No panda embryo in sight, but zoo hopeful about pregnancy
Tuesday, March 9, 2010
Mei Xiang, the female giant panda, ambled into the narrow cage and, as trained, rolled onto her back. National Zoo biologist Laurie Thompson sat near her head, feeding her apple slices from a plastic bowl. Veterinarian Jessica Siegal-Willott knelt by the bear's hind legs, running an ultrasound sensor over her shaved abdomen.
As the fuzzy, gray-and-black images flickered on the monitor, Lisa Stevens, the zoo's curator of primates, leaned forward and peered at the screen. The black blob in the middle was the panda's bladder. There, faintly, were the "horns" of the uterus. What was not there, just yet, was any evidence of an embryo.
Which was fine, for now.
Four weeks after the zoo's star giant panda, Tai Shan, was sent to China, leaving a void at the panda house, scientists have embarked on the process of monitoring Mei Xiang, 11, to see if she might bring forth a replacement.
She was artificially inseminated Jan. 9 and 10 with semen from the zoo's male panda, Tian Tian, 12. They are Tai Shan's parents.
Monday morning, as birds chirped and Mei Xiang munched apples and burped, the zoo conducted its second ultrasound on her, mostly to establish a data foundation for later and to make sure all was normal.
An embryo, at this stage probably microscopic, would not be potentially visible for weeks, the scientists said.
But the procedure was an indication that this year's panda pregnancy vigil -- more momentous, perhaps, than in times past -- has begun.
A new cub would be a coup for the zoo, as well as a public sensation. Plus, pandas often bear twins, officials said.
Even the zoo's new director, Dennis Kelly, showed up Monday for a peek at the 7:30 a.m. procedure.
Mei Xiang seemed accustomed to the drill. As soon as the door opened to the examining cage, the 241-pound animal entered and got onto her back. As Thompson kept her busy with the apple slices, Siegal-Willott, wearing blue surgical gloves, pushed the sensor across panda's abdomen.
"One of the important things is to look at changes [in the uterus], over time," Stevens whispered as the ultrasound began. A panda's uterus has two so-called horns, each of which might harbor an embryo.