Decisions, decisions: Male or female?
How germ cells decide whether to be sperm or eggs
Johns Hopkins biologists have determined how developing embryos tell their specialized "germ cells" whether to develop into a male’s sperm or a female’s eggs.
Present in both male and female embryos, germ cells are the precursors to both sperm and eggs. Unable to "decide" on their own which to become, however, germ cells must take "advice" from other cells within embryos as to which is the appropriate sex. The Johns Hopkins researchers have found that this advice is delivered by a sequence of chemical reactions called the "JAK/STAT" pathway. ("JAK/STAT" is an acronym for "Janus kinase/signal transducer and activator transcription.")
"Though we all know that the survival of the species depends on producing children, up until now we haven’t understood how germ cells in the developing embryos decide whether to eventually become the sperm or eggs needed later for adult reproduction," said Mark Van Doren, assistant professor in the Department of Biology in the university’s Krieger School of Arts and Sciences. "Now we know one way these other cells are talking to germ cells about sex."
Van Doren was co-author of the study, published in the July 28 issue of the journal Nature. The discovery promises to enhance understanding of infertility and even some forms of cancer and could eventually lead to the development of more effective treatments for both.
Led by Van Doren and post-doctoral fellow Matthew Wawersik, the Johns Hopkins team used specialized microscopes at the university’s Integrated Imaging Center to look at certain molecules and cell types in fruit fly embryos. Though they already knew that the JAK/STAT pathway was an important means of various types of cell-to-cell communication, they discovered that embryos also were using that pathway to send germ cells signals regarding sexual identity.
"This work implicates that pathway as a key regulator of early decisions made by germ cells as to whether to eventually develop into eggs or sperm," Wawersik said.
Though the team’s observations were limited to the pathway’s role in fruit fly germ cell communication, Van Doren said the same conduit also is active in humans and mice. When communication via the JAK/STAT pathway misfires, diseases such as cancer can result, he said.
"Evolutionarily, germ cells are one of the most ancient cell types, needed by every type of animal to reproduce," Van Doren said. "Their developmental program is very similar, whether we are talking fruit flies or humans. As a result, these findings could eventually help us understand and treat defects in germ cell development that lead to human infertility and disease."
Lisa De Nike | EurekAlert!
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
New success for Konstanz physicists in studying the quantum vacuum
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...