WormMine: ExpressionPattern Expr3465

• Pattern: All of the first and second round cell divisions in a vulval secondary lineage usually produced sister cells with different nuclear levels of POP-1. For example, after the division of P5.p, the anterior sister P5.pa most often had a higher level of nuclear POP-1 than the posterior sister P5.pp (23 of 25 specimens). This pattern, in which the anterior sister has the higher level of POP-1, will hereafter be called a high/low pattern; the opposite pattern, in which the anterior sister has the lower level of POP-1, will be called a low/high pattern. POP-1 was also localized in a high/low pattern after the second round of cell division. P5.paa and P5.ppa both had higher nuclear levels of POP-1 than their respective posterior sisters P5.pap and P5.ppp. The first two rounds of cell division in the secondary lineage of P7.p also produced sister cells that displayed different nuclear levels of POP-1. However, in contrast to the P5.p lineage, POP-1 was most often localized in a low/high pattern after these divisions. For example, P7.pa most often had a lower nuclear level of POP-1 than its posterior sister P7.pp (21 of 25 specimens). The first round of cell division in the primary lineage of P6.p produced sisters (P6.pa and P6.pp) that most often had equal and low levels of POP-1 (21 of 24 specimens). At the second round of cell division in the P6.p lineage, the anterior cell P6.pa produced sisters that localized POP-1 in a high/low pattern, while the posterior cell P6.pp produced sisters that localized POP-1 in a low/high pattern. In summary, these studies show that POP-1 is typically localized in a high/low pattern in the anterior half of the vulva and in a low/high pattern in the posterior half of the vulva. As cell lineages in the two halves of the vulva have opposite orientations, these studies show that the orientation of POP-1 localization correlates with the orientation of the vulval lineages. POP-1 expression was examined in strains N2 and CM1006, and similar results were obtained with both strains. CM1006 expresses an AJM-1::GFP fusion protein that localizes to a cell junction complex along the apical border of epithelial cells. The presence of this protein helped reveal the anatomy of vulval cells in immunostained animals. POP-1 was consistently observed in the vulval precursor cells of mid-L2 and older animals and in the progeny cells produced by the first two rounds of cell division in the primary and secondary lineages. The expression of POP-1 at earlier stages was not examined. The levels of POP-1 seen in the vulval precursors at the mid-L2 stage were low compared to the levels observed in the gonad, or after the division of the vulval precursors. Prior to division, all of the vulval precursor cells in an animal typically had equivalent levels of POP-1. However, in animals in which VPCs had started to divide or had divided, cells of primary and secondary lineages displayed moderately higher levels of POP-1 than cells in tertiary lineages. POP-1 was rapidly lost after the third and final round of cell division in primary and secondary lineages. The loss of POP-1 from these cells is in keeping with the observation that the POP-1 protein is not detectable in most postmitotic cell populations.
• Primary Identifier: Expr3465

1 Anatomy Terms

Definition	Name	Synonym	Primary Identifier
female genital.	vulva		WBbt:0006748

1 Genes

WormBase Gene ID	Gene Name	Sequence Name	Organism
WBGene00004077	pop-1	W10C8.2	Caenorhabditis elegans

0 Life Stages