Featured Research

from universities, journals, and other organizations

Disparate Mole-rats: Underground Soap Opera Brings New Science To Light

Date:
August 11, 2005
Source:
Texas A&M University - Agricultural Communications
Summary:
This is all underground, and naked mole-rats prefer it that way: Momma naked mole-rat is the only one having babies, and she's got several naked mole-rat boyfriends. Were it human, the family would argue it out on a national talk show. As it is, the social behavior of these tiny rodents has scientists intrigued, right down to their naked mole-rat molecules.

Such a curiosity are naked mole-rats, which live entirely underground in Africa, that researchers have established some colonies for study while others are being reared in zoos. Otherwise, people would never see the 3- to 6-inch critters such as this one. (Texas Agricultural Experiment Station photo by Dr. Rodney Honeycutt)

COLLEGE STATION – This is all underground, and naked mole-ratsprefer it that way: Momma naked mole-rat is the only one having babies,and she's got several naked mole-rat boyfriends.

Were it human, the family would argue it out on a national talkshow. As it is, the social behavior of these tiny rodents hasscientists intrigued, right down to their naked mole-rat molecules.

"African mole-rats are very good models for studying socialstructure. I'm interested in the genetic markers associated withstructure," said Colleen Ingram, whose doctoral degree will be bestowedFriday at Texas A&M University based on her findings about thecritters' parentage.

Ingram looked at regions of DNA - specifically the microsatellites,which represent distinct DNA bands, much like a satellite, whichseparate from the main DNA band. These rapidly changing regions of DNAdon'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 ofthose DNA bands, but a child only gets one set from the mother and onefrom the father," Ingram noted. These markers are used in paternitycases 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 areoversimplified and may lead to incorrect conclusions when looking atnatural populations and their social structures," Ingram said. "Therelationship among members of the mole-rat family are well-accepted.Some species (of mole-rat) are strictly solitary while others, such asthe naked mole-rat, are highly social."

DNA markers, like the satellites, are important because they canreveal how traits pass from one mother to her multitude of babiesconceived by various interrelated fathers. That may help understand whyscores of offspring in the family are willing to support the mothernaked mole-rat.

But first, naked mole-rats. They live in Somalia, Ethiopia andKenya. They are 3-6 inches long, have pink furless skin, tiny eyeswhich never see the light of day, and long front teeth for digging.Despite their tiny size, the naked mole-rat family den may stretch for2 miles entirely underground, with various rooms. In one room, a plantroot protrudes to provide a meal; in another is the "potty." When a newhallway is needed, usually for new food supplies, the naked mole-ratsiblings form an earth moving chain to pass dirt out a hole which lateris covered to block out intruders.

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

This behavior is common – even accepted and marveled over – ininsects such as bees, termites and ants. But the naked mole-rat, amammal, is the most advanced species to live in this arrangement, saidDr. Rodney Honeycutt, Texas A&M Univeristy wildlife professor whose1992 article in American Scientist explained naked mole-rat life.

Scientists call it "eusocial" in that the young are cared for by thegroup, individuals in the group give up their ability to reproduce inorder to do other jobs, and there are at least two generations thatoverlap to do the family's work, Honeycutt noted.

Why don't teenaged naked mole-rats revolt and head for their own tunnel? That's where genetics may play a role.

"Biological evolution is generally seen as a competition, a contestamong individuals struggling to survive and reproduce," said Honeycutt,who was Ingram's lead professor and began studying mole-rats in theearly 1980s while at Harvard

"It runs counter to everything we know about evolution," Honeycuttsaid. "In fact, (Charles) Darwin himself said social animals representa real challenge to his theory (of natural selection and individualfitness)."

Honeycutt explained that after several generations of inbreeding,the offspring – say two sisters – may be more closely related to eachother than to the parents. They preserve themselves by helping motherproduce more offspring with their genetic makeup.

Knowing why animals exist with or without social structures could bemore far reaching than the intricate underground tunnels of the nakedmole-rat. What scientists learn about its genetic connection to socialbehavior could ultimately impact how endangered species, for example,are managed for survival, Ingram said. The fewer the animals of onespecies, the smaller its gene pool.

Ingram will continue her work with conservation genetics in her newposition at the American Museum of Natural History in New York.


Story Source:

The above story is based on materials provided by Texas A&M University - Agricultural Communications. Note: Materials may be edited for content and length.


Cite This Page:

Texas A&M University - Agricultural Communications. "Disparate Mole-rats: Underground Soap Opera Brings New Science To Light." ScienceDaily. ScienceDaily, 11 August 2005. <www.sciencedaily.com/releases/2005/08/050811092119.htm>.
Texas A&M University - Agricultural Communications. (2005, August 11). Disparate Mole-rats: Underground Soap Opera Brings New Science To Light. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2005/08/050811092119.htm
Texas A&M University - Agricultural Communications. "Disparate Mole-rats: Underground Soap Opera Brings New Science To Light." ScienceDaily. www.sciencedaily.com/releases/2005/08/050811092119.htm (accessed July 29, 2014).

Share This




More Plants & Animals News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Ebola Virus Threatens West Africa

Deadly Ebola Virus Threatens West Africa

AP (July 28, 2014) West African nations and international health organizations are working to contain the largest Ebola outbreak in history. It's one of the deadliest diseases known to man, but the CDC says it's unlikely to spread in the U.S. (July 28) Video provided by AP
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
Powered by NewsLook.com
Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Newsy (July 28, 2014) The asteroid that killed the dinosaurs struck at the worst time for them. A new study says that if it hit earlier or later, they might've survived. Video provided by Newsy
Powered by NewsLook.com
Raw: Sea Turtle Hatchlings Emerge from Nest

Raw: Sea Turtle Hatchlings Emerge from Nest

AP (July 27, 2014) A live-streaming webcam catches loggerhead sea turtle hatchlings emerging from a nest in the Florida Keys. (July 27) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins