Linda Holland
Additional Author(s): Takayuki Onai
Published on SDB CoRe: Nov 14 2012
Morphogenic Movements: Gastrulation
Morphogenesis: Cell Movements
Mesoderm-derived: Notochord; Somites
Ectoderm-derived: Nervous System; Epidermis
Organism: Amphioxus
Stage of Development: Embryo
Fate map of amphioxus (Branchiostoma floridae) embryos. This figure shows the portions of the amphioxus unfertilized egg and gastrula that will contribute to the neural ectoderm (green), non-neural ectoderm (blue), mesoderm (orange), and endoderm (yellow). The second polar body is at the animal pole (see circle by ectoderm). The future anterior and posterior ends of the embryo are indicated by asterisks. Because tissue movements during gastrulation are minimal, the relative positions of the tissue layers do not change as the mesendoderm invaginates. The equator of the unfertilized egg (and blastula) which separates the ectoderm from the mesendoderm will become the blastoporal lips. As gastrulation progresses, the blastopore lips close bringing together the future posterior end of the embryo. During gastrulation, the animal pole shifts towards the ventral side due to the disproportionate elongation of the future neural plate (compare circle in early vs. late gastrula). The future mesoderm (orange in late gastrula cross section) is entirely dorsal until the mid-neurula stage (not shown) when ventral mesoderm forms as outgrowths from the somites. WIREs Dev Biol 2012. DOI: 10.1002/wdev.11
Holland, L.Z., Onai,T. Early development of cephalochordates (amphioxus). WIREs Dev Biol, 2012, 1:167-183.
You must be logged in to CoRe to comment. Please login or create an account.