The byssal-producing glands and proteins of the silverlip pearl oyster Pinctada maxima (Jameson, 1901)

Abstract

Pinctada maxima are most well known for their production of high-quality natural pearls. They also generate another natural material, the byssus, an adhesive thread critical for steadfast attachment underwater. Herein, P. maxima byssal threads were analysed via proteotranscriptomics to reveal 49 proteins. Further characterisation was undertaken on five highly expressed genes: glycine-rich thread protein (GRT; also known as PUF3), apfp1/perlucin-like protein (Pmfp1); peroxidase; thrombospondin 1, and Balbiani ring 3 (BR3), which showed localised tissue expression. The spatial distribution of GRT and Pmfp1 via immunodetection combined with histology helped to identify glandular regions of the foot that contribute to byssal thread production: the byssal gland, the duct gland, and two thread-forming glands of basophilic and acidophilic serous-like cells. This work advanced primary knowledge on the glands involved in the creation of byssal threads and the protein composition of the byssus for P. maxima, providing a platform for the design of marine biopolymers.

Keywords:

• Byssus
• byssal threads
• Pinctada maxima
• transcriptomics
• proteomics
• perlucin

Acknowledgements

The authors wish to acknowledge the contributions of Kane Taylor for oyster samples, and Dr Saowaros Suwansa-ard and Dr Di Liang for their assistance with histology.

Disclosure statement

The authors declare that they have no competing interests.

Authors’ contributions

AW, SC and AE conceived the project. AW performed most of the experiments, analysed the data, and was a major contributor in writing the manuscript. SC contributed to the preparation, analysis and interpretation of transcriptomic results and contributed to figure preparation. TW contributed to the preparation, analysis and interpretation of the proteomic results. AK was instrumental to the design of bioinformatics workflow. SM prepared and interpreted PCR results and contributed to figure design. AE acquired funding. All authors read and approved the final manuscript.

Availability of data and materials

The datasets generated and/or analysed during the current study are available via GenBank under the following accession number: BioProject ID: PRJNA761869, and available from the corresponding authors upon request.

Consent for publication

Not applicable.

Ethics approval and consent to participate

Not applicable.

Additional information

Funding

This research was supported by USC, and an Australian Government Research Training Program (RTP) Scholarship awarded to AW.