The apterous gene in Drosophila encodes a protein required for wing patterning and growth. It is also known to function in nerve development, fertility, and viability. When human and mouse genes whose protein products closely resemble apterous were used to generate transgenic Drosophila [Rincon-Limas et al. (1999). Proc. Nat. Acad. Sci. (USA) 96:2165–2170], the apterous mutant phenotype was rescued. In addition, the whole-body expression patterns in the transgenic Drosophila were similar to normal apterous.
What do these results indicate about the molecular nature of development?

Verified step by step guidance

1. Understand the context: The apterous gene in Drosophila is essential for wing patterning, nerve development, fertility, and viability, indicating it has multiple developmental roles.
2. Recognize that the experiment involved introducing human and mouse genes, which encode proteins similar to Drosophila apterous, into mutant flies lacking functional apterous.
3. Note that the mutant phenotype was rescued by these transgenic genes, meaning the human and mouse proteins could substitute for the Drosophila protein's function.
4. Interpret that the similar whole-body expression patterns of the transgenic genes compared to normal apterous suggest conservation not only in protein function but also in gene regulation across species.
5. Conclude that these results indicate a high degree of evolutionary conservation in the molecular mechanisms controlling development, implying that key developmental genes and their regulatory networks are preserved across diverse organisms.

Key Concepts

Gene Conservation Across Species

Gene conservation refers to the preservation of gene sequences and functions across different species through evolution. The ability of human and mouse genes to rescue the Drosophila apterous mutant phenotype demonstrates that key developmental genes are conserved, indicating similar molecular mechanisms govern development in diverse organisms.

Functional Homology of Proteins

Functional homology means that proteins from different species can perform similar biological roles due to structural and sequence similarities. The rescue of the mutant phenotype by human and mouse apterous-like genes shows that these proteins share functional domains critical for wing patterning and other developmental processes.

Molecular Basis of Developmental Processes

Developmental processes are controlled by specific genes encoding proteins that regulate growth, patterning, and differentiation. The experiment highlights that molecular pathways involving apterous are fundamental and conserved, emphasizing that development relies on precise gene expression and protein function across species.