- From Figure 4 of Christodoulou et al., 2006 [J Cell Sci 119, 2035-47]. Nuclei from mitotic stages, from left: prometaphase, metaphase, anaphase. Overlay colors from indirect immunofluorescence: alpha-tubulin (red), KIFC5A (green), DNA (blue).
In the interests of promoting science posts relating (however broadly) to my interests of cell and molecular biology, here’s my weekly installment of “Cells Weekly,” a showcase of topical blog posts by others from the past week. Enjoy!
mRNA in dendrites: this message will self-destruct in 10 seconds – Alex explains an intriguing discovery: that mRNA in post-synaptic aggregates, or granules, contain a literal self-destruct sequence that directs the nonsense-mediated decay machinery. At The Daily Transcript.
Evolutionary parameters – migration matters! – Razib notes that on a paper discussing how bacteria evolve into superbugs, which found that “the rate at which bacteria are entering a particular environment – not just the fact that they are coming in – is a key factor.” Migration really does effect change at all levels! At Gene Expression (Sb).
Immune evasion: What is it good for? – Ian chats about viral immune evasion molecules, and some disconcerting findings about the interactions between cytotoxic T lymphocytes and murine cytomegaloviruses. At Mystery Rays from Outer Space.
Carnival: I and the Bird #54
And five ScienceDaily picks below the fold:
Scientists Find Stem Cell Switch In Plants
Scientists have discovered how plant stem cells in roots detect soil structure and whether it is favourable for growth. Poor soil structure is a problem in tropical agriculture, where soil becomes compact as it dries out. Scientists have now determined that the plant hormone ethylene regulates cell division in root stem cells.
As any child knows, to answer the question “how many,” one must start by adding up individual objects in a group. This cognitive ability is shared by animals as diverse as humans and birds. Surprisingly, the exact brain mechanisms responsible for this process remained unknown until now.
Human development has long been seen as a one-way street. During gestation, stem cells were thought to develop into a succession of ever more specialized cells. As Dr. R. Ariel Gomez has discovered, the final identity of these cells is not as definite as once thought. “The identity of many cell types is in a constant state of flux,” Gomez says.
Microbiologists have coaxed less than one percent of the bacterial species that inhabit natural environments into growing in culture. But a new microfluidics device — an intricate system of miniscule valves and chambers — may help scientists who want to identify and characterize new microbes circumvent the need to culture them at all.
As people age past 50, their brains begin to decrease in mass. But even as neurons shrink, other brain cells appear to become more active. Microglia — the small immune cells that sense injury and the presence of pathogens in the nervous system — have shown increased activity, producing higher amounts of signaling molecules called cytokines and leading researchers to suggest that these cells may become dysfunctional as our brains get older. Because higher levels of cytokines have been associated with neurodegenerative diseases, scientists are paying close attention to the role of microglia in these disorders.