Inner nuclear membrane protein (PubMed:2186029, PubMed:9199347, PubMed:18410727, PubMed:22751930). Involved in the attachment of membrane vesicles to chromatin during nuclear assembly, and is probably required for centrosome maturation and cell cycle progression during mitosis (PubMed:9199347, PubMed:22751930). Essential for differentiation of certain tissues and the maintenance of progenitor cell populations (PubMed:18410727, PubMed:24700158, PubMed:23806619, PubMed:27174470). Required for the differentiation and maintenance of male and female germline stem cells (GSCs), as well as the maintenance of somatic cells in the GSC niche (PubMed:18410727, PubMed:23806619, PubMed:27174470). This role is likely to be independent of the BMP (Dpp) pathway that negatively regulates bam transcription during GSC differentiation (PubMed:18410727, PubMed:23806619). During development, plays essential and redundant functions with the other LEM domain proteins; bocks and MAN1 (PubMed:24700158). Also has a redundant but important role with bocks during larval development (PubMed:24700158). Interacts with Med (PubMed:18410727). Interacts with Lam (PubMed:9632815, PubMed:22751930). Interacts with aurA, alphaTub84B, gammaTub23C and gammaTub37C (PubMed:22751930). Component of the spindle envelope during early mitotic cycles (PubMed:2186029, PubMed:2517292). Following nuclear envelope breakdown, becomes dispersed in the cytoplasm and concentrated at the spindle poles (PubMed:22751930, PubMed:2517292). At anaphase (when the nuclear envelope begins to reassemble), locates to the chromosomes accumulating first in areas adjacent to centrosomes and at the peripheral sites of the chromosomes (PubMed:22751930, PubMed:2517292). At telophase, expressed as a continuous rim around the chromatin and increased expression in the midspindle area (PubMed:22751930). During cytokinesis, locates to the nuclear periphery with some remaining in the cytoplasm and at the mid-body (PubMed:22751930). At stage 4 of egg development, expression in the oocyte nuclear envelope is higher than in the nurse nuclear envelope (PubMed:9199347). Expression in oocyte cytoplasm increases after stages 6 to 7 of egg development (PubMed:9199347). Expressed in all cell types of the germarium and testis (PubMed:18410727, PubMed:27174470). Expressed in nurse cells, follicle cells and oocytes (PubMed:9199347). Relatively high levels of expression in eggs and 1st instar larvae compared to pupal and adult stages, with weak expression in 2nd instar larvae (at protein level) (PubMed:16439308). Expressed throughout development in all somatic cells (PubMed:9199347). Highest levels of expression in embryos and weak expression in larvae and adults (PubMed:2186029, PubMed:9199347). Expressed throughout development (at protein level) (PubMed:2517292). Phosphorylation at Thr-63 by aurA may be required for exit from mitosis (PubMed:22751930). May be phosphorylated by Cdk1 and Pka-C1 (PubMed:9199347). No obvious phenotype (PubMed:18410727, PubMed:23806619, PubMed:24700158). However females are sterile and aging males become prematurely sterile (PubMed:18410727, PubMed:23806619). Males and females exhibit a range of defects in their germarium that may be age dependent phenotypes (PubMed:18410727, PubMed:23806619, PubMed:27174470). Most phenotypes result from defects in germline stem cell (GSC) differentiation that often lead to GSC loss (PubMed:23806619, PubMed:27174470). Also affects somatic cells of the ovarian stem cell niche, with delayed terminal filament formation and cap cell loss (PubMed:27174470). In 10 day old males, stem cell niches display a decrease in hub cell number but somatic cyst stem cells are unaffected (PubMed:27174470). No significant decrease in adult survival, however double mutants with either bocks or Man1 do not survive to the adult stage (PubMed:24700158). Double bocks and Ote mutant larvae have small brains, their imaginal disks are reduced in size or absent, and only 10% of second-instar larvae reach the pupal stage (PubMed:24700158). In Ote and MAN1 double mutants, pupal survival and larval development is unaffected (PubMed:24700158). Truncated N-terminus.