Leptotene |
Locusta migratoria | Lilium grandiflorum | Petunia hybrida |
![meiosis: leptotene in Locusta](/images/cellcycle/meiosis-locusta-leptotene.jpg) | ![meiosis: leptotene in Lilium](/images/cellcycle/meiosis-lilium-leptotene.jpg) | ![meiosis: leptotene in Petunia.jpg](/images/cellcycle/meiosis-petunia-leptotene.jpg) |
Leptotene (Gr. leptos = thin; taenia = band / stripe) is the first stage of meiosis. This is also the first step in the condensation of DNA, a phenomenon that proceeds through the entire prophase I. Despite the thread-like aspect of th chromosomes each consist in fact of twee chromatides, because the DNA has been already replicated during the premeiotic S-fase. Also small regions with thickenings (so-called chromomeres) arise in the chromatine on each chromosome, which make them look like a pearl nacklace. The homolog chromosomes are still unpaired.
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