Mouse embryos as In Vivo models for proteomic identification and functional analysis of missing proteins

Area of Science:

• Developmental Biology
• Proteomics
• Genomics

Background:

• Human missing proteins are hypothesized to play roles in early organogenesis.
• Ethical considerations limit human embryo research, necessitating alternative models.
• Embryonic tissues offer a potential system for discovering missing proteins and their functions.

Purpose of the Study:

• To evaluate the feasibility of using mouse embryos to investigate human missing proteins.
• To identify human missing proteins in mouse embryonic tissues.
• To explore the temporal expression and potential functions of identified missing proteins.

Main Methods:

• Mass spectrometry (MS) analysis of mouse embryos at 6.5, 7.0, 7.5, and 8.0 days post conception (dpc).
• Utilized novel missing protein alignment software for peptide analysis.
• Antibody production and validation for NKX1, Western blot, Co-immunoprecipitation (Co-IP), and Ingenuity Pathway Analysis (IPA).

Main Results:

• Identified 112 human missing proteins in mouse embryos.
• Detected four missing proteins, including NKX1, in mouse embryonic tissues.
• NKX1 showed transient expression peaking between 7 and 7.5 dpc.
• Associated proteins (PTCHD1, ASXL3, OTOGL) were identified via Co-IP and linked to neural development and other pathways.

Conclusions:

• Mouse embryos serve as a viable in vivo model for detecting human missing proteins.
• This model allows for the elucidation of temporal expression patterns and potential functions of missing proteins during early development.
• Identified pathways suggest roles in neural development, inflammation, mitochondrial function, and anti-aging.