Q.44 - Biology

Question

Explain the role of axis formation in development. 

Step-by-Step Solution

Answer

The three axes of the animal body are established in development via the expression of specific sets of genes that regulate which cells will develop into specific structures. During development, the dorsal cells are genetically programmed to develop into the notochord and define the axis.

Step 1. Introduction

Axis formation is the formation of axis of Drosophila and vertebrates. 

The formation of axis is completed under the multi-level and network control of a series of genes. The axis refers to the anterior-posterior axis and the dorsal-ventral axis of the embryo.

Step 2. Explanation

• Animal bodies have three axes for symmetry. 
• Animal bodies have lateral-medial (left-right), dorsal-ventral (back-belly), and anterior-posterior (head-feet) axes. 
• The dorsal cells from one embryo are transplanted into the belly region of another embryo. 
• The transplanted embryo had two notochords: one at the dorsal site from the original cells and another at the transplanted site. This suggested that the dorsal cells were genetically programmed to form the notochord and define the axis. 
• Many researchers have identified many genes that are responsible for axis formation. Mutations in these genes to the loss of symmetry required for organism development.