Expression and regulation of the abd-A gene of Drosophila

Development ◽  
1990 ◽  
Vol 110 (4) ◽  
pp. 1197-1207 ◽  
Author(s):  
A. Macias ◽  
J. Casanova ◽  
G. Morata
Keyword(s):  
Transcription Unit ◽  
Normal Domain ◽  
Bithorax Complex ◽  
Posterior Border ◽  
Expression Domain ◽  
Anterior Border ◽  
Good Correspondence ◽  
Abnormal Distribution ◽  
Normal Expression ◽  
Specific Polyclonal Antibody

We have developed a specific polyclonal antibody that recognizes the protein products of the abdominal-A (abd-A) gene, a member of the bithorax complex of Drosophila. The normal expression domain extends from parasegments 7 to 13, in good correspondence with previous genetic and molecular results. However, while the anterior border of expression is precisely demarcated by a parasegmental boundary, the posterior border does not coincide with a lineage boundary. Within the normal domain, the expression of abd-A shows intrametameric modulation; the amount of product is higher in posterior compartments and in the most anterior cells of the anterior compartments and then gradually decreases. We have examined the effect on abd-A expression of a number of mutations, some mapping within and others outside the abd-A transcription unit. Those mapping to the transcription unit eliminate or severely reduce the amount of abd-A antigen, while those mapping outside produce an abnormal distribution of abd-A protein. Finally, we show that the abd-A gene is down-regulated in part of the Abdominal-B (Abd-B) domain, precisely in those regions where the Abd-B gene is expressed at high levels.

scholarly journals The knirps and knirps-related genes organize development of the second wing vein in Drosophila

Development ◽  
1998 ◽  
Vol 125 (21) ◽  
pp. 4145-4154 ◽  
Author(s):  
K. Lunde ◽  
B. Biehs ◽  
U. Nauber ◽  
E. Bier
Keyword(s):  
Target Gene ◽  
Positional Information ◽  
Transcription Unit ◽  
Expression Domain ◽  
Anterior Border ◽  
Wing Vein ◽  
Cis Acting ◽  
Gap Gene ◽  
Wing Imaginal Discs ◽  
Wing Discs

The neighboring homologous knirps (kni) and knirps-related (knrl) genes in Drosophila encode transcription factors in the steroid hormone receptor superfamily. During early embryogenesis, kni functions as a gap gene to control expression of segmentation genes within the abdominal region of the embryo. In this study, we present evidence that kni and knrl link A/P positional information in larval wing imaginal discs to morphogenesis of the second longitudinal wing vein (L2). We show that kni and knrl are expressed in similar narrow stripes corresponding to the position of the L2 primordium. The kni and knrl L2 stripes abut the anterior border of the broad central expression domain of the Dpp target gene spalt major (salm). We provide evidence that radius incompletus (ri), a well-known viable mutant lacking the L2 vein, is a regulatory mutant of the kni/knrl locus. In ri mutant wing discs, kni and knrl fail to be expressed in the L2 primordium. In addition, the positions of molecular breakpoints in the kni/knrl locus indicate that the ri function is provided by cis-acting sequences upstream of the kni transcription unit. Epistasis tests reveal that the kni/knrl locus functions downstream of spalt major (salm) and upstream of genes required to initiate vein-versus-intervein differentiation. Mis-expression experiments suggest that kni and knrl expressing cells inhibit neighboring cells from becoming vein cells. Finally, kni and knrl are likely to refine the L2 position by positively auto-regulating their own expression and by providing negative feedback to repress salm expression. We propose a model in which the combined activities of kni and knrl organize development of the L2 vein in the appropriate position.

