Involved in the control of cell movement by regulating actin cytoskeleton homeostasis and filopodium and lamellipodium formation. Associates with the membrane via the insertion of the N-terminal N-myristoyl chain and the partial insertion of the effector domain. Expressed at low levels in brain, eye and muscle. Detected from 24 to 72 hours post-fertilization (hpf). Morpholino knockdown of the protein results in reduced head and eye size and a ventrally curved body. No significant effect on formation of craniofacial cartilage. Formation of ceratohyal cartilage is disrupted with an abnormal angle relative to wild-type. Morphogenesis of the developing neural tube is abnormal, with a smaller angle between the walls of the hindbrain neuroepithelium at 24 hours post-fertilization (hpf). Retinal development is significantly delayed; no retinal ganglion cells (RGCs) are detected at 30 hours hpf and reduced numbers are found at 60 hpf. Cilium length in Kupffer's vesicle is significantly reduced. Double morpholino knockdown of marcksl1a and marckls1b results in a more pronounced developmental delay in the retina. Belongs to the MARCKS family.