SQV-7, a protein involved in Caenorhabditis elegans epithelial invagination and early embryogenesis, transports UDP-glucuronic acid, UDP-N- acetylgalactosamine, and UDP-galactose

Abstract RIC-8 (synembryn) and GOA-1 (Goα) are key components of a signaling network that regulates neurotransmitter secretion in Caenorhabditis elegans. Here we show that ric-8 and goa-1 reduction of function mutants exhibit partial embryonic lethality. Through Nomarski analysis we show that goa-1 and ric-8 mutant embryos exhibit defects in multiple events that involve centrosomes, including one-cell posterior centrosome rocking, P1 centrosome flattening, mitotic spindle alignment, and nuclear migration. In ric-8 reduction of function backgrounds, the embryonic lethality, spindle misalignments and delayed nuclear migration are strongly enhanced by a 50% reduction in maternal goa-1 gene dosage. Several other microfilament- and microtubule-mediated events, as well as overall embryonic polarity, appear unperturbed in the mutants. In addition, our results suggest that RIC-8 and GOA-1 do not have roles in centrosome replication, in the diametric movements of daughter centrosomes along the nuclear membrane, or in the extension of microtubules from centrosomes. Through immunostaining we show that GOA-1 (Goα) localizes to cell cortices as well as near centrosomes. Our results demonstrate that two components of a neuronal signal transduction pathway also play a role in centrosome movements during early embryogenesis.

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PES-1 is expressed during early embryogenesis in Caenorhabditis elegans and has homology to the fork head family of transcription factors

Development ◽

10.1242/dev.120.3.505 ◽

1994 ◽

Vol 120 (3) ◽

pp. 505-514 ◽

Cited By ~ 4

Author(s):

I.A. Hope

Keyword(s):

Transcription Factors ◽

Caenorhabditis Elegans ◽

Cell Lineage ◽

Embryonic Cell ◽

Early Embryogenesis ◽

C Elegans ◽

Promoter Trapping ◽

Fork Head ◽

Initiation Of Transcription ◽

Beta Galactosidase

Promoter trapping has identified a gene, pes-1, which is expressed during C. elegans embryogenesis. The beta-galactosidase expression pattern, directed by the pes-1/lacZ fusion through which this gene was cloned, has been determined precisely in terms of the embryonic cell lineage and has three components. One component is in a subset of cells of the AB founder cell lineage during early embryogenesis, suggesting pes-1 may be regulated both by cell autonomous determinants and by intercellular signals. Analysis of cDNA suggests pes-1 has two sites for initiation of transcription and the two transcripts would encode related but distinct proteins. The predicted PES-1 proteins have homology to the fork head family of transcription factors and therefore may have important regulatory roles in early embryogenesis.

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Determination of cell division axes in the early embryogenesis of Caenorhabditis elegans.

The Journal of Cell Biology ◽

10.1083/jcb.105.5.2123 ◽

1987 ◽

Vol 105 (5) ◽

pp. 2123-2135 ◽

Cited By ~ 214

Author(s):

A A Hyman ◽

J G White

Keyword(s):

Cell Division ◽

Caenorhabditis Elegans ◽

Early Embryogenesis ◽

The Other ◽

Nuclear Complex ◽

Centrosome Separation

The establishment of cell division axes was examined in the early embryonic divisions of Caenorhabditis elegans. It has been shown previously that there are two different patterns of cleavage during early embryogenesis. In one set of cells, which undergo predominantly determinative divisions, the division axes are established successively in the same orientation, while division axes in the other set, which divide mainly proliferatively, have an orthogonal pattern of division. We have investigated the establishment of these axes by following the movement of the centrosomes. Centrosome separation follows a reproducible pattern in all cells, and this pattern by itself results in an orthogonal pattern of cleavage. In those cells that divide on the same axis, there is an additional directed rotation of pairs of centrosomes together with the nucleus through well-defined angles. Intact microtubules are required for rotation; rotation is prevented by inhibitors of polymerization and depolymerization of microtubules. We have examined the distribution of microtubules in fixed embryos during rotation. From these and other data we infer that microtubules running from the centrosome to the cortex have a central role in aligning the centrosome-nuclear complex.

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