Scientific Frontiers in Developmental Toxicology and Risk Assessment reviews advances made during the last 10-15 years in fields such as developmental biology, molecular biology, and genetics. It describes a novel approach for how these advances might be used in combination with existing methodologies to further the understanding of mechanisms of developmental toxicity, to improve the assessment of chemicals for their ability to cause developmental toxicity, and to improve risk assessment for developmental defects. For example, based on the recent advances, even the smallest, simplest laboratory animals such as the fruit fly, roundworm, and zebrafish might be able to serve as developmental toxicological models for human biological systems. Use of such organisms might allow for rapid and inexpensive testing of large numbers of chemicals for their potential to cause developmental toxicity; presently, there are little or no developmental toxicity data available for the majority of natural and manufactured chemicals in use. This new approach to developmental toxicology and risk assessment will require simultaneous research on several fronts by experts from multiple scientific disciplines, including developmental toxicologists, developmental biologists, geneticists, epidemiologists, and biostatisticians.

During development, cells are generated at specific locations within the embryo and then migrate into their destinations. At their destinations, they assemble together through cell adhesions, eventually leading to the formation of tissues and organs. In some cases, orchestration of cell adhesion and migration produces the global movement of cell groups, called collective cell migration, which is also required for the development of basic tissue structures such as spheres, clusters, and vesicles in the morphogenetic processes of development. Therefore, individual regulation and orchestration of cell adhesion and migration are quite important for appropriate tissue/organ formation during development. However, how cell adhesion and migration are regulated, and orchestrated during development? How cell adhesion and migration affects tissue formation during development? To answer these questions, we assembled several review and research articles in this eBook. By assembling these articles, we could explore the presence of core regulatory mechanisms and deepen the current understanding of cell adhesion and migration during the development of multicellular organisms.

Biological and biomedical studies have entered a new era over the past two decades thanks to the wide use of mathematical models and computational approaches. A booming of computational biology, which sheerly was a theoretician’s fantasy twenty years ago, has become a reality. Obsession with computational biology and theoretical approaches is evidenced in articles hailing the arrival of what are va- ously called quantitative biology, bioinformatics, theoretical biology, and systems biology. New technologies and data resources in genetics, such as the International HapMap project, enable large-scale studies, such as genome-wide association st- ies, which could potentially identify most common genetic variants as well as rare variants of the human DNA that may alter individual’s susceptibility to disease and the response to medical treatment. Meanwhile the multi-electrode recording from behaving animals makes it feasible to control the animal mental activity, which could potentially lead to the development of useful brain–machine interfaces. - bracing the sheer volume of genetic, genomic, and other type of data, an essential approach is, ?rst of all, to avoid drowning the true signal in the data. It has been witnessed that theoretical approach to biology has emerged as a powerful and st- ulating research paradigm in biological studies, which in turn leads to a new - search paradigm in mathematics, physics, and computer science and moves forward with the interplays among experimental studies and outcomes, simulation studies, and theoretical investigations.

The Research Topic aims to support progress towards understanding the different sets of developmental processes that are absolutely required to complete all the steps essential for successful embryonic development, under physiological conditions. We sought contributions that dealt with single cells, interaction between cells as well as intra- and extracellular signal transduction. The Research Topic presents original studies covering experimental and theoretical approaches, descriptions of new methodologies, reviews and opinions.