Friday, August 12, 2005

Friday Naked Mole Rat Blogging

Naked mole rats have a pretty distinctive social structure - which in some ways is similar to that found in social insects.

From Science Daily:

They live in Somalia, Ethiopia and Kenya. They are 3-6 inches long, have pink furless skin, tiny eyes which never see the light of day, and long front teeth for digging. Despite their tiny size, the naked mole-rat family den may stretch for 2 miles entirely underground, with various rooms. In one room, a plant root protrudes to provide a meal; in another is the "potty." When a new hallway is needed, usually for new food supplies, the naked mole-rat siblings form an earth moving chain to pass dirt out a hole which later is covered to block out intruders.

The most unusual room is the largest. It's where Momma naked mole-rat produces more babies – as many as 12 at a time every couple of months. Here she is stoked by her numerous mates and tended to by any number of offspring whose lot in life - if not to dig tunnels - is to keep Momma happy.

Apparently, this is a really good case of altuistic social behavior in mammals, where some mole rats give up reproduction and help related mole rats care for the young. Researchers are currently investigating the relationship between DNA and social structure:

Ingram looked at regions of DNA - specifically the microsatellites, which represent distinct DNA bands, much like a satellite, which separate from the main DNA band. These rapidly changing regions of DNA don't code for any particular trait, as far as scientists can tell. Ingram thought these regions shouldn't be overlooked.

"If there is a random-mating population, there are a lot of sizes of those DNA bands, but a child only gets one set from the mother and one from the father," Ingram noted. These markers are used in paternity cases for humans, she said.

She looked for changes in the processes and patterns of this strand in mole-rats, she said.

"The current methods of analyses of microsatellite markers are oversimplified and may lead to incorrect conclusions when looking at natural populations and their social structures," Ingram said. "The relationship among members of the mole-rat family are well-accepted. Some species (of mole-rat) are strictly solitary while others, such as the naked mole-rat, are highly social."

DNA markers, like the satellites, are important because they can reveal how traits pass from one mother to her multitude of babies conceived by various interrelated fathers. That may help understand why scores of offspring in the family are willing to support the mother naked mole-rat.