The somatic-visceral subdivision of the embryonic mesoderm is initiated by dorsal gradient thresholds in Drosophila

Development ◽  
1995 ◽  
Vol 121 (7) ◽  
pp. 2107-2116 ◽  
Author(s):  
K. Maggert ◽  
M. Levine ◽  
M. Frasch
Keyword(s):  
Expression Pattern ◽  
Target Genes ◽  
Substantial Reduction ◽  
Drosophila Embryo ◽  
Germ Layers ◽  
Cardiac Tissues ◽  
Early Drosophila Embryo ◽  
Dorsal Ectoderm ◽  
Lateral Mesoderm

The maternal dorsal regulatory gradient initiates the differentiation of the mesoderm, neuroectoderm and dorsal ectoderm in the early Drosophila embryo. Two primary dorsal target genes, snail (sna) and decapentaplegic (dpp), define the limits of the presumptive mesoderm and dorsal ectoderm, respectively. Normally, the sna expression pattern encompasses 18–20 cells in ventral and ventrolateral regions. Here we show that narrowing the sna pattern results in fewer invaginated cells. As a result, the mesoderm fails to extend into lateral regions so that fewer cells come into contact with dpp-expressing regions of the dorsal ectoderm. This leads to a substantial reduction in visceral and cardiac tissues, consistent with recent studies suggesting that dpp induces lateral mesoderm. These results also suggest that the dorsal regulatory gradient defines the limits of inductive interactions between germ layers after gastrulation. We discuss the parallels between the subdivision of the mesoderm and dorsal ectoderm.

Dpp signaling thresholds in the dorsal ectoderm of the Drosophila embryo

Development ◽  
2000 ◽  
Vol 127 (15) ◽  
pp. 3305-3312 ◽  
Author(s):  
H.L. Ashe ◽  
M. Mannervik ◽  
M. Levine
Keyword(s):  
Gene Expression ◽  
Target Genes ◽  
Histone Acetyltransferase ◽  
Cell Types ◽  
Drosophila Embryo ◽  
Present Evidence ◽  
Drosophila Homolog ◽  
Dorsal Ectoderm ◽  
Transgenic Embryos ◽  
Different Cell Types

The dorsal ectoderm of the Drosophila embryo is subdivided into different cell types by an activity gradient of two TGF(β) signaling molecules, Decapentaplegic (Dpp) and Screw (Scw). Patterning responses to this gradient depend on a secreted inhibitor, Short gastrulation (Sog) and a newly identified transcriptional repressor, Brinker (Brk), which are expressed in neurogenic regions that abut the dorsal ectoderm. Here we examine the expression of a number of Dpp target genes in transgenic embryos that contain ectopic stripes of Dpp, Sog and Brk expression. These studies suggest that the Dpp/Scw activity gradient directly specifies at least three distinct thresholds of gene expression in the dorsal ectoderm of gastrulating embryos. Brk was found to repress two target genes, tailup and pannier, that exhibit different limits of expression within the dorsal ectoderm. These results suggest that the Sog inhibitor and Brk repressor work in concert to establish sharp dorsolateral limits of gene expression. We also present evidence that the activation of Dpp/Scw target genes depends on the Drosophila homolog of the CBP histone acetyltransferase.

scholarly journals The Tailless Nuclear Receptor Acts as a Dedicated Repressor in the Early Drosophila Embryo

2006 ◽  
Vol 26 (9) ◽  
pp. 3446-3454 ◽  
Author(s):  
Érica Morán ◽  
Gerardo Jiménez
Keyword(s):  
Nuclear Receptors ◽  
Nuclear Receptor ◽  
Target Genes ◽  
Activation Function ◽  
Drosophila Embryo ◽  
Intact Protein ◽  
Positive Interactions ◽  
Orphan Nuclear Receptor ◽  
Loss Of Function ◽  
Early Drosophila Embryo

ABSTRACT Tailless is an orphan nuclear receptor that controls terminal body patterning in Drosophila. Genetic analyses have revealed both positive and negative regulatory interactions of Tailless with various target genes, leading to the idea that, like many other nuclear receptors, Tailless mediates both activation and repression of transcription. In this paper, we have examined the consequences of converting Tailless into an obligate repressor and compared the activities of the resulting protein with those of wild-type Tailless. We find that this repressor form of Tailless behaves like the intact protein in gain- and loss-of-function experiments, being sufficient to support normal embryonic development and establish accurate patterns of gene expression even for positive Tailless targets such as hunchback and brachyenteron. This suggests that Tailless functions exclusively as a transcriptional repressor in the embryo and that the observed positive interactions of Tailless with specific targets are secondary effects involving repression of repressors. We provide evidence that knirps is one such repressor gene acting between Tailless and its indirect positive targets. Finally, our results indicate that Tailless exerts an active mechanism of repression via its ligand-binding domain and that this activity is largely independent of the activation function 2 (AF2) motif characteristic of most nuclear receptors.

scholarly journals Analysis of miRNAs Targeted Storage Regulatory Genes during Soybean Seed Development Based on Transcriptome Sequencing

Genes ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 408 ◽  
Author(s):  
Jing-Yao Yu ◽  
Zhan-Guo Zhang ◽  
Shi-Yu Huang ◽  
Xue Han ◽  
Xin-Yu Wang ◽  
...  
Keyword(s):  
Expression Pattern ◽  
Seed Development ◽  
Small Rna ◽  
Target Genes ◽  
Soybean Seed ◽  
Regulatory Genes ◽  
Small Rna Sequencing ◽  
Grain Development ◽  
Regulatory Relationship ◽  
Novel Mirna

Soybeans are an important cash crop and are widely used as a source of vegetable protein and edible oil. MicroRNAs (miRNA) are endogenous small RNA that play an important regulatory role in the evolutionarily conserved system of gene expression. In this study, we selected four lines with extreme phenotypes, as well as high or low protein and oil content, from the chromosome segment substitution line (CSSL) constructed from suinong (SN14) and ZYD00006, and planted and sampled at three stages of grain development for small RNA sequencing and expression analysis. The sequencing results revealed the expression pattern of miRNA in the materials, and predicted miRNA-targeted regulatory genes, including 1967 pairs of corresponding relationships between known-miRNA and their target genes, as well as 597 pairs of corresponding relationships between novel-miRNA and their target genes. After screening and annotating genes that were targeted for regulation, five specific genes were identified to be differentially expressed during seed development and subsequently analyzed for their regulatory relationship with miRNAs. The expression pattern of the targeted gene was verified by Real-time Quantitative PCR (RT-qPCR). Our research provides more information about the miRNA regulatory network in soybeans and further identifies useful genes that regulate storage during soy grain development, providing a theoretical basis for the regulation of soybean quality traits.

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