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Team:NYMU-Taipei
From 2013.igem.org
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==Overview== | ==Overview== | ||
| - | To save bees from Nosema ceranae, the culprit of colony collapse disorder (CCD), we created the so-called Bee. coli. from E. coli MG1655, which naturally resides in bees. | + | To save bees from Nosema ceranae, the culprit of colony collapse disorder (CCD), we created the so-called Bee. coli. from E. coli MG1655, which naturally resides in bees. |
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The Bee. coli are designed to work sequentially as below. First, it continuously secretes mannosidase to inhibit the sprouting of N. ceranae spores. Second, if the bee is infected, the fungus-killing-circuit with a positive feedback design will turned on to wipe out N. ceranae shortly. However, if the weapons above should fail to conquer N. ceranae, the bee-suicide-operon will activate, killing the infected bee, but saving its companions. | The Bee. coli are designed to work sequentially as below. First, it continuously secretes mannosidase to inhibit the sprouting of N. ceranae spores. Second, if the bee is infected, the fungus-killing-circuit with a positive feedback design will turned on to wipe out N. ceranae shortly. However, if the weapons above should fail to conquer N. ceranae, the bee-suicide-operon will activate, killing the infected bee, but saving its companions. | ||
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Besides, a light-inducible lysis system is created to ensure our Bee. Coil only lives inside of the bee. In addition, we have decided upon encapsulation as being the method to send our Bee. coli in to the bee. Since the capsule will only dissolve in a bee’s gut, our Bee. coli will not wantonly spread. | Besides, a light-inducible lysis system is created to ensure our Bee. Coil only lives inside of the bee. In addition, we have decided upon encapsulation as being the method to send our Bee. coli in to the bee. Since the capsule will only dissolve in a bee’s gut, our Bee. coli will not wantonly spread. | ||
Revision as of 14:22, 27 September 2013
Overview
To save bees from Nosema ceranae, the culprit of colony collapse disorder (CCD), we created the so-called Bee. coli. from E. coli MG1655, which naturally resides in bees.
The Bee. coli are designed to work sequentially as below. First, it continuously secretes mannosidase to inhibit the sprouting of N. ceranae spores. Second, if the bee is infected, the fungus-killing-circuit with a positive feedback design will turned on to wipe out N. ceranae shortly. However, if the weapons above should fail to conquer N. ceranae, the bee-suicide-operon will activate, killing the infected bee, but saving its companions.
Besides, a light-inducible lysis system is created to ensure our Bee. Coil only lives inside of the bee. In addition, we have decided upon encapsulation as being the method to send our Bee. coli in to the bee. Since the capsule will only dissolve in a bee’s gut, our Bee. coli will not wantonly spread.
Saving the Bee from CCD
In hope of protecting the eco-system, food supply and agricultural economy, the goal of our project is to solve the Colony Collapse Disorder (CCD), a severe disease that causes bees to dramatically decline or disappear. Since the culprit of CCD is a microsporidian called Nosema ceranae, we created Bee. coli to strengthen bees’ immune system and further wipe N. ceranae out.
The dormant stage of N. ceranae is a long-lived spore which is small enough to be ingested by bees through food or water. When N. ceranae travels to the bees’ midgut, it will germinate a polar filament to reach the epithelial cells. Midgut cells are then dominated by N. ceranae and thus bee’s ability to gain nutrition is decreased. In addition, some spores will come out in feces, leading to feces-oral or oral-oral infection in the beehive. N. ceranae is fatal to bees; however, so far there has been no efficient way to stop this pathogen. This year, we endow Bee. coli with multiple functions to resist the invasion of N. ceranae, hoping to cure CCD and prevent colonial infection.
Bee. coli’s functions are designed to work sequentially. Before N. ceranae approaches the midgut cells, Bee. coli will secrete mannosidase to inhibit N. ceranae from growing a polar filament. The epithelial cells will secrete reactive oxygen species (ROS) once being attacked by N. ceranae. ROS will activate promoters containing OxyR binding site in Bee. coli, serving as a signal of N. ceranae invasion, eventually resulting in Bee. coli producing substances such as defensin and abaecin to kill N. ceranae while still being safe to bees and Bee. coli itself. Moreover, if the methods above unfortunately fail, Bee. coli will secrete ethanol to kill the single bee, that is to say, to sacrifice few infected bees in order to protect the healthy bees.
Concerning safety, Bee. coli is designed to commit suicide if it escapes from midgut. Once Bee. coli senses that the pH of the environment is different from that of the midgut, Bee. coli will produce a lysis protein and kill itself. Last but not least, to make Bee. coli more practical for survival, we chose to use E. coli K-12 MG1655, a bacteria naturally occurring in honeybees' gut. We then use encapsulation to transport Bee. coli into the bee’s midgut. The beekeepers can add the Bee. coli capsules into sugar-water which are then consumed by bees. That way, Bee. coli can come into reality and solve the CCD problem.
