Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The developmental genetics of space and time

16.05.2013
Developmental genes often take inputs from two independent sources
Albert Erives, associate professor in the University of Iowa Department of Biology, and his graduate student, Justin Crocker, currently a postdoctoral researcher at the Howard Hughes Medical Institute (HHMI) Janelia Farm Research Campus, have conducted a study that reveals important and useful insights into how and why developmental genes often take inputs from two independent “morphogen concentration gradients.”

The study appears in the Genomes & Developmental Control section of the online June 1 issue of the journal Developmental Biology. The complete paper can be found at: www.sciencedirect.com/science/article/pii/S0012160613001310.

Understanding the concept of morphogen gradients—the mechanism by which a signal from one part of a developing embryo can influence the location and other variables of surrounding cells—is important to developmental biology, gene regulation, evolution, and human health.

Morphogen gradients subdivide a field of cells into territories characterized by distinct cell fate potentials and allow cells to “know” their position within a developing embryonic tissue and to differentiate appropriately. In order to function, such systems require a genetic mechanism to encode a spectrum of responses at different target genes.

This genetic mechanism takes the form of transcriptional enhancers, which are DNA sequences that display a cryptic code of transcription factor (TF) binding sites. During development and/or environmental perturbation, these enhancers serve as assembly scaffolds for TF protein complexes that orchestrate differential gene expression.

However, enhancers targeted by morphogen signaling may drive temporally inappropriate expression because morphogen gradients also provide temporal cues. That is, the morphogenic gradient builds up and decays over a specific window of developmental time.

Using the powerful Drosophila (fruit fly) genetic system, which includes diverse species with fully sequenced genomes, the Erives Lab identified a case of spatial and temporal conflict in the regulation of the ventral neurons defective (vnd) gene, which must be precisely regulated in order for the fly’s nervous system to be properly specified. The vnd gene is induced by a concentration gradient of a key embryonic factor (dorsal/NFkB) that patterns the dorsal/ventral (D/V) axis of the embryo. In particular, the vnd gene plays a critical role in specifying distinct D/V neural columnar fates of the ectodermal compartments by encoding a repressor of additional regulators.

The role of vnd in this regulatory hierarchy requires early temporal expression, which is characteristic of low-threshold responses, but its specification of ventral neurogenic ectoderm demands a relatively high-threshold response to the morphogen.

The study shows that the vnd gene’s Neurogenic Ectoderm Enhancer (NEE) takes additional input from a complementary gradient of the Dpp morphogen via a highly-conserved Schnurri/Mad/Medea silencer element (SSE), which is integral to its NEE module. In this regard, the NEE at vnd is unlike NEEs at other genetic loci, which are not involved in the neural specification circuit and have no resident SSE. They also show that an SSE could be added to a single-input NEE and cause spatial restriction of its activity. These results show how requirements for conflicting temporal and spatial responses to one morphogen gradient can be solved by additional inputs from complementary morphogen gradients.

The Erives Lab at the UI’s Department of Biology studies the structure, function, and evolution of enhancers within the context of gene regulatory circuits underlying the evolution and development of animals by using molecular, genetic, and evolutionary genomic approaches. Within these areas, the Erives Lab has published several landmark papers notable for demonstrating how whole genome sequences can be used to accelerate biological research on outstanding questions in biology.

The study is supported by an NSF CAREER award to Albert Erives (NSF IOS1239673).
Contact
Albert Erives, Department of Biology, 319-335-2418

Gary Galluzzo | EurekAlert!
Further information:
http://www.uiowa.edu

More articles from Life Sciences:

nachricht What happens in the cell nucleus after fertilization
06.12.2016 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Robot on demand: Mobile machining of aircraft components with high precision

06.12.2016 | Power and Electrical Engineering

A new dead zone in the Indian Ocean could impact future marine nutrient balance

06.12.2016 | Earth Sciences

Significantly more productivity in USP lasers

06.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>