My 11th hour post for March, Woman’s History Month. Barbara McClintock, an American scientist and cytogeneticist won the 1983 Nobel Prize in Physiology and Medicine for her discovery of transposable elements or jumping genes. Through her work with maize, she found that genes can actually move with the potential to activate and inactivate surrounding genes. Her work is pivotal to our understanding of genes and heredity. She is also an inspiration to women in the sciences (and beyond).
Why are some people right-handed and why are some people left-handed? For years it was believed that “handedness” (i.e. if you are left-handed or right-handed) was determined in the fetal brain. Researchers from Ruhr University Bochum in Germany recently suggested that asymmetrical gene expression in the spinal chord might help determine handedness. The researchers looked at gene expression in the spinal chord of fetuses between the eighth and twelfth week of pregnancy. Differences in gene expression on the left and right side could already be detected and those areas of activity correlated with arm and leg movement. The researchers also suggested that differences in left and right gene expression could be due to environmental factors.
The study of changes in genetic expression that occur without changes to genetic sequences is called Epigenetics. Environmental factors can act as a trigger for expression of certain genes both in our fetal development and throughout our lives. It will be interesting to find out more about how environmental factors determine handedness and perhaps we may also find out why left-handed people are superior 🙂
About the Illustration: Watercolor with some Photoshop magic. I kept the illustration pretty basic because handedness is a very basic part of our identity. The title is a play on the first line of the “Foot Book” by Dr. Seuss. It was his birthday a few weeks ago and I have read that book enough times this past year that it’s content might rattle around in my brain for all eternity.
Reports of two-headed sharks have increased through the years. Is it due to overfishing which reduces the size of the gene pool and allows for more of these genetic mutations to occur (think inbreeding)? Or is it just easier to report these observations (through scientific papers and social media)? It is a difficult topic to research since most of these sharks never survive. But it is a critical question that needs to be answered. Is it overfishing? Increased reporting? Pollution? Or something else entirely. Global shark populations are not doing well as it is, genetic mutations could be an additional silent threat.
A recent paper published in the journal Nature claims that the ceiling for earthly existence for human beings is 115. Dr. Jan Vijg from the Albert Einstein College of Medicine and his colleagues examined global demographic data and determined that we are reaching our life span limit. Human life spans have increased through time with medical and technological innovations but, according to Dr. Vijg and his colleagues, that has stagnated since the 1990s. Have we reached the limit? Would you really like to live to see your 150th birthday?
Ladies and gentlemen, I give you man-made human sperm (made in a laboratory and not by the birds and the bees).
French researchers recently published the results of their work to create human sperm in the journal Biology of Reproduction. The researchers even patented the process. They are not the only players in this field, Chinese researchers made mouse sperm as a stepping stone to eventually create human sperm. If (and when) any of these methods actually lead to a viable human fetus is still unknown.
Meet Migaloo, an albino humpback whale (Megaptera novaeangliae) that was first spotted off the coast of eastern Australia in the 1990’s. Migaloo is a member of the eastern Australian humpback whale population that migrates from Antarctica to eastern Australia to breed in the spring. Genetic testing determined that Migaloo is a male and definitely an albino although he has brown eyes and not the distinctive pink eyes of albinism. While albinism is rare in marine mammals there are others like Migaloo such as the albino grey whale recently spotted off the coast of Mexico. Her name is Gallon of Milk, I’m not joking. Generally albinism is not very helpful for most wildlife as it makes it that much harder to hide from predators. For these giants of the sea the impact of albinism is yet unknown.
About this Illustration: Micron pen on bristle paper. A whole lot of dots…
Soon to be available for purchase as a 9×12 print.
Young sunflowers follow the sun and turn from east to west during the course of the day. During the night they reorient themselves to the east to begin the cycle once again. When sunflowers stop growing they permanently orient themselves to the east and wait for pollinators to visit. This phenomenon is called heliotropism and other plants display this type of “sun worshipping” behavior. The underlying mechanism behind sunflower heliotropism was unknown until researchers from the University of California (Davis) published their results on sunflower heliotropism in the journal Science. According to their findings, young sunflowers regulate growth of their stems based on an internal circadian rhythm through phased gene expression that increase cell growth in stems facing the west during the night. This allows them to bend east at sunrise. During the day, stem growth on the east side increases to allow the young plant to bend westward in the afternoon and sunset. Mature plants remain eastward oriented when growth slows to attract more pollinators. An eastward orientation increases the warmth of the plant which increases pollinator attraction.
About this Illustration: Watercolor and micron pen of a sun in motion over a field of sunflowers. You can now purchase merchandise with this illustration on it via RedBubble.