Dictyotic

Dictyotic is a term used in biology, specifically in cytology, to describe a stage in the prophase of meiosis in which homologous chromosomes are paired and form a lattice-like structure. This stage is also known as the diffuse diplotene or dictyate stage. It is characterized by the presence of chiasmata, which are the visible points of crossing over between homologous chromosomes. These chiasmata hold the chromosomes together, and the chromosomes themselves become highly decondensed, appearing almost thread-like. This decondensation allows for extensive transcriptional activity during this period.

The dictyotic stage is particularly prominent in oogenesis, where it can last for extended periods, sometimes years, in many species. In females, oocytes can remain arrested in dictyotene until ovulation. This prolonged dictyotene phase is thought to allow for the synthesis of essential molecules needed for embryonic development after fertilization. In males, the dictyotic stage is generally much shorter and less pronounced, often being considered a brief interlude between diplotene and diakinesis. The term "dictyotic" itself is derived from the Greek word "diktyon," meaning net, referring to the net-like appearance of the chromosomes.