Bic-D
alpha helical coiled coiled protein that interacts with the cytoskeleton - regulates developmental fate of the the oocyte - links diverse cargo to the dynein/dynactin motor - controls spatial aspects of gene expression and polarity formation during development - supports physiology of differentiated polar cells and the function of the nervous system
Please see the JBrowse view of Dmel\BicD for information on other features
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AlphaFold produces a per-residue confidence score (pLDDT) between 0 and 100. Some regions with low pLDDT may be unstructured in isolation.
Gene model reviewed during 5.44
Stop-codon suppression (UAA) postulated; FBrf0216884.
Gene model reviewed during 5.45
Tissue-specific extension of 3' UTRs observed during later stages (FBrf0218523, FBrf0219848); all variants may not be annotated
5.7, 4.4, 3.8 (northern blot)
4.0, 3.6 (northern blot)
97 (kD)
782 (aa); 89 (kD predicted)
May homodimerize but does not interact with BicDR (PubMed:38264934). Interacts (via C-terminal domain) with Rab6.
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\BicD using the Feature Mapper tool.
The testis specificity index was calculated from modENCODE tissue expression data by Vedelek et al., 2018 to indicate the degree of testis enrichment compared to other tissues. Scores range from -2.52 (underrepresented) to 5.2 (very high testis bias).
Comment: maternally deposited
Comment: rapidly degraded
Comment: reported as posterior spiracle specific anlage
4.4kb BicD transcripts are detected in RNA from adult females, dissected ovaries and early embryos. The maternal transcripts disappear by 4-8hr embryos. The 4.4kb transcript reappears after 8 hours and is present at all stages as well as in adult males. BicD transcripts are observed by in situ hybridization in egg chambers from stage 1-2 onward. Up to stage 7, expression is observed in the oocyte concentrated around the nucleus. From stage 8 on, expression is observed in nurse cells as well. During stages 8-10B, BicD transcripts in the oocyte are localized to the anterior end forming a cap. During the last stages of oogenesis and in early embryogenesis, BicD transcripts are uniformly distributed.
In wild-type stage 10 egg chambers, BicD localizes along the oocyte cortex.
BicD protein is detected in the germline throughout oogenesis and is enriched in the oocyte. From stage 2-6, it partially co-localizes with pAbp at the posterior cortex of the oocyte. In early embryos, BicD protein is noticeably enriched apically to the blastoderm nuclei even though large amounts of the protein are also present in the basal cytoplasm. It partially co-localizes with pAbp in the early embryo.
The BicD and egl proteins, as previously described for the orb protein, accumulate in the presumptive oocyte following fusome disassembly in germarium region 2a during oocyte specification and are relocalized to the posterior of the oocyte between germarium regions 2b and 3 during oocyte polarization.
JBrowse - Visual display of RNA-Seq signals
View Dmel\BicD in JBrowse
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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 JBrowse 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.
monoclonal
polyclonal
BicD promotes the iniation of rapid minus-end directed movement of mRNAs along microtubules.
BicD is required for the formation of and cytoskeletal organisation of the egg chamber.
None of the cells in the female germline cyst form synaptonemal complex in BicD null mutants.
Only deletion of the C-terminal heptad repeat results in a BicD protein that has lost zygotic and ovarian functions. Deletion of any other of the heptad repeats results in a protein with full zygotic function but affected ovarian function. The functional importance of each domain is well correlated with its conservation in evolution. Yeast two hybrid assays show that BicD forms homodimers. BicD exists as a multimeric protein complex consisting of egl and at least two BicD monomers.
egl protein colocalises with BicD protein to the oocyte in three stages that correlate with the stepwise polarization of the oocyte. Immunoprecipitation experiments show that both proteins are part of a protein complex. Results propose that the egl-BicD protein complex links microtubule polarity and RNA transport. During early oogenesis the complex is required to transport factors promoting oocyte differentiation; during later stages the complex directs the sorting of RNA molecules required for anterior-posterior and dorsoventral patterning of the embryo.
BicD is required for oocyte growth and both dorsoventral and anterior-posterior patterning of the egg chamber. Results also provide evidence for a prepatterning of follicle cell fates independent of the underlying oocyte.
Anterior localisation of RNA during oogenesis is very sensitive to microtubule inhibitors, taxol and other microtubule depolymerising agents. These results, together with colchicine treatment studies, demonstrate that microtubules are required for RNA transport to the oocyte.
