Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Honeybee gene find ends 150-year search

22.08.2003


The genetic signal that makes a honeybee male or female has been identified by researchers in Germany, the U.S. and Norway. The finding, published in the August 22 issue of the journal Cell, shows how male bees can have no father, a scientific puzzle going back over 150 years and the explanation for why bees, ants and wasps often form colonial societies. It could also make it easier to breed honeybees.



The researchers found that female bees have two different versions of a gene called csd, one from each parent, that form an active protein that triggers female development. Unfertilized eggs, which have only one copy of csd from the mother, default to being males.

In 1845, a Polish parish priest called Johann Dzierzon proposed that male bees have no fathers: They develop from unfertilized eggs, while females grow from fertilized eggs. Later work showed that Dzierzon was right. Male bees have half as many genes (haploid) as females, which get a set of genes from each parent (diploid). About one-fifth of animal species including all ants, bees and wasps use a similar haplodiploid system of sex determination, but the actual genes and mechanisms involved are not well understood.


Martin Beye and Martin Hasselmann from the Martin Luther University of Halle/Wittenberg, Germany, and Robert Page and Kim Fondrk at the University of California, Davis, isolated a honeybee gene called complementary sex determiner, or csd. Csd exists in 19 alternative versions, or alleles, Page said. Female bees have two copies of csd which are always different alleles. Males have only one copy.

The researchers worked out the DNA sequence of four csd alleles and found that they were highly variable. But the same alleles were found in both males and females, showing that there are no alleles for "maleness" or "femaleness."

Studies on developing eggs showed that in both males and females, the csd gene becomes active about 12 hours after eggs are laid and remains active throughout development. In collaboration with Stig Omholt of the Agricultural University of Norway, the researchers used RNA interference to block activity of the csd gene. Female eggs developed into insects with male gonads. The same treatment had no effect on male eggs.

The scientists think that the proteins made by the two different versions of csd in a female pair up to form a single unit which acts on the next step in sex determination, probably by affecting the expression of other genes. If only one type of csd is made, no active protein is formed and the bee grows into a male.

"The csd gene is the major invention that enabled the evolution of the ants, bees and wasps and their complex societies by enabling the evolution of haplodiploidy," Page said. Because males have just one set of genes, sisters that work together in the nest share more genes in common with each other than they would with their own sons and daughters.

But this also has a downside for bee breeders. When bees are inbred to select desired traits, fertilized eggs with two copies of the same csd allele can occur. These eggs develop into sterile diploid males. Worker bees find and kill these sterile males as larvae. That means that inbred honeybee colonies quickly die out.

"This problem has haunted bee breeding since the 1940s. As we understand more, there will be ways to get around this problem," Page said. Beekeepers could set up matings with bees of different csd type, or find ways to manipulate the gene to get viable crosses.

Breeding bees is hard enough already. Wild bees mate only once, in flight to their new nest. In the 19th century, Gregor Mendel, who discovered the principles of inheritance in pea plants, also tried to breed bees without success. In the 1940s, Harry H. Laidlaw, Jr. now a professor emeritus of entomology at UC Davis, and others pioneered methods for artificial insemination of bees, allowing selective breeding for the first time. But attempts to create long-lived inbred strains generally failed.

Andy Fell | EurekAlert!
Further information:
http://www.ucdavis.edu/

More articles from Life Sciences:

nachricht Chains of nanogold – forged with atomic precision
23.09.2016 | Suomen Akatemia (Academy of Finland)

nachricht Self-assembled nanostructures hit their target
23.09.2016 | King Abdullah University of Science and Technology

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

Im Focus: Launch of New Industry Working Group for Process Control in Laser Material Processing

At AKL’16, the International Laser Technology Congress held in May this year, interest in the topic of process control was greater than expected. Appropriately, the event was also used to launch the Industry Working Group for Process Control in Laser Material Processing. The group provides a forum for representatives from industry and research to initiate pre-competitive projects and discuss issues such as standards, potential cost savings and feasibility.

In the age of industry 4.0, laser technology is firmly established within manufacturing. A wide variety of laser techniques – from USP ablation and additive...

Im Focus: New laser joining technologies at ‘K 2016’ trade fair

Every three years, the plastics industry gathers at K, the international trade fair for plastics and rubber in Düsseldorf. The Fraunhofer Institute for Laser Technology ILT will also be attending again and presenting many innovative technologies, such as for joining plastics and metals using ultrashort pulse lasers. From October 19 to 26, you can find the Fraunhofer ILT at the joint Fraunhofer booth SC01 in Hall 7.

K is the world’s largest trade fair for the plastics and rubber industry. As in previous years, the organizers are expecting 3,000 exhibitors and more than...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Experts from industry and academia discuss the future mobile telecommunications standard 5G

23.09.2016 | Event News

ICPE in Graz for the seventh time

20.09.2016 | Event News

Using mathematical models to understand our brain

16.09.2016 | Event News

 
Latest News

Chains of nanogold – forged with atomic precision

23.09.2016 | Life Sciences

New leukemia treatment offers hope

23.09.2016 | Health and Medicine

Self-assembled nanostructures hit their target

23.09.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>