scholarly journals Sexual dimorphism for water balance mechanisms in montane populations of Drosophila kikkawai

2010 ◽  
Vol 6 (4) ◽  
pp. 570-574 ◽  
Author(s):  
Ravi Parkash ◽  
Vineeta Sharma ◽  
Bhawna Kalra
Keyword(s):  
Sexual Dimorphism ◽  
Water Balance ◽  
Cuticular Lipids ◽  
Clinal Variation ◽  
Western Himalayas ◽  
Desiccation Resistance ◽  
Cuticular Transpiration ◽  
Ecological Success ◽  
Water Proofing

Conservation of water is critical to the ecological success of Drosophila species living in the drier montane localities of the Western Himalayas. We observed clinal variation in desiccation resistance for both sexes of Drosophila kikkawai from an altitudinal transect (512–2226 m above sea level). Since more than 90 per cent of body water is lost through cuticular transpiration, the target of selection may be cuticular lipids or cuticular melanization. We tested whether melanic females and non-melanic males of D. kikkawai have similar mechanisms of desiccation resistance. There is clinal variation in the amount of cuticular lipids per fly in males, but not in females. By contrast, for females, elevational increase in melanization is positively correlated with desiccation resistance and negatively with cuticular water loss, but there is no variation in the amount of cuticular lipids. Thus, sexual dimorphism for the mechanism of desiccation resistance in D. kikkawai matches the water proofing role of body melanization as well as cuticular lipids.

Sex-specific differences in the physiological basis of water conservation in the fruit fly Drosophila hydei from the western Himalayas

2014 ◽  
Vol 92 (6) ◽  
pp. 545-555 ◽  
Author(s):  
Ravi Parkash ◽  
Divya Singh ◽  
Chanderkala Lambhod
Keyword(s):  
Relative Abundance ◽  
Water Loss ◽  
Water Conservation ◽  
Seasonal Changes ◽  
Fruit Fly ◽  
Cuticular Lipids ◽  
Western Himalayas ◽  
Desiccation Resistance ◽  
Physiological Basis ◽  
Drosophila Hydei

In the cosmopolitan fruit fly Drosophila hydei Sturtevant, 1921 (Diptera: Drosophilidae), the relative abundance of males is significantly higher than females, but the physiological basis of such sex-specific differences are largely unknown. For wild populations of D. hydei, we found seasonal changes (summer versus autumn) in desiccation-related traits, but the desiccation tolerance of males was higher than that of females in all seasons. For desiccation-related traits, we tested whether thermal developmental acclimation at three temperatures (17, 21, and 28 °C) matched seasonal changes observed under wild conditions. Male flies showed significantly higher trait values for desiccation resistance, cuticular lipid mass, hemolymph content, carbohydrate content, and dehydration tolerance compared with females when reared at lower or higher temperatures despite the lack of significant sex-specific differences in the total body-water content of flies reared at a particular growth temperature. We observed plastic changes in the amount of cuticular lipids consistent with corresponding differences in the rate of water loss. Treatment of cuticular surface with organic solvent (hexane) supported the role of cuticular lipids in affecting transcuticular water loss. We found significant thermal plastic effects for desiccation-related traits of D. hydei, but the sexual dimorphism was in the opposite direction, i.e., males were more desiccation resistant than females in D. hydei, whereas the reverse is true for many other Drosophila species. Our results suggest that sex-specific differences in the level of desiccation resistance in D. hydei are good predictors of relative abundance levels of male and female flies under wild conditions.

Thermal developmental plasticity affects body size and water conservation of Drosophila nepalensis from the Western Himalayas

2014 ◽  
Vol 104 (4) ◽  
pp. 504-516 ◽  
Author(s):  
R. Parkash ◽  
C. Lambhod ◽  
D. Singh
Keyword(s):  
Body Size ◽  
Water Balance ◽  
Mass Culture ◽  
Growth Temperature ◽  
Water Loss ◽  
Water Conservation ◽  
Developmental Plasticity ◽  
Seasonal Abundance ◽  
Western Himalayas ◽  
Desiccation Resistance

AbstractIn the Western Himalayas, Drosophila nepalensis is more abundant during the colder and drier winter than the warmer rainy season but the mechanistic bases of such adaptations are largely unknown. We tested effects of developmental plasticity on desiccation-related traits (body size, body melanization and water balance traits) that may be consistent with changes in seasonal abundance of this species. D. nepalensis grown at 15°C has shown twofold higher body size, greater melanization (∼15-fold), higher desiccation resistance (∼55 h), hemolymph as well as carbohydrate content (twofold higher) as compared with corresponding values at 25°C. Water loss before succumbing to death was much higher (∼16%) at 15°C than 25°C. Developmental plastic effects on body size are associated with changes in water balance-related traits (bulk water, hemolymph and dehydration tolerance). The role of body melanization was evident from the analysis of assorted darker and lighter flies (from a mass culture of D. nepalensis reared at 21°C) which lacked differences in dry mass but showed differences in desiccation survival hours and rate of water loss. For adult acclimation, we found a slight increase in desiccation resistance of flies reared at lower growth temperature, whereas in flies reared at 25°C such a response was lacking. In D. nepalensis, greater developmental plasticity is consistent with its contrasting levels of seasonal abundance. Finally, in the context of global climate change in the Western Himalayas, D. nepalensis seems vulnerable in the warmer season due to lower adult as well as developmental acclimation potential at higher growth temperature (25°C).

scholarly journals Regulatory Role of Sex Hormones in Cardiovascular Calcification

