Practice question

P-granule segregation depends on microtubule cytoskeleton immediately after fertilization. Sperm centrosome generates radial microtubule array, and cytoplasmic dynein heavy chain DHC-1 with accessory LIS-1, DNC-1 dynactin and DLC-1 light chain transports RNP granules containing PIE-1, GLH-1, PGL-1 toward posterior cortex using minus-end directed movement. Actomyosin cortical flows assist initiation, but dynein inhibition via RNAi randomizes granules throughout AB and P1, disrupting germline. Proper posterior localization ensures partitioning solely into P1-P4 lineage, protecting germline RNAs, preventing somatic differentiation, preserving totipotency until Z2/Z3 formation.