Anterior-posterior subdivision and the diversification of the mesoderm in Drosophila

Development ◽  
1995 ◽  
Vol 121 (12) ◽  
pp. 4183-4193 ◽  
Author(s):  
O.M. Borkowski ◽  
N.H. Brown ◽  
M. Bate

We have used a novel cell marker, in which the twist promoter directs the synthesis of the cell surface protein CD2 (twi-CD2) to examine the development of the mesoderm in the Drosophila embryo after gastrulation and to locate the progenitor cell populations for different mesodermal derivatives. We find that the early mesoderm in each segment is divided into a more anterior region with relatively low levels of twist and twi-CD2 expression and a more posterior region where twist and twi-CD2 expression are high. This subdivision coincides with regional assignments of cells to form different progenitors: dorsal anterior cells invaginate to form an internal layer from which the visceral mesoderm is derived. Ventral anterior cells form progenitors of mesodermal glial cells. Dorsal posterior cells form heart. Ventral and dorsal posterior cells form somatic muscles. We conclude that the metamerically repeated anterior-posterior subdivision of the mesoderm is an essential element in laying out the pattern of mesodermal progenitor cells and in distinguishing between an internal cell layer which will give rise to the progenitors of visceral muscles and an external layer which will generate the somatic muscles and the heart.

Development ◽  
2001 ◽  
Vol 128 (17) ◽  
pp. 3331-3338 ◽  
Author(s):  
Beatriz San Martin ◽  
Mar Ruiz-Gómez ◽  
Matthias Landgraf ◽  
Michael Bate

The embryonic Drosophila midgut is enclosed by a latticework of longitudinal and circular visceral muscles. We find that these muscles are syncytial. Like the somatic muscles they are generated by the prior segregation of two populations of cells: fusion-competent myoblasts and founder myoblasts specialised to seed the formation of particular muscles. Visceral muscle founders are of two classes: those that seed circular muscles and those that seed longitudinal muscles. These specialisations are revealed in mutant embryos where myoblast fusion fails. In the absence of fusion, founders make mononucleate circular or longitudinal fibres, while their fusion-competent neighbours remain undifferentiated.


Development ◽  
1998 ◽  
Vol 125 (4) ◽  
pp. 713-723 ◽  
Author(s):  
V. Riechmann ◽  
K.P. Rehorn ◽  
R. Reuter ◽  
M. Leptin

The somatic muscles, the heart, the fat body, the somatic part of the gonad and most of the visceral muscles are derived from a series of segmentally repeated primordia in the Drosophila mesoderm. This work describes the early development of the fat body and its relationship to the gonadal mesoderm, as well as the genetic control of the development of these tissues. Segmentation and dorsoventral patterning genes define three regions in each parasegment in which fat body precursors can develop. Fat body progenitors in these regions are specified by different genetic pathways. Two regions require engrailed and hedgehog for their development while the third is controlled by wingless. decapentaplegic and one or more unknown genes determine the dorsoventral extent of these regions. In each of parasegments 10–12 one of these regions generates somatic gonadal precursors instead of fat body. The balance between fat body and somatic gonadal fate in these serially homologous cell clusters is controlled by at least five genes. We suggest a model in which tinman, engrailed and wingless are necessary to permit somatic gonadal develoment, while serpent counteracts the effects of these genes and promotes fat body development. The homeotic gene abdominalA limits the region of serpent activity by interfering in a mutually repressive feed back loop between gonadal and fat body development.


2018 ◽  
Author(s):  
Xiao-Yong Li ◽  
Michael B. Eisen

AbstractThe maternal factor Zelda is broadly bound to zygotic enhancers during early fly embryogenesis, and has been shown to be important for the expression of a large number of genes. However, its function remains poorly understood. Here, we carried out detailed analysis of the functional role of Zelda on the activities of a group of enhancers that drive patterned gene expression along the anterior -posterior axis. We found that among these enhancers, only one lost its activity entirely when all its Zelda bind sites were mutated. For all others, mutations of all of their Zelda binding sites only had limited effect, which varied temporally and spatially. These results suggest that Zld may exert a quantitative effect on a broad range of enhancers, which presumably is critical to generate highly diverse spatial and temporal expression patterns for different genes in the developmental gene network in fly embryo. Lastly, we found that the observed effect of Zelda site mutations was much stronger when a mutant enhancer was tested using a BAC based reporter construct than a simple reporter construct, suggesting that the effect of Zld is dependent on chromatin environment.


Development ◽  
1993 ◽  
Vol 118 (3) ◽  
pp. 719-729 ◽  
Author(s):  
R. Bodmer

The homeobox-containing gene tinman (msh-2, Bodmer et al., 1990 Development 110, 661–669) is expressed in the mesoderm primordium, and this expression requires the function of the mesoderm determinant twist. Later in development, as the first mesodermal subdivisions are occurring, expression becomes limited to the visceral mesoderm and the heart. Here, I show that the function of tinman is required for visceral muscle and heart development. Embryos that are mutant for the tinman gene lack the appearance of visceral mesoderm and of heart primordia, and the fusion of the anterior and posterior endoderm is impaired. Even though tinman mutant embryos do not have a heart or visceral muscles, many of the somatic body wall muscles appear to develop although abnormally. When the tinman cDNA is ubiquitously expressed in tinman mutant embryos, via a heatshock promoter, formation of heart cells and visceral mesoderm is partially restored, tinman seems to be one of the earliest genes required for heart development and the first gene reported for which a crucial function in the early mesodermal subdivisions has been implicated.


