scholarly journals Dietary cardenolides enhance growth and change the direction of the fecundity-longevity trade-off in milkweed bugs (Heteroptera: Lygaeinae)

2021 ◽  
Author(s):  
Prayan Pokharel ◽  
Anke Steppuhn ◽  
Georg Petschenka

1. Sequestration, i.e., the accumulation of plant toxins into body tissues for defence, is primarily observed in specialised insects. Sequestration was frequently predicted to incur a physiological cost mediated by increased exposure to plant toxins and may require resistance traits different from those of non-sequestering insects. Alternatively, sequestering species could experience a cost in the absence of toxins due to selection on physiological homeostasis under permanent exposure of sequestered toxins in body tissues. 2. Milkweed bugs (Heteroptera: Lygaeinae) sequester high amounts of plant-derived cardenolides. Although being potent inhibitors of the ubiquitous animal enzyme Na+/K+-ATPase, milkweed bugs can tolerate cardenolides by means of resistant Na+/K+-ATPases. Both adaptations, resistance and sequestration, are ancestral traits shared by most species of the Lygaeinae. 3. Using four milkweed bug species and the related European firebug (Pyrrhocoris apterus) showing different combinations of the traits ′cardenolide resistance′ and ′cardenolide sequestration′, we set out to test how the two traits affect larval growth upon exposure to dietary cardenolides in an artificial diet system. While cardenolides impaired the growth of P. apterus nymphs neither possessing a resistant Na+/K+-ATPase nor sequestering cardenolides, growth was not affected in the non-sequestering milkweed bug Arocatus longiceps, which possesses a resistant Na+/K+-ATPase. Remarkably, cardenolides increased growth in the sequestering dietary specialists Caenocoris nerii and Oncopeltus fasciatus but not in the sequestering dietary generalist Spilostethus pandurus, which all possess a resistant Na+/K+-ATPase. 4. We then assessed the effect of dietary cardenolides on additional life history parameters, including developmental speed, the longevity of adults, and reproductive success in O. fasciatus. Remarkably, nymphs under cardenolide exposure developed substantially faster and lived longer as adults. However, fecundity of adults was reduced when maintained on cardenolide-containing diet for their entire life-time but not when adults were transferred to non-toxic sunflower seeds. 5. We speculate that the resistant Na+/K+-ATPase of milkweed bugs is selected for working optimally in a ′toxic environment′, i.e. when sequestered cardenolides are stored in the body tissues. Contrary to the assumption that toxins sequestered for defence produce a physiological burden, our data suggest that they can even increase fitness in specialised insects.

2016 ◽  
Vol 8 ◽  
pp. IJIS.S40566 ◽  
Author(s):  
Karel Sláma ◽  
Jan Lukáš

The physiological and biochemical mechanisms that enable insects to feed on dry food to secure enough water for larval growth were investigated. The study was carried out with a plethora of physiological methods, ranging from the simple volumetric determination of O2 consumption and water intake to more advanced methods such as scanning microrespirography and thermovision imaging of insect's body temperature. The experiments were done on the European firebug, Pyrrhocoris apterus, which feeds exclusively on dry linden seeds. In order to survive, it needs to drink water or suck a sap from plants occasionally. It was found that the young larval instars compensate the occasional water deficiency by the increased production of metabolic water. The juvenile hormone (JH)-dependent production of metabolic water, which was previously found in other species consuming dry food, was achieved in P. apterus by total metabolic combustion of the dietary lipid (neutral seed oil). The water-producing, hypermetabolic larvae were heated from inside by endothermic energy released from the uncoupling of oxidation from oxidative phosphorylation. The “warm”, hypermetabolic larvae burning the dietary oil into CO2 and water showed the increased rates of respiratory metabolism. Microrespirographic recording of these larvae revealed the ratio of the respiratory quotient (RQ, CO2/O2) of 0.7, which indicated the breakdown of a pure triglyceride. The warm hypermetabolic larvae could be easily spotted and distinguished from the “cold” larvae on the screen of a thermovision camera. The last instar larvae lacking the JH were always only cold. They metabolized a carbohydrate substrate exclusively (RQ = 1.0), while the dietary lipid was stored in the fat body. In comparison with the hypermetabolic larvae of some other species fed on dry food, which exhibited the highest rates of O2 consumption ever recorded in a living organism (10–20 mL O2/g per hour), the metabolic difference between the warm and cold larvae of P. apterus was only some 30% (not a reported 10-fold difference), which was presumably due to their ability to drink. We conclude that a very important, though still largely neglected, epigenetic biochemical role of insect JH depends on switchover between the utilization of dietary lipid (+JH; production of metabolic water) and carbohydrate (-JH; lipid storage in the fat body). The hypermetabolic water supply in insects fed on dry food, which is associated with enormous rates of O2 consumption, liberates endothermic energy that heats the body and potentially influences the insect thermoregulation. A possibility that the JH-dependent lipolytic hormone stimulates the total metabolic breakdown of nutritional lipids may be absolutely different from the currently known adipokinetic peptides that have been emphasized.


