The small GTPases Rab are key regulators of intracellular membrane trafficking, from the formation of transport vesicles to their fusion with membranes (PubMed:21320697, PubMed:24843160). Rabs cycle between an inactive GDP-bound form and an active GTP-bound form that is able to recruit to membranes different set of downstream effectors directly responsible for vesicle formation, movement, tethering and fusion (PubMed:21320697, PubMed:24843160). Involved in regulating the meiotic maturation of oocytes (PubMed:18472420). Plays a role in egg shell formation, regulating exocytosis of chondroitin proteoglycans following fertilization (PubMed:18765566, PubMed:26506309). Controls cortical granule localization and targets them to the plasma membrane for exocytosis (PubMed:18765566, PubMed:22992455). Acts as a major regulator of membrane delivery during cytokinesis (PubMed:18765566, PubMed:20116245, PubMed:26506309). Regulates the cytoskeleton by facilitating astral microtubule elongation and organization during metaphase to ensure proper spindle alignment and polarity in the first embryonic cell division (PubMed:18385514). Maintains normal endoplasmic reticulum morphology during metaphase (PubMed:18385514). Involved in vesicle formation and plasma membrane repair following exposure to pore forming toxins (PubMed:21320697). Regulates endocytic recycling (PubMed:24843160). May play a role in yolk receptor endocytosis in growing oocytes (PubMed:18354496, PubMed:26506309). Plays a role in the shedding of pathogen spores from intestinal cells via its involvement in spore fusion and endocytic trafficking (PubMed:24843160). Interacts with rei-1 and rei-2. The GDP-form preferentially binds to rei-1 and rei-2. Expressed in endosomal vesicles which localize to the pericentriolar region of embryos during prophase and metaphase (PubMed:19158384). Localizes along the spindle in embryos during anaphase (PubMed:19158384). Transiently accumulates on secretory vesicles before their exocytosis (PubMed:18765566). Localizes to recycling endosomes and Golgi apparatus membrane in growing oocytes (PubMed:18765566, PubMed:26506309). Translocates to cytoplasmic granules and extracellular matrix components in mature oocytes (PubMed:26506309). Accumulates on ring-shaped structures in ovulating oocytes and in early one-cell stage embryos (PubMed:18765566). Redistributes to recycling endosomes and Golgi apparatus in embryos (PubMed:26506309). Co-localizes with rei-1 at Golgi apparatus membrane in embryos (PubMed:26506309). Reycling endosomes co-localize with the endoplasmic reticulum in embryos (PubMed:18385514). Co-localizes with rab-6.1-positive vesicles near the plasma membrane until vesicle exocytosis in embryos (PubMed:22992455). Localizes to the cytosol during the meront-stage of N.parisii infection and around the resulting spores that are to be shed from intestinal cells (PubMed:24843160). Expressed weakly in sperm, but more predominantly in oocytes (PubMed:18472420). Expressed in the intestine (PubMed:24843160). Expressed during embryogenesis (PubMed:18385514, PubMed:20116245, PubMed:26506309). Transiently expressed during cytokinesis in embryos on the ingressing furrow and at the midbody during early abscission (PubMed:20116245). Expressed during the L4 stage and young adult stage of development (PubMed:22634595). Zygotic lethal (PubMed:18765566). RNAi-mediated knockdown results in a reduced meiotic maturation rate of oocytes (PubMed:18472420). Embryos are multinucleated and osmotically sensitive with permeable and therefore defective eggshells (PubMed:18765566, PubMed:18385514). During the first cell cycle, 52% of embryos fail to extrude polar bodies, 83% of embryos display no or minimal pseudocleavage and the centrosomal-nuclear complex does not migrate to the center of embryos (PubMed:18385514). Animals display mitotic spindle alignment defects whereby in 73.9% of embryos, the P0 spindle does not rotate to the anterior-posterior axis of the embryo during anaphase, but during the metaphase to anaphase transition, the movements of the spindle are more abrupt with the spindle migrating to the posterior pole and then rebounding to the anterior-posterior axis (PubMed:18385514). In 17.4% of embryos the centrosomes are unstable and the spindle is displaced further towards the posterior pole (PubMed:18385514). Impaired localization of proteins important for establishing cell polarity such as par-2, par-3, gpr-1 and gpr-2 (PubMed:18385514). Altered microtubule organization and dynamics during metaphase including a greater distance between the growing microtubule plus ends and the posterior cortex, impeded microtubule growth with fewer growing astral microtubules reaching the cortex, and a reduced microtubule nucleation rate (PubMed:18385514). Slight defect in endoplasmic reticulum morphology whereby the large endoplasmic reticulum aggregates that normally form during metaphase and persist during anaphase, form, but do not persist during anaphase and disperse (PubMed:18385514). Mild endocytosis defect with an accumulation of the yolk protein vitellogenin in the pseudocoelom (PubMed:18354496). Impaired cortical granule (secretory vesicle) localization with granules abnormally clustered around the nuclear envelope of proximal oocytes, irregulary dispersed in the cytoplasm of oocytes and retained in the embryo following entry into the uterus (PubMed:18765566). Cortical granule exocytosis defects whereby cav-1-positive cortical granules are not tethered to the plasma membrane, but are distributed throughout the cytoplasm and accumulate around the nucleus in embryos following fertilization (PubMed:22992455). Disrupted fusion of spores, containing intracellular pathogen N.parisii, with the apical cell membrane and thus disrupted clearance from intestinal cells (PubMed:24843160). RNAi-mediated knockdown in RNAi-sensitive mutants exposed to bacterial pore-forming toxin Cry5B results in intoxification and impaired plasma membrane repair (PubMed:21320697). RNAi-mediated knockdown in the intestine results in reduced survival upon exposure to Cry5B (PubMed:21320697). Belongs to the small GTPase superfamily. Rab family.