Concept 37 Master genes control basic body plans. Eric Wieschaus
and Christiane Nüsslein-Volhard explain research of Drosophila's
developmental stages. I’m Christiane Nüsslein-Volhard and I’m
Eric Wieschaus. We were interested in the genes involved in
development, and how they work to change one egg cell into a
complex organism. In the ‘70s, we started looking at development
of the fruit fly, Drosophila melanogaster – which goes through
several distinct stages of development. DROSOPHILA MELANOGASTER:
EGG, LARVA, PUPA, ADULT We isolated many mutants that led to the
death of the embryo. These all had developmental errors. Using
these mutants, we found the genes that control early embryonic
development. Although the fertilized egg initially shows no
polarity, proteins in the egg soon establish the head-to-tail
and top-to-bottom orientation of the embryo. Some proteins are
expressed and concentrated in a gradient, highest in the head.
Others are expressed only in the head, or in both the head and
the tail of the