WormMine: RNAi WBRNAi00087595

• WormBase ID: WBRNAi00087595
• Phenotype Remark: The results were striking, with 100% embryonic lethality by the 100-cell stage in lem-2(RNAi); emr-1(RNAi) embryos laid 12 - 36 h after injection of dsRNA. Immunostaining of these dead and dying embryos showed complete loss of Ce-emerin protein and > 90% reduction of Ce-MAN1 protein. Thus, in the absence of Ce-emerin, lowering the levels of Ce-MAN1 caused a complete arrest of embryonic development. DAPI staining of double-RNAi embryos at the stages when they arrested (<100 cells) showed that more than 50% of the nuclei examined had abnormally condensed chromatin (n = 30 embryos). This condensed chromatin phenotype probably was not the result of anaphase chromatin bridges, because nuclei with condensed chromatin were observed even at the one-cell stage. Differential interference contrast time-lapse microscopy was used to follow the fate of nuclei and chromatin in lem-2(RNAi); emr-1(RNAi) embryos. This analysis showed that unlike loss of Ce-lamin, which destabilizes nuclear shape, the loss of both Ce-emerin and Ce-MAN1 did not affect nuclear shape. Thus, at least some lamina functions were still normal. Microtubule patterns as determined by immunof luorescence also appeared normal. The most striking phenotype in lem-2(RNAi); emr-1(RNAi) embryos was anaphase chromatin bridges, which were present as early as the first nuclear divisions. The differential interference contrast time-lapse analysis showed that these anaphase bridges eventually were torn apart; the resulting daughter cells then progressed into the next cell cycle and formed more anaphase bridges.

1 Organism

• Name: Caenorhabditis elegans
• Taxon Id: 6239

1 Data Sets

• WormBaseAcedbConverter

2 Inhibits Gene

WormBase Gene ID	Gene Name	Sequence Name	Organism
WBGene00001309	emr-1	M01D7.6	Caenorhabditis elegans
WBGene00002275	lem-2	W01G7.5	Caenorhabditis elegans

2 Inhibits Predicted Gene

WormMine ID	Sequence Name	Length (nt)	Chromosome Location
CDS:M01D7.6	M01D7.6	501	I: 1842460-1842598
CDS:W01G7.5	W01G7.5	1503	II: 14063455-14063595

0 Laboratories

3 Phenotype

Identifier	Name	Description
WBPhenotype:0000050	embryonic lethal	Animals die during embryonic development. In C. elegans, often assayed as refractile eggs that fail to hatch; when applied to large-scale RNAi screens in C. elegans, more than 10% of embryos die.
WBPhenotype:0000773	chromosome segregation variant	Any variation in the processes that regulate the apportionment of chromosomes to each of two daughter cells compared to control.
WBPhenotype:0001361	chromosome condensation variant	Any variation in the progressive compaction of dispersed interphase chromatin into threadlike chromosomes prior to mitotic or meiotic nuclear division, or during apoptosis, in eukaryotic cells compared to control.

1 Phenotype _ Not _ Observed

Identifier	Name	Description
WBPhenotype:0001028	nuclear appearance variant	The morphological appearance of nuclei differs from control animals.

1 Reference

First Author	Title	Year	Journal	Volume	Pages	PubMed ID
						WBPaper00005828

1 Strain

WormBase ID
WBStrain00000001