Partial rescue of <i>dorsal</i>
, a maternal effect mutation affecting the dorso-ventral pattern of the <i>Drosophila</i>
 embryo, by the injection of wild-type cytoplasm

Santamarı́a, Pedro; Nüsslein‐Volhard, Christiane

doi:10.1002/j.1460-2075.1983.tb01644.x

Cited by 46 publications

(9 citation statements)

References 7 publications

(3 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous studies had demonstrated that the transplanted cytoplasm of wild‐type embryos is capable of rescuing the dorsalized phenotypes of embryos derived from mothers mutant for Toll , snake , tube , easter , pelle and, to a lesser extent, dorsal. With the exception of Toll , the DV axis of these embryos is invariably oriented normally with respect to the intrinsic DV polarity of the eggshell. In contrast, in rescued embryos maternally mutant for Toll , the polarity of the DV axis is determined by the site of injection, which develops as the most ventral part of the rescued pattern .…”

Section: The Dorsal Group Genesmentioning

confidence: 99%

Maternal control of the Drosophila dorsal–ventral body axis

Stein

Stevens

2014

WIREs Developmental Biology

View full text Add to dashboard Cite

The pathway that generates the dorsal–ventral (DV) axis of the Drosophila embryo has been the subject of intense investigation over the previous three decades. The initial asymmetric signal originates during oogenesis by the movement of the oocyte nucleus to an anterior corner of the oocyte, which establishes DV polarity within the follicle through signaling between Gurken, the Drosophila Transforming Growth Factor (TGF)-α homologue secreted from the oocyte, and the Drosophila Epidermal Growth Factor Receptor (EGFR) that is expressed by the follicular epithelium cells that envelop the oocyte. Follicle cells that are not exposed to Gurken follow a ventral fate and express Pipe, a sulfotransferase that enzymatically modifies components of the inner vitelline membrane layer of the eggshell, thereby transferring DV spatial information from the follicle to the egg. These ventrally sulfated eggshell proteins comprise a localized cue that directs the ventrally restricted formation of the active Spätzle ligand within the perivitelline space between the eggshell and the embryonic membrane. Spätzle activates Toll, a transmembrane receptor in the embryonic membrane. Transmission of the Toll signal into the embryo leads to the formation of a ventral-to-dorsal gradient of the transcription factor Dorsal within the nuclei of the syncytial blastoderm stage embryo. Dorsal controls the spatially specific expression of a large constellation of zygotic target genes, the Dorsal gene regulatory network, along the embryonic DV circumference. This article reviews classic studies and integrates them with the details of more recent work that has advanced our understanding of the complex pathway that establishes Drosophila embryo DV polarity.

show abstract

Section: The Dorsal Group Genesmentioning

confidence: 99%

Maternal control of the Drosophila dorsal–ventral body axis

Stein

Stevens

2014

WIREs Developmental Biology

View full text Add to dashboard Cite

show abstract

“…2015). DL is deposited maternally and functions as a master regulator in specifying the DV axis (Santamaria and Nüsslein-Volhard 1983; Roth et al . 1989; Ratnaparkhi and Courey 2015).…”

Section: Resultsmentioning

confidence: 99%

SUMOylation of Dorsal attenuates Toll/NF-κB signalling

Hegde

Sreejan

Gadgil

et al. 2021

Preprint

View full text Add to dashboard Cite

In Drosophila, Toll/NF-κB signalling plays key roles in both animal development and in host defence. The activation, intensity and kinetics of Toll signalling is regulated by post-translational modifications such as phosphorylation, SUMOylation or ubiquitination that target multiple proteins in the Toll/NF-κB cascade.Here, we have generated a CRISPR-Cas9 edited Dorsal (DL) variant that is SUMO conjugation resistant (SCR). Intriguingly, embryos laid by dlSCR mothers overcome dl haploinsufficiency and complete the developmental program. This ability appears to be a result of higher transcriptional activation by DLSCR. In contrast, SUMOylation dampens DL transcriptional activation, ultimately conferring robustness to the dorso-ventral program. In the larval immune response, dlSCR animals show increase in crystal cell numbers, stronger activation of humoral defence genes, high cactus levels and cytoplasmic stabilization of DL:Cactus complexes. A mathematical model that evaluates the contribution of the small fraction of SUMOylated DL (<5%) suggests that it acts to block transcriptional activation, driven primarily by DL that is not SUMO conjugated.Our findings define SUMO conjugation as an important regulator of the Toll signalling cascade, in both development and in host defense. Our results broadly indicate that SUMO attenuates DL at the level of transcriptional activation. Further, we hypothesize that SUMO conjugation of DL may be part of a Ubc9 dependant feedback circuit that restrains Toll/NF-κB signalling.

