SciPak

Science Prize Goes to Undergrad Course that Incorporates Faculty Research

A Stanford biology class that involves undergraduates in their instructors’ research and has been shown to engage students much more effectively than standard lab classes has been awarded the Science Prize for Inquiry-Based Instruction (IBI).

Read more about this article from the 29 March issue of Science here.

[Video by Eric Koziol]

Masterminding Mitochondrial Fission

Mitochondria are best known for their energy-generating roles in cells, but their ability to undergo fission and fusion and to move around is also very important. Defects that hamper this ability have been implicated in many neurodegenerative diseases. A new study sheds light on how mitochondrial fission occurs near the endoplasmic reticulum, or ER.

Read more about this research from the 25 January issue of Science here.

[Image courtesy of Farida Korobova & Henry Higgs. Click the image for more information.]

Flipping the Switch that Arms a Bacterium

Photorhabdus luminescens bacteria, carried in the gut of nematodes, can be switched from a friendly to a formidable form with a small genetic rearrangement. Vishal Somvanshi at Michigan State University and colleagues show that this flipped switch is enough to arm the bacteria with toxins. When the nematodes penetrate an insect host, they regurgitate the killer bacteria, which kill the insect and provide the nematodes with a nutrient-rich meal.

Read more about this research from the 6 July issue of Science here.

[Image courtesy of Alexander Martin. Click the image for more information.]

Special Section on Computational Biology

Advances in computing power are giving us new insights into the mechanisms of life. Four Reviews in this issue describe how scientists are using models to simulate biological processes. Also, a News story in this special section looks at how physiological ecologists who design computer models to predict how animals handle heat are forecasting the effects of climate change.

Read more about this research from the 13 April issue of Science here.

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The Root of Resistant Malaria in Southeast Asia?

Researchers have identified a particular region on a chromosome in P. falciparum — a major malaria parasite — that helps to explain how such parasites in Southeast Asia are developing resistance to the current generation of artemisinin-based drugs. Currently, artemisinin-based combination therapies represent the first-line treatment in nearly all countries where malaria has become endemic. But, emerging resistance to these therapies has recently been confirmed in western Cambodia and western Thailand.

Read more about this research from the 6 April issue of Science here.

[Photo provided by Tim Anderson; click the image for caption information.]

Female Geladas Miscarry When New Male Moves in

Wild female gelada monkeys terminate their pregnancies when a new male takes charge of the group, researchers report. Geladas live in groups consisting of multiple females and one male, and when a new male ousts an old one, he often kills any offspring sired by his predecessor. Terminating their pregnancies spares females from having to invest energy in giving birth to and nursing a “doomed” infant.

Read more about this research from the 24 February issue of Science here.

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Cell Biology Word of the Week: Membrane Potential

What it means: The electrical charge (voltage) across the plasma membrane of a cell.

Why you should care: When at rest, the inside of one of your body’s cells has a negative voltage with respect to the outside of the cell. (In most mammalian cells, the inside is charged at about -50mV.) When perturbed by a mechanical action like stretching or a chemical agent such as a neurotransmitter, the membrane potential of a cell may transiently change, triggering something called hyperpolarization, which lets negatively charged ions in and positively charged ions out, or the reverse process, called depolarization. So, changes in membrane potential can change cell behavior, causing muscle cells to contract or endocrine cells to release hormones. They can also generate electrical impulses that travel as signals through the nervous system.

Read about some recent research in Science involving membrane potentials here and here.

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Cell Biology Word of the Week: Centromere

What it means: A centromere is the region of a chromosome that appears constricted between two identical copies of DNA. It’s generally—but not always—found directly at the center of a chromosome.

Why you should care: Chromosomes are duplicated when a cell prepares to divide. Its two identical copies of DNA, or its “sister” chromatids, are joined together at the centromere, giving the chromosome its familiar X-shape. Centromeres attach their paired “sisters” to a spindle structure that then guides each one into a different “daughter” cell. When centromeres don’t function correctly, daughter cells can receive the wrong number of chromosomes, which leads to conditions such as Down syndrome.

Read about centromeres in Science here.

Parasites Need DOC2 Protein to Penetrate Host Cells

Scientists have pinpointed a protein that “apicomplexan” parasites, such as those responsible for malaria and toxoplasmosis, need to invade and subsequently release their progeny from host cells. Andrew Farrell, of Boston College, and colleagues now describe a mutant form of Toxoplasma gondii with an impaired ability to enter and exit host cells.

Read more about this research from the 13 January issue of Science here.

[Click the image for caption information.]

Cell Biology Word of the Week: Plasmodesmata

What it means: These are passageways that interconnect adjacent plant cells to each other, raising the question of whether individual cells or multi-nucleated cells actually comprise plant tissue!

Why you should care: Plasmodesmata are conduits for moving all sorts of things—ions, amino acids, proteins, sugars, RNAs, and even viral genomes—from cell to cell, over short and long distances in a plant. Their conductivity, or the ease at which these things pass through, changes during plant development and in response to different physiological cues. We’re still learning about their molecular composition and the how they determine what can pass through.

Read about some recent research in Science involving plasmodesmata here and here.