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 Enduring cold temperatures alters fat cell epigenetics
19.04.2018 | University of Tokyo

nachricht Full of hot air and proud of it
18.04.2018 | University of Pittsburgh

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

Im Focus: The Future of Ultrafast Solid-State Physics

In an article that appears in the journal “Review of Modern Physics”, researchers at the Laboratory for Attosecond Physics (LAP) assess the current state of the field of ultrafast physics and consider its implications for future technologies.

Physicists can now control light in both time and space with hitherto unimagined precision. This is particularly true for the ability to generate ultrashort...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Diamond-like carbon is formed differently to what was believed -- machine learning enables development of new model

19.04.2018 | Materials Sciences

Electromagnetic wizardry: Wireless power transfer enhanced by backward signal

19.04.2018 | Physics and Astronomy

Ultrafast electron oscillation and dephasing monitored by attosecond light source

19.04.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>