Development ◽  
2002 ◽  
Vol 129 (14) ◽  
pp. 3325-3334 ◽  
Author(s):  
Ira E. Clark ◽  
Krista C. Dobi ◽  
Heather K. Duchow ◽  
Anna N. Vlasak ◽  
Elizabeth R. Gavis

Translational repression of maternal nanos (nos) mRNA by a cis-acting Translational Control Element (TCE) in the nos 3′UTR is critical for anterior-posterior patterning of the Drosophila embryo. We show, through ectopic expression experiments, that the nos TCE is capable of repressing gene expression at later stages of development in neuronal cells that regulate the molting cycle. Our results predict additional targets of TCE-mediated repression within the nervous system. They also suggest that mechanisms that regulate maternal mRNAs, like TCE-mediated repression, may function more widely during development to spatially or temporally control gene expression.


Pathogens ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 278
Author(s):  
Gabriela B. C. Colichio ◽  
Giuliana S. Oliveira ◽  
Tasson C. Rodrigues ◽  
Maria Leonor S. Oliveira ◽  
Eliane N. Miyaji

Widespread use of pneumococcal conjugate vaccines (PCVs) has led to substitution of vaccine-type (VT) strains by non-vaccine type (NVT) strains in nasopharyngeal carriage. We compared the efficacy of PCV13 and a nasal protein formulation containing pneumococcal surface protein A (PspA) adjuvanted with the whole-cell pertussis vaccine (wP) in the protection against co-colonization challenge models in mice with VT and NVT strains expressing different PspAs. Immunized mice were challenged with two different mixtures: i. VT4 (PspA3) + NVT33 (PspA1) and ii. VT23F (PspA2) + NVT15B/C (PspA4). Results from the first mixture showed a reduction in loads of VT4 strain in the nasopharynx of mice immunized with PCV13. A statistical difference between the loads of the VT and NVT strains was observed, indicating a competitive advantage for the NVT strain in PCV13-immunized animals. In the second mixture, no reduction was observed for the VT23F strain, probably due to low levels of anti-23F polysaccharide IgG induced by PCV13. Interestingly, a combination of the PspA formulation containing wP with PCV13 led to a reduction in colonization with both strains of the two mixtures tested, similar to the groups immunized nasally with wP or PspA plus wP. These results indicate that a combination of vaccines may be a useful strategy to overcome pneumococcal serotype replacement.


2006 ◽  
Vol 65 (2) ◽  
pp. 169-181 ◽  
Author(s):  
Martin R. Broadley ◽  
Philip J. White ◽  
Rosie J. Bryson ◽  
Mark C. Meacham ◽  
Helen C. Bowen ◽  
...  

Se is an essential element for animals. In man low dietary Se intakes are associated with health disorders including oxidative stress-related conditions, reduced fertility and immune functions and an increased risk of cancers. Although the reference nutrient intakes for adult females and males in the UK are 60 and 75 μg Se/d respectively, dietary Se intakes in the UK have declined from >60 μg Se/d in the 1970s to 35 μg Se/d in the 1990s, with a concomitant decline in human Se status. This decline in Se intake and status has been attributed primarily to the replacement of milling wheat having high levels of grain Se and grown on high-Se soils in North America with UK-sourced wheat having low levels of grain Se and grown on low-Se soils. An immediate solution to low dietary Se intake and status is to enrich UK-grown food crops using Se fertilisers (agronomic biofortification). Such a strategy has been adopted with success in Finland. It may also be possible to enrich food crops in the longer term by selecting or breeding crop varieties with enhanced Se-accumulation characteristics (genetic biofortification). The present paper will review the potential for biofortification of UK food crops with Se.


Development ◽  
2021 ◽  
Vol 148 (18) ◽  
Author(s):  
Dongsun Shin ◽  
Mitsutoshi Nakamura ◽  
Yoshitaka Morishita ◽  
Mototsugu Eiraku ◽  
Tomoko Yamakawa ◽  
...  

ABSTRACT Proper organ development often requires nuclei to move to a specific position within the cell. To determine how nuclear positioning affects left-right (LR) development in the Drosophila anterior midgut (AMG), we developed a surface-modeling method to measure and describe nuclear behavior at stages 13-14, captured in three-dimensional time-lapse movies. We describe the distinctive positioning and a novel collective nuclear behavior by which nuclei align LR symmetrically along the anterior-posterior axis in the visceral muscles that overlie the midgut and are responsible for the LR-asymmetric development of this organ. Wnt4 signaling is crucial for the collective behavior and proper positioning of the nuclei, as are myosin II and the LINC complex, without which the nuclei fail to align LR symmetrically. The LR-symmetric positioning of the nuclei is important for the subsequent LR-asymmetric development of the AMG. We propose that the bilaterally symmetrical positioning of these nuclei may be mechanically coupled with subsequent LR-asymmetric morphogenesis.


Sign in / Sign up

Export Citation Format

Share Document