WormMine: LifeStage WBls:0000006

• Definition: Also called zygote. -50min till 0min of first cleavage at 20 Centigrade. Contains 1 cell.
• Primary Identifier: WBls:0000006
• Public Name: 1-cell embryo Ce

2 Anatomy Terms

Definition	Name	Synonym	Primary Identifier
Single cell zygote	P0	lineage name: Z	WBbt:0004422
nucleus of pedigree P0	P0 nucleus		WBbt:0000102

2 Contained In

Remark	Definition	Other Name	Public Name	Primary Identifier
	The C. elegans life stage spanning 0-100min after first cleavage at 20 Centigrade. Proliferate from 1 cell to 28 cells. From first cleavage until the start of gastrulation.		blastula embryo Ce	WBls:0000005
	A C. elegans life stage that occurs during the blastula embryo life stage		C. elegans life stage occurring during blastula embryo	WBls:0000813

4 Expression Clusters

Regulated By Treatment	Description	Algorithm	Primary Identifier
	mRNAs that showed decreased expression in 1 cell mebryo comparing to in oocyte, according to RNAseq analysis.	Gaussian error propagation. As cutoff for the up-regulated genes authors used log2 fold change > 1 and P < 0.05 and as cutoff for the down-regulated genes authors used log2 fold change < -1 and P < 0.05.	WBPaper00045420:fertilization_downregulated_transcript
	mRNAs that showed increased expression in 1 cell mebryo comparing to in oocyte, according to RNAseq analysis.	Gaussian error propagation. As cutoff for the up-regulated genes authors used log2 fold change > 1 and P < 0.05 and as cutoff for the down-regulated genes authors used log2 fold change < -1 and P < 0.05.	WBPaper00045420:fertilization_upregulated_transcript
	Proteins that showed decreased expression in 1 cell mebryo comparing to in oocyte, according to proteomic analysis.	Gaussian error propagation. As cutoff for the up-regulated genes authors used log2 fold change > 1 and P < 0.05 and as cutoff for the down-regulated genes authors used log2 fold change < -1 and P < 0.05.	WBPaper00045420:fertilization_downregulated_protein
	Proteins that showed increased expression in 1 cell mebryo comparing to in oocyte, according to proteomic analysis.	Gaussian error propagation. As cutoff for the up-regulated genes authors used log2 fold change > 1 and P < 0.05 and as cutoff for the down-regulated genes authors used log2 fold change < -1 and P < 0.05.	WBPaper00045420:fertilization_upregulated_protein

27 Expression Patterns

• Primary Identifier: Expr12265
• Pattern: The localization of tetraThymosin-beta is shown in oocytes (in dissected gonads of adult worms), in embryos and in whole adult organisms. TetraThymosin-beta was maternally expressed and in the adult gonad diffusely present in the cytoplasm of the oocytes, with strong staining at the cell cortex where also actin is present. In the distal arm of the gonad, tetraThymosin-beta localized to the inside edges of the membrane cubicles surrounding germ cell nuclei. Here, tetraThymosin-beta did not localize to the lateral side of the membrane cubicles where actin is arranged in a 'honeycomb' structure (Strome, 1986). In two-cell stage embryos, tetraThymosin-beta was enriched in the cell-cell contact where actin was also concentrated. The tetraThymosin-beta signal was clearly apparent until the four-cell stage and became weaker later on. At the comma stage (290 min after the first cell division), tetraThymosin-beta staining was observed at the developing nerve ring that is the largest axonal bundle in the nematode body and that positions around the isthmus of the pharynx. TetraThymosin-beta was evident in this region even before a clear actin signal was apparent. In larvae and adults, immunofluorescence yielded a diffuse but specific staining of the entire worm body with enrichment at the intestinal tract and spermatheca. At these stages, in contrast to what is observed in developing embryo, no prominent signal was observed in the head region where the nerve ring is located. In young adults is expressed in theposterior bulb of the pharynx. These immunostaining patterns were reproducible in three or more experiments and in 20 or more worms or embryos.

• Primary Identifier: Expr14961
• Pattern: In the one-cell embryo, maternally provided ZF1::GFP::PKC-3 enriched at the anterior cortex, like endogenous PKC-3 (TABUSE et al. 1998), but by the 24-cell stage ZF1::GFP::PKC-3 had degraded to undetectable levels in somatic cells. Zygotically expressed ZF1::GFP::PKC-3 reappeared during the middle stages of embryogenesis at the apical surfaces of differentiating epithelia, including the epidermis, pharynx, and intestine, where itcolocalized with PAR-6.