2021 ◽  
Author(s):  
Josefine Just ◽  
Mara Laslo ◽  
Ye Jin Lee ◽  
Michael C Yarnell ◽  
Zhuofan Zhang ◽  
...  

Sexual dimorphism is a common feature of animals. Sex determination mechanisms vary widely among species and evolve rapidly. Until recently studies have found consistent mechanisms across the body of each individual determine female or male dimorphic body structures. In sexually dimorphic cells throughout the body of Drosophila, the relative dosage of autosomes and X chromosomes leads indirectly to alternatively spliced transcripts from the gene doublesex. The female Dsx isoform interacts with the mediator complex protein encoded by intersex to activate female development in flies. In males the transcription factor encoded by fruitless promotes male-specific behavior. In the milkweed bug Oncopeltus fasciatus, we find a requirement for different combinations of these genes during development of distinct dimorphic structures, within the same sex, suggesting a previously unappreciated level of diversity in sex determination. While intersex and fruitless are structurally conserved, doublesex has a history of duplication and divergence among Paraneoptera. Three doublesex paralogs in O. fasciatus produce multiple transcripts with sex- and tissue-specific expression. intersex and fruitless are expressed across the body, in females and males. RNA interference reveals only one doublesex paralog functions in somatic sex determination. Knockdown of doublesex and fruitless produces intersex phenotypic conditions in two sexually dimorphic structures: genitalia and abdominal sternites. In contrast, intersex is required for dimorphic development of female and male genitalia, but not for sternite dimorphism. These results reveal sex determination roles for intersex and fruitless distinct from their orthologs in other insects. Our results illuminate a novel form of developmental diversity in insect sex determination.


2019 ◽  
Vol 11 (4) ◽  
pp. 277-284
Author(s):  
Vitrianingsih Vitrianingsih ◽  
Sitti Khadijah

Studi memperkirakan emesis gravidarum terjadi pada 50-90% kehamilan. Mual muntah pada kehamilan memberikan dampak yang signifikan bagi tubuh dimana ibu menjadi lemah, pucat dan cairan tubuh berkurang sehingga darah menjadi kental (hemokonsentrasi). Keadaan ini dapat memperlambat peredaran darah dan berakibat pada kurangnya suplay oksigen serta makanan ke jaringan sehingga dapat membahayakan kesehatan ibu dan janin. Salah satu terapi yang aman dan dapat dilakukan untuk mengurangi keluahan mual muntah pada ibu hamil adalah pemberian aromaterapi lemon. Penelitian bertujuan untuk mengetahui efektifitas aroma terapi lemon untuk menangani emesis gravidarum. Penelitian ini menggunakan rancangan Quasi experiment  dengan  one group pre-post test design. Populasi penelitian adalah ibu hamil yang mengalami emesis gravidarum di Kecamatan Berbah, Sleman. Jumlah sampel 20 ibu hamil trimester pertama yang diambil dengan teknik purposive sampling. Pengukuran mual muntah dilakukan debelum dan setelah  pemberian aromaterapi lemon menggunakan Indeks Rhodes. Analisa data menggunakan uji Paired t-test. Hasil penelitian didapatkan rata-rata skor mual muntah sebelum pemberian aromaterapi lemon berdasarkan Indeks Rhodes pada Ibu Hamil dengan emesis gravidarum yaitu 22,1 dan terjadi penurunan skor setelah pemberian aromaterapi lemon menjadi 19,8. Ada pengaruh pemberian aromaterapi lemon dengan pengurangan mual muntah pada ibu hamil (p-value = 0.017). Berdasarkan hasil penelitian dapat disimpulkan pemberian aromaterapi lemon efektif untuk mengurangi emesis gravidarum pada ibu hamil trimester pertama.  Kata kunci: aromaterapi lemon, emesis gravidarum THE EFFECTIVENESS OF LEMON AROMATHERAPY FOR HANDLING EMESIS GRAVIDARUM   ABSTRACT Studies estimate that nausea and vomiting (emesis gravidarum) occur in 50 – 90% of pregnancies. Nausea and vomiting of pregnancy have a significant impact on the body in which it makes a mother becomes weak, pale, and decreasing body fluid so that the blood becomes thick (hemoconcentration). This situation can slow down blood circulation and inflict the lack of oxygen and food supplies to the body tissues so that it can endanger the health of the mother and fetus. One of the therapies that is safe and can be conducted to reduce nausea and vomiting of pregnancy is by giving the lemon aromatherapy treatment. The research aims to determine the effectiveness of the aroma of lemon therapy to deal with emesis gravidarum. This study applied quasi-experimental research with one group pretest-posttest design. The population of this study was pregnant women who experienced emesis gravidarum. Furthermore, samples were 20 mothers from Berbah, Sleman taken by using a purposive sampling technique. Nausea and vomiting were assessed between before and after giving lemon aromatherapy using the Rhodes Index. The data were analyzed using the paired t-test. The mean score of nausea and vomiting before giving lemon aromatherapy on mother with emesis gravidarum based on the Rhodes Index was 22.1. However, it decreased after given lemon aromatherapy treatment to 19.8. Therefore, there was an effect on giving lemon aromatherapy treatment toward the decrease of nausea and vomiting for pregnant women (p-value = 0.017). Lemon aromatherapy is effective to reduce emesis gravidarum.  Keywords: lemon aromatherapy, emesis gravidarum


