Ethical aspects associated with genome alteration techniques applied to animal reproduction research

The revolution in biology triggered by the different genome-editing tools has of course arrived to the research field of animal reproduction. Yeast meganucleases, zinc-finger nucleases, TALEN and, particularly, the several generations of CRISPR tools have landed in animal reproduction thereby providing novel strategies to optimize or modify some of the features and capabilities of the recipient animals. All these genome-editing proposals and activities are associated with ethical considerations regarding how those planned genome alterations might affect important animal welfare issues. The ethical dimension of all these genome editing must be seriously considered. Hence, all ethical aspects bound to any given genome-edited allele in animals should be discussed in order to ensure that we are maximizing benefits and reducing any potential risk or negative considerations of these modifications. In this review, I will summarize some of the experiments reported aiming to investigate or improve animal reproduction and I will address the ethics issues that should also be considered.