• Primary Identifier: Expr2582
• Subcellular Localization: The OMA-1::GFP fluorescence in the developing oocytes and one-cell embryos recapitulated the wild-type spatial and temporal patterns of OMA-1 antibody staining. The punctate staining appeared more pronounced and resembled the characteristic pattern of germline P granules. Starting with the onset of the first mitotic division, the intensity of OMA-1-GFP fluorescence rapidly decreased, and by the time the division was complete, only approximately 10% remained. Interestingly, that remaining 10% of the GFP signal in the two-cell embryo was predominantly found in the germline precursor, P1, associated with what appeared to be P granules. The GFP signal continued to decrease in two-cell embryos and again was asymmetric after the next division, with most of the remaining fluorescence segregated to P2, where it was also predominantly associated with granules. The OMA-1-GFP signal became too weak to detect in the embryo after the four-cell stage.

• Primary Identifier: Expr746
• Remark: This information was extracted from published material (Archana Sharma-Oates, Andrew Mounsey and Ian A. Hope).
• Pattern: pal-1 RNA evenly distributed in 1- and 2-cell embryos. In 4-cell embryos, pal-1 RNA was either uniformly distributed (approximately 50%) or preferentially localized to the posterior blastomere. Nuclear localized transcripts were not detected before the 24-cell stage. In 6 cell and older embryo, pal-1 RNA was more abundant in cells that express PAL-1 protein.

• Primary Identifier: Expr3781
• Subcellular Localization: These antibodies detect a strong and uniform signal at the cell cortex of early embryos. This distribution corresponds to bona fide GPA-16 because it is significantly diminished in gpa-16(RNAi) embryos. These antibodies also label the cytoplasm, with a slight enrichment in the vicinity of microtubule asters, but this aspect of the signal is barely diminished in gpa-16(RNAi) embryos, suggesting that it is not specific or corresponds to a particularly stable pool of GPA-16. In summary, GPA-16 is present predominantly at the cortex of one-cell stage embryos.

• Primary Identifier: Expr573
• Remark: early embryo(author) = 1-cell + 2-cell + 4-cell embryo(curator).
• Pattern: mex-3 mRNA is detected in the syncytial core of gonad arm and distribute uniformly in oocyte and early 1-cell embryo. mex-3 mRNA is more abundant in AB and its daughter cells than P1 and its daughter cells. After 4-cell stage, mex-3 mRNA disappears. MEX-3 protein is present in oocytes and uniformly distributed until the first division, when they become more abundant in the anterior AB cell. At the 4-cell stage, AB daughters have more MEX-3. Both the mRNA and protein disappear after the 4-cell stage.
• Subcellular Localization: MEX-3 is cytoplasmic, and in the P cells, MEX-3 is associated with P granules.

• Primary Identifier: Expr14312
• Subcellular Localization: GFP tagged Myosin and Anillin, expressed under endogenous promoters, are visible in the cortex and contractile ring in 1 to 4 cell stage embryos.

• Primary Identifier: Expr9127
• Subcellular Localization: Expressed in the cytoplasm with increasing levels in growing oocytes, peaking in the oocyte undergoing maturation. The level of OMA-1 protein remain very high following fertilization as well as throughout the first mitotic cycle. The antibody staining often included a slight punctate pattern of fluorescence. Immediately after the first mitotic division, the levels of OMA-1 protein rapidly decreased and became difficult to detect with antibody staining.

• Primary Identifier: Expr1161
• Remark: The fact that NOS-2 can be detected in the germ lineage as early as the 28-cell stage strongly suggest that NOS-2 is expressed from maternal RNA, since zygotic transcription is not thought to begin in the germ lineage until the 100-cell stage. The specificity of antibody was confirmed by staining embryos deficient for NOS-2. Affinity-purified anti-NOS-2 antibody detected NOS-2 in nos-1(RNAi) and nos-1(gv5) embryos, but not in nos-2(RNAi) embryos. NOS-1 and NOS-2 thus do not depend on each other for expression.
• Pattern: NOS-2 protein is expressed sequentially during embryogenesis. First detected expression of NOS-2 in the 1-cell stage; at this stage, NOS-2 was present uniformly throughout the embryo. No NOS-2 expression was detected in 2- to 20-cell embryos. NOS-2 expression reappeared in the 28-cell stage in the cytoplasm of the germline blastomere P4. In some embryos, NOS-2 staining appeared to be concentrated in a few perinuclear foci. NOS-2 expression continued in P4 and its two daughters Z2 and Z3 until approximately the 200-cell stage. NOS-2 levels decreased sharply in later stages and were undetectable by the 550-cell stage.
• Subcellular Localization: cytoplasm

