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Full-Text Articles in Life Sciences
Human Cryptochrome Exhibits Light-Dependent Magnetosensitivity, Lauren Foley, Robert Gegear, Steven Reppert
Human Cryptochrome Exhibits Light-Dependent Magnetosensitivity, Lauren Foley, Robert Gegear, Steven Reppert
Robert J. Gegear
Humans are not believed to have a magnetic sense, even though many animals use the Earth's magnetic field for orientation and navigation. One model of magnetosensing in animals proposes that geomagnetic fields are perceived by light-sensitive chemical reactions involving the flavoprotein cryptochrome (CRY). Here we show using a transgenic approach that human CRY2, which is heavily expressed in the retina, can function as a magnetosensor in the magnetoreception system of Drosophila and that it does so in a light-dependent manner. The results show that human CRY2 has the molecular capability to function as a light-sensitive magnetosensor and reopen an area …
Defining Behavioral And Molecular Differences Between Summer And Migratory Monarch Butterflies, Haisun Zhu, Robert Gegear, Amy Casselman, Sriramana Kanginakudru, Steven Reppert
Defining Behavioral And Molecular Differences Between Summer And Migratory Monarch Butterflies, Haisun Zhu, Robert Gegear, Amy Casselman, Sriramana Kanginakudru, Steven Reppert
Robert J. Gegear
BACKGROUND: In the fall, Eastern North American monarch butterflies (Danaus plexippus) undergo a magnificent long-range migration. In contrast to spring and summer butterflies, fall migrants are juvenile hormone deficient, which leads to reproductive arrest and increased longevity. Migrants also use a time-compensated sun compass to help them navigate in the south/southwesterly direction en route for Mexico. Central issues in this area are defining the relationship between juvenile hormone status and oriented flight, critical features that differentiate summer monarchs from fall migrants, and identifying molecular correlates of behavioral state. RESULTS: Here we show that increasing juvenile hormone activity to induce summer-like …