2021 ◽  
Vol 22 (9) ◽  
pp. 4620
Author(s):  
Holly J. Woodward ◽  
Dongxing Zhu ◽  
Patrick W. F. Hadoke ◽  
Victoria E. MacRae
Keyword(s):  
Cardiovascular Disease ◽  
Sex Differences ◽  
Sexual Dimorphism ◽  
Aortic Stenosis ◽  
Sex Hormones ◽  
Sex Hormone ◽  
Increased Risk ◽  
Male Sex ◽  
Primary Male

Sex differences in cardiovascular disease (CVD), including aortic stenosis, atherosclerosis and cardiovascular calcification, are well documented. High levels of testosterone, the primary male sex hormone, are associated with increased risk of cardiovascular calcification, whilst estrogen, the primary female sex hormone, is considered cardioprotective. Current understanding of sexual dimorphism in cardiovascular calcification is still very limited. This review assesses the evidence that the actions of sex hormones influence the development of cardiovascular calcification. We address the current question of whether sex hormones could play a role in the sexual dimorphism seen in cardiovascular calcification, by discussing potential mechanisms of actions of sex hormones and evidence in pre-clinical research. More advanced investigations and understanding of sex hormones in calcification could provide a better translational outcome for those suffering with cardiovascular calcification.

Role of Plasma Vasopressin in Changes of Water Balance Accompanying Acute Alcohol Intoxication

1995 ◽  
Vol 19 (3) ◽  
pp. 759-762 ◽  
Author(s):  
Hanna Taivainen ◽  
Kalevi Laitinen ◽  
Riitta Tahtela ◽  
Kalervo Kiianmaa ◽  
Matti J. Valimaki
Keyword(s):  
Water Balance ◽  
Alcohol Intoxication ◽  
Acute Alcohol Intoxication ◽  
Plasma Vasopressin

Abstract P199: Mas Receptor Deficiency Regulates Obesity-Hypertension and Cardiac Function in Female and Male Mice

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Robin C Shoemaker ◽  
Yu Wang ◽  
Sean Thatcher ◽  
Lisa Cassis
Keyword(s):  
Blood Pressure ◽  
Sexual Dimorphism ◽  
Cardiac Function ◽  
Male Mice ◽  
Reduced Ejection Fraction ◽  
Obesity Hypertension ◽  
Obese Male ◽  
Deficient Mice ◽  
Cmr Imaging

Angiotensin-1-7 (Ang-(1-7)) counteracts angiotensin II through effects at Mas receptors (MasR). We demonstrated that sexual dimorphism of obesity-hypertension was associated with dysregulated production of Ang-(1-7). However, the role of MasR in sexual dimorphism of obesity-hypertension has not been examined. MasR deficient mice have also been reported to exhibit deficits in cardiac function. In this study, we hypothesized that deficiency of the MasR would differentially regulate obesity-hypertension in male versus ( vs ) female mice. In addition, we quantified effects of MasR deficiency on cardiac function in obese male mice. Male and female MasR +/+ and -/- mice were fed a low fat (LF, 10%kcal) or high fat (HF, 60% kcal) diet for 16 weeks, and blood pressure was quantified by radiotelemetry. As demonstrated previously, male MasR +/+ mice (24 hr diastolic blood pressure, DBP: LF, 90 ± 3; HF, 96 ± 2 mmHg; P<0.05), but not females (LF, 85 ± 1; HF, 85 ± 2 mmHg), developed hypertension in response to HF feeding. MasR deficiency converted female HF-fed mice to an obesity-hypertension phenotype (DBP: 92 ± 1 mmHg; P<0.05). Surprisingly, male HF-fed MasR -/- mice exhibited reduced DBP compared to HF-fed MasR +/+ males (90 ± 1 vs 96 ± 2 mmHg; P<0.05). To define mechanisms for reductions in DBP of HF-fed male MasR -/- mice, we performed cardiac magnetic resonance (CMR) imaging in both genotypes at 1 month of HF feeding. MasR -/- mice had significantly reduced ejection fraction (EF) compared to MasR +/+ mice at baseline (51.4 ± 2.5 vs 59.3 ± 2.1%; P<0.05) and after one month of HF-feeding (49.8 ± 2.4 vs 52.6 ± 1.9%; P<0.05). Further, CMR imaging demonstrated a thickening of the ventricle wall in MasR -/- mice with 1 month of HF-feeding. MasR +/+ , but not MasR -/- mice, exhibited diet-induced reductions in EF (by 16%; P<0.05) at 1 month of HF feeding, which were reversed by infusion of Ang-(1-7). These results demonstrate that MasR contributes to sexual dimorphism of obesity-hypertension. Ang-(1-7) protects females from obesity-hypertension through the MasR. In contrast, reductions in DBP in obese male mice with MasR deficiency may arise from deficits in cardiac function. These results suggest that MasR agonists may be effective therapies for obesity-associated cardiovascular conditions.

Bora wind and heavy persistent precipitation: atmospheric water balance and role of air-sea fluxes over the Adriatic Sea

2017 ◽  
Vol 143 (703) ◽  
pp. 1165-1177 ◽  
Author(s):  
Silvio Davolio ◽  
Riccardo Henin ◽  
Paolo Stocchi ◽  
Andrea Buzzi
Keyword(s):  
Water Balance ◽  
Adriatic Sea ◽  
Atmospheric Water ◽  
Bora Wind

scholarly journals Critical role of PPARγ in water balance

2015 ◽  
Vol 47 (11) ◽  
pp. 538-540 ◽  
Author(s):  
Ningjun Li
Keyword(s):  
Water Balance ◽  
Critical Role
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