The Csd gene, of which there may be more than 100 variations, plays a key function in identifying the sex of bees. These genes are brought together throughout sexual recreation: Where the genome subsequently includes 2 different variants of the Csd gene, a female bee develops, which is then raised (left). Where fertilization brings together 2 versions that are the same, a male bee would develop, but it is not raised by the employee bees. The next finding of the bee scientists in Düsseldorf: Where the two alleles of the Csd gene are various, a female bee develops. As the bees desire to prevent this to avoid inbreeding, the employee bees do not raise these eggs.
Sex Determination in Bees.
Unlike people, bees do not have just one sex-determining chromosome. A research study team headed by Professor Dr. Martin Beye from the Institute of Evolutionary Genetics at HHU has now developed that sex is determined by a single gene, described as “Csd” (Complementary sex determiner) via an unique system.
This gene can have more than 100 variations, so-called alleles. In other cases, e.g. in flowers, the numerous alleles of a gene can figure out petal color.
In the case of sexual fertilization, the easy chromosome sets from the egg and sperm cells come together to create a double– diploid– chromosome set. Accordingly, 2 Csd gene variants are now present in each sexually fertilized bee.
The next finding of the bee scientists in Düsseldorf: Where the two alleles of the Csd gene are different, a female bee establishes. By contrast, if the alleles of the gene are the very same on both chromosomes, a male bee establishes. As the bees want to avoid this to prevent inbreeding, the employee bees do not raise these eggs.
Molecular Mechanism of Sex Determination.
The concern remained regarding how this sex determination occurs at molecular level. Lead author Dr. Marianne Otte: “It is necessary to know here that each various allele of the Csd gene produces a different variant of the associated Csd protein, all of which vary somewhat. We were able to show that only different Csd proteins can bind with each other and thus activate a molecular switch that identifies female bee. By contrast, if the proteins are the very same, they bind in a different way and the switch is not triggered. In this case, a male bee would establish, but it is not raised.”.
Professor Beye, last author of the study in Science Advances: “It is comparable to a molecular video game involving two dice: However, in this case, the throw that produces a double is not the winner. Rather, the throw should produce two different numbers to enable a new bee– a woman– to be raised.”.
By contrast, the drones establish from unfertilized eggs. Appropriately, these male bees just have an easy chromosome set with similar Csd proteins. The queen bee decides not to add sperm to the egg throughout the laying process.
Conclusion and Future Directions.
Dr. Otte: “We have been able to solve a genetic mystery that has existed for more than 100 years by tracing it back to the switch function of the Csd protein.” Professor Beye comments on additional research study concerns: “The mechanism the worker bees utilize to recognize whether the fertilized egg contains 2 different Csd proteins and is hence changed to female is still unknown. As it is dark inside the hive, there need to be an olfactory clue.”.
The results will be used to advance bee breeding measures.
Reference: “Recognition of polymorphic Csd proteins identifies sex in the honeybee” by Marianne Otte, Oksana Netschitailo, Stefanie Weidtkamp-Peters, Claus A. M. Seidel and Martin Beye, 4 October 2023, Science Advances.DOI: 10.1126/ sciadv.adg4239.
The Csd gene, of which there might be more than 100 variations, plays a crucial role in determining the sex of bees. These genes are united during sexual recreation: Where the genome subsequently contains two various variations of the Csd gene, a female bee develops, which is then raised (left). Where fertilization combines two variants that are the exact same, a male bee would develop, however it is not raised by the employee bees. Male bees– the drones– are instead created through nonsexual reproduction. Credit: HHU/Paul Schwaderer/stock. adobe.com– Alekss, Tran-Photography
To date it has actually been uncertain precisely how the sex of a bee is identified. A research team from Heinrich Heine University Düsseldorf (HHU) making up biologists and chemists has actually now recognized a crucial gene and the molecular mechanism related to it. In the present issue of the clinical journal Science Advances, they describe how this process is comparable to a video game involving 2 dice.
The sex of a living animal has substantial effects for its kind, function, and behavior. The biological sex of an organism is usually figured out at the start of its life. In people, for instance, the presence of the sex-determining “Y chromosome” chooses whether a guy will be born.
The Silesian priest Johann Dzierzon already analyzed the sex-determining mechanisms of honeybees (Apis mellifera) back in 1845. To name a few things, he discovered the nonsexual reproduction of male bees– the “drones.”.