WormMine: ExpressionPattern Expr2621

• Pattern: The antisera indicate that early expression occurs during gastrulation. lam-3 is also associated with the nervous system. During elongation and throughout the rest of development, lam-3 is localized at the nerve ring, at the right fascicle of the ventral nerve cord and at the sublateral nerves. lam-3 is first detected between tissue layers near the end of gastrulation and then becomes localized along the muscle cells as the embryo begins to elongate. By the 3-fold stage of elongation, staining along the muscle quadrants is weaker and becomes restricted to a band at the center of each quadrant, which colocalizes with the dorsal and ventral sublateral nerve tracts in the adult. Staining is intense around the pharynx, pharyngeal-intestinal valve, and intestine during morphogenesis. In larvae and adults, the antiserum stains the spermatheca strongly and only weakly stains the pharynx, the intestine and the excretory canal.
• Primary Identifier: Expr2621
• Remark: Colocalization Assay: In order to compare directly the distribution of lam-3 and epi-1, both subunits were co-stained using species-specific secondary antibody conjugates. As the germ layers develop, both subunits are deposited between the layers. However, the staining for laminin A is most intense around the pharyngeal and intestinal precursor cells, whereas staining for laminin B is most intense around the myoblast cells and along epidermal cells. By the onset of elongation, distinct layers of laminin A and laminin B staining can be distinguished, particularly anteriorly between the developing pharynx and the body wall. This indicates that the segregation of the laminin isoforms begins early, before or as organogenesis proceeds. In mnDf90, the two subunits remain differentially localized after elongation. lam-3 is localized to the pharyngeal basement membrane, whereas epi-1 is associated mainly with the body wall basement membranes and only weakly with the pharyngeal basement membrane. These results indicate that each laminin alpha subunit is segregated in the embryo to different adjacent basement membranes and that each membrane retains its unique subunit composition.
• Subcellular Localization: In nid-1(ur41) animals, lam-3 is localized with the mispositioned axons rather than along the normal nerve pathways. This suggests that lam-3 is localized to neuronal cell surfaces by specific lam-3 receptors.

8 Anatomy Terms

Definition	Name	Synonym	Primary Identifier
A chain of very large cuboidal cells forming a wide central lumen in which food arrives from the posterior pharynx, is digested, and from which waste products proceed to the rectum. Intestinal rings form in groups of two and four cells surrounding the common lumen; thus the epithelium is only one cell deep at any point, with neighboring cells firmly secured to their neighbors by apical adherens junctions. These cells have very large nuclei and many large vacuoles, yolk granules, and other inclusions; the latter increase in number and electron density as the animal ages.	intestine	gut	WBbt:0005772
A group of six equivalent cells forms a tightly constructed `valve` that links the posterior bulb of the pharynx to the anterior four cells of the intestine. These six cells comprise a small epithelial channel with a cuticular lining in continuity with the pharyngeal cuticle and link the lumen of the pharynx to the large lumen of the anterior intestine.	pharyngeal-intestinal valve	cardia	WBbt:0005767
an accordion-like tube that contains sperm and is the site of oocyte fertilization.	spermatheca		WBbt:0005319
a large process bundle that runs along the vental mid-line extending from the ventral region of the nerve ring.	ventral nerve cord	ventral cord	WBbt:0005829
the feeding organ, a neuro-muscular pump in the head of the animal, used to ingest food, bacteria suspended in liquid, filter them out, grind them up and transport posteriorly into the instestine.	pharynx	esophagus	WBbt:0003681
Contractile cell that makes up muscle tissue.	muscle cell		WBbt:0003675
the most extensive region of neuropil in the animal, consists of a large toroidal bundle of processes.	nerve ring	circumpharyngeal nerve ring	WBbt:0006749
Four processes (canals) of the excretory canal cell each contain a central collecting lumen which feeds to a central lumenal canal in the cell body; the central canal forms a specialized membrane to release fluids into the excretory duct. These five canals form a continuous H-shaped channel which extends almost the full length of the body, generally in contact with the lateral hypodermis and the pseudocoelom.	excretory canal	canal	WBbt:0005775

1 Genes

WormBase Gene ID	Gene Name	Sequence Name	Organism
WBGene00002248	lam-3	T22A3.8	Caenorhabditis elegans

9 Life Stages

Remark	Definition	Other Name	Public Name	Primary Identifier
	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 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 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