When boundaries benefit science and society.

In the rapidly moving field of stem cell and embryo research, research questions often sit at the intersection of scientific inquiry and ethical considerations. The International Society for Stem Cell Research (ISSCR) produces guidelines to help navigate decisions in this area. For Cell's 50th Anniversary Focus on Developmental Biology, scientific editor Sarah Geisler discussed the importance of the ISSCR guidelines on stem cell and embryo research for both the stem cell community and the broader public with Amander Clark, Robin Lovell-Badge, and Janet Rossant, who have been involved in the ongoing evolution of the guidelines. A lightly edited transcript of their conversation is shared here.

An ethical framework for human embryology with embryo models.

A human embryo's legal definition and its entitlement to protection vary greatly worldwide. Recently, human pluripotent stem cells have been used to form in vitro models of early embryos that have challenged legal definitions and raised questions regarding their usage. In this light, we propose a refined legal definition of an embryo, suggest "tipping points" for when human embryo models could eventually be afforded similar protection to that of embryos, and then revisit basic ethical principles that might help to draft a roadmap for the gradual, justified usage of embryo models in a manner that aims to maximize benefits to society.

IVF embryos in the bin, embryo-like structures in the spotlight.

Embryo-like structures (ELS) are intended for the study of embryonic development without the use of human supernumerary embryos. Scientists working in countries that do not allow research on embryos hope that these structures will replace natural embryos. The interest in ELS is largely based on two misconceptions: the belief that there is a shortage of research embryos and the belief that research on ELS will make research on natural embryos redundant. This paper argues that research efforts should be refocused on natural embryos.

Stem cell research: toward greater unity in Europe?

There are four major positions on human embryonic stem cell research in the different member states of the European Union, ranging from permissive to very restrictive. This reflects the diversity of research systems within Europe and poses a challenge to developing a common European research policy.

Importance of In Vitro Embryo Model Procedure Standardization.

In vivo studies offer a detailed understanding of organism functioning, surpassing the insights provided by in vitro studies. These experiments are crucial for comprehending disease emergence, progression, and associated mechanisms in humans, as well as for developing treatments. When choosing experimental models, factors such as genomic similarity, physiological relevance, ethical appropriateness, and economic feasibility must be considered. Standardized protocols enhance the reliability, and reproducibility of scientific methods, promoting the assessment of research in the scientific literature. Researchers conducting embryo studies should establish and document standardized protocols for increased data comparability. Standardization is vital for scientific validity, reproducibility, and comparability in both in vivo and in vitro studies, ensuring the accuracy and reliability of experimental results and advancing scientific knowledge.