Which one is the real matchmaker for the pair?

Abstract

A fundamental question for meiosis is how homologous chromosomes (homologs) find each other and pair together to ensure homologous recombination and segregation. Intuitively, the answer to the question is related to the interaction between homologous sequences. However, that is not the whole story according to some studies on the role of cohesins in homolog pairing. The most recent one by Ishiguro et al.[1] of the Watanabe group indicates that chromosome architecture defined by a meiosis-specific cohesin protein RAD21L is the key to homology searching. Moreover, they report that homologous pairing is dependent on neither SPO11, an evolutionarily conserved type 2 isomerase responsible for generating DNA double-strand breaks (DSBs), nor SUN1, which tethers the ends of chromosomes to the nuclear envelop (NE) and facilitates chromosome movement and bouquet formation. These discoveries are quite some surprises!