Birds and reptiles, unlike mammals, have erythrocytes that still conserve a well-defined nucleus. The shape of the nuclei, as well as the presence of micronuclei, has been used as a classical marker for genotoxic damage. However, most of the tests used in this determination rely on subjective metrics that can be observer-dependent and are extremely time-consuming.

​

    It turns out that how the nuclei of an erythrocyte change upon exposure to toxic environments can be seen as a geometry problem; thus, in collaboration with Prof. Vanessa Labrada-Martagon we first developed a very simple way to characterize the geometric parameters with classical observation for genotoxic damage (Aida Guevara-Melendez). We found that these observer-independent parameters can be as useful as the classical, sometimes subjective, categories. Then we used this tool to observe regional and annual fluctuations in this type of cellular damage in sea turtles inhabiting the Mexican Caribbean (Lorena Rodríguez-Salazar).

    Now, we have expanded this idea and, with the help of Prof. Flavio Vigueras-Gómez, we have found that we do not need to measure thousands of nuclei; we only need to measure a few hundred and to determine the focus and the major axis of the nuclei to distinguish the population of sea turtles that may have suffered genotoxic damage. This tool is not on the path to full automation, has almost no observational bias, and, with a few hundred measurements (rather than thousands), has the statistical power to separate populations of healthy and endangered sea turtles (Lorena Rodrígeuz-Salazar, Ph.D. thesis).

​

​

​

​

​

​

​

​

​​

​

​

​

​

​​

​​​

Figure taken from https://www.sciencedirect.com/science/article/abs/pii/S0166445X25004096

​

     Finally, we are performing the first systematic study to determine the morphology (by thin-section TEM) of the nuclear envelope of sea turtle erythorcytes of individuals that exhibit either serious or low genotoxic damage. This project is very interesting because the nuclear envelope of these cells is extremely surprising and not what it appears to be.

​

​

​

​​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

 

Micograph of an erythrocyte of a green turtle that has a high prevalence of nuclear abnormalities (our archive).

​

​

Update: November 2025.​

​​