Pleurotus ostreatus, also known as the oyster mushroom, is a popular edible mushroom cultivated worldwide. This review discusses recent progress in the molecular genetics of this fungus and highlights its potential as a model mushroom for future research. Advances in molecular genetic techniques and genome sequencing have led to breakthroughs in mushroom science. Efficient transformation protocols and multiple selection markers have enabled the development of powerful tools, including gene knockout and genome editing, leading to new findings in areas such as wood component degradation, sexual development, protein secretion systems, and cell wall structure. These techniques also enable the identification of new horizons in enzymology, biochemistry, cell biology, and material science through protein engineering, fluorescence microscopy, and molecular breeding. Pleurotus ostreatus has a well-established transformation system with practical and efficient protocols, making it suitable for both forward and reverse genetic approaches. Recent studies have demonstrated its status as a model mushroom in research topics such as wood degradation, sexual development, and cell wall structure. Future perspectives on cell biology and mushroom materials are also discussed. CRISPR/Cas9 technology has been successfully applied to P. ostreatus, enabling precise genome editing. This technology allows for the disruption of multiple genes in a single operation and has been used to study the role of lignin-modifying enzymes in wood degradation. The availability of a reverse genetic approach based on high-frequency gene targeting and a forward genetic approach using genome sequence information has allowed for the identification of various regulators involved in the transcriptional expression of lignocellulose-degrading enzymes in P. ostreatus. The cell wall structure of P. ostreatus has been analyzed, revealing the presence of β-glucan and chitin as key components. The structural role of the cell wall is critical in the formation of fruiting bodies that can withstand the environment, disperse spores, and be flexible enough to change their shape and size during development. The β-glucan from fruiting bodies has beneficial properties for human health, and its structure and functional properties have been focused on. The synthesis of cell wall components in P. ostreatus is regulated by various synthases, including β-glucan synthases (FKS), α-glucan synthases (AGS), and chitin synthases (CHS). These enzymes play essential roles in the formation and maintenance of the cell wall structure. The analysis of these enzymes has provided insights into the structural differences between basidiomycetes and ascomycetes, as well as the evolutionary history of cell wall components in fungi.Pleurotus ostreatus, also known as the oyster mushroom, is a popular edible mushroom cultivated worldwide. This review discusses recent progress in the molecular genetics of this fungus and highlights its potential as a model mushroom for future research. Advances in molecular genetic techniques and genome sequencing have led to breakthroughs in mushroom science. Efficient transformation protocols and multiple selection markers have enabled the development of powerful tools, including gene knockout and genome editing, leading to new findings in areas such as wood component degradation, sexual development, protein secretion systems, and cell wall structure. These techniques also enable the identification of new horizons in enzymology, biochemistry, cell biology, and material science through protein engineering, fluorescence microscopy, and molecular breeding. Pleurotus ostreatus has a well-established transformation system with practical and efficient protocols, making it suitable for both forward and reverse genetic approaches. Recent studies have demonstrated its status as a model mushroom in research topics such as wood degradation, sexual development, and cell wall structure. Future perspectives on cell biology and mushroom materials are also discussed. CRISPR/Cas9 technology has been successfully applied to P. ostreatus, enabling precise genome editing. This technology allows for the disruption of multiple genes in a single operation and has been used to study the role of lignin-modifying enzymes in wood degradation. The availability of a reverse genetic approach based on high-frequency gene targeting and a forward genetic approach using genome sequence information has allowed for the identification of various regulators involved in the transcriptional expression of lignocellulose-degrading enzymes in P. ostreatus. The cell wall structure of P. ostreatus has been analyzed, revealing the presence of β-glucan and chitin as key components. The structural role of the cell wall is critical in the formation of fruiting bodies that can withstand the environment, disperse spores, and be flexible enough to change their shape and size during development. The β-glucan from fruiting bodies has beneficial properties for human health, and its structure and functional properties have been focused on. The synthesis of cell wall components in P. ostreatus is regulated by various synthases, including β-glucan synthases (FKS), α-glucan synthases (AGS), and chitin synthases (CHS). These enzymes play essential roles in the formation and maintenance of the cell wall structure. The analysis of these enzymes has provided insights into the structural differences between basidiomycetes and ascomycetes, as well as the evolutionary history of cell wall components in fungi.