Heart tube patterning in Drosophila requires integration of axial and segmental information provided by the Bithorax Complex genes and hedgehog signaling

Development ◽  
2002 ◽  
Vol 129 (19) ◽  
pp. 4509-4521 ◽  
Author(s):  
Romina Ponzielli ◽  
Martine Astier ◽  
Aymeric Chartier ◽  
Armel Gallet ◽  
Pascal Thérond ◽  
...  
Keyword(s):  
Hedgehog Signaling ◽  
Spatial Information ◽  
Morphological Changes ◽  
Cardiac Cells ◽  
Homeotic Genes ◽  
Bithorax Complex ◽  
Heart Tube ◽  
Expression Domain ◽  
Axial Patterning ◽  
On Line

The Drosophila larval cardiac tube is composed of 104 cardiomyocytes that exhibit genetic and functional diversity. The tube is divided into the aorta and the heart proper that encompass the anterior and posterior parts of the tube, respectively. Differentiation into aorta and heart cardiomyocytes takes place during embryogenesis. We have observed living embryos to correlate morphological changes occurring during the late phases of cardiogenesis with the acquisition of organ function, including functional inlets, or ostiae. Cardiac cells diversity originates in response to two types of spatial information such that cells differentiate according to their position, both within a segment and along the anteroposterior axis. Axial patterning is controlled by homeotic genes of the Bithorax Complex (BXC) which are regionally expressed within the cardiac tube in non-overlapping domains. Ultrabithorax (Ubx) is expressed in the aorta whereas abdominal A (abd-A) is expressed in the heart, with the exception of the four most posterior cardiac cells which express Abdominal B (Abd-B). Ubx and abd-A functions are required to confer an aorta or a heart identity on cardiomyocytes, respectively. The anterior limit of the expression domain of Ubx, abd-A and Abd-B is independent of the function of the other genes. In contrast, abd-A represses Ubx expression in the heart and ectopic overexpression of abd-A transforms aorta cells into heart cardiomyocytes. Taken together, these results support the idea that BXC homeotic genes in the cardiac tube conform to the posterior prevalence rule. The cardiac tube is also segmentally patterned and each metamere contains six pairs of cardioblasts that are genetically diverse. We show that the transcription of seven up (svp), which is expressed in the two most posterior pairs of cardioblasts in each segment, is dependent on hedgehog (hh) signaling from the dorsal ectoderm. In combination with the axial information furnished by abd-A, the segmental hh-dependent information leads to the differentiation of the six pairs of svp-expressing cells into functional ostiae. Movies available on-line

The spatial and temporal dynamics of Sax1 (CHox3) homeobox gene expression in the chick's spinal cord

Development ◽  
1994 ◽  
Vol 120 (7) ◽  
pp. 1817-1828 ◽  
Author(s):  
P. Spann ◽  
M. Ginsburg ◽  
Z. Rangini ◽  
A. Fainsod ◽  
H. Eyal-Giladi ◽  
...  
Keyword(s):  
Temporal Dynamics ◽  
Homeobox Gene ◽  
Primitive Streak ◽  
Neural Plate ◽  
Transverse Plane ◽  
Posterior Border ◽  
Anterior Border ◽  
Spatial And Temporal Dynamics ◽  
Specific Localization

Sax1 (previously CHox3) is a chicken homeobox gene belonging to the same homeobox gene family as the Drosophila NK1 and the honeybee HHO genes. Sax1 transcripts are present from stage 2 H&H until at least 5 days of embryonic development. However, specific localization of Sax1 transcripts could not be detected by in situ hybridization prior to stage 8-, when Sax1 transcripts are specifically localized in the neural plate, posterior to the hindbrain. From stages 8- to 15 H&H, Sax1 continues to be expressed only in the spinal part of the neural plate. The anterior border of Sax1 expression was found to be always in the transverse plane separating the youngest somite from the yet unsegmented mesodermal plate and to regress with similar dynamics to that of the segregation of the somites from the mesodermal plate. The posterior border of Sax1 expression coincides with the posterior end of the neural plate. In order to study a possible regulation of Sax1 expression by its neighboring tissues, several embryonic manipulation experiments were performed. These manipulations included: removal of somites, mesodermal plate or notochord and transplantation of a young ectopic notochord in the vicinity of the neural plate or transplantation of neural plate sections into the extraembryonic area. The results of these experiments revealed that the induction of the neural plate by the mesoderm has already occurred in full primitive streak embryos, after which Sax1 is autonomously regulated within the spinal part of the neural plate.

scholarly journals Genetic structure of the abd-A gene of Drosophila

Development ◽  
1989 ◽  
Vol 107 (3) ◽  
pp. 575-583 ◽  
Author(s):  
A. Busturia ◽  
J. Casanova ◽  
E. Sanchez-Herrero ◽  
R. Gonzalez ◽  
G. Morata
Keyword(s):  
Genetic Structure ◽  
Regulatory Region ◽  
Regulatory Elements ◽  
Transcription Unit ◽  
Bithorax Complex ◽  
Coding Region ◽  
Regulatory Regions ◽  
Protein Coding ◽  
Spatial Regulation ◽  
Correct Level

