—1 anraster Farming, Saturday, January 6, 1973 12 Turkey Breeding Industry Sees Possible Breakthrough Virgin birth in the turkey has been confirmed at The Penn sylvania State University to stem from eggs whose germ cells are normal The findings, which emerge after 12 years of cooperative research by Dr Edward Buss and Dr MW Olsen (USDA), clear the way for an intensive effort to determine if a virus is the trigger of the phenomenon, known as parthenogemcity. Parthenogenesis, like cancer, is a form of unexpected cell proliferation The term means virgin birth- female germ cells begin to divide and multiply without benefit of male sperm Parthenogenesis is known in insects but the turkey is the highest animal m which it has been observed In that bird it is an extremely fragile mechanism less than half of one percent of all eggs that are self-fertilized result in mature individuals Aborted embryos, spots of blood, or mere fragments of membrane are the issue of rule However, parthenogenesis could throw new light on the role of the virus in abnormal cell growth It also has virtue that could prove a bonanaza to the half-bilhon-dollar turkey breeding industry. Until now, scientists have believed that some error in the process by which chromosomes separate (meiosis) was responsible for parthenogenesis But Buss and Olsen proved that no such errors take place Eggs of parthenogenic mothers, they found, begin as haploids, that is, they contain one set of chromosomes, which is normal In view of this evidence, Buss and Olsen concluded that some outside agency is very likely the trigger of virgin birth in the turkey That agency might be a \ irus In joint but deliberately separated experiments con cluded in 1966 the two men had demonstrated that the fowl pox (a virus! seems to enchance parthenogenicity In a family of birds kept in a supposed virus-free environment at University Park, Buss, by selective mating, observed an 18 per cent increase in par thenogenicity but no embryos At Beltsville, when females were vaccinated with virus the same 18 per cent increase was noted but, along with it, some embryos were produced This was encouraging, but not con clusive evidence that a virus is involved Now, Dr Buss has just em barked on a new experiment in which he will mate birds in the presumed absence of the virus, then remate the same birds after the male has been vaccinated with fowl pox “What we are after,” says Buss, “is evidence as to whether the outside agent causing par thenogenicity is passed on piggyback — from one generation to another This would mean it had not only stimulated virgin birth but had infiltrated the cell nucleus and caused a genetic change Positive results from the experiments—which are ex pected to take five years—would constitute strong evidence for the theory that a virus can trigger abnormal cell proliferation ” It has long been known that parthenogenesis may be triggered by mechanical means (one scientist got reproduction going in a frog by poking into its eggs with a needle), but it is not known if the virus works by mechanical or chemical means, or both If mechanical, the virus is presumed to act somewhat like a | ) > V T t % O \*A| >.» speck of sand in an oyster: a foreign body, the sand stimulates growth that can result in a pearl. So the virus: its presence sometimes irritates the genetic material into activity. The process, if it proves con trollable, could lead to a pearl of spectacular dimensions for the turkey breeding industry. For, if virgin birth can be deliberately induced in turkeys of top pedigree, by viral inoculation, a sort of “super bird” might be achieved, one in which undesirable charac teristics have been eliminated by parthenogenesis because of the fragility associated with it. Milking System can eliminate machine-caused mastitis. i VISIT THE AGWAY BOOTH AT THE FARM SHOW That fragility is due to inequities in one of nature’s most delicate balancing acts; the “juggling” of genetic material (chromosomes) so that the contributions of both a male and female are intermixed. In parthenogenesis, because no male is represented, this balance is impossible. Thus, “bad” genes from the mother have no chance of being tempered by “good” genes donated by a father. The difficulty becomes manifest when cells undergo a genetic change known as diploidy A diploid cell is one that has two sets of chromosomes. In normal germ cells, after Agway s Sta-Rite Full-View 1027 Dillerville Road, Lancaster, Pa. diploidy, the crucial balance is maintained between male and female donations. In parthenogenetic cells, however, when bad genes are doubled the balance is lost: their influence becomes lethal. This is why most parthenogenetic off spring never see the light of day. By the same token, those few who do survive (all males) are likely to be genetically clean: they must have been purged of bad genes or they would not have survived. 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SUPPLY 24 Hour Service Daily Ph. 717-397-4761 '-•-i-V/V-t <9* MS' * 4 r JTJP.V.r *Sr*WM •« •r.JCjr.Vi Dr. Buss’ experiments are funded in part by the Agricultural Experiment Station at The Pennsylvania State University. Graduate Research Assistant Mr. L. J. Gaffney, of Australia, assists in one phase of the project. The Buss-Olsen research into parthenogemcity was originally stimulated by the turkey breeding industry, which an nually suffers millions of dollars of losses due to infertile eggs. These are thought to be the result of parthenogenesis which, as stated in the theory, usually results in abortions of only (ContinuedOn Page 13) CENTER
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