This antibody stains the two to three most proximal oocytes only in the presence of sperm. The MAPK-YT antibody only recognizes mpk-1 MAP kinase gene products because no staining is observed in gonads from mpk-1(ga117) homozygotes, a likely protein null.
Expression of mpk-1::gfp was observed in the rectal epithelial cells, including F and U, in 100% of wild type L1 (16/16), L2 (19/19), L3 (15/15), L4 (21/21) and adult (16/16)worms.
MPK-1A was present in both GL+ and GL- animals, but MPK-1B protein was found only in GL+ animals. Thus mpk-1b RNA and its MPK-1B protein are predominantly expressed in the germline.
In wild-type hermaphrodites 24 hr post mid-L4, total MPK-1 is found throughout the germline, with slightly lower levels in the distal-most end and slightly higher levels in the proximal region. dpMPK-1(diphosphorylated activated) is undetectable in the mitotic and transition zone regions, peaks in the proximal part of pachytene, becomes low but detectable in the loop region, and peaks again in diakinesis oocytes in the proximal gonad.
The mpk-1ab mRNA was abundant in both GL+ and GL- animals, but mpk-1b mRNA was very low or undetectable in GL- animals. Therefore, mpk-1b appears to be enriched in the germline.
Within the gonad, activated, di-phosphorylated MAP kinase (MPK-1) is first detectable at the mid-pachytene stage of the meiotic prophase I. The activated form of MAP kinase disappears as germ cells pass the pachytene stage and enter the diplotene/diakinesis phase of meiotic prophase I. Activated, M.A.P kinase become detectable again in the most proximal oocyte(s) that are undergoing maturation, prior to fertilization. This proximal MAP kinase activity is induced by a cue from sperm.
Endogenously tagged LIN-2, LIN-7, LIN-10 and LET-23 EGFRallow for the analysis of their localization and expression patterns in other tissues. We found that all four proteins are expressed inneurons and sensory tissue in the head, and along the ventral anddorsal nerve chords. The intestine is prone to a highdegree of autofluorescence and was excluded from the initialanalysis. Whereas LET-23 EGFR and LIN-7 overlapped minimallyin the head, LIN-2 and LIN-7 colocalized strongly in theneural ring, and the ventral and dorsal nerve chords. Ofnote, we observed that LIN-2 was more strongly expressed in theisthmus of the pharynx than LIN-7. In contrast, LIN-7 wasmore strongly expressed in the gonad and uterus than LIN-2. LIN-10 overlapped minimally with LIN-2 in the neural ring and nerve chords, and shared very little overlap with LET-23 EGFR in other neural tissues in the head of the worm. LET-23::mK2 was strongly expressed in the excretory duct cell in which it signals through the LET-60 Ras/MPK-1 ERK pathway to regulate excretory duct cell development (Abdus-Saboor et al., 2011; Yochem et al., 1997).
Endogenously tagged LIN-2, LIN-7, LIN-10 and LET-23 EGFRallow for the analysis of their localization and expression patterns in other tissues. We found that all four proteins are expressed inneurons and sensory tissue in the head, and along the ventral anddorsal nerve chords. The intestine is prone to a highdegree of autofluorescence and was excluded from the initialanalysis. Whereas LET-23 EGFR and LIN-7 overlapped minimallyin the head, LIN-2 and LIN-7 colocalized strongly in theneural ring, and the ventral and dorsal nerve chords. Ofnote, we observed that LIN-2 was more strongly expressed in theisthmus of the pharynx than LIN-7. In contrast, LIN-7 wasmore strongly expressed in the gonad and uterus than LIN-2. LIN-10 overlapped minimally with LIN-2 in the neural ring and nerve chords, and shared very little overlap with LET-23 EGFR in other neural tissues in the head of the worm. LET-23::mK2 was strongly expressed in the excretory duct cell in which it signals through the LET-60 Ras/MPK-1 ERK pathway to regulate excretory duct cell development (Abdus-Saboor et al., 2011; Yochem et al., 1997).
Endogenously tagged LIN-2, LIN-7, LIN-10 and LET-23 EGFRallow for the analysis of their localization and expression patterns in other tissues. We found that all four proteins are expressed inneurons and sensory tissue in the head, and along the ventral anddorsal nerve chords. The intestine is prone to a highdegree of autofluorescence and was excluded from the initialanalysis. Whereas LET-23 EGFR and LIN-7 overlapped minimallyin the head, LIN-2 and LIN-7 colocalized strongly in theneural ring, and the ventral and dorsal nerve chords. Ofnote, we observed that LIN-2 was more strongly expressed in theisthmus of the pharynx than LIN-7. In contrast, LIN-7 wasmore strongly expressed in the gonad and uterus than LIN-2. LIN-10 overlapped minimally with LIN-2 in the neural ring and nerve chords, and shared very little overlap with LET-23 EGFR in other neural tissues in the head of the worm. LET-23::mK2 was strongly expressed in the excretory duct cell in which it signals through the LET-60 Ras/MPK-1 ERK pathway to regulate excretory duct cell development (Abdus-Saboor et al., 2011; Yochem et al., 1997).