DNA Synthesis during Maturation of Starfish Oocytes

IN Xenopus, nuclear DNA is replicated at an early stage of meiosis and there is no measurable DNA synthesis during the long diplotene stage characterized by the presence of the lampbrush chromosomes^1–3; this is probably a general phenomenon in animals. But in the case of pollen formation in plants, autoradiographic data suggest that, in addition to normal replication during S phase, some chromosomal DNA is synthesized throughout meiosis⁴. Limited DNA synthesis also follows replication during the S phase in Lilium anthers⁵.