E(eve), Complementation group F, l(2)46Ce
transcription factor - homeodomain - pair rule gene establishing epidermal cell fate - aCC motoneuron identity is specified by a genetic cascade involving and - and are required for cardiac-specific differentiation of a numb-dependent lineage decision
Gene model reviewed during 5.46
There is only one protein coding transcript and one polypeptide associated with this gene
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\eve using the Feature Mapper tool.
After division of the ganglion mother cell GMC4-2a, both daughter cells are eve-positive, but as development proceeds, the RP2sib neuron (sibling cell to RP2 motor neuron) becomes eve-negative, whereas RP2 retains eve.
Expression was examined at four phases of embryonic stage 5. The striped pattern becomes visible in phase 1 (0-5'), all stripes except stripe 7 are expressed during phase 2 (5-17'), and their spacing and expression levels become largely uniform by phase 3 (17-30'). The stripes initially appear less clearly separated and more graded.
eve transcripts are first detected in stage 3 embryos, and displays a low level of expression throughout the embryo. The expression pattern is refined over the next four hours of development. eve expression exhibits a pair-rule pattern, and is expressed in a graded fashion, both along the anterior-posterior axis and the dorsal-ventral axis, with the highest levels of transcript being present in the dorsal-posterior regions. eve is expressed in odd-numbered parasegments in seven stripes, but later in development is expressed coincidently with en, in the posterior section of each parasegment. In the later stages of embryonic development, following germ band retraction, eve transcripts are detected in the neurogenic region in the ganglion mother cells of each segment.
Comment: small cluster of dorsal mesoderm cells in parasegments 2-12 and 14
eve colocalises with the cholinergic markers Scer\GAL4ChAT.7.4 and, in a strain also expressing Scer\GAL4EL.eveRC, cha in nearly all EL neurons. It also colocalizes with GABA, in a strain coexpressing Scer\GAL4EL.eveRC, in ~25% of EL neurons in larval abdominal segment 1, ~50% in segment 2, and 70-75% in segments 3 and 4.
eve protein is expressed in the DA1 muscle and two pericardial cells per hemisegment in embyros.
eve is expressed in two pericardial cell nuclei and in 10-11 nuclei of the dorsal acute muscle 1 in each segment.
eve is expressed in two Eve pericadial cells (EPC) and one DA1 muscle per hemisegment in stage 13 embryos.
The position of run protein stripes was compared to that of other segmentation genes. The eve protein stripes lie anterior to the run protein stripes but overlap them partially. Two rows of eve expression are anterior to a two-row region of overlap with run followed by two rows of run expression and then two rows of non-expression before the next eve stripe.
eve protein is expressed in a complementary pattern to ftz protein. eve and ftz expression domains overlap at earlier stages of development, and then after stripe sharpening appear to be mutually exclusive, perhaps due to the regulation of ftz by eve.
In the early embryo,eve protein is expressed at low levels in a broad band from ~20% to ~70% egglength, as embryogenesis continues, the eve expression pattern is resolvedinto seven stripes of expression in every odd-numbered parasegemt. Thisparir-rule pattern is first visable at the end of the cleavage stage, andpersists through gastrulation and germ band elongation, where the stripes areresolved to span approximately three cells each. At the beginning of germ bandelongation, seven additional stripes of approximately two cells each can bedetected in the even-numbered parasegments. At this time, the anterior boarderof the eve stripes becomes well defined and sharp. Prior to germ bandretraction the segmentally repeated pattern disappears, and eve expressionpersists only in the posterior-most region of the germ band. As germ bandretaction begins, eve protein is detected in the neurogenic region of theembyo, and is observed in clusters of approximately four to six cells on eitherside of the ventral furrow in a segmentally repeated fashion. Prior to thecompletion of germ band retraction, lateral clusters of eve expressing cellsappear. Ultimately eve expression is detected in a subset of neurons in eachsegment, and this expression persists through embryonic and larval development.