We report the embryonic and adult phenotypes of a number of mutations of the abd-A gene of the bithorax complex. Some of them result in loss of abd-A function in the whole abd-A domain and are usually lethal. These probably eliminate or inactivate abd-A protein products. Other mutations affect only part of the abd-A domain. These are viable, appear to map outside the abd-A transcription unit, and presumably alter the normal spatial regulation of abd-A products. We propose a model of abd-A structure based on a protein-coding region and two cis-regulatory regions. Regulatory region 1, 3′ to the transcription unit, contains positive and negative regulatory elements. Regulatory region 2, 5′ to the transcription unit, establishes the correct level of abd-A activity in the abdominal metameres.

scholarly journals BARE SPOT LOCATION IN GLENOID CAVITY: COMPARISON BETWEEN ARTHROSCOPY AND CT SCAN

2020 ◽  
Vol 28 (5) ◽  
pp. 243-246
Author(s):  
MAX ROGÉRIO FREITAS RAMOS ◽  
PEDRO FILGUEIRAS HIDALGO ◽  
DIOGO FAGUNDES ◽  
YONDER ARCHANJO CHING SAN JUNIOR
Keyword(s):  
Posterior Margin ◽  
Three Dimensional ◽  
Glenoid Cavity ◽  
Posterior Border ◽  
Posterior Edge ◽  
Anterior Border ◽  
Level Of Evidence ◽  
Injury Repair ◽  
Bare Spot ◽  
Dimensional Reconstruction

ABSTRACT Objective: To assess whether Bare Spot is previously displaced by proportion (MEASURE BP-A × 1.25/MEASURE BP-P = 1). Methods: 35 patients with surgical indication for rotator cuff injury repair were evaluated. The distances from the Bare Spot to the anterior edge of the glenoid cavity (BS-A) and to the posterior edge (BS-P) were measured by arthroscopy and computed tomography with three-dimensional reconstruction of the scapula. Results: The distance from the Bare Spot to the anterior border (BS-A tc) was 11.6 mm with a median 12 mm; The distance to the posterior border (BS-P tc) was on average 15.5 mm with a median 15 mm. The distances from BS to anterior cavity edge measured by arthroscopy were on average (BS-A video) 12.25 mm with a median of 12 mm, and from BS to posterior edge (BS-P video) 16.25 mm on average with median 16 mm (p < 0.005). Conclusion: Bare Spot is displaced anteriorly at a proportion of 40% of the anterior margin and 60% of the posterior margin. Level of Evidence II - Development of diagnostic criteria on consecutive patients (with universally applied reference “gold standard”).

scholarly journals Regulated expression of two sets of paternally imprinted genes is necessary for mouse parthenogenetic development to term

Reproduction ◽  
2006 ◽  
Vol 131 (3) ◽  
pp. 481-488 ◽  
Author(s):  
Qiong Wu ◽  
Takuya Kumagai ◽  
Manabu Kawahara ◽  
Hidehiko Ogawa ◽  
Hitoshi Hiura ◽  
...  
Keyword(s):  
Transcription Unit ◽  
Imprinted Genes ◽  
Wild Type ◽  
Expression Levels ◽  
Paternal Contribution ◽  
Parthenogenetic Development ◽  
Normal Expression ◽  
Regulated Expression ◽  
Insight Into ◽  
Parthenogenetic Embryos

