Borcs6 is required for endo-lysosomal degradation during early development

Area of Science:

• Cell Biology
• Developmental Biology
• Molecular Biology

Background:

• Lysosomal degradation is crucial for cellular homeostasis and embryonic development.
• The role of lysosomal function in mammalian embryos before gastrulation remains largely unknown.
• Borcs6 protein is implicated in lysosomal trafficking and membrane fusion events.

Purpose of the Study:

• To investigate the function of Borcs6 in early mammalian embryonic development.
• To determine the impact of Borcs6 deficiency on lysosomal degradation and cellular processes.
• To elucidate the role of Borcs6 in embryonic cell lineage allocation and gastrulation.

Main Methods:

• Generation and analysis of Borcs6-deficient mouse embryos.
• Assessment of lysosomal function, including endosome-lysosome fusion and degradation.
• Evaluation of embryonic development, cell morphology, and gastrulation progression.

Main Results:

• Borcs6-deficient embryos exhibit impaired endo-lysosomal degradation.
• Absence of Borcs6 leads to enlarged cells with increased late endosomes and abnormal nuclei.
• Borcs6 mutant embryos show skewed cell lineage ratios, developmental delay, and failed gastrulation.

Conclusions:

• Borcs6 is essential for efficient endo-lysosomal degradation in early embryos.
• Lysosomal positioning and fusion with endosomes are critical for embryonic development.
• Early lethality in Borcs6 mutant embryos is attributed to defects in HOPS-related BORC function, not solely lysosomal positioning.