In the early embryo,eve protein is expressed at low levels in a broad band from ~20% to ~70% egglength, as embryogenesis continues, the eve expression pattern is resolvedinto seven stripes of expression in every odd-numbered parasegemt. Thisparir-rule pattern is first visable at the end of the cleavage stage, andpersists through gastrulation and germ band elongation, where the stripes areresolved to span approximately three cells each. At the beginning of germ bandelongation, seven additional stripes of approximately two cells each can bedetected in the even-numbered parasegments. At this time, the anterior boarderof the eve stripes becomes well defined and sharp. Prior to germ bandretraction the segmentally repeated pattern disappears, and eve expressionpersists only in the posterior-most region of the germ band. As germ bandretaction begins, eve protein is detected in the neurogenic region of theembryo, and is observed in clusters of approximately four to six cells oneither side of the ventral furrow in a segmentally repeated fashion. Prior tothe completion of germ band retraction, lateral clusters of eve expressingcells appear. Ultimately eve expression is detected in a subset of neurons ineach segment, and this expression persists through embryonic and larvaldevelopment.
GBrowse - Visual display of RNA-Seq signalsView Dmel\eve 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.
eve functions in an eve --> grn --> zfh1 regulatory cascade within the aCC motoneuron, along with suppressing exex expression. By contrast, there is only partial cross-regulation between eve, grn, zfh1 and exex in the RP2 motoneuron.
eve represses exex in a gro-dependent fashion. Cross-repressive interactions between exex and eve delimit exex expression to ventral and lateral motor neurons and eve expression to dorsal motor neurons.
The 7.7kb 3' regulatory region of eve contains both composite and discrete neuronal and early blastoderm enhancers, and multi-stripe positioning by gap gene repressor gradients.
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.
prd regulates late even skipped expression through a composite binding site for the paired domain and the homeodomain. Mutagenesis of either binding site leads to significant reduction in the activity of the late element, indicating that both domains are required for regulation.
Despite the absence of a syncytium in C.floridanum embryos monoclonal antibodies to en, Ubx and abd-A demonstrate their cognate proteins are expressed in a conserved pattern in the post-gastrulation stages of development. The expression of the eve cognate protein is not completely conserved ad lacks a pair rule phase to its expression.
The stripe 3+7 enhancer is about 500bp in length and maps about 3.3kb upstream of the transcription start site. The enhancer is regulated by one or more ubiquitously distributed activators.
eve protein has broad DNA recognition properties in vitro that are likely to be important determinants of its distribution on DNA in vivo.
In vitro transcription experiments suggest that eve protein represses transcription by inhibiting binding of TFIID to the promoter.
The full length and 0.9kb fragment of scs and a 430bp fragment from gypsy carrying 12 su(Hw) binding sites (gypsy\su(Hw)BR430) can block the interaction of defined eve stripe enhancers when positioned between the enhancer and target promoter.
cas, eve, unpg and ac are expressed in specific neuroblast sublineages. Expression studies using pbl and stg mutants suggest that neuroblasts have an intrinsic gene regulatory hierarchy controlling unpg and ac expression but that cell cycle- or cytokinesis-dependent mechanisms are required for cas and eve CNS expression.
Early and late eve expression have distinct roles in regulating downstream genes. Early expression is required for the activation of both even and odd numbered en stripes and late eve stripes strengthen the expression of odd numbered en stripes.
Crystallographic of the eve homeodomain complexed to an AT-rich oligonucleotide at 2.0 A resolution reveals a novel arrangement of two homeodomains bound to one 10bp DNA sequence in tandem fashion.
The development of eve cells (cells from parasegments 4-12 that give rise to the pericardial cells of the heart) depends on at least wg and hh. Mosaic analysis demonstrates wg produced in the mesoderm alone is sufficient to generate eve cells. Also action of wg+ in the wild type ectoderm can restore the eve cells in the underlying wg- mesoderm. These two classes of mosaic clones demonstrate that wg protein in either germ layer is sufficient for the development of eve cells in the mesoderm and the patterning the mesoderm. Uniform expression of wg in the mesoderm only is sufficient to rescue the repeated clusters of eve expressing cells.
eve stripe 2 and 3 enhancers have been used to misexpress segmentation and homeotic genes.
eve efficiently blocks, or "squelches", Tbp-enhanced transcription in cotransfected Schneider L2 cells. Squelching does not require eve DNA-binding sites on the reporter plasmids used, but is dependent on the presence of the eve repression domain.
Cell cycle progression and progression through S phase is required for eve expression in the CNS, cytokinesis is not required. Pc group genes are required for the repression of eve expression in the CNS.
A potent repressor domain within the eve protein has been identified; localised between amino acids 212 and 245 and rich in Pro and hydrophobic amino acids.
Comparisons of early development to that in other insects have revealed conservation of some aspects of development, as well as differences that may explain variations in early patterning events.