Mouse parthenogenetic embryos (PEs) are developmentally arrested until embryo day (E) 9.5 because of genomic imprinting. However, we have shown that embryos containing genomes from non-growing (ng) and fully grown (fg) oocytes, i.e. ngwt/fgwt PE (wt, wild type), developed to E13.5. Moreover, parthenogenetic development could be extended to term by further regulation of Igf2 and H19 expression using mice with deletion of the H19 transcription unit (H19Δ13) together with its differentially unit (DMR). To gain an insight into the extended development of the parthenotes to term, we have here investigated the expression levels of paternally imprinted genes in ngH19Δ13/fgwt PE throughout their development. In ngH19Δ13/fgwt Pes that died soon after recovery, the expression of Igf2 and H19 was restored to the appropriate levels except for low Igf2 expression in the liver after E15.5. Further, the paternally expressed Dlk1 and Dio3 were repressed, while the expression levels of the maternal Gtl2 and Mirg were twice those of the controls. However, the above-mentioned four genes showed almost normal expression in the surviving ngH19Δ13/fgwt PEs. The methylation analysis revealed that the intragenic DMR of the Dlk1-Gtl2 domain was hypermethylated in the ngH19Δ13/fgwt PEs that survived, but not in the PEs that died soon after recovery. The present study suggests that two sets of co-ordinately regulated but oppositely expressed genes, Igf2-H19 and Dlk1-Gtl2, act as a critical barrier to parthenogenetic development in order to render a paternal contribution obligatory for descendants in mammals.

scholarly journals A New Formica from Northern Maine, with a Discussion of its Supposed Type of Social Parasitism (Hymenoptera: Formicidae)

1949 ◽  
Vol 81 (1) ◽  
pp. 13-17 ◽  
Author(s):  
M. W. Wing
Keyword(s):  
Social Parasitism ◽  
Isosceles Triangle ◽  
Frontal Area ◽  
Medium Size ◽  
Posterior Border ◽  
Uneven Surface ◽  
Anterior Border ◽  
Maximum Width ◽  
Strongly Convex ◽  
Basal Half

While on a short visit in northern Maine during the summer of 1946, I collected a new and interesting ant of the Microgyna group of the genus Formica. The description follows below:Formica dirksi sp. nov.Deälate queen, total length 5.1 mm. Head, maximum width through eyes 1.2 mm., at base of mandibles 0.78 mm., length to anterior border of clypeus 1.3 mm. Thorax, Weber's (1938: 155, footnote) measurement 2.1 mm. General characters of the Microgyna group. Mandibles 7-toothed. Clypeus evenly rounded in front, with uneven surface and carina just barely distinguishable as a line anteriorly, but becoming a low blunt ridge through the mid-region and disappearing posteriorly. Head, excluding mandibles and eyes, somewhat longer than broad; narrower in front than in behind, with posterior corners evenly rounded, posterior border and sides slightly convex. Antennae of medium size, scape slightly stouter apically than basally, bent slightly and gradually in basal half, joints 2 and 3 of funiculus distinctly longer than broad; the apical joints only slightly longer than broad. Frontal area distinct, subtriangular, and about twice as broad at base as high. Frontal carinae diverging posteriorly, about as long as width of frontal area. Eyes black, more or less oval, strongly convex, remote from mandibular insertions and close to posterior corners of head. Ocelli medium-sized, round, white and forming an isosceles triangle with a base, which is situated posteriorly, equal to 0.24 mm. Ratio of base to the shorter sides is 10 to 7.

scholarly journals Nodal patterning without Lefty inhibitory feedback is functional but fragile

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Katherine W Rogers ◽  
Nathan D Lord ◽  
James A Gagnon ◽  
Andrea Pauli ◽  
Steven Zimmerman ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Ectopic Expression ◽  
Nodal Signaling ◽  
Wild Type ◽  
Expression Domain ◽  
Normal Expression ◽  
Developmental Signaling ◽  
Inhibitory Feedback ◽  
Inhibitor Drug ◽  
Temporal Extent

Developmental signaling pathways often activate their own inhibitors. Such inhibitory feedback has been suggested to restrict the spatial and temporal extent of signaling or mitigate signaling fluctuations, but these models are difficult to rigorously test. Here, we determine whether the ability of the mesendoderm inducer Nodal to activate its inhibitor Lefty is required for development. We find that zebrafish lefty mutants exhibit excess Nodal signaling and increased specification of mesendoderm, resulting in embryonic lethality. Strikingly, development can be fully restored without feedback: Lethal patterning defects in lefty mutants can be rescued by ectopic expression of lefty far from its normal expression domain or by spatially and temporally uniform exposure to a Nodal inhibitor drug. While drug-treated mutants are less tolerant of mild perturbations to Nodal signaling levels than wild type embryos, they can develop into healthy adults. These results indicate that patterning without inhibitory feedback is functional but fragile.

