Required for the cellularization of the syncytial blastoderm embryo. Involved in the localization of the actin filaments just prior to and during plasma membrane invagination. Sry-alpha together with nullo and bnk may provide auxiliary functions, by acting both to stabilize a large and dynamic microfilament structure and regulate its functions. Inner membrane-associated and cytoplasmic. Colocalizes with the structural transitions in the microfilament network during cellularization. Transient expression in blastoderm from nuclear cycle 11 to the onset of gastrulation. Transcript levels rise steadily during syncytial stages to reach a peak in early cycle 14 and then decline rapidly during cellularization.