Rabbit zona pellucida composition: a molecular, proteomic and phylogenetic approach

Area of Science:

• Reproductive Biology
• Developmental Biology
• Molecular Genetics

Background:

• The zona pellucida (ZP) is crucial for sperm-egg interactions during fertilization.
• Previous research indicated ZP matrices consist of three glycoproteins in many species.
• Recent studies suggest a four-glycoprotein composition in some species' ZP.

Purpose of the Study:

• To investigate the presence of a fourth glycoprotein in the rabbit (Oryctolagus cuniculus) zona pellucida.
• To characterize the rabbit ZP1 glycoprotein and its evolutionary significance.

Main Methods:

• Complementary deoxyribonucleic acid (cDNA) encoding rabbit ZP1 was amplified using reverse transcribed polymerase chain reaction (RT-PCR).
• The ZP1 cDNA sequence and deduced amino acid sequence were analyzed.
• Proteomic analysis using mass spectrometry was performed.
• Molecular phylogenetic analysis of ZP1 was conducted.

Main Results:

• A fourth glycoprotein was identified in the rabbit ZP.
• Rabbit ZP1 cDNA has an open reading frame of 1825 nucleotides, encoding a 608-amino acid polypeptide.
• Rabbit ZP1 shows high amino acid sequence identity with ZP1 from other species (e.g., 70% with human and horse).
• Mass spectrometry detected peptides corresponding to four ZP glycoproteins.
• Phylogenetic analysis revealed at least four instances of ZP1 gene pseudogenization during mammalian evolution.

Conclusions:

• This study provides the first evidence that the rabbit zona pellucida is composed of four glycoproteins.
• The findings contribute to a deeper understanding of ZP structure and evolution across mammals.
• The characterization of rabbit ZP1 offers insights into species-specific variations in reproductive processes.