SciPak

Wings Not Lost, Just Hidden in Some Insects

A new study shows that decreasing expression of the Hox gene in mealworm beetles, Tenebrio molitor, coaxes wing-like appendages to sprout from certain non-winged segments of their bodies. The finding suggests that other wingless insects could still have wing-development programs that were modified—but not lost—over evolutionary time too.

Read more about this research from the 15 March issue of Science Express here.

[Image courtesy of Takahiro Ohde. Click the image for more information.]

Tracking Brain Connectivity In Utero

A new study uses fMRI to watch and quantify the development of brain connections in fetuses of different ages. Many brain disorders like autism, ADHD and dyslexia are thought to arise from disrupted communication in brain networks. Understanding how brain networks form and what events can impact brain connectivity may help researchers identify abnormal brain development earlier and develop targeted treatments.

Read more about this research from the 20 February issue of Science Translational Medicine here.

[Image courtesy of Rob Widdis. Click the image for more information.]

Cracked Skin and Crocodile Scales

Head of a juvenile Nile crocodile (Crocodylus niloticus). The irregular polygonal scales on the face and jaws of crocodiles are not controlled genetically. Instead, the patterns are generated through a self-organizational process in which the stiff skin cracks in a tensional stress field as the crocodile grows. Click here for more information.

[Photo: Michel C. Milinkovitch and Adrien Debry]

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Cracked Skin and Crocodile Scales

Researchers have discovered how the scaly skin pattern on crocodile faces and jaws is created. Mammalian hairs, bird feathers, and many reptile scales grow from genetically-controlled processes, but the crocodile’s head scales don’t follow this nearly universal rule. Instead, crocodile face and jaw scales seem to emerge from the physical cracking of skin, which creates distinct, random, non-overlapping polygonal shapes.

Read more about this research from the 29 November issue of Science Express here.

[Image courtesy of Michel C. Milinkovitch; click the image for more information.]

Coordinating Fruit-Fly Metamorphosis and Growth

A pair of new studies sheds light on the signaling system that helps a fruit fly’s body parts all reach the proper adult size even when early growth is disrupted. In fruit fly larvae, tissues called imaginal discs give rise to the adult appendages. These tissues regenerate in response to damage. When the imaginal discs are injured or grow tumors, they signal to the rest of the larval animal to slow down growth and delay morphogenesis.

Read more about this research from the 4 May issue of Science here and here.

[Image courtesy of Andres Garelli; click the image for caption information]

Coral Embryos Clone Themselves

Even fairly gentle waves can break apart fragile coral embryos. But, these fragments simply start dividing again, becoming clones of the original embryo. These are the findings of a Brevium in the 2 March issue of Science, which reveals another mode of reproduction in the animal kingdom. Unlike the embryos of multicellular animals, the embryos of reef-building corals lack a protective capsule or membrane. Coral spawning events can produce billions of naked embryos that float at the sea surface, where even gentle or moderate sea breezes generate small white-cap waves.

Read more about this research from the 2 March issue of Science here.

[Image courtesy of Heyward & Negri, AIMS; click the image for caption information.]