Biocanvas

Muscles contract and relax to allow for locomotion, and they...

Wed, 08 May 2013 20:00:51 -0400

Muscles contract and relax to allow for locomotion, and they accomplish this with structures called sacromeres. In this fruit fly larva, sacromeres appear as the thin, striped bands within the red muscle tissue along the body wall. Flying insects have sacromeres that are not built for maximum energy output; rather, they are long with a limited range of motion in order to assist in wing movement during flight.

Image by Timothy Mosca, Stanford University.

Nearly 85% of cancers derive from epithelial cells that line...

Mon, 22 Apr 2013 20:00:44 -0400

Nearly 85% of cancers derive from epithelial cells that line almost every organ in the human body. When cancers become aggressive, they can lose their epithelial characteristics and become more motile. Motile cancerous cells can result in cancer metastasis. To understand the process by which epithelial cells become more motile, the fruit fly egg chamber is an excellent model system as groups of epithelial cells detach and migrate during egg development. Seen here are several egg chambers from Drosophila melanogaster.

Image by Denise Montell.

The stinging nettle has hollow stinging hairs called trichomes...

Fri, 12 Apr 2013 20:01:04 -0400

The stinging nettle has hollow stinging hairs called trichomes that, when broken, inject chemicals like histamine under the skin. Ironically, nettle leaf extract also has compounds that reduce TNF-α, an inflammation-promoting molecule.

Image by Marek Mis.

Just as gills allow crustaceans to breathe underwater, tracheae...

Thu, 11 Apr 2013 20:00:52 -0400

Just as gills allow crustaceans to breathe underwater, tracheae (yellow, with cell nuclei in blue) allow insects to breath on land. Crustacean gills and insect tracheae share many similarities, indicating an evolutionary relationship exists between them. It will take the discovery of new fossils that capture insects’ water-to-land transition to understand this relationship in better detail.

Image by Dr. Robert Markus, Stockholm University.

Sensory neurons convey signals from the outside world to our...

Wed, 10 Apr 2013 20:00:44 -0400

Sensory neurons convey signals from the outside world to our brain for interpretation. As they mature, sensory neurons grow radially outward, expanding their volume over 1,000 times that of other animal cells. This growth in size is important, because the conduction speed of signals increases as the diameter of a neuron increases. In these sensory neurons, axons (which transmit signals) are stained in green while the cell body is stained red.

Image by Dr. María Alejandra Lopez-Verrilli, Pontificia Universidad Católica de Chile.

Mushrooms have evolved gills, called lamella, that grow...

Tue, 09 Apr 2013 20:00:45 -0400

Mushrooms have evolved gills, called lamella, that grow underneath the main cap of some species. Lamella function to dramatically increase the surface area of a mushroom, increasing the amount of spores produced and dispersed during reproduction.

Image by Charles Krebs.

Butterfly wing scales at 75-times magnification. Butterfly...

Wed, 03 Apr 2013 20:00:41 -0400

Butterfly wing scales at 75-times magnification. Butterfly scales most likely evolved in order to provide insulation, as high body temperatures are required for efficient flight. Scales that are pigmented with bright colors warn predators of a butterfly’s potential toxicity or inedibility. Other inert butterfly species mimic this bright coloration scheme to fool predators into thinking they too are poisonous, thus sparing the butterfly’s life.

Image by Oleg Kolesnikov, Russian State Agrarian University.

Astrocytes (in red) are the most abundant cell in the brain and...

Tue, 02 Apr 2013 20:00:37 -0400

Astrocytes (in red) are the most abundant cell in the brain and help support neurons (in green) by recycling old cellular byproducts and regulating a healthy environment for neuronal function. Unlike other organs of the body where an injury results in a fibrous scar, the brain instead forms an astrocyte scar to promote neuron survival.

Image by Dr. Shelley Jacobs, McMaster University.

The green algae Acetabularia is a remarkable tool for studying...

Mon, 01 Apr 2013 20:00:00 -0400

The green algae Acetabularia is a remarkable tool for studying cell biology because, although complex in shape and giant in size, it is a single-celled organism. Acetabularia were used in an experiment by Joachim Hämmerling to show that the nucleus determines a cell’s development and characteristics.

Image by Dr. John Huisman, Western Australian Herbarium.

Epithelial cells line surfaces and cavities throughout the body,...