• Primary Identifier: Expr2581
• Subcellular Localization: Expressed in the cytoplasm with increasing levels in growing oocytes, peaking in the oocyte undergoing maturation. The level of OMA-2 protein remain very high following fertilization as well as throughout the first mitotic cycle. The antibody staining often included a slight punctate pattern of fluorescence. Immediately after the first mitotic division, the level of OMA-2 proteins rapidly decreased and became difficult to detect with antibody staining.

• Primary Identifier: Expr1558
• Remark: No detailed description on cellular expression pattern at later stages.
• Subcellular Localization: No staining was seen in gonads or unfertilized oocytes. The PAR-3 protein was first detected at the cell periphery in fertilized eggs during the meiotic divisions. In 10 out of 13 positively stained embryos, the protein was undetectable in the posterior third of the embryo. stained very strongly on the lateral periphery, and stained weakly at the periphery at the extreme anterior pole. The other embryos showed uniform peripheral staining. After meiosis II is completed and as the pronuclei start to decondense, PAR-3 is restricted to the anterior periphery at all cases, extending to about 65% of the total length of the embryo. As pronuclear migration processes, PAR-3 become more concentrated at the anterior pole, extending to about 54% of the embryonic length. During prophase, metaphase, and early anaphase of the first mitosis, the signal is strongest and extends to 48% embryo length. In addition to peripheral staining, at all stages, unlocalized PAR-3 appears to be present in the cytoplasm.

• Primary Identifier: Expr1254
• Remark: No detailed description on cellular expression pattern of later developmental stages.
• Pattern: Staining of DNC-1 in one-cell and two-cell embryos revealed a striking accumulation at the cell-division remnant (also known as the residual body or midbody).
• Subcellular Localization: Centrosomal and kinetochore staining was also seen. In addition, cytoplasmic staining was seen. Initially, the accumulation of DNC-1 at cell-division remnants appeared upon completion of the first meiosis during polar-body formation. This spot persisted until the end of the first mitosis. DNC-1 appeared at the leading edge of the cleavage furrow of one-cell stage embryos, and persisted at the cell-division remnant until the end of the two-cell stage.

• Primary Identifier: Expr1850
• Pattern: OMA-1 expression is detectable prior to oocyte cellularization. Expression is not detected in sperm or the spermatheca, nor are they detected in oma-1(te33);oma-2(te51) mutant oocytes. The expression of OMA-1 continues in the 1-cell embryo, but is not detected in 2-cell or older embryos.
• Subcellular Localization: Expression is cytoplasmic and increases as the oocytes develop, peaking in the maturing oocyte.

• Primary Identifier: Expr1851
• Pattern: OMA-2 is expressed only in fully cellularized oocytes. Expression is not detected in sperm or the spermatheca, nor are they detected in oma-1(te33);oma-2(te51) mutant oocytes. The expression of OMA-2 continues in the 1-cell embryo, but is not detected in 2-cell or older embryos.
• Subcellular Localization: Expression is cytoplasmic and increases as the oocytes develop, peaking in the maturing oocyte.

• Primary Identifier: Expr12116
• Subcellular Localization: GFP::MEG-3 was detected in the cytoplasm of immature germ cells and oocytes. In zygotes, cytoplasmic GFP::MEG-3 formed an anterior-to-posterior gradient with highest levels in the posterior.

• Primary Identifier: Expr13458
• Subcellular Localization: Epifluorescence microscopy revealed that mCherry::DHC-1 and eGFP::DHC-1 are expressed in all somatic tissues and in the germline. After imaging early embryos by spinning-disk confocal fluorescence microscopy (SDCM), DHC-1 was detected in the cytoplasm during all stages of the cell cycle and localized specifically to the nuclear envelope, centrosomes, kinetochores, kinetochore MTs, central spindle, astral MTs, and the cell cortex during mitosis. This localization pattern is in accordance with previous immunohistochemistry and overexpression studies (Schmidt et al., 2005; Nguyen-Ngoc et al., 2007; Gassmann et al., 2008; Kimura and Kimura, 2011). In addition, we noticed comet like accumulations of dynein radiating from the centrosomes to the cell periphery in a pattern that appeared to follow the mitotic astral MT network.Endogenous dynein complex tracks MT plus ends. This was observed in one cell embryos and in later stages of C. elegans embryos (4-cell embryos).

