"It is not birth, marriage, or death, but gastrulation which is truly the most important time in your life." - Lewis Wolpert
Embryonic development is a highly intricate process, in which even the smallest misstep can have drastic consequences. This image shows one such example, in which a two-day-old chicken embryo developed two separate "tails". Neurons developing in the head and tail were labeled with the tissue-specific genetic marker Tuj1 (shown in red), while another genetic marker, Pax7 (shown in magenta), was used to label precursors of the craniofacial skeleton and pigment cells in the head and skeletal muscle, cartilage, tendon, and vertebrae in the tail. The nucleus of every cell in the embryo was labeled with the DNA stain DAPI (shown in cyan). The image was taken using an LSM 880 Zeiss confocal microscope at the Biological Imaging Facility of the Beckman Institute with technical assistance from Giada Spigolon.