Fri, 29 Mar 2013 20:00:41 -0400

Epithelial cells line surfaces and cavities throughout the body, forming skin, glands, and tracts. This mouse embryo has been genetically engineered to allow for the visualization of epithelial cells, showing the pattern of whisker placement on the face.

Image by Evan Heller, Rockefeller University.

Sexual reproduction allows for genetic exchange between two...

Thu, 28 Mar 2013 20:00:45 -0400

Sexual reproduction allows for genetic exchange between two organisms, generating greater genetic diversity and increasing the chance for reproductive fitness and survival. Some biologists believe the first form of sexual reproduction was a process called conjugation, where two compatible cells line up, form a bridge between each other, and exchange DNA. These are two Nassula ornata, a type of ciliate, undergoing conjugation.

Image by Wim van Egmond, Micropolitan Museum.

A cultured neuron from the hippocampus of a rat. The hippocampus...

Wed, 27 Mar 2013 20:01:03 -0400

A cultured neuron from the hippocampus of a rat. The hippocampus is located within the brain and plays a significant role in consolidating memories and navigating space. In Alzheimer’s disease, a neurodegenerative disorder characterized by memory loss, the hippocampus is one of the first areas to suffer neuronal damage.

Image by Dr. Kieran Boyle, University College London.

Light strikes the retina located in the back of our eyes,...

Tue, 26 Mar 2013 20:00:00 -0400

Light strikes the retina located in the back of our eyes, allowing us to see. Within the retina are neurons that transmit a signal to the brain when they are stimulated with light. Seen here is the surface of the retina from a mouse, with neurons converging towards the optic disc (bottom), the location where neurons exit the eye towards the brain.

Image by Dr. Alejandra Bosco, University of Utah.

All insects have antennae, which allow them to respond to...

Mon, 25 Mar 2013 20:00:39 -0400

All insects have antennae, which allow them to respond to free-floating molecules much like noses do in higher organisms. This is a high-magnification view of an antenna from a moth.

Image by Dr. Donna Stolz, University of Pittsburgh.

As sedimentary grains get trapped with bacteria in shallow...

Sun, 24 Mar 2013 20:00:52 -0400

As sedimentary grains get trapped with bacteria in shallow water, stromatolites form, giving a window into microbial life that date back more than 3.5 billion years ago. Shown here is a stromatolite with cyanobacteria, one of the first producers of oxygen that radically altered our atmosphere to what it is today.

Image by Douglas Moore, University of Wisconsin.

Before a cell divides, it must carefully check that all of its...

Sat, 23 Mar 2013 20:00:43 -0400

Before a cell divides, it must carefully check that all of its systems are normal and operational before initiating division. Cancers are often riddled with mistakes in this machinery, allowing a cell to divide uncontrollably without first ensuring everything is “good to go.” In this Ashbya gossypii fungus, the CLN3 protein (orange, with nuclei in blue) helps initiate the commitment to cell division given that the cell correctly passes its initial checkpoint.

Image by ChangHwan Lee, Dartmouth College.

As marine life like the parrot fish consumes coral, mollusks,...

Fri, 22 Mar 2013 20:00:41 -0400

As marine life like the parrot fish consumes coral, mollusks, and crustaceans, it excretes inorganic material that contributes to coral sand. Seen here is a high magnification of coral sand, depicting the fragments of skeletons from once living creatures.

Image by Dr. David Maitland.

Just before the fruit fly Drosophila enters metamorphosis to...

Thu, 21 Mar 2013 20:00:57 -0400

Just before the fruit fly Drosophila enters metamorphosis to become an adult fly, the developing eye begins to form a furrow where specialized light-sensitive cells will develop.

Image by Dr. Michael Bridge, University of Utah.

Bloods vessels in the brain of a live zebrafish embryo. Image by...

Wed, 20 Mar 2013 20:00:50 -0400

Bloods vessels in the brain of a live zebrafish embryo.

Image by Dr. Jennifer Peters and Dr. Michael R. Taylor, St. Jude Children’s Research Hospital.

Daphnia, commonly known as the water flea, are mostly...

Tue, 19 Mar 2013 20:00:53 -0400

Daphnia, commonly known as the water flea, are mostly transparent plankton less than 5 mm large. One can be seen here playing with a colony of Volvox, a type of green algae.

Image by Dr. Ralf Wagner.