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Fig. 1. Embryo dissection at the 8-cell stage. An 8-cell Xenopus laevis embryo was fixed in
EtOH-acetic acid, and manually separated into three portions: the 4 animal blastomeres (AN,
view from blastocoel); the 4 vegetal blastomeres were cut into a vegetal pole (VP) portion and
an equatorial (EQ) portion. AN and VP samples were collected for microarray analyses and EQ
samples were discarded.
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Fig. 2. The majority of animal transcripts enriched >3-fold over vegetal pole encode unknown
genes. A pie chart identifies the proportion of genes within different gene ontologies.
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Fig. 3. qRT-PCR comparisons of AN and VP samples. Of the 11 genes identified by microarray
to be animal-enriched for which successful primers were designed, 8 were detected at significantly
higher levels (*P<0.05) in AN (blue) versus VP (red) samples. Numbers on Y-axis indicate
fold differences relative to vegetal value (mean values from a minimum of three independent
samples replicated twice). Bars represent standard error of the mean. As a control, a known VP
mRNA, Vg1, also was tested, and as expected from the literature is highly enriched in the VP
samples.
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Fig. 4. Location of maternal transcripts of the 14 characterized genes assayed by ISH at the 8-cell-stage cleavage embryo. All 14 are enriched
in the animal blastomeres, whose equatorial cleavage furrow is indicated by an arrow. Animal pole is up and vegetal pole is down. For some
embryos, ISH signal is also detected in the equatorial region (see Table 2).
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Fig. 5. Developmental time course of expression in whole embryos as detected by qRT-PCR. A: Two genes (aurka-b, Xl.54800) are most highly
expressed during the maternal phase of development (st 4), gradually decrease during the onset of zygotic transcription (st 8–10), and remain at
relatively low levels during the remaining stages analyzed. B: Four genes (srebf2, WBP2NL, SMCR7L, Xl.86248) are highly expressed during the
maternal phase of development and gradually decrease during the onset of zygotic transcription, but rebound to higher expression levels at neurulation
(st 19) through larval (st 35–38) stages. C: Two genes (Xl.15460, Xl.29665) are expressed at the lowest level maternally and at relatively high
levels after neural plate stages. D: Three genes (Xl.11373, TNFAIP1, gskip) are strongly expressed maternally, with decreasing expression at early
zygotic stages and strong larval expression. Y-axis indicates relative expression compared to lowest expression for that transcript (mean values
from a minimum of three independent samples replicated twice). X-axis indicates developmental stage. Bars represent standard error of the
mean.
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Fig. 6. Expression of the 14 characterized genes assayed by ISH in stage 8–9 blastula embryos. All 14 genes are strongly expressed in the animal
cap ectoderm (top), but for some ISH signal is also detected in the equatorial region (*, also see Table 2). Animal pole is up and vegetal pole
is down.
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Fig. 7. Expression patterns of animal-enriched genes from neural plate to late tail bud stages. A: Expression patterns of the seven highest ANenriched
genes that were characterized. B: Expression patterns of the remaining seven AN-enriched genes that were characterized. Early (left)
and late (third from right) neural plate stages are anterior views with dorsal to the top. Early (second from right) and late (far right) tail bud stages
are side views with anterior to the right and dorsal to the top. ba, branchial arch; br, brain; cg, cement gland; epi, epidermis; h, heart; le, lens; li,
liver; nc, neural crest; ne, nephric mesoderm; np, neural plate; olf, olfactory, oto, otocyst; ov, optic vesicle; pm, paraxial mesoderm; ppe, preplacodal
ectoderm; ret; retina; sc, spinal cord; so, somites; vg, ventral gut.
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Fig. 7. Expression patterns of animal-enriched genes from neural plate to late tail bud stages. A: Expression patterns of the seven highest ANenriched
genes that were characterized. B: Expression patterns of the remaining seven AN-enriched genes that were characterized. Early (left)
and late (third from right) neural plate stages are anterior views with dorsal to the top. Early (second from right) and late (far right) tail bud stages
are side views with anterior to the right and dorsal to the top. ba, branchial arch; br, brain; cg, cement gland; epi, epidermis; h, heart; le, lens; li,
liver; nc, neural crest; ne, nephric mesoderm; np, neural plate; olf, olfactory, oto, otocyst; ov, optic vesicle; pm, paraxial mesoderm; ppe, preplacodal
ectoderm; ret; retina; sc, spinal cord; so, somites; vg, ventral gut.
