Note to our Biomedical Beat readers: Echoing the sentiments NIH Director Francis Collins made on his blog, NIGMS is making every effort during the COVID-19 pandemic to keep supporting the best and most powerful science. In that spirit, we’ll continue to bring you stories across a wide range of NIGMS topics. We hope these posts offer a respite from the coronavirus news when needed.
Mitosis is fundamental among all organisms for reproduction, growth, and cell replacement. When a cell divides, it’s vital that the two new daughter cells maintain the same genes as the parent.
In one step of mitosis, chromosomes are segregated into two groups, which will go into the two new daughter cells. But if the chromosomes don’t divide properly, one daughter cell may have too many and the other too few. Having the wrong number of chromosomes, a condition called aneuploidy, can trigger cells to grow out of control.
An illustration of chromosomes being segregated equally and unequally during mitosis. Credit: Deluca Lab, Colorado State University.
How chromosome segregation errors disrupt cell division is an important area of research. Although it’s been studied for decades, new aspects are still being uncovered and much remains unknown. NIGMS-funded scientists are studying different aspects of mitosis and chromosome segregation. Understanding the details can provide vital insight into an essential biological process and may also be the key to developing better drugs for cancer and other diseases.
Over the past 12 months, we’ve explored a variety of topics in genetics, cell biology, chemistry, and careers in the biomedical sciences. As we ring in the new year, we bring you our top three posts of 2019. If your favorite is missing, let us know what it is in the comments section below!
Hawaiian bobtail squid. Credit: Dr. Satoshi Shibata.
Studying research organisms, such as those featured in this post, teaches us about ourselves. These amazing creatures, which have some traits similar to our own, may hold the key to preventing and treating an array of complex diseases.
Dr. Melissa Wilson.
Credit: Chia-Chi Charlie Chang.
The X and Y chromosomes, also known as sex chromosomes, differ greatly from each other. But in two regions, they are practically identical, said Melissa Wilson , assistant professor of genomics, evolution, and bioinformatics at Arizona State University.
Women have two X chromosomes (XX) and men have one X and one Y (XY), right? Not always, as you’ll learn from the quiz below. Men can be XX and women can be XY. And many other combinations of X and Y are possible.
The first known descriptions of cancer come from ancient Egypt more than 3,500 years ago. Early physicians attributed the disease to several factors, including an imbalance in the body’s humoral fluids, trauma, and parasites. Only in the past 50 years or so have we figured out that mutations in critical genes are often the trigger. The sea lamprey, a slimy, snake-like blood sucker, is proving to be an ideal tool for understanding these mutations.
The sea lamprey, often called the jawless fish, is an ancient vertebrate whose ancestor diverged from the other vertebrate lineages (fish, reptiles, birds and mammals) more than 500 million years ago. Jeramiah Smith, associate professor of biology at the University of Kentucky, has discovered that lamprey have two separate genomes: a complete genome specific to their reproductive cells, consisting of 99 chromosomes (humans have 23 pairs) and another genome in which about 20 percent of genes have been deleted after development. Using the lamprey model, Smith and his colleagues have learned that many of these deleted genes—such as those that initiate growth pathways—are similar to human oncogenes (i.e., cancer-causing genes).