Practice question

Pole cells arise at posterior pole early, incorporating germ plasm containing oskar, vasa helicase, nanos and mitochondrial ribosomal RNAs organized within polar granules. They bud from blastoderm before cellularization via actin-dependent budding, cease division early and maintain germ lineage transcriptional quiescence via Polar granule component suppressing transcription. During gastrulation they involute with posterior midgut, migrate through midgut lumen and actively move towards dorsal mesoderm coalescing with somatic gonadal precursors to form embryonic gonad. Genetic lineage tracing demonstrates pole cells contribute exclusively to germ cells differentiating into sperm or eggs providing continuity across generations.