scholarly journals Fertility and mortality impacts of thermal stress from experimental heatwaves on different life stages and their recovery in a model insect

2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Kris Sales ◽  
Ramakrishnan Vasudeva ◽  
Matthew J. G. Gage
Keyword(s):  
Heat Stress ◽  
Thermal Stress ◽  
High Temperatures ◽  
Adult Male ◽  
Reproductive Function ◽  
Testis Size ◽  
Life Stages ◽  
Mature Adult ◽  
Male Reproductive Function ◽  
Survival And Reproduction

With climate change creating a more volatile atmosphere, heatwaves that create thermal stress for living systems will become stronger and more frequent. Using the flour beetle Tribolium castaneum , we measure the impacts of thermal stress from experimental heatwaves in the laboratory on reproduction and survival across different insect life stages, and the extent and pace of any recovery. We exposed larvae, pupae, juvenile and mature adult male beetles to 5-day periods of heat stress where temperatures were maintained at either 40°C or 42°C, a few degrees above the 35°C optimum for this species' population productivity, and then measured survival and reproduction compared with controls at 30°C. Mortality due to thermal stress was greatest among juvenile life stages. Male reproductive function was specifically damaged by high temperatures, especially if experienced through pupal or immature life stages when complete sterility was shown at reproductive maturity; larval exposure did not damage adult male fertility. High temperatures impaired testis development and the production of viable sperm, with damage being strongest when experienced during pupal or juvenile adult stages. Despite this disruption, males recovered from heat stress and, depending on the stage of exposure, testis size, sperm production and fertility returned to normal 15–28 days after exposure. Our experiments reveal how thermal stress from heatwave conditions could impact on insect survival and reproduction across different life stages, and the potential and timescales of recovery.

The influence of maternal phthalate exposure upon adult male reproductive function

2017 ◽  
Vol 108 (3) ◽  
pp. e30
Author(s):  
R. Hart ◽  
H. Frederiksen ◽  
D.A. Doherty ◽  
J. Keelan ◽  
N.E. Skakkebaek ◽  
...  
Keyword(s):  
Adult Male ◽  
Reproductive Function ◽  
Male Reproductive Function ◽  
Phthalate Exposure

scholarly journals Antioxidant Enzymes and Heat Shock Protein Genes from Liposcelis bostrychophila Are Involved in Stress Defense upon Heat Shock

Insects ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 839
Author(s):  
Ze Qing Miao ◽  
Yan Qing Tu ◽  
Peng Yu Guo ◽  
Wang He ◽  
Tian Xing Jing ◽  
...  
Keyword(s):  
Antioxidant Enzymes ◽  
Heat Stress ◽  
Thermal Stress ◽  
Heat Shock ◽  
Oxidative Damage ◽  
High Temperatures ◽  
Defense Mechanisms ◽  
Molecular Mechanisms ◽  
Instar Nymph ◽  
Liposcelis Bostrychophila

Psocids are a new risk for global food security and safety because they are significant worldwide pests of stored products. Among these psocids, Liposcelis bostrychophila has developed high levels of resistance or tolerance to heat treatment in grain storage systems, and thus has led to investigation of molecular mechanisms underlying heat tolerance in this pest. In this study, the time-related effects of thermal stress treatments at relatively high temperatures on the activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), peroxidases (POD), glutathione-S-transferases (GST) and malondialdehyde (MDA), of L. bostrychophila were determined. Thermal stress resulted that L. bostrychophila had a significantly higher MDA concentration at 42.5 °C, which indicated that the heat stress increased lipid peroxidation (LPO) contents and oxidative stress in this psocid pest. Heat stress also resulted in significant elevation of SOD, CAT and GST activities but decreased POD activity. Our data indicates that different antioxidant enzymes contribute to defense mechanisms, counteracting oxidative damage in varying levels. POD play minor roles in scavenging deleterious LPO, while enhanced SOD, CAT and GST activities in response to thermal stress likely play a more important role against oxidative damage. Here, we firstly identified five LbHsps (four LbHsp70s and one LbHsp110) from psocids, and most of these LbHsps (except LbHsp70-1) are highly expressed at fourth instar nymph and adults, and LbHsp70-1 likely presents as a cognate form of HSP due to its non-significant changes of expression. Most LbHsp70s (except LbHsp70-4) are significantly induced at moderate high temperatures (<40 °C) and decreased at extreme high temperatures (40–45 °C), but LbHsp110-1 can be significantly induced at all high temperatures. Results of this study suggest that the LbHsp70s and LbHsp110 genes are involved in tolerance to thermal stress in L. bostrychophila, and antioxidant enzymes and heat shock proteins may be coordinately involved in the tolerance to thermal stress in psocids.

scholarly journals Effect of GnRH conjugated to pokeweed antiviral protein on reproductive function in adult male dogs

Reproduction ◽  
2003 ◽  
pp. 801-806 ◽  
Author(s):  
K Sabeur ◽  
BA Ball ◽  
TM Nett ◽  
HH Ball ◽  
IK Liu
Keyword(s):  
Adult Male ◽  
Area Under The Curve ◽  
Reproductive Function ◽  
Serum Testosterone ◽  
Control Group ◽  
Gnrh Analogue ◽  
Testis Size ◽  
Pokeweed Antiviral Protein ◽  
Antiviral Protein ◽  
Lh Release

