WormMine: LifeStage WBls:0000037

• Definition: The stage when an animal shifts from L3 larva to L4 larva. It includes the synthesis of new cuticle, cease of phrayngeal pumping during a lethargus stage, and the shed off of old cuticle.
• Primary Identifier: WBls:0000037
• Public Name: L3-L4 molt Ce

0 Anatomy Terms

2 Contained In

Remark	Definition	Other Name	Public Name	Primary Identifier
	A developmental life stage of the nematode Caenorhabditis elegans that occurs from egg hatching until adulthood.		larva Ce	WBls:0000023
	C. elegans life stage that occurs during a larval molt		C. elegans life stage occurring during larval molt	WBls:0000824

0 Expression Clusters

6 Expression Patterns

• Primary Identifier: Expr11043
• Pattern: F48A11.1 was expressed specifically in the period immediately preceding each moult. Expression appeared limited to the pharynx and specifically to the glandular cells g1 and g2 (5 nuclei) in the terminal bulb, the three m4 myo-epithelial cells (6 nuclei) in the metacorpus and the three m3 myo-epithelial cells (6 nuclei) in the pro- corpus. No GFP was detected elsewhere in transgenic nematodes despite careful examination of the reproductive tissues and intestine.

• Primary Identifier: Expr9861
• Reporter Gene: [lin-42ap::gfp-pest] transcriptional fusion. The start codon of lin-42a and 3,043 bps of upstream sequence were fused with gfp-pest. --precise ends.
• Pattern: GFP expressed from the lin-42a promoter was robustly expressed in the pharyngeal myoepithelium midway through the L1 stage and continuously thereafter. The lin-42a reporter was also expressed in hyp7 and the lateral seam cells of late L1-stage larvae undergoing the first molt. Expression of the lin-42a reporter in the hypodermis was detected later in the L1 stage than expression of the lin-42b reporter. Fluorescence from the lin-42a reporter also persisted through ecdysis, whereas fluorescence from the lin-42b reporter dissipated during lethargus. To fully define the cyclical expression pattern of the lin-42ap::gfp-pest fusion gene, we measured the relative intensity of the associated fluorescence in the hypodermis throughout larval development. The intensity of fluorescence repeatedly increased 2- to 10-fold during the molts and dropped to background levels early in the next life stage.

• Primary Identifier: Expr11055
• Pattern: An nhr-165::gfp translational reporter shows nuclear expression in the lateral hypodermis (hyp7, but not hyp8-11) near the time of larval molts. This expression is highest and seen in the largest number of cells in the tail prior to the L3-L4 molt.

• Primary Identifier: Expr12813
• Pattern: bli-5 was found to be less abundantly expressed than bli-4 but displayed peaks of expression at the L2-L3 moult at 18 h, then another peak prior to the L3-L4 moult, from 22 to 24 h.

• Primary Identifier: Expr12812
• Pattern: The bli-4 transcript was relatively constitutively expressed, being detected in all C. elegans lifecycle stages, but displayed peaks of abundant expression at each larval transition, most significantly at the L2-L3, L3-L4 and L4-adult moults.

• Primary Identifier: Expr15165
• Pattern: nlp-2 mRNA expression peaked in preparation of the L3 and L4 molts, when lin-42 levels are low, suggesting that nlp-2 expression is regulated, at least partially, at the transcriptional level.

1 Followed By

Remark	Definition	Other Name	Public Name	Primary Identifier
	The first sub-stage of the L4 larva. All vulval cells are migrating toward the center of the future vulva. vulA, vulB, and vulE have divided, but vulC and vulF have not. At 20 Centigrade: 34.3 hours after hatching, 0.3 hours from the L3-to-L4 molt.		L4.0 larva Ce	WBls:0000683

1 Preceded By

Remark	Definition	Other Name	Public Name	Primary Identifier
	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

2 Sub Stages

Remark	Definition	Other Name	Public Name	Primary Identifier
	The stage during L3-L4 molt when an animal becomes lethargic, ceases pharyngeal pumping and synthesizes new cuticle under the old.		L3-L4 lethargus Ce	WBls:0000036
	The stage during L3-L4 molt, after the brief lethargus period, when an animal sheds off old cuticle.		L3-L4 ecdysis Ce	WBls:0000049