WormMine: ExpressionPattern Expr4285

• Pattern: In transgenic embryos, this larger tbx-2::gfp reporter was expressed in a dynamic pattern, including in a subset of pharyngeal precursors in the premorphogenetic embryo, as well as body wall muscle and pharyngeal neurons. tbx-2::gfp expression initiated in 2 anterior cells in approximately 100 cell embryos and increased to 12 cells by approximately the 200 cell stage. The increasing number of GFP expressing cells was not due to cell divisions; rather tbx-2::gfp expression appeared to initiate asynchronously in individual cells. Expression in these cells was transient and was undetectable by the bean stage. Prior to the bean stage, tbx-2::gfp expression was also observed in body wall muscles, and later, in 2- to 3-fold embryos, expression was observed in a number of pharyngeal neurons. Expression in both of these tissues continued in larvae.
• Primary Identifier: Expr4285
• Remark: Embryos at the ~200 cell stage contain 24 clonally committed pharyngeal precursors located in the anterior of the embryo (13 ABa-derived and 11 MS-derived), and the location of the 12 tbx-2::gfp expressing cells at this stage suggests that they are included among these precursors. To determine if these early tbx-2::gfp expressing cells were indeed pharyngeal precursors and to characterize their lineal origin, athors examined expression of a tbx-2::gfp promoter fusion containing the same tbx-2 5'-flanking sequences characterized above fused to gfp just downstream of the tbx-2 translation initiation codon (pOK206.30). Previous studies demonstrated that such promoter fusions can produce a longer lived GFP signal than full-length protein fusions. This tbx-2::gfp promoter fusion produced cytoplasmic GFP first detected in premorphogenetic embryos in the same pattern as full-length fusion protein, but GFP perdured in the pharynx until near hatching. GFP expression was observed in 3-fold embryos and early larvae in a reproducible subset of pharyngeal muscles, with occasional expression in body wall muscles and head neurons. GFP was observed predominantly in pharyngeal muscle types derived solely from ABa or from mixed lineages, and the number of these GFP-positive cells was generally consistent with those containing ABa-derived cells. However, exceptions to this generalization were found. Most notably, GFP was reproducibly observed in one MS-derived m7 muscle and all three m4 muscles (of which 2 contain only MS-derived cells). Taken together, these results strongly suggest that tbx-2::gfp expression in premorphogenetic embryos is limited to pharyngeal precursors, and most of these are ABa-derived, although expression is also likely in a small number of MS-derived pharyngeal precursors.
• Subcellular Localization: This full-length fusion protein is nuclear localized.

6 Anatomy Terms

Definition	Name	Synonym	Primary Identifier
Longitudinal bands of muscle cells surrounding animal body, with one band running in each quadrant of the body, regulated contraction and relaxation of these muscles cause locomotion.	body wall musculature	body muscle	WBbt:0005813
neuron of the pharyngeal nervous system.	pharyngeal neuron		WBbt:0005439
seventh pharyngeal muscle cell layer	pm7	m7	WBbt:0003721
third pharyngeal muscle cell layer	pm3	M3	WBbt:0003740
fifth pharyngeal muscle cell layer	pm5	M5	WBbt:0003737
fourth pharyngeal muscle cell layer	pm4	M4	WBbt:0003739

1 Genes

WormBase Gene ID	Gene Name	Sequence Name	Organism
WBGene00006543	tbx-2	F21H11.3	Caenorhabditis elegans

9 Life Stages

Remark	Definition	Other Name	Public Name	Primary Identifier
	The stage that begins when a C.elegans individual is fully-developed and has reached maturity.		adult Ce	WBls:0000041
	The third stage larva. At 25 Centigrade, it ranges 32.5-40 hours after fertilization, 18.5-26 hours after hatch.		L3 larva Ce	WBls:0000035
	The second stage larva. At 25 Centigrade, it ranges 25.5-32.5 hours after fertilization, 11.5-18.5 hours after hatch.		L2 larva Ce	WBls:0000027
	The fourth stage larva. At 25 Centigrade, it ranges 40-49.5 hours after fertilization, 26-35.5 hours after hatch.		L4 larva Ce	WBls:0000038
	The first stage larva. At 25 Centigrade, it ranges 14-25.5 hours after fertilization, 0-11.5 hours after hatch.		L1 larva Ce	WBls:0000024
	The C. elegans life stage spanning 620-800min(hatch) after first cleavage at 20 Centigrade. Cell number remains at ~560 cells, with some new cells generated and some cells go through programmed cell death. A stage after elongation is over. The last stage of embryogenesis. Also called pre-hatched embryo, late embryo or morphogenetic embryo.		fully-elongated embryo Ce	WBls:0000021
	The C. elegans life stage spanning 350-620min after first cleavage at 20 Centigrade. Cell number remains at ~560 cells, with some new cells generated and some cells go through programmed cell death. The stage that embryo starts elongation until elongation is over.		elongating embryo Ce	WBls:0000015
	The C. elegans life stage spanning 290-350min after first cleavage at 20 Centigrade. Proliferate from 421 cells to 560 cells. The stage when embryo just finished gastrulation and is enclosing.		enclosing embryo Ce	WBls:0000013
	The C. elegans life stage spanning 100-290min after first cleavage at 20 Centigrade. Proliferate from 28 cells to 421 cells. Referring to the whole period of gastrulation.		gastrulating embryo Ce	WBls:0000010