Nestor Saiz Arenales

Research Fellow

Pictured: Nestor Saiz Arenales

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Education & Training


Postdoctoral Research Fellow, Developmental Biology Program, Sloan Kettering Institute (lab of Kat Hadjantonakis)


PhD degree in developmental biology, University of Manchester, UK (lab of Berenika Plusa)


BSc degree in biological sciences, University of Salamanca, Spain

Research Interests

Unlike other organisms, mammals spend their earliest days of development getting ready for the time of implantation, when the embryo embeds itself in the mother’s uterus. These preparations involve the formation of extra-embryonic tissues that will support the growth of the embryo to term. These extra-embryonic tissues, though essential for embryonic development, are dispensable for adult life.

My research interests focus on how cells make fate decisions (i.e., how they differentiate) individually or collectively. I am currently studying how extra-embryonic membranes are formed, focusing particularly on the primitive endoderm, which is the second membrane to develop. I want to understand the genes and cellular behaviors that allow the formation of these tissues, as well as their evolutionary origin.

I am also interested in understanding how, at the same time, a small group of cells called the epiblast is set aside and kept in an undifferentiated, pluripotent state. These cells need to remain naïve until the time comes for them to give rise to the embryo itself.

A central question in stem cell biology is how these cells remain pluripotent in the embryo and whether we can reproduce similar conditions in vitro using embryonic stem cells.