Impacts of oxygen deficiency on embryo life‐history traits of migratory locust Locusta migratoria from low and high altitudes

Abstract

Hypoxia challenges aerobic organisms in numerous environments, and hypoxic conditions may become more severe under future climate‐change scenarios. The impact of hypoxia on the development of terrestrial insect embryos is not well understood. Here, to address this gap, embryonic life‐history traits of migratory locust Locusta migratoria from low‐altitude and high‐altitude regions were compared under 2 oxygen levels: normoxia (i.e., 21 kPa oxygen partial pressure and mild hypoxia (i.e., 10 kPa oxygen partial pressure). Our results demonstrated that, whether reared under normoxia or mild hypoxia, L. migratoria from high‐altitude populations had longer developmental times, reduced weight, and lower mean relative growth rate as compared with those from low‐altitude populations. When transferred from normoxia to mild hypoxia, nearly all the tested life‐history traits presented significant negative changes in the low‐altitude populations, but not in the high‐altitude populations. The factor ‘strain’ alone explained 18.26%–54.59% of the total variation for traits, suggesting that the phenotypic differences between L. migratoria populations from the 2 altitudes could be driven by genetic variation. Significant genetic correlations were found between life‐history traits, and most of these showed differentiation between the 2 altitudinal gradients. G‐matrix comparisons showed significant structural differences between L. migratoria from the 2 regions, as well as several negative covariances (i.e., trade‐offs) between traits in the low‐altitude populations. Overall, our study provides clear evidence that evolutionary divergence of embryonic traits between L. migratoria populations from different altitudes has occurred.

The Effectiveness of L-arginine in Clinical Conditions Associated with Hypoxia

“…The NO system function in conditions of L-arginine supplementation needs to be preliminarily evaluated via the profile of individual resistance to hypoxia in light of the statistical results presented in the literature. It is believed that this can be done in a statistically valid way if the analysed parameters of animals (as well as groups of analysed volunteers) exhibit normal distribution and the studied sample can be correlated with the general population of individuals to be analysed, called the population transfer [107][108][109]. At the same time, it is known that, in laboratory animals and humans, there are always differences in individual sensitivity to hypoxic factor effects, which often correlates with resistance to dynamic stress and stress tolerance [19,109,110].…”