scholarly journals Study of Mandibular Foramen in Adult Human Mandible Bones: An Osteological Study

2022 ◽  
Vol 19 (1) ◽  
pp. 18-21
Author(s):  
Anil Kumar Gupta ◽  
Gaurav Jung Shah ◽  
Ram Jiban Prasad
Keyword(s):  
Average Distance ◽  
Inferior Alveolar Nerve ◽  
Clinical Importance ◽  
Posterior Border ◽  
Anterior Border ◽  
Mandibular Foramen ◽  
Lower Jaw ◽  
Accurate Position ◽  
The Mean ◽  
Mandibular Notch

Introduction: The mandibular foramen is located on the medial surface of the ramus of mandible through which inferior alveolar nerve and vessels pass and supply the lower jaw. For dentists inferior alveolar nerve block is important to anesthetize the lower jaw for conducting various surgical procedures. Aims: To determine the accurate position of mandibular foramen through which inferior alveolar nerve and vessels were passing and supply the lower jaw and its clinical importance. Methods: This study was conducted on 35 dry mandible bones consisting of 70 mandibular foramens of unknown sex. All the important parameters were studied using vernier caliper. Results: The mean distance of mandibular foramen from mandibular notch was 21.00 mm on right side and 20.29 mm on left side, from posterior border was 12.63 mm on right side and 12.37 mm on left side, from angle of mandible was 20.60 mm on right side and 20.46 mm on left side, from base of the mandible was 23.57 mm on right side and 23.6 mm on left side, from anterior border was 16.74 mm on right side and 16.89 mm on left side. Conclusion: The accurate position of mandibular foramen varies. The knowledge of the average distance of mandibular foramen from various landmarks is useful for dental anesthesia and also helps to avoid complications.

Extent and properties of the regeneration field in the larval legs of cockroaches (Leucophaea maderae)

Development ◽  
1974 ◽  
Vol 32 (1) ◽  
pp. 69-79
Author(s):  
Horst Bohn
Keyword(s):  
Abdominal Segment ◽  
Anterior Margin ◽  
Posterior Border ◽  
Anterior Border ◽  
Leucophaea Maderae ◽  
Anterior Half ◽  
Regenerative Ability ◽  
Transplantation Experiments ◽  
Anterior Posterior

The investigation of the regeneration field of the larval legs of cockroaches (Leucophaea maderae), which commenced in a previous paper with extirpation experiments, has been continued by transplantation experiments. The extirpation experiments showed that there are two regions near the leg which are indispensable for leg regeneration: the basal sclerites, and the membranous region extending behind the leg up to the spiracle of the next segment, called ‘leg-inducing membrane’ (LIM). The LIM is followed by ‘sclerite-inducing membrane’ (SIM) which, upon contact with sclerites, only allows formation of sclerite structures. The results of the extirpation experiments have been confirmed by transplantation experiments. When the whole leg including the basal sclerites is removed, no leg regeneration occurs. The regenerative ability can be restored by implantation of part of the basal sclerites (for instance, the trochantin), but leg regeneration takes place only when the implantation area is covered by LIM. When the sclerites are transplanted to a region which is covered by SIM only additional basal sclerites are formed. Whole sets of basal sclerites have been implanted at different distances behind the uninjured hindleg. Additional legs are regenerated only in the anterior half of the membranous field extending between the hindleg and the first abdominal segment. Thus, there is adistribution of LIM and SIM in the region of the hindleg, similar to that near the midleg. Whole sets of basal sclerites have been implanted at various sites on the dorsal or ventral surfaces of the abdomen. Legs are formed on both surfaces, but only when the transplanted sclerites contact the intersegmental membranes. This means that the intersegmental membranes of the abdomen also have leg-inducing capacities. The implantation of a trochantin into a field of LIM is followed by the development of two regenerates - a normal one at the posterior border of the field, and one with reverse anterior-posterior polarity at the anterior border. When the trochantin is transplantedtogether with the praecoxa in a similar way, only one normal regenerate is formed at theposterior margin of the trochantin. The praecoxa prevents contact of the anterior margin of the trochantin with LIM, and contact of the anterior margin of the praecoxa with LIM does not promote leg regeneration.

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