Table 2.1.

Proteins in germ plasm

Protein	Domains	Protein localization	Loss-of-function phenotype	Proposed function	References
PIE-1	CCCH fingers	P blastomeres Nuclear, cytoplasmic, P granules, centrosomes	Maternal effect embryonic lethality P2 transformed to EMS fate No germ cells	Repression of RNA Polymerase II Translational control of mRNAs	Mello et al. (1992), Seydoux et al. (1996), Tenenhaus et al. (2001)
POS-1	CCCH fingers	P blastomeres Cytoplasmic, P granules	Maternal effect embryonic lethality Complex cell fate transformations No germ cells	Translational control of mRNAs	Tabara et al. (1999)
MEX-1	CCCH fingers	P blastomeres Cytoplasmic, P granules	Maternal effect embryonic lethality Complex cell fate transformations No germ cells	Unknown	Mello et al. (1992), Guedes and Priess (1997)
MEX-3	KH domain	Present in oocytes through 4-cell stage Cytoplasmic in multiple cell types P granules in P1 through P4	Maternal effect embryonic lethality D transformed to P4, as a result more than two Z2/Z3 like cells are formed	Translational control of mRNAs	Draper et al. (1996)
MES-1	Receptor tyrosine kinase related	In P2 at junction with EMS contact In P3 at junction with E contact	Maternal effect sterility P4 transformed to D fate No germ cells	Signaling from EMS to P2 to reverse polarity in P2	Strome et al. (1995), Berkowitz and Strome (2000)
Sm proteins	LSm fold	P granules	Embryonic arrest at 50- to 100-cell stage Mislocalization of PIE-1, P granules Symmetric divisions and short cell cycles	Regulation of mRNAs	Barbee et al. (2002), Barbee and Evans (2006)
PAR-1	KIN1/MARK kinase	Cortical—P blastomeres and Z2 and Z3 until morphogenesis	Maternal effect embryonic lethality No germ cells	Polarization of P blastomeres	Kemphues et al. (1988), Guo and Kemphues (1995)
MES-2/3/6	Polycomb orthologs	Nuclear in both somatic and germ cells in embryos. Persists in Z2 and Z3 in embryos and L1 larvae.	Maternal effect sterility Germ cell death at L3 and L4 stages	Repression of X chromosome transcription	Bender et al. (2004), Strome (2005)
MES-4	SET domain	Chromatin, preferentially autosomes. Present in somatic and germ cells in early embryogenesis, persists in Z2 and Z3	Maternal effect sterility Germ cell death at L3 and L4 stages	Transmission of germline transcriptional program from mother to progeny Repression of X chromosome transcription	Fong et al. (2002), Bender et al. (2006), Rechtsteiner et al. (2010)
NOS-1/2	Nanos orthologs	NOS-1: expressed in Z2 and Z3 from zygotic mRNA, cytoplasmic NOS-2: expressed in P4 from maternal mRNA, cytoplasmic	Z2 and or Z3 outside somatic gonad Germ cell death at L3 stage	Regulation of mRNAs	Subramaniam and Seydoux (1999)
MEG-1/2	Novel	P granules from P2 through P4	Maternal effect sterility Germ cell death at L3 stage	Unknown	Leacock and Reinke (2008)
PGL-1/2/3	RGG box	Constitutive P granule components	Sterility with variable phenotypes	Unknown, primarily post-embryonic	Kawasaki et al. (2004)
GLH-1/2/3/4	DEAD box helicase	Constitutive P granule components	Sterility with variable phenotypes	Unknown, primarily post-embryonic	Spike et al. (2008)
Anti-germ plasm:
MEX-5/6	CCCH fingers	High levels in somatic founder blastomeres—cytoplasmic High/low levels in Ant/Post cytoplasm of P blastomeres—cytoplasmic and enriched on P granules and centrosomes	Embryonic lethality Complex cell fate transformations No germ cells	Dispersal of P granules in dividing P blastomeres Degradation of germ plasm in somatic blastomeres	Schubert et al. (2000) Gallo et al. (2010)