Newfound features of meiotic chromosome organization that promote efficient congression and segregation in oocytes.

Although end-on microtubule-kinetochore attachments typically drive chromosome alignment, oocytes do not form these connections. Instead, microtubule bundles run laterally alongside chromosomes and a ring-shaped protein complex facilitates congression (the "ring complex", RC). Here, we report new aspects of RC and chromosome structure that are required for congression and segregation.