“If someone called and said the cows were out, and it’s 2 A.M., you drop everything and go.” Welcome to the topsy-turvey world of cattle breeding, a world with challenges quite unlike those of the everyday world most of us experience. Those nighttime words were from this city boy’s interview of Rebecca Mason, a member of our congregation who came to Turlock in February 2019, to begin working for Trans Ova Genetics. While I do know that milk comes from cows, beef from cattle, and that artificial insemination is an important part of the dairy industry, there were lots of surprises for me when I talked to Rebecca on the phone recently. I had met Rebecca at our evening “Painting the Stars” class, where about ten of us had weekly discussions about faith and science, two topics that often seem these days to reside in separate sections of our planet. Rebecca was a fairly recent graduate from Cal Poly San Luis Obispo, and I was encouraged that a young person with an interest in scientific matters was attending our church.
“I’m an embryologist,” she told me. I was quite baffled by the term. I knew that an embryo was something that could grow to become a fetus, and eventually a human being, so I wondered briefly if this cheerful young woman might be working on improving our species, perhaps involved in a sort of biological Frankenstein Project, funded by the government. With further questioning, I learned that Rebecca works with Petri dishes, on cow embryos, that would eventually be placed into cows. Embryology is not exactly the same thing as artificial insemination. In artificial insemination, bull semen is placed into the cow, to join with an ovum, so the cow is the actual mother of the calf. Since I was pretty confused, Rebecca encouraged me to go to the Trans Ova Genetics website. Their explanation was not entirely clear at first to me:
“In Vitrio Fertilization (IVF) is the process of creating embryos from oocytes (unfertilized egg cells) by fertilizing them with semen in a Petri dish. Oocytes are first collected from ovaries of donors by ultrasound-guided follicular aspiration. They are then matured in a Petri dish and fertilized 20-24 hours later. Conventional, sexed frozen, or reverse-sorted semen may be used for fertilization. Oocytes then develop in an incubator for 7 days, at which point the resulting viable embryos are transferred into recipients.”
After reading more on the website, and consulting the Encyclopedia Britannica, I think I have a primitive understanding of what happens in Rebecca’s line of work. Basically, sperm cells that are gathered (and usually frozen) must be sorted by various methods, so that the embryos that will be made in the Petri dish will be either male or female, depending upon what the customer wants. An oocyte is the name for a late stage in the development of the egg that must be removed from a follicle (which is a set of cells surrounding the egg in the uterus of the cow). Either a veterinarian or a dairy technician gathers the oocytes. After the sperm has fertilized the egg, Rebecca is responsible for monitoring the development of the embryo. The embryo grows in a maturation media for 6-7 days, until the embryo is placed into a cow. So, the cow is called a “recipient,” because it is not the genetic mother. The genetic mother Is called the donor.
Sometimes, the embryos might be clones, which means that the calf will be almost exactly like the father or mother. The website calls this “genetic preservation”: “A genetic preservation serves as an insurance policy for breeders and owners of valuable cattle by enabling them to extend and develop a specific bloodline when additional production is needed, or untimely losses or reproductive inabilities occur.” [Rebecca’s side note: the genetic preservation is just the 1st step before the clone is actually made; they just grow a cell bank to make the clone from later.]
If you want to know more, check the website, where you can see two amazing photos: the genetic donor next to her clone, some years later, both photos taken at about the same age.
But, I’d rather go on to tell what I learned about Rebecca.
