistic as well as for a parasitic relationship, whose outcome could depend on the environmental context. In particular we show that the endosymbiont is dependent on the host for growth and reproduction and that the latter could benefit from a supply with essential amino acids and important cofactors. These findings call for further studies to clarify the actual benefit for the placozoan host and to investigate a possible role of the endosymbiont for ecological separation between placozoan species.


2011 ◽  
Vol 15 (1) ◽  
pp. 56-61 ◽  
Author(s):  
Gema Lucena ◽  
Candela Reyes-Botella ◽  
Olga García-Martínez ◽  
Lourdes Díaz-Rodríguez ◽  
Francisco Alba ◽  
...  

Aminopeptidases (APs) are enzymes involved in a wide variety of biological processes and present in a variety of different cell populations. The authors studied these enzymes in primary cultured human osteoblasts in order to establish an activity profile and thereby contribute to knowledge of bone tissue. The authors used 13 different substrates ( N-terminal amino acids) and a fluorimetric assay to examine AP activity associated with the membranes of cultured osteoblasts. The authors demonstrated activity > 10 pmol/min/104 cells when glycine, alanine, leucine, arginine, phenylalanine, methionine, and lysine were used as substrates. The activity was markedly lower (<1.6 pmol/min/104 cells) when the other N-terminal amino acids were used. Puromycin and bestatin inhibited AP activity, though not completely, when we used AlaNA or LeuNA as substrates. Further studies are warranted to determine the role of these enzymes in bone tissue physiology.


1994 ◽  
Vol 72 (8) ◽  
pp. 841-848 ◽  
Author(s):  
G. Harvey Anderson ◽  
Shuqin Luo ◽  
Leonidas Trigazis ◽  
Greta Kubis ◽  
Edmund T. S. Li

This study examined the effects of selected groups of essential amino acids (EAAs), given by gavage, on short-term food and water intake. Amino acid groups were selected on the basis of their common physiologic functions in relation to current hypotheses on the role of amino acids in food intake control, and the quantities given were based on the proportions in 1.5 g of the EAA content of albumin. The complete EAA mixture (1.5 g) suppressed food intake by an average of 60 and 37% during the 1st and 2nd h of feeding, respectively, but had no influence on feeding in the subsequent 12 h. Total daily (14 h) intake was decreased by 9%. With the exception of the aromatic amino acid (Phe + Tyr + Trp, 0.34 g) group, all groups significantly decreased food intake by a comparable magnitude (32%) during the 1st h. In this time period, rats given the EAAs, Arg + Met + Val (0.38 g), and Arg + His + Lys (0.44 g) mixtures increased their water intake, whereas intake by rats given the Phe + Tyr + Trp + Thr (0.46 g) and Ile + Leu + Val (0.45 g) mixtures was unchanged. Thus, the food intake suppression caused by EAAs was not accounted for by an equal effect of its component amino acid groups. As well, food intake suppression by amino acid groups was not explained by increased water consumption, nor was it simply related to the quantity of nitrogen provided by the treatment.Key words: food intake, water intake, essential amino acids.


1933 ◽  
Vol 5 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Samuel Morris ◽  
Norman C. Wright

The results of the present experiments and of those reported in the previous paper(1) may be summarised as follows:1. When minimal quantities of protein are fed in the production rations of milking cows, a deficiency of either lysine or tryptophane will lead to a marked reduction in milk yield. There is, however, some evidence of the storage of reserve N, which can be utilised when the food protein is inadequate.2. The feeding of a lysine- or tryptophane-deficient ration causes a marked increase in urinary N, indicating a poor utilisation of food protein. On the other hand, the feeding of a ration containing adequate quantities of these essential amino acids reduces the urinary N, indicating efficient protein utilisation.3. The utilisation of body tissue in an attempt to maintain normal milk production on a deficient protein ration is shown by the high creatine excretion. The fact that the S: N ratio of the excess sulphur and nitrogen excreted during the deficient protein periods approximates that of body tissue (circa 1: 15·7) confirms this conclusion.


1959 ◽  
Vol 197 (1) ◽  
pp. 27-30 ◽  
Author(s):  
D. F. Magee ◽  
S. S. Hong

Evidence is presented that the chronic pancreatic fistula dogs can be used effectively to study pancreatic physiology on a daily output basis. By increasing the amount of a mixed diet fed or by adding fat to the diet the volume and protease and lipase activities can be increased. Additions of cellulose, milk, casein hydrolysate were ineffective. On the basal mixed diet neither volume, amylase nor protease increased independently of each other. Changes in one enzyme activity without the other or in volume without enzymes were seen with supplements of essential amino acids or soy flour. The possible mechanism of these effects is discussed.


1957 ◽  
Vol 41 (1) ◽  
pp. 91-100 ◽  
Author(s):  
R. F. Haff ◽  
H. E. Swim

Strain RM3-56 of rabbit fibroblasts was found to require arginine, cystine, glutamine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, serine, threonine, tryptophan, tyrosine, and valine for growth in a medium containing 2 per cent dialyzed serum as the only undefined component. The requirement for serine is less specific than that of the other 13 amino acids and it is partially replaced by glycine, or alanine, or by several combinations of so called accessory amino acids. The concentrations of essential amino acids which permit maximal proliferation range from 0.005 to 0.3 mM. Cystine, glutamine, lysine, tryptophan, tyrosine, valine are toxic at concentrations of 5 mM. The rate of proliferation of RM3-56 in a medium containing all 14 essential amino acids is increased significantly by the addition of alanine and to a lesser extent by the addition of aspartic and glutamic acids and glycine. A deficiency of cystine or glutamine results in cellular degeneration within 3 to 5 days, whereas the cells remain in good condition for 2 to 3 weeks in the absence of each of the remaining 12 essential amino acids. The results obtained with RM3-56 are compared with strains HeLa, L, and U12, whose amino acid requirements have been investigated under similar conditions.


1986 ◽  
Vol 43 (11) ◽  
pp. 2320-2327 ◽  
Author(s):  
J. D. Castell ◽  
J. C. Kean

Many of the hypotheses and proposals presented here on the role of nutrition in lobster recruitment have been derived from research on other aquatic animals. Little research has focused on the determination of nutritional requirements of lobsters and even that has been primarily with small juveniles (36–1000 mg). Despite the tacit acknowledgement that maternal fecundity and egg viability are a function of quantity and quality of available food, little is known about the nutrition of reproductively mature lobsters. The importance of broodstock nutrition and possible methods for evaluating nutritional status are discussed. Information on protein, essential amino acids, vitamins, minerals, carbohydrates, and lipids is summarized. Additionally, some proposals for field application of nutritional response criteria used in the laboratory are discussed. Though research on larvae adult broodstock nutrition, effects of environmental factors (e.g. temperature, salinity, photoperiod, etc.), as well as many other aspects of nutrition is yet to be done, there is "good opportunity" for nutrition to be a significant part of the current lobster recruitment research program.


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