Try to think ahead, or else, before you can react, it will be “going, going… gone.” No, that is not the advice of a baseball coach to some little league pitcher, but the message of head of the Genetics Division at the San Diego Zoo’s CRES, Dr. Oliver Ryder. In his presentation he told us that there will never be a magic phone call from the future telling us what animals will go extinct, so we must do all that we can now to save species. For many species there really is no time to lose before they go the way of the dodo.

The Genetics Division tries to help by analyzing and storing the cells and DNA of animals. The Frozen Zoo now has preserved samples of over 7,200 animals from more than 600 species, making it the largest collection of its kind in the world. Genetic information taken from the Frozen Zoo and new animals can be used for many different things such as analyzing health, population assessment, reproduction information, identifying genes involved in adaptations, and paternity tests. They also use it for determining the sex of birds since around fifty percent of birds show no visible differences between males and females.

We actually got to help determine the gender through gel electrophoresis of several California condors with the help of laboratory technician Emily Mork. The process began when DNA was isolated from the condors in question. Since DNA can be extracted from feathers, fur, hair, blood, eggshells, cheek swabs and even fecal matter, determining sex through DNA analysis is much less invasive than the other option of using laparoscopy to look at the reproductive organs. After the DNA is isolated, parts of that DNA are then duplicated using a polymerase chain reaction (PCR) machine. The resulting DNA must be mixed with fluorescent dye and put into small square wells on one end of a sheet of agarose gel. This is the part where we interns got to try our skills at injecting the DNA into the delicate gel. It sounds simple enough but I found it tricky because the DNA must be injected deep enough into the well so that it doesn’t run, but go too deep into the well and you break the gel. Thankfully I filled my well with no problems and didn’t end up being the only person to mess the gel up.

Different DNA is put into neighboring wells, such as the parent’s, and a sample whose sex is known. The gel is then submerged in a box surrounded by liquid. The box is charged and the DNA fragments travel down the gel pulled by the positive electrode at one end, separated by the gel, which acts like a sieve allowing smaller fragments to travel further. This separation creates the banding that we were then able to read and use to determine the sex of the bird.

Besides basic procedures (if you can call it that) such as sexing birds, the staff in the Genetics Division is also sometimes asked to solve some unusual cases. One case still under investigation is the mysterious paw found in the feces of one dhole. It could just be the remnants of some groundhog that ran through the dhole’s enclosure, but it could also be a dhole pup. Determining the identity of this unknown animal by looking at its genes will help keepers know what is going on so that if it was a pup, in the future that event may be avoided.

Genetics is a field in which many degrees are needed to fully understand but is one that holds so many possibilities that it may just drive a molecular biology-challenged person such as myself to seek a place in the lab. To think that twenty years ago cloning was a theory doubted by many, including Dr. Ryder! Now cloning is a reality, as evidenced by the cloned Javan banteng we got to feed at the Zoo just one day before this presentation. One more remarkable thing that I had to keep in mind was that here, unlike in biology class, everything does not just appear labeled and bottled with all the procedures laid out by some teacher. Everything they do is from scratch and the outcome is not for a grade, but for the sake of the future.

Contributed by Mariah - Zoo InternQuest Conservation Team

Posted in Intern Journals, Zoo InternQuest | Link to this post

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