CGC Bibliography Paper 5116

POP-1 controls axis formation during early gonadogenesis in C. elegans.

Siegfried KR, Kimble J

Medline:

11807036

Citation:

Development 129: 443-453 2002

Type:

ARTICLE

Genes:

bar-1 cfz-1 cwn-1 cwn-2 egl2- fog-1 lin-12 lin-17 lin-44 lit-1 mek-2 mom-1 mom-2 mom-4 mom-5 pop-1 rde-1 sys-2 wrm-1 tDf3 tDf4

Abstract:

The shape and polarity of the C elegans gonad is defined during early gonadogenesis by two somatic gonadal precursor cells, Z1 and Z4, and their descendants. Z1 and Z4 divide asymmetrically to establish the proximal-distal axes of the gonad and to generate regulatory leader cells that control organ shape. In this paper, we report that pop-1, the C elegans TCF/LEF-1 transcription factor, controls the first Z1/Z4 asymmetric division and hence controls proximal-distal axis formation. We have identified two pop-1(Sys) alleles (for symmetrical misters) that render the Z1/Z4 divisions symmetrical. The pop-1(q645) allele is fully penetrant for the Sys gonadogenesis defect in hermaphrodites, but affects male gonads weakly; pop-l(q645) alters a conserved amino acid in the beta-catenin binding domain. The pop-1(q624) allele is weakly penetrant for multiple defects and appears to be a partial loss-of-function mutation; pop-1(q624) alters a conserved amino acid in the HMG-box DNA binding domain. Zygotic pop-1(RNAi) confirms the role of pop-1 in Z1/Z4 asymmetry and reveals additional roles of pop-1, including one in leader cell migration. Two other Wnt pathway regulators, wrm-1 and lit-1, have the same effect as pop-1 on Z1/Z4 asymmetry. Therefore, wrm-1 and lit-1 are required for pop-1 function, rather than opposing it as observed in the early embryo. We conclude that POP-1 controls the Z1/Z4 asymmetric division and thereby establishes the proximaldistal axes of the gonad. This control over proximal-distal polarity extends our view of Wnt signaling in C. elegans, which had previously been known to control