Proximal vs. distal collochores in Coleopteran chromosomes

One important mechanical requirement of meiotic chromosomes is to maintain sister chromatids in contact until the onset of anaphase-2. Monocentric chromosomes normally achieve this by means of specialized pericentric regions. However, in some cases the sites of the last chromatid contact can be shifted from such regions to the distal tips of the chromatids, or even to interstitial segments. It is proposed that all three variants, documented by observations in male meiosis of certain flea beetles, can be accommodated by the common term collochore.