• Primary Identifier: Expr13457
• Subcellular Localization: DHC-1::GFP was readily detectable on growing MT plus ends in early embryos. dhc-1::gfp knock-in allele.

• Primary Identifier: Expr13024
• Subcellular Localization: ATX-2: exhibits diffuse cytoplasmic expression in early embryo with occasional punctate foci.

• Primary Identifier: Expr15869
• Pattern: Cah-1, cah-2, cah-5 and cah-6 show very little transcript accumulation.

• Primary Identifier: Expr15870
• Pattern: Cah-1, cah-2, cah-5 and cah-6 show very little transcript accumulation.

• Primary Identifier: Expr15872
• Pattern: Cah-1, cah-2, cah-5 and cah-6 show very little transcript accumulation.

• Primary Identifier: Expr15871
• Pattern: Cah-1, cah-2, cah-5 and cah-6 show very little transcript accumulation.

• Primary Identifier: Expr15868
• Pattern: Cah-3 and cah-4 are expressed throughout development, with the highest expression levels seen during the L1 to L3 stages.

• Primary Identifier: Expr15867
• Pattern: Cah-3 and cah-4 are expressed throughout development, with the highest expression levels seen during the L1 to L3 stages.

• Primary Identifier: Expr14311
• Subcellular Localization: GFP tagged Myosin and Anillin, expressed under endogenous promoters, are visible in the cortex and contractile ring in 1 to 4 cell stage embryos.

• Primary Identifier: Expr1287
• Remark: No detailed description on cellular localization at later stages.
• Pattern: Blastula embryo.
• Subcellular Localization: The antibodies stained the cell periphery of early blastomeres as well as the nuclear envelope. Nuclear envelope staining however, appears to be non-specific. The staining in 1-cell embryos is weak and uniform just after the completion of meiosis, but increases in intensity and becomes concentrated at the anterior periphery during pronuclear migration. The peripheral PKC-3 staining becomes restricted to about 50% embryo length during the pronuclear meeting and pronuclear fusion stage (n=23). By early anaphase, the staining extends posteriorly beyond the midline of the zygote and covers about 60% of the total length of embryos (n=29). In 2- and 4-cell stages, staining is uniform at the periphery of the AB cell, its daughters and the EMS cell, but peripheral staining in P1 and P2 is restricted to the boundaries with other blastomeres.

• Primary Identifier: Expr1162
• Remark: To confirm that the localization patterns described are specific to POD-1, pod-1(ye11) mutant embryos were stained with both POD-1 antibodies. All cortical and cytoplasmic POD-1 staining was eliminated in the mutant embryos.
• Pattern: POD-1 localization in P cells is cell cycle dependent. In the earliest one-cell embryos before pronuclear meeting (P0), cortical POD-1 is either anteriorly enriched (12/24 embryos), posteriorly enriched (5/24 embryos), or uniformly localized (7/24 embryos). From pronuclear meeting to metaphase, cortical POD-1 is almost always anteriorly enriched (30/39 embryos). At anaphase, POD-1 begins to transition from asymmetric to symmetric localization, such that by telophase cortical POD-1 can be found at equivalent levels in the anterior and posterior cortices (10/11 embryos). In addition to cell cortices, POD-1 antibodies stain punctate cytoplasmic structures. POD-1 can be found in the posterior-most cortex, albeit at lower levels than the anterior. The localization of POD-1 in the germ-line precursors of the two-cell and four-cell embryo is also cell cycle dependent such that early in the cell cycle, POD-1 is not asymmetric along the a-p axis, but becomes anteriorly enriched leading up to metaphase.
• Subcellular Localization: punctate cytoplasmic structures

1 Followed By

Remark	Definition	Other Name	Public Name	Primary Identifier
	The C. elegans life stage spanning 0-20min after first cleavage at 20 Centigrade. Contains 2 cells.		2-cell embryo Ce	WBls:0000007

1 Preceded By

Remark	Definition	Other Name	Public Name	Primary Identifier
	A developmental life stage of the nematode Caenorhabditis elegans that occurs in an egg (oocyte), before fertilization by sperm.		unfertilized egg Ce	WBls:0000669

0 Sub Stages