Author(s):  
A. E. Chernikova ◽  
Yu. P. Potekhina

Introduction. An osteopathic examination determines the rate, the amplitude and the strength of the main rhythms (cardiac, respiratory and cranial). However, there are relatively few studies in the available literature dedicated to the influence of osteopathic correction (OC) on the characteristics of these rhythms.Goal of research — to study the influence of OC on the rate characteristics of various rhythms of the human body.Materials and methods. 88 adult osteopathic patients aged from 18 to 81 years were examined, among them 30 men and 58 women. All patients received general osteopathic examination. The rate of the cranial rhythm (RCR), respiratory rate (RR) heart rate (HR), the mobility of the nervous processes (MNP) and the connective tissue mobility (CTM) were assessed before and after the OC session.Results. Since age varied greatly in the examined group, a correlation analysis of age-related changes of the assessed rhythms was carried out. Only the CTM correlated with age (r=–0,28; p<0,05) in a statistically significant way. The rank dispersion analysis of Kruskal–Wallis also showed statistically significant difference in this indicator in different age groups (p=0,043). With the increase of years, the CTM decreases gradually. After the OC, the CTM, increased in a statistically significant way (p<0,0001). The RCR varied from 5 to 12 cycles/min in the examined group, which corresponded to the norm. After the OC, the RCR has increased in a statistically significant way (p<0,0001), the MNP has also increased (p<0,0001). The initial heart rate in the subjects varied from 56 to 94 beats/min, and in 15 % it exceeded the norm. After the OC the heart rate corresponded to the norm in all patients. The heart rate and the respiratory rate significantly decreased after the OC (р<0,0001).Conclusion. The described biorhythm changes after the OC session may be indicative of the improvement of the nervous regulation, of the normalization of the autonomic balance, of the improvement of the biomechanical properties of body tissues and of the increase of their mobility. The assessed parameters can be measured quickly without any additional equipment and can be used in order to study the results of the OC.


2019 ◽  
Vol 20 (7) ◽  
pp. 661-665
Author(s):  
Cunxi Nie ◽  
Fei Xie ◽  
Ning Ma ◽  
Yueyu Bai ◽  
Wenju Zhang ◽  
...  

As a major component of biologically active compounds in the body, proteins contribute to the synthesis of body tissues for the renewal and growth of the body. The high level of dietary protein and the imbalance of amino acid (AA) composition in mammals result in metabolic disorders, inefficient utilization of protein resources and increased nitrogen excretion. Fortunately, nutritional interventions can be an effective way of attenuating the nitrogen excretion and increasing protein utilization, which include, but are not limited to, formulating the AA balance and protein-restricted diet supplementing with essential AAs, and adding probiotics in the diet. This review highlights recent advances in the turnover of dietary proteins and mammal’s metabolism for health, in order to improve protein bioavailability through nutritional approach.


1974 ◽  
Vol 82 (1) ◽  
pp. 87-95 ◽  
Author(s):  
E. F. Annison ◽  
R. Bickerstaffe ◽  
J. L. Linzell

SUMMARYThe effects of changing to a high starch: low roughage diet have been studied in two Friesian and two Jersey cows, surgically prepared for the simultaneous study of udder metabolism (arteriovenous difference x udder blood flow) and whole body turnover of milk precursors (isotope dilution).In the Friesian cows milk fat concentration was lower on the high starch diet but in the Jerseys fell only slightly in one animal. In both Friesians and in the one Jersey these changes were accompanied by an increase in total rumen VFA concentration. Rumen acetate concentration did not change but propionate doubled. Thus this confirms that the usually reported fall in ‘acetate:propionate ratio’ is due to a rise in propionate production rather than due to a fall in acetate production.There were significant falls in the blood concentrations of acetate and β-hydroxy-butyrate. The rate of extraction by the udder of acetate and β-hydroxybutyrate did not change but triglyceride extraction fell. Therefore since udder blood flow did not alter the uptake of all three fat precursors fell.The entry rate of glucose into the circulation and its contribution to total body CO2 increased. The entry rate and contribution to CO2 of acetate decreased but this was probably mainly due to a fall in endogenous acetate production by the body tissues. Plasma FFA concentration showed little change but the entry rate of palmitate fell on the high starch diet. There was also an increased proportion of unsaturated and trans fatty acids in the plasma and milk triglycerides.


1966 ◽  
Vol 12 (11) ◽  
pp. 1411-1421 ◽  
Author(s):  
Hugh S. Forrest ◽  
Michael Menaker ◽  
Jennifer Alexander

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