Effects of ⁶⁰Co γ Irradiation on the Reproductive Function of Caenorhabditis elegans

Abstract

The effects of ionizing radiation on the reproductive system have always been a matter of great interest. Both artificial and naturally occurring ionizing radiation can directly or indirectly affect the reproductive system via the introduction of DNA single-strand and double-strand breaks, the excitation of water molecules, and the generation of free radicals. In order to quantitatively investigate the effects of ionizing radiation on reproductive function, 60Co γ irradiation was applied on a model organism, Caenorhabditis elegans (C. elegans). The egg-laying and embryo-hatching activities were observed for the parent (F0) and the first 2 progeny (F1 and F2) generations. The incidence rate of ovipositor malformation was also recorded. Acridine orange was used to detect the number of apoptotic germ cells. With the above metrics, the effects of 60Co γ irradiation on the reproductive function of C. elegans were systematically evaluated. The results showed that the postirradiation egg-laying and embryo-hatching activities of the F0 generation were increasingly suppressed by increasing doses of 60Co γ irradiation. Those of the F1 generation showed a trend toward recovery although also suppressed by the radiation to the F0 generation compared with the control. Those activities were restored to normal or near-normal levels for the F2 generation. The incidence rate of ovipositor malformation was greatly increased by 60Co γ irradiation according to radiation doses. Gamma irradiation by 60Co also substantially induced germ cell apoptosis, and the apoptosis rate increased with increasing radiation doses. Therefore, 60Co γ irradiation affects the reproductive function of C. elegans. The suppression on its reproductive function increases with increasing radiation doses. The reproductive functions of progeny generations are also affected and weakened.

The Phenotypic and Transcriptomic Response of the Caenorhabditis elegans Nematode to Background and Below-Background Radiation Levels

“…While an argument could be made that the observed increase in egg laying rate in the low radiation group is a stress response, such a response is the opposite to that usually seen when C. elegans is exposed to environmental stressors. When exposed to an array of environmental stresses such as reduced food levels, vibrations, temperature extremes, osmotically taxing environments, exposure to high radiation levels, moderate amounts of glucose, and hypoxia, C elegans typically both reduces its growth and egg laying rate ( 27 , 28 , 31 – 33 , 48 , 49 ). Early reproduction appears to be a critical factor in C. elegans ecology.…”

Transgenerational reproductive and developmental toxicity of tebuconazole in Caenorhabditis elegans

“…The number of offspring larvae in each plate was recorded as the live egg count, and the number of unhatched eggs was recorded as the dead egg count. The incubation rate was calculated as the ratio of the offspring to the total number of eggs laid (the sum of offspring and the dead eggs) (Cui et al, ).…”

Ionizing Radiation as a Source of Oxidative Stress—The Protective Role of Melatonin and Vitamin D

“…IR, absorbed by tissues and cells, affects their functioning and structure to various extents, depending on the dose and type of radiation [13,14]. In affected cells, ROS are generated mainly through the radiolysis of water molecules (decay by the action of radiation quanta) or the excitation of water molecules and their decay [15,16,39]. IR can also indirectly influence the oxidative-antioxidant homeostasis by damaging different biomolecules [12].…”

“…IR is capable of penetrating the cells of living organisms, where it induces the ionization of both organic and inorganic compounds [13,14]. Due to the high water content in cells, radiolysis of water molecules by IR is the main process contributing to the increased formation of reactive oxygen species (ROS) [15,16]. ROS rapidly react with macromolecules, including proteins, nucleic acids and lipids, leading to cell dysfunction and apoptotic cell death [12].…”