WormBase Tree Display for Expr_pattern: Expr1425
expand all nodes | collapse all nodes | view schema
| Expr1425 | Expression_of | Gene | WBGene00004855 | |
|---|---|---|---|---|
| Reflects_endogenous_expression_of | WBGene00004855 | |||
| Expression_data | Life_stage | WBls:0000003 | ||
| Anatomy_term | WBbt:0003681 | Certain | ||
| WBbt:0005772 | Certain | |||
| WBbt:0005812 | Certain | |||
| WBbt:0007028 | Certain | |||
| Type | In_situ | Whole-mount RNA in situ hybridization. | ||
| Pattern | sma-1 transcripts are present in the embryonic epidermis at the start of morphogenesis. In a population of mixed-stage embryos hybridized with a sma-1 antisense probe, sma-1 RNA was not observed in pre-morphogenesis embryos. In particular, there was no sign of sma-1 transcripts in early cleavage-stage embryos (2-8 cells). In embryos just beginning morphogenesis, sma-1 RNA was present in cells along the dorsal surface of the embryo, corresponding to the location of the epidermis at this point in development. Examining embryos at successive stages of morphogenesis, it was found that sma-1 RNA changed in a pattern that exactly matched the movements of the migrating epidermal cells. During early morphogenesis, when the epidermal cell sheet spreads over the lateral surfaces of the embryo, sma-1-expressing cells were observed on the dorsal and lateral surfaces of the embryo, but not on the ventral surface or in the head region, which at this stage are not yet covered by the spreading epidermis. In cross-section, it can be seen that the sma-1 RNA is located in the outermost cell layer of the embryo. As morphogenesis progresses, the spreading epidermis encloses first the ventral surface of the embryo and then the head as the embryo bends ventrally and begins to elongate. In embryos at this stage of morphogenesis, there was a corresponding pattern in which sma-1 RNA was seen first on the ventral surface and then on the anterior (head) surface of the embryo. At the same time, the overall level of sma-1 RNA rapidly decreased as the embryo began to elongate. sma-1 RNA in the epidermis was not observed in embryos past the 2-fold stage. In addition to sma-1 expression in the cells of the epidermis, a line of sma-1 RNA was observed in the interior of the embryo, oriented along the anterior-posterior axis. Based on its location, this sma-1 RNA seems located in the developing digestive tract of the embryo, consisting of the pharynx and intestine. During early morphogenesis, it is difficult to determine the anterior extent of sma-1 staining in the interior of the embryo, but as the embryo begins to elongate, the level of sma-1 RNA increases and at the 1.5-fold stage sma-1 RNA is clearly present in both the pharynx and intestine. A lower level of pharyngeal/intestinal RNA was observed in 2- to 3-fold stage embryos. In these older embryos, sma-1 RNA was also found in the excretory cell and in an unidentified cell near the anus. Expression of sma-1 RNA was observed in several epithelial tissues: epidermis, pharynx, intestine and excretory cell. sma-1 RNA was not seen in the body wall muscle cells, which are arranged in four stripes underlying the epidermis. The highest level of sma-1 RNA was observed in the epidermis during the early stages of morphogenesis, prior to when differences are observed between development of wild-type and sma-1 embryos. | |||
| Picture | WBPicture0000007981 | |||
| Reference | WBPaper00003094 |
