Everything from the egg.
Bariani, M. V., Rhon-Calderon, E. A. and Beltrame, J. S.
Frontiers in Reproduction Course, Marine Biological Laboratories, Massachusetts, United States of America.
Laboratorio de Biotecnologias Aplicadas a la Reproduccion y Mejoramiento Genetico Animal, Instituto de Investigaciones Biotecnologicas (IIB-INTECH) (UNSAM-CONICET), Catedra de Teriogenologia, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Buenos Aires, Argentina.
Department of Cell And Developmental Biology, Perelman School of Medicine, Smilow Center for Translational Research, University of Pennsylvania, Philadelphia, Pennsylvania.
Laboratorio de Fisiologia y Farmacologia de la Reproduccion, Centro de Estudios Farmacologicos y Botanicos (CEFyBO), CONICET - Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.
In 1651, William Harvey opened a real debate when he postulated that the egg is the origin of all life. The central pillar of Harvey's theory sustains that all adults are already present in a smaller size in the egg. The frontispiece of his famous treatise attributed to Richard Gaywood shows Zeus holding an egg that releases small creatures as humans, others animals, and plants. The treatise concludes that no generation occurs without a primordial egg, representing the establishment of ex Ovo Omnia doctrine. Nowadays, evidence supports that both male and female gametes are essential for embryo development following sexual reproduction. Despite obvious differences in morphology and in scale, the oocytes carry out the same role in the development and still demonstrate the mystery of reproduction.
Molecular Reproduction and Development 86(5): 479 (2019)