Alleles of egl and BicD were used to show that the differentiation of an oocyte is required for maintainance but not establishment of follicle polarity.
BicD,osk, BicD,vas and BicD,nos embryos suppress all abdominal development: osk, vas and nos genes are critical for the normal and ectopic presence of the posterior signal.
Mutations in maternal anterior class gene BicD interact with RpII140wimp.
The BicD locus affects early oogenesis: mutations cause the production of few, defective germ cells.
Cell biological and genetic evidence suggest that transport of determinants from cystocytes to the pro-oocyte is essential for oocyte determination. Phosphorylation of the BicD protein is essential for its accumulation in the pro-oocyte and this process leads to the gradual localization to the pro-oocyte of the factors required for oocyte differentiation. BicD expression patterns were investigated in egl embryos to determine the relationship between BicD and egl.
In embryos derived from BicD mutant females bcd transcripts localized at the anterior are subjected to ectopic nos activity.
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.
BicD embryos that have abdominal determinants incorrectly localized to the anterior pole do not show ectopic vas localization. Abdominal development in the anterior depends on the level of vas protein in the embryo.
Mutations at BicD have no effect on vas protein expression.
Mohler and Wieschaus describe a polygenic strain, designated YC67 that parallels the behavior of BicD in all respects except that it is unmappable.
A maternal-effect semi-lethal; substantial numbers of embryos produced by BicD/+ mothers give rise to normal larvae; the remainder fail to hatch and vary in phenotype. The array of phenotypes encountered is the same as that produced by BicC/+ females. The incidence and severity of abnormal embryos vary with genetic background and temperature, the incidence being highest at 18oC and decreasing at higher temperatures. BicD homozygotes, either homoallelic or heteroallelic and BicC/BicD heterozygotes are female fertile, although producing eggs with fused or reduced chorionic appendages; the majority of their embryos are abnormal and the influence of temperature, if any, obscure. BicD/+/+ duplication-bearing females produce few if any abnormal embryos, whereas BicD/Df(2L)TW119 females produce more abnormal embryos than BicD/+, i.e., with respect to the severity of phenotype, BicD/0 > BicD/+ > BicD/+/+; however, simply a deficiency of BicD product does not account for the abnormal phenotype, since embryos produced by females carrying one dose of BicD+ over a deficiency develop normally. Embryos produced by homozygous BicD females display symmetrical patterns of cad+ polypeptide distribution during early development (Mlodzik and Gehring, 1987). Abnormal embryo production by BicD/+ females enhanced by the heterozygosity for the mutant allele of or deficiency for l(2)49; Mohler and Wieschaus (1986) speculate that l(2)49 is an allele of bic In addition, eg, stau, tor, and trk, maternal-effect mutants that affect early anterior but not posterior development, act as dominant enhancer of BicD; other maternal-effect mutants ineffective. Bicaudal embryos exhibit nanos protein at both anterior and posterior poles and the absence of hunchback protein in both ends of the embryo; embryos produced by BicD1/BicD2;osk/osk females do not express nos; display a burst of anterior, bcd-dependent hb expression not seen in bicaudal embryos, which is correlated with a dramatic expansion of kni expression (abdominal) and failure to express Kr (thorax and anterior abdomen). BicD expressed early in oogenesis; in wild type, protein first appears in the cytoplasm of all cells in 16-cell cysts in the middle of the germarium; upon entering the vitellarium, protein begins to accumulate in the oocyte and continues to do so for as long as observations are possible. The early embryos produced by such females show uniform distribution of BicD protein, which becomes localized to the cortical cytoplasm at blastoderm formation; anterior-to-posterior distribution remains uniform. Protein disappears at gastrulation. In BicD1/BicD2 females protein accumulation in the oocyte is precocious and greater than normal and the adjacent nurse cells may become visibly depleted; in the embryo, the protein appears to be concentrated as a cap over the anterior third and uniformly less concentrated in the remainder of the embryo. BicDR26 females display extreme concentration of product in the presumptive oocyte and virtually none in the nurse cells; however, the presumptive oocyte never develops as an oocyte but remains nurse-cell like until the cyst degenerates.
Source for merge of: BicD anon- EST:fe2A11
Source for identity of: BicD CG6605
