Cloning, expression and bioinformatics analysis of a putative pigeon melanoma differentiation-associated gene 5

Area of Science:

• Immunology
• Molecular Biology
• Avian Biology

Background:

• Melanoma differentiation-associated gene 5 (MDA5) is a crucial cytosolic pattern recognition receptor (PRR) that detects viral RNA.
• MDA5 plays a vital role in initiating type I interferon secretion, a key component of the host innate immune response against viral infections.

Purpose of the Study:

• To identify and characterize the structure of pigeon Melanoma differentiation-associated gene 5 (MDA5).
• To determine the expression patterns and distribution of pigeon MDA5 across various tissues.

Main Methods:

• Full-length pigeon MDA5 cDNA was isolated using reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE).
• Quantitative reverse transcription-polymerase chain reaction (QRT-PCR) was employed to assess MDA5 transcript levels in different pigeon tissues.

Main Results:

• The full-length pigeon MDA5 cDNA comprises 3858 nucleotides, encoding a 1009-amino acid polypeptide with conserved structural domains characteristic of RIG-I-like receptors (RLRs).
• Pigeon MDA5 shares high amino acid sequence identity (84.8–87.9%) with homologous MDA5 proteins from other avian species, indicating a close evolutionary relationship.
• Pigeon MDA5 transcripts were ubiquitously detected in all tested tissues, with notably high expression levels observed in the thymus and kidney.

Conclusions:

• The characterization of pigeon MDA5 provides essential molecular data for understanding its structure and function.
• The ubiquitous expression of pigeon MDA5, especially in immune-rich organs like the thymus and kidney, suggests a significant role in the innate immune system of pigeons.
• These findings establish a foundation for future investigations into MDA5's involvement in pigeon immunity, particularly concerning responses to vaccinations and infectious diseases.