In honor of Mother’s Day, today we’re featuring two recent science publications on mothering. Enjoy!

Last month a study in the Journal of Experimental Biology found that bees age faster when parenting. Those of us with our own brood at home might respond, “Well, duh!” My (well-covered) gray hair could tell you that.

But now we have proof. Norwegian scientist Daniel Münch wondered why winter bees were much longer lived than summer bees. In the summer, worker bees are mostly busy tending to the queen’s young and only live about two months total. In the winter, there are no young to tend to, and the bees can live up to seven months.

Münch and his colleagues performed the old switcheroo and transferred the winter bees’ hives indoors and brought the lab to more summery conditions. The queen started reproducing and the worker bees began their parenting. Sure enough, they witnessed a quicker decline.

In another experiment, when the scientists removed the young’uns, the worker bees showed no sign of aging. Get me a babysitter! Long-term!

Another recent study demonstrates that a mother’s arms are the best place for a young baby to be in terms of his or her chances of survival. Publishing in Current Biology, Kumi Kuroda and her colleagues determined that human babies and mouse pups alike automatically relax deeply when they are carried.

Whether held in a human mother’s arms or a mouse mom’s mouth, the research team found the infant calming response to maternal carrying is a coordinated set of nervous, motor and cardiac regulations. The scientists propose that it might be an evolutionarily conserved and essential component of mother-infant interaction.

Both mouse and human babies also stop moving when they are carried. And when baby mice are carried, their ultrasonic cries stop, too.

“This infant response reduces maternal burden of carrying and is beneficial for both the mother and the infant,” explains Kuroda, noting how stressful a crying baby can be on a parent.

Unfortunately, the study has no solution for when that calm and relaxed child starts crying again as soon as she is put back down. Further studies, please!

And to all of you moms out there, Happy Mother’s Day!

Image: Firmin Baes/Public Domain

At over three feet, you’d think the solo coral grouper would be threatening enough. Threatening sure, but a successful lone hunter? Well, not so much, according to National Geographic News Watch:

When hunting alone, groupers only catch their prey about 1 out of every 20 attempts.

So the grouper teams up with the even fiercer moray eel, or the very large Napolean wrasse, to go hunting. The fish are looking for smaller coral reef fishes that hide from their predators under rocks and coral. When the grouper detects the hiding prey, it signals its hunting friend and together they both flush the prey out of hiding.

The cooperation, however, ends there. Whoever gets the prey, eats it whole. There’s no sharing of the spoils. Still, for the grouper, it’s worth the shared hunting, says National Geographic News Watch:

When they have help, the ratio is significantly better—about one out of seven.

What’s most significant about this shared hunting are the signals the grouper makes to its partner during the hunt, say scientists. Researchers studying the fish observed dozens of events where groupers performed upside-down headstands with concurrent head shakes to indicate the presence and location of particular prey to cooperative partners. Their study, published last week in Nature Communications, call the groupers’ signals “referential gestures”. From the abstract:

In humans, referential gestures intentionally draw the attention of a partner to an object of mutual interest, and are considered a key element in language development. Outside humans, referential gestures have only been attributed to great apes and, most recently, ravens.

It’s likely that these gestures have been understudied in non-primate species, say Academy researchers, who point to hunting dogs and even bee dances as potential consideration for referential gestures.

The researchers of the study say that the mental processes underlying these gestures in fish, apes and ravens are unclear and may well vary among these taxa. Their findings point to the fish having developed cognitive skills according to their particular ecological needs.

Whatever the cause, these hunting tactics are pretty extraordinary. Videos of the behaviors can be found here. For more information on the study, visit the University of Cambridge website.

Image: jon hanson/Wikipedia

“They started to fall on their face, to die like crazy. We’ve been doing this 30 years, and we’ve never experienced this kind of loss before.” That’s a Montana beekeeper in last week’s New York Times describing the death of his honeybees.

Bees continue to die from Colony Collapse Disorder (CCD) while scientists race to discover the cause—and to determine the effects of the drastic loss in the population of these important pollinators.

The last couple weeks have witnessed incredible acceleration in the race to save bees. It started on March 21st, when beekeepers and environmentalists sued the EPA over neonicotinoid, urging the agency to ban the pesticide linked to CCD.

Then, last Wednesday, a study in Nature Communications demonstrated the effects of pesticides on bee brains. The researchers looked at neonicotinoid and another type of pesticide, coumaphos, and found within 20 minutes of exposure, neurons in the major learning center of the brain stopped firing. A parallel study earlier this year in the Journal of Experimental Biology found that bees exposed to the combined pesticides were slower to learn—or completely forgot—important associations between floral scent and food rewards. These findings provide a possible underlying cellular mechanism for the observed disruption and altered foraging behavior seen in bees during CCD.

Finally, two studies published in Science last Friday, describe the loss of diversity of bees and the effect that loss and the decline of all bee species is having on crops that humans depend on. The news is not good. According to a related article in the journal, the studies find “that native wild pollinators are declining… [and] that managed honeybees cannot compensate for this loss.”

For those of us who enjoy the fruits of the bees’ labors—from almonds and apples to onions and watermelons—we should hope that the lawsuit, the research, and the attention will lead to a rapid solution to bee decline.

One way gene expression is altered through epigenetics is called DNA methylation. These are chemical tags that can regulate how genes function. Ed Yong puts it this way in his Discover blog:

These marks, known as methyl groups, are like Post-It notes that dictate how a piece of text should be read, without altering the actual words.

Epigeneticist Andy Feinberg, of John Hopkins, wanted to understand how DNA methylation might be identified in changes in behavior so he teamed up with Gro Amdam, of Arizona State University, a bee behavior expert.

Honeybees make excellent study subjects for this purpose because they are social creatures with very compartmentalized behavior. Female bees are either queens or worker bees, and once the path is chosen, there’s no turning back.

Within the worker bees, however, there are behavior distinctions that are a bit more transient. Workers begin as nurses—tending to the larvae. After two to three weeks, they become foragers, leaving the hive to gather pollen.

The researchers decided to study the chemical tags, DNA methylation, of the two groups—nurses and foragers. “Genes themselves weren’t going to tell us what is responsible for the two types of behavior,” Feinberg says. “But epigenetics—and how it controls genes—could.”

Analyzing the patterns of DNA methylation in the brains of 21 nurses and 21 foragers, the team found 155 regions of DNA that had different tag patterns in the two types of bees. The genes associated with the methylation differences were mostly regulatory genes known to affect the status of other genes.

Then the scientists got tricky. They removed some of the nurses from the hive. When this happens in nature, some of the foragers are able to revert to nursing to fill the gap. Sure enough, the same thing happened in Feinberg’s and Amdam’s experiment—several of the foragers went back to being nurses.

This time, 107 DNA regions showed different tags between the foragers and the reverted nurses, suggesting that the epigenetic marks were not permanent but reversible and connected to the bees’ behavior and the facts of life in the hive.

“It’s like one of those pictures that portray two different images depending on your angle of view,” Amdam says. “The bee genome contains images of both nurses and foragers. The tags on the DNA give the brain its coordinates so that it knows what kind of behavior to project.”

The researchers say they hope their results may begin to shed light on complex behavioral issues in humans, such as learning, memory, stress response and mood disorders, which all involve interactions between genetic and epigenetic components similar to those in the study.

The study is published this week in Nature Neuroscience.

Image: Louise Docker/Wikipedia