Invasive clams (Ruditapes philippinarum) are better equipped to deal with harmful algal blooms toxins than native species (R. decussatus): evidence of species-specific toxicokinetics and DNA vulnerability

Unveiling the nexus between parental exposure to toxicants and heritable spermiotoxicity - Is life history a shield or a shadow?

The knowledge on parental experiences is critical to predict how organisms react to environmental challenges. So, the DNA integrity of Procambarus clarkii spermatozoa exposed ex vivo to the herbicide penoxsulam (Px) or ethyl methanesulfonate (EMS; model genotoxicant) was assessed with and without the influence of in vivo parental exposure to the same agents. The parental exposure alone did not affect the DNA of unexposed spermatozoa. However, the history of Px exposure increased the vulnerability to oxidative lesions in Px-exposed offspring. Otherwise, parental exposure to EMS allowed the development of protection mechanisms expressed when F₁ was also exposed to EMS, unveiling life history as a shield. The parental exposure to a different agent adverse and decisively affected Px spermiotoxic potential, pointing out life history as a shadow to progeny. Given the complexity of the aquatic contamination scenarios, involving mixtures, the spermiotoxicity of Px to wild P. clarkii populations emerged as probable.

Lymphocyte-based challenge DNA-repair assays for personalized health risk assessment

Combinations of genetic and environmental factors are responsible for the development of many human diseases, such as cancer, as demonstrated using various biomarkers. Within this scenario, DNA repair holds a gate-keeper position which determines outcomes after appearance of DNA damage and, therefore, adverse cellular consequences, e.g., initiation of carcinogenesis. DNA repair deficiency and some of the subsequent events can be validated from studies using live cells from cancer patients. However, these deficiencies/events are difficult to demonstrate in live cells from normal individuals because individual variations in DNA repair capacities (DRC) are too low to be measured easily. Such lack of information has been hindering progress in developing personalized disease prevention and intervention protocols, especially among exposed populations. However, using a variety of challenge assays as biomarkers, variations in individual's DRC can be amplified in live cells and be determined. Furthermore, evidence indicates that DRC are not only inherited but can also be modified by environmental factors (e.g., nutritional status and exposure to genotoxic substances). Using these challenge assays, e.g., in live lymphocytes, individual's DRC can be holistically and functionally determined as well as quantitated. With the more precise information, assessment of health risk can be better determined on an individual rather than on a population basis. This review provides a succinct summary on the development and application of recent challenge assays in lymphocytes which can provide measurements of individuals' DRC, and on the latest data for more precise disease prevention and intervention.