In vivo crosslinking has been used to directly measure DNA binding of the homeodomain protein eve. eve protein binds at uniformly high levels throughout the length of their genetically identified target genes and at a lower, but significant level to genes eve is not expected to regulate. Studies suggest that ftz and eve has similar DNA binding specificities in vivo.
Ectopic ttk causes complete or near complete repression of ftz and significant repression of eve, odd, h and runt.
Expression of eve has been used as a marker for a subset of neuroblasts in study of requirement for wg gene product for neuroblast specification and formation in the CNS.
Complementation group identified in an EMS and DEB screen to isolate deficiencies that uncover Jra.
Expression of prd depends on activation by gap gene hb, Kr, kni and gt products. Primary pair rule gene products act primarily in subsequent modulation rather than activation of prd stripes. Factors activating prd expression in the pair rule mode interact with those activating it along the dorso-ventral axis.
The eve gene product is a direct repressor that can repress activated transcription but does not function by binding to the TATA box of promoters. Deletion analysis reveals that both the proline and alanine rich regions of the eve gene product are required for maximal repression.
wg expression is aberrantly activated and regulated in pair rule mutant embryos.
Elements redundantly involved in enhancer activity in the autoregulatory domain of ftz are conserved in the AE homologs of D.virilis and D.hydei and in the developmentally regulated genes eve and Ubx.
The eve stripe 3 enhancer lies 1.7kb upstream of the stripe 2 enhancer. The two enhancers must be separated by a minimum distance for proper stripe expression, though the order of enhancers can be reversed without affecting the normal expression pattern.
eve can repress transcription at a distance. Tissue culture cell, in vitro transcription and DNaseI footprinting assays suggest that repression involves cooperative binding between eve molecules bound at distant sites in a manner similar to that used by some prokaryotic repressors.
Expression analysed in CNS study of neuroblasts and ganglion mother cells.
In vitro studies showed that Ubx and eve protein exert active and opposite effects on in vitro transcription when bound to a common site upstream of a target (Adh) core promoter: Ubx acts as an activator and eve acts as a repressor, and both affect the extent of preinitiation complex formation. A subsequent step renders mature complexes transiently refractory to activation and repression.
Heat shock inducible eve transgene has been used to test the effects of eve expression on transcription of ftz, odd, run, prd, wg (proposed to be direct targets of eve), and eve, h and en (proposed to be indirect targets of eve). Delayed effects on eve and en appear to be mediated by odd and run. Ectopically expressed eve acts in a concentration-dependent manner on its different target genes.
Comparison of CpG distribution in the coding region of 121 genes from six species supports the mCpG mutational hotspot explanation of CpG suppression in methylated species at position II-III and III-I.
Mutant analysis shows that wild type eve function is required to set up expression of ac in row D of the embryonic proneural cluster.
Promoter fusions and expression pattern analysis show that a 480bp region is necessary and sufficient to direct eve stripe 2 expression. The gene products of bcd, hb, Kr and gt all bind within this 480bp region.
Apical localization of pair-rule transcripts restricts lateral protein diffusion allowing pair-rule proteins to define sharp boundaries and precise spatial domains.
The cis and trans activating factors responsible for autoregulation are characterised using a combination of DNA binding and P-element transformation assays. Ecol\lacZ reporter gene studies demonstrate that eve autoregulation is mediated, at least in part, by a 100bp minimal autoregulatory sequence (MAS) located about 5kb upstream from the eve transcription start site. Results provide evidence that the eve protein acts combinatorially with other transcription factors to enhance its own expression.
Mutations in zygotic pair rule gene eve interact with RpII140wimp.
DNA binding assays and transient co-transfection assays in cultured cells suggest that repression of eve stripe 2 expression involves competition or short-range quenching mechanism. The binding of gt and Kr interferes with the binding of bcd and hb activators at overlapping or neighbouring sites within the eve stripe 2 promoter element.
Ecol\lacZ reporter gene constructs carrying an eve promoter fragment were used to analyse the bcd, hb, Kr and gt binding sites present in the eve promoter. bcd, hb, Kr and gt are responsible for the expression of stripe 2. Mutations in the bcd or hb protein binding sites cause reduced expression of stripe 2 but do not alter the spatial limits. Mutations in Kr or gt protein binding sites do change the spatial limits of stripe 2.
