# Vulva development chapter/negative signal

**URL:** <https://community.alliancegenome.org/t/vulva-development-chapter-negative-signal/3034>\
**Category:** WormBook\
**Created:** [July 26, 2007, 5:43pm UTC](https://community.alliancegenome.org/t/vulva-development-chapter-negative-signal/3034 "2007-07-26T17:43:18Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![pws](https://community.alliancegenome.org/letter_avatar_proxy/v4/letter/p/c89c15/32.png) [@pws](https://community.alliancegenome.org/u/pws)\
**Post date:** [July 26, 2007, 5:43pm UTC](https://community.alliancegenome.org/t/vulva-development-chapter-negative-signal/3034/1 "2007-07-26T17:43:18Z")

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The “Negative Signal” from hyp7 is now likely to be inhibition of lin-3 expression by synmuv proteins (Cui et al., Dev Cell 2006; Andersen and Horvitz, Development 2007). In the absence of synmuv function, lin-3 is expressed from hyp7 (and possibly other sites) and simulates LET-23 in the VPCs. Synmuv backgrounds (for example, lin-15A-B-) have been used to create a uniform level of LET-23 activation; this new finding does not affect any of the conclusions using these strains, and provides a satisfactory mechanistic understandig of why lin-15 has been so useful!. With respect to mechanism of synmuv action, these results provide a bona fide target of synmuv represssion; this is very exciting.  
The discussion of the negative signal will be fixed in the revised version of the Vulva Development Chapter. -Paul