Genetics & Molecular Biology

Scientists say they have discovered a unique 'DNA signature' in human sperm, which may act as a key that unlocks an egg's fertility and triggers new life. 

Drs David Miller and David Iles from the University of Leeds, in collaboration with Dr Martin Brinkworth at the University of Bradford, say they have found that sperm writes a DNA signature that can only be recognized by an egg from the same species. This enables fertilization and may even explain how a species develops its own unique genetic identity. 

Without the right 'key', successful fertilization either cannot occur, or if it does, development will not proceed normally. Notably, disturbances in human sperm DNA packaging are known to cause male infertility and pregnancy failures. 
Scientists in New York and North Carolina say they have assembled the first functioning prototype of an artificial Golgi organelle, a key structure inside cells which helps process and package hormones, enzymes, and other substances that allow the body to function normally.

They say their 'lab-on-a-chip' device could lead to a faster and safer method for producing heparin, the widely used anticoagulant or blood thinner, the researchers note. The study is published in the Journal of the American Chemical Society

The Golgi organelle is named for Camillo Golgi, the Italian scientist and Nobel Prize winner who discovered the structure in 1898.
Genetic disease such as leukemia are a big target in 21st century science thanks to advancements in our understanding of how the body works.  

Some of our treatments, like chemotherapy, are rather brute force in their solution.   Now scientists from the Université de Montréal and McGill University say they have re-engineered a human enzyme, a protein that accelerates chemical reactions within the human body, to become highly resistant to harmful agents like chemotherapy.
Millions of children, as many as 2% of all births in the U.S. and Europe, have been born to couples with fertility problems through assisted reproductive techniques such as in vitro fertilization (IVF). Because it is a newer field, relatively little research has been conducted to evaluate the long term effects of assisted reproductive techniques. 

Research presented at the Annual Meeting of the Society for the Study of Ingestive Behavior (SSIB) says that assisted reproductive techniques alter the expression of genes that are important for metabolism and the transport of nutrients in the placenta of mice. 
Pop Quiz: What is the role of the mitochondria in a cell?

Until just a few days ago, the only correct answer to this question would have been #3. The mitochondria of a cell are well recognized as the powerhouses of the cell. They are the location where energy-rich nutrients such as carbohydrates and fats are brought in and "burned"in the presence of oxygen to produce the energy (in the form of ATP) to power our cells. It is one of the earliest lessons of any introductory biology course.
As antibiotic resistances continue evolve in a smaller world they become a more difficult problem to eradicate.

Acquisition of mutations is one of the ways by which bacteria become resistant to antibiotics. But this comes with a cost: although crucial for bacteria survival in a medium with antibiotics, in its absence bacteria growth rate is reduced. Although it is not possible to impaired bacteria to evolve and adapt to the environment, it is possible to choose the type of selective pressure (antibiotics) to administrate and, in this way, alter the course of evolution to our favor.

A new study shows the importance of knowing the costs of multi-resistance to find the best antibiotic combinations - the ones that carry more costs to the bacteria. 
Talk to any molecular biologist, and you'll find that most of them feel that there is something that we're missing when we analyze complex biological systems. These systems are often too difficult to reason about verbally in any sort of detailed or rigorous way. So we build mathematical models, sometimes going to great effort to perform very precise measurements so that we can properly parameterize our models.
There's a coevolutionary struggle between a New Zealand snail and its worm parasite but it ends up being sexually advantageous for the snail, whose females favor asexual reproduction in the absence of parasites, according to scientists who say their report represents direct experimental evidence for the "Red Queen Hypothesis" of sex, suggesting sexual reproduction allows host species to avoid infection by their coevolving parasites by producing genetically variable offspring.

They say their Current Biology report also supports the "Geographic Mosaic Theory," meaning natural selection need not act uniformly on all members of a species, but can be intense in pockets of a population (hot spots) and absent elsewhere (cold spots).
One of my recently developed rules: avoid the last minute rush. I don't run to catch the Metro train, and I don't scramble to put my data into some sort of coherent form when I have to give a lab meeting presentation on short notice.

So I'm not scrambling for my lab meeting talk tomorrow. My plan is, in the absence of any solid results to present, to go visionary, saying whatever I want to, without having to back it up with supporting data. And in the spirit of scientific openness, I'm providing a sneak preview of what may tomorrow turn out to be a terrific mess of a lab meeting talk.
I assume all of you know this but, if not, here is the blurb I keep getting from the kind marketing folks at Science.

The upside: $25,000

The catch: The topic is limited to molecular biology.   

The criteria: This is for 'early career life scientists' so you may be excited, since the average age is now 42 years old before getting an R01 grant but, no, they mean only those who were awarded their Ph.D. in 2008.  So the only ones eligible are what you researchers call 'slave labor'.