Hi worm community,
I would be grateful if someone tells me what promoter to use to express a gene before “the bean stage” or during bean stage or before “comma stage”.
Is there a website showing all the promoters?
You need to focus your question more.
- How early do you want the expression to activate?
- How late do you want the expression to last?
- Are you looking for something ubiquitous, or is tissue-specific ok?
elt-7 activates in the E linage, visible at 4E but definitely at 8E and beyond. (bean is late 16E, for reference).
dlg-1 would be activate in all of the epithelial tissues, and it would turn on in the epidermis at the 8E and in the digestive tract in the early/mid 16E.
pha-4 would be active in the foregut lineage, most obvious at 8E but visible at 4E and then throughout the life of the embryo and animal.
The Jorgensen lab uses eft-3 for many of their transgenes made by mosSCI. I believe it is active at all life stages (and importantly in the germline and early embryo), and is fairly ubiquitous.
Hi Steve,
Thank you for your reply,
Here are my answers:
Specifically, I wan to know how apical polarity is working in the intestine and how molecules find their way to the luminal membrane (apical surface).
My focus is on “how the intestinal apical surface is going to be made”.
I am aiming to track apical supplies (membranes or proteins).
- How early do you want the expression to activate?
When the intestine is forming. I think any time from early intestine development to the time that lumen is formed (before bean stage) must be evaluated.
- How late do you want the expression to last?
It doesn’t matter, but it could be good if it last, then I can track molecules in other stages (L1-adult).
- Are you looking for something ubiquitous, or is tissue-specific ok?
Intestine only.
I would be grateful if you were kind enough again to answer my questions help me.
Please check Wormbook, it has a full section devoted to intestinal promoters, and a large amount of info describing studies of apical polarity in intestine.
http://www.wormbook.org/chapters/www_intestine/intestine.html
"6.1. Analysis of intestine specific promoters
Beginning with the early work on vitellogenin genes by Blumenthal and coworkers, promoters of the following genes, expressed exclusively or primarily in the intestine and at a range of developmental stages, have been analyzed to the point where specific cis-acting sites have been mutated: vit-2 (MacMorris and Blumenthal, 1993; MacMorris et al., 1994); cpr-1 (Britton et al., 1998); ges-1 (Egan et al., 1995; Marshall and McGhee, 2001); mtl-1 and mtl-2 (Moilanen et al., 1999); pho-1 (Fukushige et al., 2005); spl-1 (Oskouian et al., 2005); elo-6 (Pauli et al., 2006) and three genes encoding the enzmyes of polyamine synthesis (Luersen et al., 2004). For all of the genes investigated, an extended GATA-like site is critically important for intestine-specific transcription. This conclusion has been confirmed by computational analyses of intestine gene promoters (McGhee et al., 2007; Pauli et al., 2006). Only a small number of non-GATA sites have been experimentally implicated in the control of intestine gene transcription: the VPE1/TGTCAAT elements in vitellogenin promoters (MacMorris et al., 1992; MacMorris et al., 1994), MAB-3 binding sites in vitellogenin promoters (Yi and Zarkower, 1999) and a SKN-1 binding site in the promoter of the gcs-1 gene (An and Blackwell, 2003). In the case of the gcs-1 gene, the critical SKN-1 site overlaps with a GATA site so it remains possible that a GATA factor is also involved here as well. A plausible interaction between MAB-3 and GATA sites in regulating vitellogenin transcription will be discussed below."
and
"6.3. Other transcription factors in the intestine
6.3.1. Embryonic
Analysis of a SAGE library prepared from FACS-sorted embryonic intestine cells identifies dozens of different transcription factors (D. G. Moerman and JDM, in preparation) but only a small number have been investigated experimentally.
tbx-8 and tbx-9 are highly similar T-box genes expressed in the embryo posterior (intestine, muscles and hypodermis). Expression in the intestine can be detected in the 2E and 4E cells but declines thereafter. Most phenotypes of tbx-8 and tbx-9 double knockouts are associated with hypodermis and muscle but cells in the mutant intestine appear mis-positioned and clumped (Pocock et al., 2004).
The forkhead factor PHA-4 is critical for embryonic formation of the pharynx and the rectum (Mango et al., 1994; Azzaria et al., 1996; Horner et al., 1998; Kalb et al., 1998). However, pha-4 is also expressed in the intestine at all stages; rather subtle morphological changes can be detected in the embryonic intestine of pha-4 mutants. Intestinal expression of pha-4 may well be controlled by ELT-2 (Kalb et al., 1998).
The UNC-130 protein is a forkhead transcription factor best known for its role in regulating cell migration (Nash et al., 2000). unc-130 is expressed in a variety of tissues, among which is the intestinal primordium. Intestinal expression begins at the approximately 8E cell stage and persists into adulthood (Nash et al., 2000).
The ceh-13 homeobox gene is expressed in the posterior cells of the intestinal primordium (Wittmann et al., 1997), among several other places in the embryo. It is not clear what causes this patterned expression nor whether ceh-13 expression has any consequences for overall anterior-patterning in the intestine. As mentioned earlier, the pal-1 homeobox gene is expressed in the int5 cells of the developing intestine primordium (Edgar et al., 2001).
The die-1 gene encodes a zinc-finger protein, possibly a transcription factor, that was identified because mutants show aberrant morphogenesis of the hypodermis (Heid et al., 2001). However, die-1 is expressed widely in the embryo, including in the developing intestine; die-1 mutants show intestinal defects in which the intestine does not attach to the pharynx or to the rectum.
NHR-25, the C. elegans homolog of FtzF1, has an early phase of expression restricted to the E lineage (approximately 4E cell stage to comma stage) but subsequently becomes expressed more widely (Asahina et al., 2000). Knockout of NHR-25 causes embryonic arrest but the intestine primordium still expresses differentiation markers. HNF-4 type nuclear hormone receptors (like NHR-25) are usually associated with endoderm in other animals but this does not appear to be true of the same family of factors in C. elegans (Robinson-Rechavi et al., 2005)."
Hi Polar,
If you look carefully at my message, I did indeed give you what you wanted. The E-lineage IS the intestine. 
PM me, and when I’m in lab again I can give you the sequence I’ve used for as the elt-7 promoter.
Steve
Thank you everyone.
Such a great community! 8)