Nav: Home

Scientists tackle breeding challenges of land mine-finding rats

January 24, 2019

ITHACA, N.Y. - Thousands of people - many of them children - are hurt or killed by land mines each year, so finding these devices before they explode is critical.

There is a surprising champion of detection: the African giant pouched rat. Native to sub-Saharan Africa, the pouched rats are large - they can grow up to 3 feet long, including the tail - but are still too small to set off the land mines. They have an exceptional sense of smell - they are also used to detect tuberculosis - but scientists know very little about their biology or social structure, and they're difficult to breed in captivity.

"We wanted to understand their reproductive behaviors and olfactory capabilities, because they have been so important in humanitarian work," said Alex Ophir, assistant professor of psychology in the College of Arts and Sciences.

Cornell University researchers have found that the pouched rats' reproductive system is unlike any other species. They report their findings in a study, "Anogenital Distance Predicts Sexual Odour Preference in African Giant Pouched Rats," published Jan. 17 in Animal Behaviour. Co-authors were Ophir, postdoctoral researcher Angela Freeman and Michael Sheehan, assistant professor of neurobiology and behavior.

For male rats searching for a mate, identifying which adult females are reproductively available, or patent, is critical. Female pouched rats have extremely delayed sexual development. When the researchers looked at whether male pouched rats have a preference for the scent of females who are patent, they found something unexpected.

Males with longer anogenital distances (AGD) could detect the difference between patent and non-patent females and preferred the scent of patent females. AGD, an indirect marker of masculinization, is determined by developmental exposure in utero to sex hormones like testosterone. Males with shorter AGD showed no preference for patent females. Similarly, patent females showed a preference for the scent of masculinized males, while non-patent females did not.

This is the first time it's been shown that longer AGD is associated with more efficient communication and signal processing, according to Freeman, first author of the paper.

Ophir noted that being able to distinguish viable from non-viable partners in a split second has long-term repercussions for reproductive success among the species.

"It is amazing to think that in utero experiences can lock in the ability of these males to detect differences in female reproductive availability," Ophir said. "Our results raise interesting evolutionary questions, like how does natural selection operate on characteristics that are largely determined by chance features of the uterine environment?"

In other rodent species, patency is dictated by the estrous cycle. But that does not seem to be the case with pouched rats.

"This kind of patency change is different from basically every other rodent that's been studied up until this point," said Freeman. "Further studies to understand this process will help explain why breeding pouched rats is so difficult in captivity."
-end-
The study was supported by funding from the Army Research Office and DARPA and the College of Arts and Sciences.

Cornell University has dedicated television and audio studios available for media interviews supporting full HD, ISDN and web-based platforms.

Cornell University

Related Biology Articles:

Experimental Biology press materials available now
Though the Experimental Biology (EB) 2020 meeting was canceled in response to the COVID-19 outbreak, EB research abstracts are being published in the April 2020 issue of The FASEB Journal.
Structural biology: Special delivery
Bulky globular proteins require specialized transport systems for insertion into membranes.
Cell biology: All in a flash!
Scientists of Ludwig-Maximilians-Universitaet (LMU) in Munich have developed a tool to eliminate essential proteins from cells with a flash of light.
A biology boost
Assistance during the first years of a biology major leads to higher retention of first-generation students.
Cell biology: Compartments and complexity
Ludwig-Maximilians-Universitaet (LMU) in Munich biologists have taken a closer look at the subcellular distribution of proteins and metabolic intermediates in a model plant.
Cell biology: The complexity of division by two
Ludwig-Maximilians-Universitaet (LMU) in Munich researchers have identified a novel protein that plays a crucial role in the formation of the mitotic spindle, which is essential for correct segregation of a full set of chromosomes to each daughter cell during cell division.
Cell biology: Dynamics of microtubules
Filamentous polymers called microtubules play vital roles in chromosome segregation and molecular transport.
The biology of color
Scientists are on a threshold of a new era of color science with regard to animals, according to a comprehensive review of the field by a multidisciplinary team of researchers led by professor Tim Caro at UC Davis.
Kinky biology
How and why proteins fold is a problem that has implications for protein design and therapeutics.
A new tool to decipher evolutionary biology
A new bioinformatics tool to compare genome data has been developed by teams from the Max F.
More Biology News and Biology Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Making Amends
What makes a true apology? What does it mean to make amends for past mistakes? This hour, TED speakers explore how repairing the wrongs of the past is the first step toward healing for the future. Guests include historian and preservationist Brent Leggs, law professor Martha Minow, librarian Dawn Wacek, and playwright V (formerly Eve Ensler).
Now Playing: Science for the People

#565 The Great Wide Indoors
We're all spending a bit more time indoors this summer than we probably figured. But did you ever stop to think about why the places we live and work as designed the way they are? And how they could be designed better? We're talking with Emily Anthes about her new book "The Great Indoors: The Surprising Science of how Buildings Shape our Behavior, Health and Happiness".
Now Playing: Radiolab

The Third. A TED Talk.
Jad gives a TED talk about his life as a journalist and how Radiolab has evolved over the years. Here's how TED described it:How do you end a story? Host of Radiolab Jad Abumrad tells how his search for an answer led him home to the mountains of Tennessee, where he met an unexpected teacher: Dolly Parton.Jad Nicholas Abumrad is a Lebanese-American radio host, composer and producer. He is the founder of the syndicated public radio program Radiolab, which is broadcast on over 600 radio stations nationwide and is downloaded more than 120 million times a year as a podcast. He also created More Perfect, a podcast that tells the stories behind the Supreme Court's most famous decisions. And most recently, Dolly Parton's America, a nine-episode podcast exploring the life and times of the iconic country music star. Abumrad has received three Peabody Awards and was named a MacArthur Fellow in 2011.