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Fig. 8. Expression patterns of animal-enriched genes at late larval stages. A: Expression patterns of the five highest AN-enriched genes that
were characterized. B: Expression patterns of the five next highest AN-enriched genes that were characterized. C: Expression patterns of the
remaining four AN-enriched genes that were characterized. Left: Side views of embryos with anterior to the right and dorsal to the top. Right:
Transverse vibratome sections of whole mount ISH preparations showing internal histology. ba, branchial arch; br, brain; cg, cement gland; epi,
epidermis; h, heart; le, lens; li, liver; nc, neural crest; ne, nephric mesoderm; np, neural plate; olf, olfactory, oto, otocyst; ov, optic vesicle; pm, paraxial
mesoderm; ppe, pre-placodal ectoderm; ret; retina; sc, spinal cord; so, somites; vg, ventral gut.
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Fig. 8. Expression patterns of animal-enriched genes at late larval stages. A: Expression patterns of the five highest AN-enriched genes that
were characterized. B: Expression patterns of the five next highest AN-enriched genes that were characterized. C: Expression patterns of the
remaining four AN-enriched genes that were characterized. Left: Side views of embryos with anterior to the right and dorsal to the top. Right:
Transverse vibratome sections of whole mount ISH preparations showing internal histology. ba, branchial arch; br, brain; cg, cement gland; epi,
epidermis; h, heart; le, lens; li, liver; nc, neural crest; ne, nephric mesoderm; np, neural plate; olf, olfactory, oto, otocyst; ov, optic vesicle; pm, paraxial
mesoderm; ppe, pre-placodal ectoderm; ret; retina; sc, spinal cord; so, somites; vg, ventral gut.
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Fig. 8. Expression patterns of animal-enriched genes at late larval stages. A: Expression patterns of the five highest AN-enriched genes that
were characterized. B: Expression patterns of the five next highest AN-enriched genes that were characterized. C: Expression patterns of the
remaining four AN-enriched genes that were characterized. Left: Side views of embryos with anterior to the right and dorsal to the top. Right:
Transverse vibratome sections of whole mount ISH preparations showing internal histology. ba, branchial arch; br, brain; cg, cement gland; epi,
epidermis; h, heart; le, lens; li, liver; nc, neural crest; ne, nephric mesoderm; np, neural plate; olf, olfactory, oto, otocyst; ov, optic vesicle; pm, paraxial
mesoderm; ppe, pre-placodal ectoderm; ret; retina; sc, spinal cord; so, somites; vg, ventral gut.
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aurka (aurora kinase A) gene expression in Xenopus laevis embryo, assayed via in situ hybridization, NF stage 32, lateral view, anterior right, dorsal up.
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denr (density-regulated protein) gene expression in Xenopus laevis embryo, assayed via in situ hybridization, NF stage 32, lateral view, anterior right, dorsal up.
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mief1 (mitochondrial elongation factor 1) gene expression in Xenopus laevis embryo, assayed via in situ hybridization, NF stage 32, lateral view, anterior right, dorsal up.
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nop14 (NOP14 nucleolar protein) gene expression in Xenopus laevis embryo, assayed via in situ hybridization, NF stage 32, lateral view, anterior right, dorsal up.
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wbp2nl (WBP2 N-terminal like) gene expression in Xenopus laevis embryo, assayed via in situ hybridization, NF stage 32, lateral view, anterior right, dorsal up.
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fam222b (family with sequence similarity 222, member B) gene expression in Xenopus laevis embryo, assayed via in situ hybridization, NF stage 32, lateral view, anterior right, dorsal up.
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gskip (GSK3B interacting protein) gene expression in Xenopus laevis embryo, assayed via in situ hybridization, NF stage 32, lateral view, anterior right, dorsal up.
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srebf2 (sterol regulatory element binding transcription factor 2) gene expression in Xenopus laevis embryo, assayed via in situ hybridization, NF stage 32, lateral view, anterior right, dorsal up.
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tnfaip1 (tumor necrosis factor, alpha-induced protein 1) gene expression in Xenopus laevis embryo, assayed via in situ hybridization, NF stage 32, lateral view, anterior right, dorsal up.
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