Conversations from the Hall of Fame

Lawrence A. Johnson, research scientist, interviewed 2004

(Time: ~10:42 minutes)

I was born in Luck, Wisconsin which is northwestern Wisconsin about 250 miles northwest of Madison. I grew up on a dairy farm. My dad farmed milk cows and that's really where I became interested in agricultural things of course and working on the farm and participating with him and he was interested always in improving the genetics of his herd so that they produce more milk and what have you.

So I took agricultural education in high school and various projects there, belonged to the Future Farmers of America and won their State Farmer Award in 1954 from projects that I had done and then went off to the service and came back in 1957 and entered college at the University Wisconsin River Falls just about sixty miles south of Luck and majored in agriculture education and chemistry and that was my interests there and I had a professor there that thought you know when I wanted to decide what to do my life after you graduate with a bachelor's of science degree and he suggested that I go to graduate school.

So I went to University of Minnesota which is only thirty miles west of Gun River Falls at University of Minnesota, St. Paul campus at Ag school there and got involved with semen physiology. The professor there was Ed Graham and he was looking for a graduate student and he was well known in the area of preserving semen for livestock.

So it was out of that background then that I came to Beltsville and ARS in 1964 and began working in the area of animal physiology particularly in semen preservation with respect to swine. 

In the first years when I came to Beltsville, I began working in the area of swine reproduction and particularly semen preservation because that's where my graduate work had been and began working with Roger Gerrits in that area and some years into that work in 1975 a colleague of mine, Vernon Pursel, and myself were able to successfully freeze swine sperm so that it could be used for artificial insemination on a wider scope and that procedure is still commercially used to date. So that it was the area that really kind of kindled my interest in the importance of artificial insemination.

Gender Preselection 

About 1981, I started a new project which was gender preselection in other words the idea of improving genetics by having more females or more males depending on which each marketing influence would be in the industry that your in and so it became a high priority project for ARS because farmers wanted to be able to control the sex of their offspring. A dairy farmer, he wants mostly milk cows so he would want heifer calves.

And then in 1989, we had a significant breakthrough where we were able to prove that by separating sperm based on their DNA content and then using those sperm that we have collected from a flow cytometer cell sorter system that I'd set up in the laboratory and use those for insemination of rabbits and pigs at that time and found that the sex ratio of a litter of rabbits or litter of pigs was about nine to one in favor of the female and so that was basically what led up to the breakthrough in 1989 that started gender preselection by flow cytometry which is continuing today in a commercial sense.

Many other people had worked in this area and always had come up with a data ratio of 50/50 so when those rabbits were born and we were able to sex them, look at to determine which was females and which was males that, it was an exciting. The whole lab was very excited.

Since biblical times people had been seeking to guide or preselect the sex of off spring whether it be in humans or in animals. 

Today and Tomorrow

The cattle portion of the research is pretty well in hand. It's being commercially used through ARS licensing to a company in Colorado which has sub-licensed it to a company in England called Cogent and then they have ten of these flows cytometers cell sorters operating on a daily basis, twenty four hours a day to produce enough semen which they freeze then and sell to the English cattle producers.

It's on the verge of being put on the commercial market here in the United States as well. So from that standpoint that's where the progress is yet to come. It's in the commercial arena cattle but for example in the pig where many more sperm are required for insemination it's not directly applicable at this time.

We're looking at ways to use sorted sperm from the pig with special insemination technology and it is being applied in the horse and it's working quite well there. It's also being applied in zoo animals and in that sort of thing and there is uses for it in these specialized areas along with whether its use in the livestock industry and then it also, we proved in the early 90s that it would also work in the human. 

And that's also been a very satisfying situation because couples who desire to have children but carry,  through no fault of their own but because of their genetic makeup, carry a sex-linked disease a lot of times it's quite difficult and so they either don't have children or they have children that end up with the disease.  And so what this process does in human medicine is that a couple who might carry a sex-linked disease usually the female, the mother carries the disease but it's expressed in the male for a lot of diseases,  hemophilia for example, is only exhibited in the male. So by using this process you see a couple could select for a female which it's about 90 percent accurate and they would avoid the possibility then of having a male child which would have the particular disease of which hemophilia is an example.

Thanks, ARS ...

ARS has been a terrific employer as far as I am concerned. I mean I have absolutely no regrets. The resources are here and the freedom is here to do the research as long as you target your research to help the agency meet the needs of the farmer or the consumer. ARS is helping agency in my opinion. They serve the farm community and the consumer community in various ways and it's very rewarding to work with that kind of outlook and it's hard work, research is hard work but when you work for ARS you're rewarded.

I've been very fortunate in my work to see the fruits of my labors in the laboratory be applied in the commercial sector. That doesn't always happen but nevertheless all of this, all of the research that goes on before that or is involved in someone's project is kind of a building block to meet a particular need, you know, in the community.

Mentoring

Mentoring is really important relative to research and I've benefitted by having good strong people mentoring me over the course of my career--people that either hired me or I've worked for through the course of my career. That something that's very important and ARS is good at I believe.