Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A new male-specific gene in algae unveils an origin of male and female

19.12.2006
By studying the genetics of two closely related species of green algae that practice different forms of sexual reproduction, researchers have shed light on one route by which evolution gave rise to reproduction though the joining of distinct sperm and egg cells.

The findings, which indicate that a gene underlying a more primitive system of reproduction was likely co-opted during evolution to participate in sex-specific sperm development, are reported by Hisayoshi Nozaki and colleagues at the University of Tokyo, Rikkyo (St. Paul’s) University, and Osaka University. The paper appears in the December 19th issue of the journal Current Biology, published by Cell Press.

The familiar notion of the separate male and female sexes exhibited by animal and plant species is based in part on the anatomically and genetically distinct gametes, sperm and egg, produced by members of each sex. But the evolutionary origin of oogamy—reproduction though joining of distinct sperm and egg cells—is in fact poorly understood. In particular, it has remained unclear how oogamy arose from isogamy, a more simple form of sex in which very similar reproductive cells take on different "mating types" but do not differentiate as distinct sperm and egg. The transition from isogamy to oogamy has apparently occurred multiple times during the evolution of animals, plants, and some algae, but how did such transitions occur"

In their new work, the researchers established a genetic connection between male sexuality of an oogamous multicellular green algae species, Pleodorina starrii, and one of the mating types of its isogamous ancestor, the unicellular alga Clamydomonas reinhardtii.

... more about:
»Evolution »MT- »Reproduction »Sex »alga »sperm

In C. reinhardtii, isogamous sexual reproduction occurs through "plus" (MT+) and "minus" (MT-) mating types. MT- represents a "dominant sex" because a particular gene, MID ("minus-dominance") of C. reinhardtii is both necessary and sufficient to cause the cells to differentiate as MT- isogametes. However, no sex-specific genes related to MID had been identified in closely related oogamous species. The researchers now report that they have successfully identified a version of the MID gene in Pleodorina starrii. This "PlestMID" gene is present only in the male genome, and it encodes a protein localized abundantly in the nuclei of mature sperm. The findings indicate that P. starrii maleness evolved from the dominant sex (MT-) of its isogamous ancestor. This breakthrough in understanding provides an opportunity to address any number of extremely interesting questions regarding evolution of oogamy and the origins of male-female dichotomy.

Erin Doonan | EurekAlert!
Further information:
http://www.current-biology.com

Further reports about: Evolution MT- Reproduction Sex alga sperm

More articles from Life Sciences:

nachricht Making fuel out of thick air
08.12.2017 | DOE/Argonne National Laboratory

nachricht ‘Spying’ on the hidden geometry of complex networks through machine intelligence
08.12.2017 | Technische Universität 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: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

Im Focus: Virtual Reality for Bacteria

An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications

Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...

Im Focus: A space-time sensor for light-matter interactions

Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.

The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Midwife and signpost for photons

11.12.2017 | Physics and Astronomy

How do megacities impact coastal seas? Searching for evidence in Chinese marginal seas

11.12.2017 | Earth Sciences

PhoxTroT: Optical Interconnect Technologies Revolutionized Data Centers and HPC Systems

11.12.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>