show abstract

“…The phenotypic series suggested a morphogen gradient with a maximum at the ventral side of the egg determining the dorsoventral axis (Figure 3D) [7][8][9]. Pedro Santamaria later demonstrated that transplantation of wild-type cytoplasm could indeed partially rescue the mutant phenotype [10]. By that time, however, the advent of gene technology and germ line transformation in Drosophila meant that the road to the gene product would be via cloning the gene and not via protein purification.…”

Section: Open Accessmentioning

confidence: 99%

“…The results of the transplantation experiment singled out two genes, dorsal and Toll. In the case of dorsal, cytoplasm from the ventral side of older preblastoderm embryos is more active than that from the dorsal side, and the cytoplasm has to be delivered at the ventral side to be active [10]. Supported by the strong dosage dependence, dorsal appeared the best candidate for encoding the morphogen determining the dorsoventral axis.…”

Section: Trends In Geneticsmentioning

confidence: 99%

The Toll gene in Drosophila pattern formation

Nüsslein‐Volhard

2022

Trends in Genetics

Self Cite

View full text Add to dashboard Cite

Toll-like receptors (TLRs) play a crucial role in innate immunity in animals. Their discovery was rewarded a Nobel Prize to Jules Hoffmann and Bruce Beutler in 2011. The name Toll stems from a Drosophila mutant that was isolated in 1980 by Eric Wieschaus and myself as a byproduct of our screen for segmentation genes in Drosophila for which we received the Nobel Prize in 1995. It was named Toll due to its amazing dominant phenotype displayed in embryos from Toll/+ females. The analysis of Toll by Kathryn Anderson in my laboratory in Tübingen and subsequently in her own laboratory in Berkeley singled out Toll as a central component of the complex pathway regulating dorsoventral polarity and pattern of the Drosophila embryo. The Drosophila Toll story provides a striking example for the value of curiosity-driven research in providing fundamental insights that later gain strong impact on applied medical research. The discovery of dorsalThe Drosophila egg is a huge cell that is built during oogenesis in the female organism by two cell types, the somatic follicle cells surrounding the germ line-derived nurse cell-oocyte complex. Upon fertilization, it develops rapidly to form a larva by 24 h. In the first 3 h, the cleavage nuclei are not separated by cell membranes until there are about 6000 cleavage nuclei, which get included into cells forming the cellular blastoderm (Figure 1). The cuticle pattern of the Drosophila larva is richly endowed with markers for position and polarity (Figure 2A-C), and a blastoderm fate map of the larval hypoderm has been constructed [1] (Figure 2D). This pattern develops under the control of maternal genes that have been active during oogenesis and placed morphogenetic cues into the egg and the zygotic genes of the embryo itself. The long history of Drosophila genetics allowed systematic mutational approaches for the identification of maternal as well as zygotic genes affecting patterning of the larva by means of a visible phenotype displayed in the larval cuticle.

show abstract

Partial rescue of dorsal , a maternal effect mutation affecting the dorso-ventral pattern of the Drosophila embryo, by the injection of wild-type cytoplasm

Cited by 46 publications

References 7 publications

Maternal control of the Drosophila dorsal–ventral body axis

Maternal control of the Drosophila dorsal–ventral body axis

SUMOylation of Dorsal attenuates Toll/NF-κB signalling

The Toll gene in Drosophila pattern formation

Contact Info

Product

Resources

About