This study evaluated the effect of a GnRH analogue conjugated to the cytotoxin, pokeweed antiviral protein (PAP), on reproductive function in adult, male dogs. Four dogs received 0.0042 mg GnRH-PAP kg(-1) hourly for 36 h, and four other dogs received 0.1 mg GnRH-PAP kg(-1) as one bolus injection daily for three consecutive days. One dog received a single bolus (0.1 mg x kg(-1)). Three adult male dogs received GnRH without the PAP conjugate, as controls. Twenty-five weeks after the initial treatment, all treated dogs received 0.1 mg GnRH-PAP kg(-1) as a single administration, whereas dogs in the control group received 0.0045 mg kg(-1) of the GnRH analogue. Serum concentrations of testosterone and LH were determined by radioimmunoassay, and testis size was measured for 9 months after treatment. Stimulation tests (5 microg GnRH kg(-1)) were used to evaluate LH release (-15, 0, 30, 60, 90, 120 min), which was assessed by measuring area under the curve. Serum testosterone concentrations were significantly lower (P<0.05) after treatment in the bolus and hourly groups than in the control group. Testosterone concentrations fell to less than 50 pg x ml(-1) in three of four dogs in the bolus group and one of four dogs in the hourly group by week 8-9 after treatment. Basal LH was lower (P<0.05) in the bolus and hourly groups than in the control group between weeks 0 and 33 after treatment. Treatment with GnRH-PAP reduced (P<0.05) LH release after GnRH stimulation in the bolus and hourly groups compared with the control group. Testis volume was lower (P<0.05) in all treated versus control dogs. In conclusion, administration of the conjugate GnRH-PAP at a 25 week interval resulted in a major disruption of reproductive parameters in male dogs; this effect was maintained for 11-12 weeks after a second injection of GnRH-PAP.

Heat-Stress-Induced Metabolic Changes and Altered Male Reproductive Function

2015 ◽  
Vol 14 (3) ◽  
pp. 1495-1503 ◽  
Author(s):  
Yuanlong Hou ◽  
Xiaoyan Wang ◽  
Zhihai Lei ◽  
Jihui Ping ◽  
jiajian Liu ◽  
...  
Keyword(s):  
Heat Stress ◽  
Reproductive Function ◽  
Metabolic Changes ◽  
Male Reproductive Function

scholarly journals Circular RNAs from BOULE play conserved roles in protection against stress-induced fertility decline

2020 ◽  
Vol 6 (46) ◽  
pp. eabb7426
Author(s):  
Liuze Gao ◽  
Shuhui Chang ◽  
Wenjuan Xia ◽  
Xiaolin Wang ◽  
Chenwang Zhang ◽  
...  
Keyword(s):  
Heat Stress ◽  
Male Fertility ◽  
Reproductive Function ◽  
Large Family ◽  
Human Sperm ◽  
Evolutionary Significance ◽  
Circular Rnas ◽  
Male Reproductive Function ◽  
Shock Proteins ◽  
Fertilization Capacity

Circular RNAs (circRNAs) are a large family of newly identified transcripts, and their physiological roles and evolutionary significance require further characterization. Here, we identify circRNAs generated from a conserved reproductive gene, Boule, in species from Drosophila to humans. Flies missing circular Boule (circBoule) RNAs display decreased male fertility, and sperm of circBoule knockout mice exhibit decreased fertilization capacity, when under heat stress conditions. During spermatogenesis, fly circBoule RNAs interact with heat shock proteins (HSPs) Hsc4 and Hsp60C, and mouse circBoule RNAs in sperm interact with HSPA2. circBoule RNAs regulate levels of HSPs by promoting their ubiquitination. The interaction between HSPA2 and circBoule RNAs is conserved in human sperm, and lower levels of the human circBoule RNAs circEx3-6 and circEx2-7 are found in asthenozoospermic sperm. Our findings reveal conserved physiological functions of circBoule RNAs in metazoans and suggest that specific circRNAs may be critical modulators of male reproductive function against stresses in animals.

Impairment of adult male reproductive function in rats exposed to ethanol since puberty

2006 ◽  
Vol 22 (4) ◽  
pp. 599-605 ◽  
Author(s):  
Samara U. Oliva ◽  
Alessandra G. Messias ◽  
Daniela A.F. Silva ◽  
Oduvaldo C.M. Pereira ◽  
Daniela C.C. Gerardin ◽  
...  
Keyword(s):  
Adult Male ◽  
Reproductive Function ◽  
Male Reproductive Function

scholarly journals Oxygen supply limits the heat tolerance of locusts during the first instar only

2020 ◽  
Author(s):  
Jacob P. Youngblood ◽  
John M. VandenBrooks ◽  
Oluwatosin Babarinde ◽  
Megan E. Donnay ◽  
Deanna B. Elliott ◽  
...  
Keyword(s):  
Heat Stress ◽  
Heat Tolerance ◽  
Thermal Tolerance ◽  
Oxygen Supply ◽  
Oxygen Limitation ◽  
Life Stages ◽  
First Instar ◽  
Wide Range ◽  
Survival And Reproduction ◽  
Respiratory Systems

AbstractExtreme heat directly limits an organism’s survival and reproduction, but scientists cannot agree on what causes organisms to lose function or die during heating. According to the theory of oxygen- and capacity-limitation of thermal tolerance, heat stress occurs when a warming organism’s demand for oxygen exceeds its supply, triggering a widespread drop in ATP concentration. This model predicts that an organism’s heat tolerance should decrease under hypoxia, yet most terrestrial organisms tolerate the same amount of warming across a wide range of oxygen concentrations. This point is especially true for adult insects, who deliver oxygen through highly efficient respiratory systems. However, oxygen limitation at high temperatures may be more common during immature life stages, which have less developed respiratory systems. To test this hypothesis, we measured the effects of heat and hypoxia on the survival of locusts (Schistocerca cancellata) throughout development. We demonstrate that the heat tolerance of locusts depends on oxygen supply during the first instar but not during later instars. This finding provides further support for the idea that oxygen limitation of thermal tolerance depends on respiratory performance, especially during immature life stages.

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