Navigation Links
How monarch butterflies are wired for navigation

In their extraordinary annual migration from North America to Mexico, monarch butterflies are known to use the angle of polarized sunlight as a celestial guide to help them keep to a straight and true path southward. But details of their navigational machinery have remained a mystery.

Now, researchers, led by Steven Reppert of University of Massachusetts Medical School, Ivo Sauman of the Czech Academy of Sciences and Adriana Briscoe of the University of California at Irvine, have explored the infinitesimal butterfly brain to uncover new insights into that machinery. Their findings show that the same ultraviolet light that has become an anathema to cancer-wary humans is critical for butterfly navigation. Also, the researchers were surprised to discover a key wiring connection between the light-detecting navigation sensors in the butterfly's eye and the creature's circadian clock--a critical link if the butterflies are to compensate for the time of day in using their "sun compass."

The researchers' techniques include molecular analysis of butterfly brain proteins, as well as flight tests in which the scientists manipulated the light reaching their insect subjects and measured the navigational response.

In their studies, the researchers discovered that ultraviolet photoreceptors dominated in the region of the butterfly visual system known to specialize in polarized light detection. To confirm that the butterflies, indeed, required ultraviolet polarized light to navigate, the researchers tested the insects in a "flight simulator," in which they could control the light polarization and thus influence the butterflies' direction of flight. The researchers found that when they placed a UV-interference filter over the polarized light source, the butterflies lost their orientation response.

The researchers also pinpointed the location of the circadian clock in the butterfly brain. Such circadian clocks govern the approximately 24 hour activity a nd metabolic cycles of animals from the simplest insects to humans. Reppert and his colleagues found that key genes responsible for the clock's molecular "ticks" were expressed in a brain region called the dorsolateral protocerebrum. Using tracer molecules, they were surprised to discover tiny neural fibers containing a key clock protein that connected with the polarization photoreceptors in the butterfly eye.

"This pathway has not been described in any other insect, and it may be a hallmark feature of butterflies that use a time-compensated sun compass," wrote the researchers. They also speculated that another such clock-related pathway of fibers they detected between two regions of the butterfly brain may play a role in regulating the insects' hormonal system, to induce the longevity that enables the butterfly to extend its survival in its overwintering grounds in Mexico.

The researchers include Ivo Sauman of the Czech Academy of Sciences; Adriana D. Briscoe of the University of California, Irvine; Haisun Zhu, Dingding Shi, Quan Yuan, Amy Casselman, and Steven M. Reppert of the University of Massachusetts Medical School; Oren Froy of the University of Massachusetts Medical School (Current Address: The Hebrew University of Jerusalem); and Julia Stalleicken of the University of California, Irvine (Current address: University of Oldenburg). This work was supported in part by grants from the NIH, GAAVCR, NSF and German Academy Exchange Service Grant, as well as the Volkswagenstiftung.

Sauman, I., Briscoe, A.D., Zhu, H., Shi, D., Froy, O., Stalleicken, J., Yuan, Q., Casselman, A., and Reppert, S.M. (2005). Connecting the Navigational Clock to Sun Compass Input in Monarch Butterfly Brain. Neuron 46, 457?67. http://www.neuron.org


'"/>

Source:Cell Press


Related biology news :

1. In the migratory marathon, parasitized monarchs drop out early
2. Expanding forests darken the outlook for butterflies, study shows
3. Female butterflies go for sparkle -- not size -- when choosing to mate
4. Where have all the butterflies gone?
5. Some butterflies travel farther, reproduce faster
6. Male-killing bacteria makes female butterflies more promiscuous
7. The brain is broadly wired for reproduction
8. How taste response is hard-wired into the brain
9. Animal brains hard-wired to recognize predators foot movements, Queens study suggests
10. Is the brain wired for faces?
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:6/30/2017)... 2017 Today, American Trucking Associations announced ... face and eye tracking software, became the newest ... "Artificial intelligence and advanced sensing ... a driver,s attentiveness levels while on the road.  ... detect fatigue and prevent potential accidents, which could ...
(Date:5/16/2017)... 2017   Bridge Patient Portal , an ... MD EMR Systems , an electronic medical record ... have established a partnership to build an interface ... GE Centricity™ products, including Centricity Practice Solution (CPS), ... These new integrations will allow healthcare delivery networks ...
(Date:4/17/2017)... MELBOURNE, Florida , April 17, 2017 ... security technology company, announces the filing of its 2016 Annual Report ... Securities and Exchange Commission. ... Report on Form 10-K is available in the Investor Relations section ... well as on the SEC,s website at http://www.sec.gov . ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... HILLS, Calif. , Oct. 11, 2017  SkylineDx today ... (ICR) and University of Leeds ... risk-stratify patients with multiple myeloma (MM), in a multi-centric Phase ... University of Leeds is the sponsor ... and ICR will perform the testing services to include high-risk ...
(Date:10/11/2017)... , ... October 11, 2017 , ... ... the implantation and pregnancy rates in frozen and fresh in vitro fertilization ... progesterone and maternal age to IVF success. , After comparing the results from ...
(Date:10/10/2017)... CALIF. (PRWEB) , ... October 10, 2017 , ... San ... part of its corporate rebranding initiative announced today. The bold new look is ... reach, as the company moves into a significant growth period. , It will also ...
(Date:10/10/2017)... ... October 10, 2017 , ... For ... has won a US2020 STEM Mentoring Award. Representatives of the FirstHand program travelled ... Volunteer Experience from US2020. , US2020’s mission is to change the trajectory of ...
Breaking Biology Technology: