Genetic transformation in chicken by the use of irradiated male gametes

Abstract

Genetic transformation for egg and feather colour hs been obtained in the whole animal, chicken, by the use of irradiated male gametes. In this technique recipient females are first inseminated with irradiated semen from the donor and 24 h later are reinseminated with unirradiated, normal semen of the recipient strain. The transformed progeny are identical to the female strain but for one or a few genes derived from the irradiated semen. The expression of the transferred gene is irregular and may occur either in the first generation, after insemination with irradiated semen, or may occur in the following backcross generation. It is suggested that integration of a normally recessive, transferred gene at non-homologous sites in the recipient chromosomes might affect not only its regularity of expression but also its dominance relationship with the original maternal gene, "releasing" it from the dominance of the latter. The technique potentially offers a rapid method of improving an already established strain of an animal.

Genetic transformation of chickens using irradiated male gametes

“…The results presented here confirm those of Pandey and Patchell (1982) in suggesting that, whether by -66 pseudofertilisation or by another mechanism, genetic material from lethally irradiated sperm -becomes incorporated into otherwise normally fertilised embryos. The presence of the haplotypes of both normal parents in addition to that from the irradiated sperm precludes the possibility that either a fraction of the irradiated sperm remained -2-3 fertile or that the parental lines were contaminated -2-0 or incorrectly mated.…”

“…Following the protocol of Pandey and Patchell (1982) birds were inseminated twice weekly (Mondays and Thursdays) with irradiated semen. The hens received normal semen on Tuesdays and Fridays.…”

“…Unfortunately their technique of injecting DNA into a pronucleus at fertilisation would be much more difficult to apply in birds because of the far greater size of the ovum and because of its subsequent pattern of development. An alternative means of introducing genetic material has been reported by Pandey and Patchell (1982) who used heavily irradiated sperm, apparently to pseudofertilise the egg, prior to normal fertilisation by unirradiated semen. They In view of the potential significance of this technique we have attempted to confirm the procedures of Pandey and Patchell (1982), using a slightly modified experimental design to avoid the two possible sources of error in an experiment of this nature-that the parent flocks were contaminated and that the supposedly lethally irradiated semen retained some capacity for fertilisation.…”

Breeding for disease resistance ‐ the prospective role of genetic manipulation

“…It was argued that irradiated spermatozoa might similarly provide novel genetic material for incorporation into the zygote when fertilisation by a normal sperm took place. With the use of feather and egg colour as markers Pandey and Patchell (1982) showed that chicks expressed these markers at a frequency of 3.5%.…”

Gene transfer through the use of sublethally irradiated pollen: the theory of chromosome repair and possible implication of DNA repair enzymes

“…The procedures, when better understood, have the potential of not only considerably expediting plant, and possibly animal (Pandey, 1980c;Pandey and Patchell, 1982) breeding but also producing desirable recombinants which could not be produced before because of close linkage between desirable and undesirable genes, or because of inviability of the normal hybrid zygotes or complete sterility of the normal hybrids.…”