cDNA array analysis of Japanese quail lines divergently selected for four-week body weight

Area of Science:

• Animal Genetics
• Molecular Biology
• Poultry Science

Background:

• Divergent selection for body weight over decades has produced distinct Japanese quail lines.
• The P line is significantly larger than the control C line, while H and L lines show high and low body weight, respectively.

Purpose of the Study:

• To identify differentially expressed genes contributing to growth variations in selected Japanese quail lines.
• To evaluate the effectiveness of anonymous cDNA array analysis in discovering growth-related genes in poultry.

Main Methods:

• Screening a DNA array of 4,704 random anonymous cDNA clones from 8-day C line embryos.
• Utilizing isotopically-labeled cDNA from different quail lines (C, H, L, P) for array hybridization.
• Confirming differentially expressed genes using Northern blot analysis and BLASTN searches against chicken EST libraries.

Main Results:

• Identified three differentially expressed cDNA clones, including a novel 35-kD quail EB1 protein.
• Quail EB1 transcripts were elevated in the L line and decreased in H and P lines compared to the C line.
• Two novel sequences showed higher expression in the L line and lower in H and P lines, with one exhibiting selective tissue expression.

Conclusions:

• Anonymous cDNA array analysis is a viable method for identifying differentially expressed genes in growth-selected poultry.
• The identified genes, including quail EB1, may play a role in the observed growth differences among quail lines.
• Further research can elucidate the specific functions of these novel genes in avian growth regulation.