Table 2.

Summary of VAB-1 EphR biological functions and pathway components.

Function	Pathway components (upstream, downstream, or parallel)	Comments
Ventral enclosure and epidermal morphogenesis	EFN-1-4, BUS-8, SAX-3, PTP-3, MAB-20, PLX-2	Complex process involving the integration of multiple signaling pathways in neuroblasts and epidermal cells. May also involve VPR-1.
Male tail development	EFN1-4, MAB-20, PLX-2	Involves multiple signaling pathways.
Neuron and axon guidance	EFN1-3, VPR-1, WRK-1, NCK-1, WSP-1, UNC-34, ARP2/3, SAX-3	Includes multiple independent guidance decisions.
Muscle cell migration	EFN-1	Other ephrins may be involved.
Oocyte meiotic maturation and oocyte growth	EFN-1-3, MSPs, DAF-18, RAN-1, DAB-1, NMR-1, GSA-1, INX-14, INX-22, MPK-1, PTP-2, LET-60	Complex process involving the integration of multiple signaling pathways in sheath cells and oocytes (some components not shown). The biochemical relationships among some components are not well understood.
Germ line apoptosis	EFN1-3
Axon regeneration		Likely involves ephrins.
Hypoxia protection	HIF-1	HIF-1 up-regulates VAB-1 transcription.