[JE Gomes] Defective orientation of the mitotic spindle at 2-cell stage. Patternig defects: reduced gut and pharynx, excess of body wall muscle and germline
[Gomes JE] RNAi phenotype mimics mutant alleles phenotype. or191ts is temperature sensitive, viable at 15C and embrionic lethal at 25C. Transformation rescue was done with or191ts. or25 and or191ts are point mutations resulting in single amino acid changes in the RNA Recognition Motif.or80 is a deletion in the 3'UTR
[Gomes JE] or191 homozygotes have temperature-sensitive defects in mitotic spindle orientation during early embryonic divisions.
spn-4 encodes a protein containing an RNP-type RNA-binding domain; SPN-4 is required for rotation, but not polarization, of the mitotic spindle in the P1 blastomere of the two-cell stage embryo; SPN-4 is also required for mesectoderm and mesendoderm formation in conjunction with proper localization of maternal cell-fate determinants such as SKN-1; in addition, SPN-4 binds the glp-1 3' UTR and is necessary for glp-1 mRNA translation in the anterior blastomeres of the early embryo; conversely, SPN-4 binds and suppresses translation of pal-1 and skn-1 mRNAs in anterior blastomeres; in vitro, SPN-4 interacts with POS-1, a CCCH-type zinc finger protein that negatively regulates glp-1 mRNA translation in posterior blastomeres; SPN-4 is a P granule component, but is also detected in oocytes, the AB and P1 blastomeres at the two-cell stage, and in all four blastomeres at the four-cell stage, with higher levels in EMS and P2.
Predicted to enable mRNA binding activity. Predicted to be involved in nervous system development and regulation of alternative mRNA splicing, via spliceosome. Located in P granule. Expressed in several structures, including Psub4; Z2; Z3; germ line; and oocyte.