Figure 5. Effects of heterochronic mutations on the transcription of
unc-5 and
lin-29 in DTCs. (A) Persistent BLMP-1 expression in DTCs suppresses
unc-5 transcription during late larval development. DIC, GFP, and mCherry images at the mid L4 stage of two worms carrying the Pblmp-1::
bmp-1::gfp and Punc-5(4.6 kb)::mCherry transgenes. (a-c) A representative worm in which BLMP-1 was normally down-regulated. The DTC has undergone a dorsal turn (a) and does not express BLMP-1::GFP (b), but expresses
unc-5. (D-f) A representative worm in which BLMP-1 was still expressed. The DTC has failed to turn dorsalward and is moving centrifugally (d), shows persistent BLMP-1::GFP expression (e), and does not express
unc-5 (f). The arrows indicate DTCs and the asterisks the developing vulva. Scale bar 40 mm. (B) The
blmp-1 mutation causes precocious
unc-5 transcription through precocious expression of
lin-29. (a-c) DIC and GFP images of the posterior DTC at the early L3 stage in a wild-type worm (a), a
blmp-1(
s71) worm (b), and a Plag-2::
lin-29-expressing worm (c). All worms carried a Punc-5(4.6 kb)::gfp transgene. Scale bar 20 mm. (C) DIC and GFP images of transgenic animals carrying Plin-29::gfp (a) during late L3 stage. The transgenic animal carrying Plin-29::gfp treated with control vector RNAi (b) or
blmp-1 RNAi (c) during the early L2 stage. The arrows indicate DTCs. Scale bars 20 um.