Gene model reviewed during 5.52
There is only one protein coding transcript and one polypeptide associated with this gene
May be a homo- or heterodimer.
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\swa using the Feature Mapper tool.
The 2.1 kb maternal swa transcript is detected in early embryos and adult females. swa is first detected by in situ hybridization in stage S3 egg chambers, and reaches its highest levels in the nurse cells and oocytes of stage S10 egg chambers. At stage S14, swa is uniformly distributed in oocytes. During early embryogenesis, swa is distributed uniformly in the embryo, but as nuclei migrate to the periphery, it localizes to the peripheral cytoplasm surrounding the nuclear layer. By gastrulation, swa is no longer detected.
swa protein is expressed throughout oogenesis, and in 0-6 hr embryos. During oogenesis, swa protein is first detected in stage S5 egg chambers, and is cytoplasmic. Oocytes of stage S5-S6 egg chambers accumulate swa protein. swa protein is detected in nurse cells starting at stage S7, until stage S10. swa protein continues to be localized in the cytoplasm for a short time after fertilization, but by embryonic cycle 8, swa protein is nuclear. swa protein is not detected by the retracted germ band stage.
GBrowse - Visual display of RNA-Seq signalsView Dmel\swa in GBrowse 2
Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see GBrowse for alignment of the cDNAs and ESTs to the gene model.
For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.
swa is required for overall actin organisation and for the maintenance of a distinct subset of microtubules in the oocyte.
swa protein transiently but tightly co-localizes with bcd RNA in mid-oogenesis, at stage 10. swa protein also localizes to the anterior pole of the oocyte in the absence of bcd RNA. This localization does not require exu protein but does require microtubules. ctp is a swa-binding protein. swa protein may act as an adaptor for the dynein complex enabling dynein to transport bcd RNA along microtubules to their minus ends at the anterior pole of the oocyte.
In a sample of 79 genes with multiple introns, 33 showed significant heterogeneity in G+C content among introns of the same gene and significant positive correspondence between the intron and the third codon position G+C content within genes. These results are consistent with selection adding against preferred codons at the start of genes.
Compared to the swa sequence swaΨ exhibits eight deletions in the coding region ranging from 3 to 138bp. No insertions are found. Data suggests that the preponderance of relatively large mutations is likely to be a general property of mutation.
There is not a simple relationship between the position of the swa protein and the site of its action in bcd RNA localisation. Studies of the distribution of swa protein during early embryogenesis reveals a cycle whereby the swa gene product enters each nucleus at the beginning of mitosis, occupies a position complementary to that of condensed chromatin, and leaves each nucleus at the end of mitosis.
Some blastoderms irregularly populated, with some areas on surface devoid of nuclei, others display asynchronous nuclear divisions and nuclei of non uniform size. Gastrulation occurs before full complement of nuclei achieved; mitosis continues into gastrulation. Developmental arrest at time of first muscular activity. Morphology of developing embryos shows variable temperature-sensitive failure of head-segment development and abdominal segmentation defects. Anterior defects more severe at 29oC and posterior ones cold-sensitive, strongly enhanced at 18oC. ftz expression pattern abnormal; number of stripes varies from three (PS 2, 4, & 6) at 18oC to seven at 29oC.
swa mutants exhibit weak anterior deletions and segmentation defects in the abdomen.
Mature follicles are immunologically stained for asymmetric distribution of ecdysteroid-related antigen. During late oogenesis localisation of the antigen changes dramatically suggesting the antigen plays a role in early embryogenesis and, perhaps, in pattern formation.
Unlike wild-type cytoplasm, anterior cytoplasm from embryos of swa mothers ineffective in rescuing bcd phenotype; also embryos from swa females resistant to the bcd-phenocopying effects of removing anterior cytoplasm.