Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UT Southwestern researchers learn importance of insulin family signaling in male sex determination

20.11.2003


Researchers at UT Southwestern Medical Center at Dallas have shown that insulin family signaling is important for male sex determination, a discovery that furthers the understanding of testes formation and eventually could lead to treatments for reproductive disorders.


"Dr. Luis F. Parada (left) and Dr. Sunita Verma-Kurvari have found insulin family signaling is important for male sex determination, furthering the understanding of testes formation and perhaps someday leading to treatments for reproductive disorders."



Their findings appear in the current issue of Nature and are available online.

"We are excited by this research for two reasons," said Dr. Luis Parada, senior author of the Nature study and director of the Center for Developmental Biology. "First, the intracellular signaling pathways that mediate male sexual differentiation have remained elusive despite the fact that the controlling gene that unleashes the process was identified almost 15 years ago. Second, our experience with studying receptors and signaling in development provides us with the skills and tools to tackle this problem, which has tremendous implications in newborn disorders."


UT Southwestern researchers now want to determine if the insulin-signaling pathway is active in human gonad formation. It has been found only in mice, but there is a strong likelihood it exists in humans.

"If the insulin-signaling pathway turns out to be important in humans, we’ll be able to activate the pathway because we know what proteins to manipulate," said Dr. Sunita Verma-Kurvari, postdoctoral researcher in the Center for Developmental Biology and co-first author of the study. "We someday may even be able to correct reproductive disorders by activating them with therapeutics."

In mice, the male sex-determining process begins in a region of the Y chromosome called Sry, Dr. Verma-Kurvari said. Sry triggers differentiation of the Sertoli cells, which act as organizing centers and direct formation of the testes.

Without Sry, XX or XY gonads failed to develop testes (male reproductive organs producing sperm and male sex hormones), and male to female sex reversal ensued in the mice studied. If insulin family signaling is altered, Dr. Verma-Kurvari said, Sry is changed and the downstream signaling pathway is inactive. This shows that besides playing a role in glucose metabolism and growth, insulin family signaling is critical for male sex determination, she said.

Along with the insulin family signaling pathway, Dr. Parada, who directs the Kent Waldrep Center for Basic Research on Nerve Growth and Regeneration, and his colleagues are studying the hormone Insl3, a component of the insulin-like genes. They already have found that mutations in mice cause cryptorchidism – impaired testicular descent – a congenital abnormality affecting 2 percent to 3 percent of full-term human males at birth.

Sex determination switches are diverse and can vary based on the presence of a Y or an X chromosome, environmental factors and social factors. Also, the structure of testes is quite similar among different species and suggests the presence of common players in their formation, said Dr. Verma-Kurvari.

"Little is known about the proteins and the exact pathway required for the formation of testis in different species," she said. "Sry, for example, does not exist outside of mammals. There are testis-specific proteins that are common between species, but the timing of their expression suggests that they perform slightly different functions in different species. Since insulin family members are present in both vertebrates and invertebrates, this pathway becomes potentially interesting for playing a role in testis formation in other species as well."

Other UT Southwestern contributors to the Nature study were Dr. Serge Nef, a co-first author, and Dr. Jussi Merenmies, both former research fellows who are now at the University of Geneva and University of Helsinki, respectively. Dr. Jean-Dominique Vassalli from the University of Geneva, and Dr. Argiris Efstratiadis and Dr. Domenico Accili, both from Columbia University College of Physicians and Surgeons, also contributed.


The research was supported by an Excellence in Education Endowment.

Scott Maier | UT Southwestern
Further information:
http://www.utsouthwestern.edu/utsw/cda/dept37389/files/127503.html
http://www.utsouthwestern.edu/home/news/index.html

More articles from Life Sciences:

nachricht Two Group A Streptococcus genes linked to 'flesh-eating' bacterial infections
25.09.2017 | University of Maryland

nachricht Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: LaserTAB: More efficient and precise contacts thanks to human-robot collaboration

At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.

Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Fraunhofer ISE Pushes World Record for Multicrystalline Silicon Solar Cells to 22.3 Percent

25.09.2017 | Power and Electrical Engineering

Usher syndrome: Gene therapy restores hearing and balance

25.09.2017 | Health and Medicine

An international team of physicists a coherent amplification effect in laser excited dielectrics

25.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>