Navigation Links
Marsupial embryo jumps ahead in development
Date:11/29/2010

DURHAM, N.C. Long a staple of nature documentaries, the somewhat bizarre development of a grub-like pink marsupial embryo outside the mother's womb is curious in another way.

Duke University researchers have found that the developmental program executed by the marsupial embryo runs in a different order than the program executed by virtually every other vertebrate animal.

"The limbs are at a different place in the entire timeline," said Anna Keyte, a postdoctoral biology researcher at Duke who did this work as part of her doctoral dissertation. "They begin development before almost any other structure in the body."

Biologists have been pursuing the notion that limb development is triggered by other organ systems coming on line first, but this study shows the marsupial's limbs begin development without such triggers.

"Development is probably more flexible than we might have known otherwise," said biology professor Kathleen Smith. Their study animals were gray short-tailed opossums (Monodelphis domestica) native to Brazil and Bolivia, but the same should hold true for any marsupial, Smith said.

For the undeveloped embryo to be able to drag itself across the mother's belly from the birth canal to the teat, it needs a formidable pair of forelimbs. To get them, its developmental program has been rearranged to start building the forelimbs much sooner.

"A lot of these genes were turned on earlier than you'd see in a mouse or a chick," Keyte said. The researchers were also able to show that the forelimbs received cells from a much larger part of the developing embryo than is normally seen in other vertebrates. What surprised the researchers was that the genetic program to establish the hind limbs also appeared to be turned on early.

Gene expression sets up the pattern of where each of the four limbs will be, but the marsupial's forelimbs grow much faster than the hind limbs because the embryo devotes more of its scarce number of early cells to building those structures, Smith said. The plans are in place for the hind limbs, but not the bricks to build them.

The embryo emerges from the mother with burly forearms that include bones and well developed muscles, while the hind limbs are small and rubbery.

Blind, hairless and with an incomplete brain, a marsupial embryo is shockingly underdeveloped to be living outside the womb. But the system obviously works for marsupials.

"There are probably 50 explanations for why marsupials develop outside the womb, and none of them are very good," Smith said. It's pretty clear however that the external development gives the female a lot more control over her reproduction. If conditions change or she runs out of food, the marsupial mother can easily terminate an external pregnancy.


'/>"/>

Contact: Karl Leif Bates
919-681-8054
Duke University
Source:Eurekalert

Related biology news :

1. Researchers insert identification codes into mouse embryos
2. Snap of fruit fly embryo wins scientific photo competition
3. Earlier, more accurate prediction of embryo survival enabled by Stanford research
4. Auxogyn licenses noninvasive embryo assessment technology from Stanford University
5. Twins provide clue that genetic epilepsy can originate in the embryo
6. Research!America asks Congress to support embryonic stem cell research now
7. Test-tube calf embryos more likely to survive Texas summers
8. Congressman, CSHL president urge quick action to reverse judicial embryonic stem cell research ban
9. What makes a good egg and healthy embryo?
10. Digital embryo gains wings
11. New measurement of telomeres; DNA could help identify most viable embryos for IVF
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/22/2016)... December 22, 2016 SuperCom (NASDAQ: ... solutions for the e-Government, Public Safety, HealthCare, and Finance sectors announced ... has been selected to implement and deploy a community-based supportive services ... Northern California , further expanding its presence in the state. ... This new program, ...
(Date:12/16/2016)... , Dec. 16, 2016   IdentyTechSolutions America ... management products and solutions and a cutting-edge manufacturer ... that it is offering seamless, integrated solutions that ... entrance products. The solutions provide IdentyTech,s customers with ... their facilities from crime and theft. ...
(Date:12/15/2016)... Dec. 15, 2016   WaferGen Bio-systems, Inc. ... technology company, announced today that on December 13, 2016, ... of The Nasdaq Stock Market LLC which acknowledged that, ... of WaferGen,s common stock had been at $1.00 or ... regained compliance with Listing Rule 5550(a)(2) of the Nasdaq ...
Breaking Biology News(10 mins):
(Date:1/18/2017)... Portland, OR (PRWEB) , ... January 18, 2017 ... ... modules that provide essential device-to-computer interconnect using USB or PCI Express, announced the ... Altera Cyclone V E FPGA into a compact business-card sized form factor suitable ...
(Date:1/18/2017)...   Parent Project Muscular Dystrophy (PPMD) , a ... muscular dystrophy (Duchenne) , today announced a $600,000 grant ... Technology (NJIT) and Talem Technologies (Talem) as part of ... to assist people living with Duchenne. PPMD is funding ... embedded computer, software, a force sensor and a motor ...
(Date:1/18/2017)... , ... January 18, 2017 , ... ... federally funded bio-focused Manufacturing Innovation Institutes (MII). U.S. Secretary of Commerce Penny Pritzker ... Biopharmaceuticals (NIIMBL), and the Department of Defense has announced the award of a ...
(Date:1/18/2017)... ... January 18, 2017 , ... ... 2017, to sell research and genetic testing lab equipment from two different leading institutes. ... Northwest and Northeast regions of the United States. This 1-day online auction will ...
Breaking Biology Technology: