Concentrated in punctuate and fibrillar structures during G2 and M phases. Localized to the cell division plane during cytokinesis. Isoform 1 is constitutively expressed (PubMed:16240174, PubMed:16460730). Isoform 2 is specifically expressed in flowers bud during sporogenesis and gametogenesis (PubMed:16240174). Mostly expressed in actively proliferating tissues (PubMed:16460730). Specifically expressed in degenerating megaspores of normal ovules and in enlarged megaspore mother cells and embryo sacs of apomeiotic ovules. Also detected in microspore tetrads at the beginning of pollen development as well as in tapetum cells of anthers undergoing programmed cell death (PCD) to allow pollen dispersal at maturity (PubMed:16240174). Belongs to the MOB1/phocein family.