The effects of an altered nucleocytoplasmic ratio on transcripts that normally undergo changes in transcript pattern in cell cycle 14 is studied. The development of the seven-striped transcript pattern of the segmentation gene eve is independent of the nuclear density and cell cycle program.
eve amorphic mutants eliminate all segmental periodicity.
Injection of protein synthesis inhibitors into early embryos induces expression of eve mRNA in virtually all regions of the embryo.
A transient expression assay has been employed to investigate the potential of homeobox genes to function as transcriptional activators.
Ecol\lacZ reporter gene constructs have been used to identify cis control elements within the eve promoter that might mediate interactions with trans-acting factors encoded by gap and pair-rule genes.
The development of the eve and ftz stripes in h-, run-, eve- and en- embryos demonstrates that individual cells are allocated to parasegments with respect to the anterior margins of the eve and ftz stripes.
Mutations in eve do not affect the spatial expression pattern of gt.
Genetic analysis demonstrates that eve is required for efficient homeotic gene expression in the visceral mesoderm.
eve protein expression has been analysed in various mutants that disrupt segmentation.
Homozygous lethal; embryos homozygous for a null allele or a deficiency fail to undergo segmentation and their ventral surfaces are covered by a lawn of short denticles pointed toward the midline; denticles in the anterior region show thoracic characteristics suggesting that segmental identities persist in the absence of segmentation. All derivatives of gnathal segments are missing, such as maxillary sense organs, cirri, mouth hooks, labial sense organs and the mandibular parts of the cephalopharyngeal skeleton; the labrum, antennal sense organs and a rudimentary skeleton are the only remains of the larval head. Posteriorally, anal plates and some sensory organs persist as do remnants of spiracles, filzkorper and tufts. Homozygotes and hemizygotes for hypomorphic alleles display pair-rule segmentation defects. Denticle bands and adjacent naked cuticle of the prothoracic, metathoracic and even-numbered abdominal segments removed; some naked cuticle of the adjacent segment removed as well (i.e., the odd numbered parasegments are removed). Combinations of alleles with Df(2R)eve raised at different temperatures can achieve an array of phenotypes between these extremes. Expression of eve is first detected at the eleventh nuclear division following fertilization; at this stage, eve protein is uniformly distributed among the nuclei, both at the periphery and deep within the egg; by the thirteenth nuclear division, the anterior one-third of the embryo is devoid of detectable protein; over the next 20 minutes, the antibody staining in the posterior two-thirds of the embryo becomes concentrated in seven transverse stripes four or five cells wide separated by stripes three to four cells wide with lower levels of staining. By the time of germ-band elongation, the seven stripes have become narrowed and sharply defined and seven new weakly expressing stripes, one to two cells wide, appear between the major stripes; during germ-band elongation all stripes gradually disappear. As eve stripes become more sharply defined so too do ftz stripes, no longer overlapping eve stripes, but forming a complementary pattern. At the same time, a group of expressing cells appears at the posterior end of the germ band; these cells form a ring around the anal plate during germ-band shortening. Also during germ-band shortening, a specific subset of sixteen neurons in each hemisegment of the CNS expresses eve product as does a row of cell clusters on either side of the dorsal midline; lateral to these clusters are curious rings of weakly staining cells; the dorsal cells do not appear to be neuronal (Frasch, Hoey, Rushlow, Doyle and Levine, 1987; Frasch and Levine, 1987). In homozygous eve1 embryos switched to restrictive temperature during neurogenesis, four specifically studied eve-expressing neurons in each hemisegment are found to persist; two of them develop normally, but two send axonal processes to abnormal destinations (Doe, Smouse and Goodman, 1988). Frasch and Levine observe that segmentation-gene-mutations generally have reciprocal effects on the expression of eve and ftz, leading them to postulate that their promoters respond reciprocally to the same positional cues. eve concluded to be an early pair-rule gene, since its expression is modified by gap-gene mutations, but not by most other pair-rule gene mutations nor by segment-polarity gene mutations. Three pair-rule genes do influence eve expression: in either eve or h genotypes, eve expression is reduced and in run embryos eve is overexpressed (Frasch and Levine, 1987). In eve embryos, en stripes do not appear (Macdonald, Ingham, and Struhl, 1986). Ubx protein is detected at high level in odd-numbered parasegments from 7 through 13 rather than in every parasegment from 6 through 12 (Martinez-Arias and White, 1988). ftz stripes are disrupted in regularity of position, size and timing (Carroll and Scott, 1986).