Tailing blunt-ended DNA fragments with TaqDNA Polymerase allows efficient cloning of these fragments into T-Vectors such as the pGEM®-T Vectors. This method also eliminates some of the requirements of conventional blunt-end cloning — Fewer steps, who can argue with that?
Continue reading “Cloning Modified Blunt-ended DNA Fragments into T-Vectors”
One hundred years ago, the world was taking its first deep breaths as it celebrated the end of World War I. The Armistice of Compiègne, was signed on November 11,1918, officially ending the four-year long conflict, which claimed the lives of more than 8 million soldiers (1). What the world didn’t yet realize was that they had been battling a far deadlier enemy in the hospitals and at home than any army the soldiers faced on the fields of war.
During the last year of the war, a deadly influenza virus rampaged around the globe leaving between 50 and 100 million dead in its wake.
Continue reading “Over 50 Million Died in the Pandemic of 1918-A Century Later We are still Searching for a Universal Flu Vaccine”
The boys were coming in with colds and a headache and they were dead within two or three days. Great big handsome fellows, healthy men, just came in and died. There was no rejoicing in Lille the night of the Armistice.
Sister Catherine Macfie from her post at casualty clearing station no. 11 at St André near Lille, France (2).
We inherit our cells’ mitochondria from our mother. These energy-producing organelles are present in large numbers in most cells, meaning that cells can contain thousands of copies of the DNA associated with the mitochondria (mtDNA)—all passed on wholly from our mother. New evidence suggests, however, that this cannon principle of maternal-only inheritance of mtDNA might need to be refined. And it all started with a four-year-old boy.
MicroRNAs (miRNAs) are small, non-coding RNAs that play a role in regulating cancer by acting as both tumor suppressors and oncogenes. Ranging in size from 18–25 nucleotides, miRNAs function in feedback mechanisms to regulate many cellular processes including cell proliferation, apoptosis, cell signaling and tumorigenesis (1).
Not surprisingly, dysregulation of miRNA expression can have serious repercussions. For example, miRNAs are dysregulated in almost all human cancers (1). Because of the potential to influence cancer growth and development, there is growing interest in miRNA profiling to identify possible biomarkers for cancer diagnosis or prognosis, as well as potential therapeutic targets (1).
Growing interest in miRNAs as both biomarkers of disease and therapeutic targets drives the need for fast and effective methods for miRNA profiling. Profiling miRNA targets follows a relatively simple workflow: sample selection, RNA extraction, RNA QC and quantitation, RNA profiling and data analysis (2,3). So what happens at each step?
Whether your first encounter was peering through the thick glass of an aquarium tank or peeking through your fingers in a darkened theater, there is something about sharks that captures our imagination. These fierce, and sometimes fearsome, creatures have existed in our oceans for over 400 million years, and survived multiple mass extinction events, including the one that killed the dinosaurs. They are not, however, the vicious, vengeful villain that some movies would have us believe. Sharks are apex predators, who play an important role in the world’s ocean ecosystem by regulating the population of prey species below them. Unfortunately, they are also part of one of the most threatened group of marine fish in the world. Of the more than 400 species of sharks that exist in our oceans today, approximately 15% are considered vulnerable, endangered or critically endangered. Continue reading “Fished to the Edge: How DNA Identification Can Help Fight the Illegal Trade of Threatened Shark Species”
We can learn a lot about the past and its people from the written records of the time. What people write and how they write it can gives us glimpses into historical events, interpersonal relationships, social standing and even social and cultural norms. From paper to papyrus to clay tablets, the surface that holds the writing can tell us things that the words cannot.
For plant-based writing surfaces, the quality of the surface or even the technique used to make it can give historians and archeologists insight into the people who used them. What more could we learn if we knew what plant, or plants, were used in the production of ancient writing material? Continue reading “Beneath the Writing: Non-Invasive DNA Sampling from Modern and Historic Writing Surfaces”
In April of 2017 a profile appeared on the dating app Tinder. Describing himself as “One of a kind”, the poster was 43 years old, not in great physical shape, and yet so sought after he required around the clock body guards. His name was Sudan, and he was the last living male northern white rhino. His keepers at the Ol Pejeta Conservancy in Kenya weren’t expecting Sudan to find love. They were hoping to raise awareness of the species’ dire situation and money for the research and development of an in vitro fertilization (IVF) method for rhinos.
Northern white rhinos used to range over all or parts of Uganda, Sudan, Chad, the Democratic Republic of the Congo and the Central African Republic. In the 1960s there were an estimated 2,360 northern white rhinos left in the wild (1). Civil unrest in the region made conservation difficult, and by 2003 poaching and other pressures had reduced the number of northern white rhinos living in the wild to four individuals living in the Garamba National Park in the Democratic Republic of the Congo. There has been no sign of that wild population since 2007 (2), and they are considered extinct in the wild as of 2008. Continue reading “From Dating Apps to In Vitro Fertilization, the Challenges to Saving the Endangered Northern White Rhino”
Everyone has their favorite microscopic creature—you all do have a favorite, right? Mine is unquestionably the tardigrade. Tardigrades, also called water bears or moss piglets, are microscopic invertebrates that are composed of five segments: one head segment and four body segments, each with a pair of legs. They are 0.1–1.2mm in length, making them easy to see under low magnification, and have a brain and well-developed nervous system. Tardigrades are found in just about every environment on earth. Termed “extremophiles”, they have adapted to survive in even extremely harsh environments. Your neighborhood pond? The Himalayas? Antarctica? Deep sea? Tardigrades live in all those places.
Although many of us fell in love with these microscopic animals the first time we saw them—because there is no denying that they are darn cute— there are other good reasons why scientists are so fascinated by these creatures. Tardigrades are incredibly resilient. And by resilient, I mean almost indestructible. Continue reading “The Amazing, Indestructible—and Cuddly—Tardigrade”
Say the words “climate change” in a room full of people and you are bound to inspire some passion in the response—and very likely start an argument. There is no question that emotions and opinions run high whenever this topic is introduced. Most often the debate centers around who or what might be causing changes in the earth’s climate and what should be done about it. So for the sake of everyone’s blood pressure, I want to set some expectations around this blog.
This is not a blog about the causes of climate change. I am not going to talk about who or what might be causing it, nor am I going to discuss ways the changes could be stopped, slowed down or altered.
The earth’s climate has warmed and cooled before. Looking at ice-core and geological records, we know that the earth has been much warmer than it is now, and we know that it has been much colder. Climate is dynamic, there are always fluctuations in temperature and moisture from year to year and decade to decade. Some of these fluctuations become trends where the changes consistently track in one direction, and some are anomalies, with more extreme climate conditions and less predictable patterns. Plant and animal populations are unquestionably affected by both the year-to-year fluctuations and the long-term trends. In this blog I am going to talk about two rather dramatic examples of the effects climate change. One example looks at the impact of warming global temperatures over time on the breeding populations of green sea turtles. The other is an example of the devastating results of one warm, remarkably humid, spring on the calving aggregations of the saiga antelope.
Continue reading “Feminization and Mass Die Offs: The Effects of Climate Change”
Every year around the beginning of December, a magical transformation begins in Promega offices in Madison and around the world. In Madison, even as our own Promega cookie elf is busily baking the last of her Holiday treats, employees are donning their own elf hats and bedecking our halls and cubes with their own form of Holiday magic.
Different teams put different spins on their decorating; from an all-out coordinated effort, to individualized decorations that reflect the personality of the decorator . It is fun to see how different areas get into the Holiday spirit. Continue reading “Deck the Halls…and Cubes…and Desks”
