During interphase II, there is no S phase in which DNA replicates. However, in this stage, do the chromosomes remain wound? Or have they unwound into chromatin form, and recondense during prophase II?
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asked Jan 14, 2016 at 12:42
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3 Answers
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In many cases the chromosomes do undergo some dispersion, they do not reach the extremely extended state of the interphase nucleus, this all happens in telophase -I. It would be correct to refer to the stage between two meiotic divisions as interkinesis which is generally short lived.
The prophase-II is initiated immediately after cytokinesis, usually before the chromosomes have fully elongated.
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According to the diagram found on this site, chromosomes do unwind during Interphase II of meiosis.
Sparknotes, although it's not necessarily a reputable scientific source, seems to concur:
Once the nuclear envelope has re-formed after the first meiotic division, the cell enters a short interphase. This interphase is not as specific as mitotic interphase; during meiotic interphase, chromosomes may decondense as the cell waits to proceed with meiosis.
Finally, this website provides a clarification in stating that there is no true "interphase" between meiosis I and II (I guess true interphase would be marked by replication of DNA which, as you state, does not occur):
The period between meiosis I and meiosis II is sometimes called "interphase," this is confusing because it is not a true interphase such as that seen between rounds of mitosis because no synthesis occurs (all chromosomes have two chromatids throughout this stage).
answered Jan 14, 2016 at 14:05
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Interestingly, the very own existence of an interphase II between meiosis I and meiosis II is highly questionable, and a search on Pubmed found an article by Vernet et al., according to which interphase-II exists only in male meiosis.
