Abstract: A transgenic animal such as a transgenic snake or other reptile that expresses a heterologous expression product is described, along with methods of making the same. In general, the animal comprises cells containing a sequence encoding the heterologous expression product. The sequence encoding the heterologous expression product is integrated into the genome of the animal (e.g., in some or all cells thereof, and in some embodiments into germ cells thereof). The sequence encoding the heterologous expression product is, in general, operatively associated with an expression sequence or promoter. The animals are useful for, among other things, testing of repellents, testing of toxicological compounds, as teaching aids, for venom production, etc.

Abstract: Methods for modulating primordial germ cell (PGC) numbers and/or development in avians are provided. In one embodiment, the presently disclosed subject matter provides a method for modulating primordial germ cells numbers in an avian embryo comprising immunizing a female bird with an antigen associated with primordial germ cells, whereby an egg produced by the female bird comprises a sufficiently high concentration of antibodies specific for the antigen to modulate numbers of endogenous PGCs in an avian embryo present within in the egg. Also provided are methods for producing chimeric avians, methods for increasing the proportion of male birds in a plurality of eggs, methods of producing avian gametes, and methods for enhancing germ line transmission of nucleic acids in birds.

Abstract: The present invention provides methods for the production of avian gametes, comprising reducing endogenous primordial germ cells (PGCs) in a recipient bird in ovo and introducing donor primordial germ cells from another bird into the recipient bird in ovo. The present invention further provides a method of increasing the ratio of male offspring from a female bird, comprising reducing endogenous PGCs in the female bird in ovo, introducing donor PGCs from another bird into the female bird in ovo, and incubating the female bird to hatch. The female bird is raised to sexual maturity and bred to produce a plurality of eggs having a higher proportion of male eggs than in the absence of the inventive methods. In some embodiments, the donor PGCs are from a different species than the recipient bird. In preferred embodiments, endogenous PGCs are reduced using busulfan.

Abstract: A method of altering the phenotype of a bird comprises introducing a DNA sequence into somatic cells of a bird contained within an egg during in ovo incubation. The DNA sequence is selected to be effective to cause a change in phenotype, such as an increase in growth rate, feed efficiency, or both in the bird after hatch. A DNA sequence may further be selected to increase disease resistance or induce disease prevention by the expression of an antigen over a period of time.

Abstract: The present invention provides methods for the production of avian gametes, comprising reducing endogenous primordial germ cells (PGCs) in a recipient bird in ovo and introducing donor primordial germ cells from another bird into the recipient bird in ovo. The present invention further provides a method of increasing the ratio of male offspring from a female bird, comprising reducing endogenous PGCs in the female bird in ovo, introducing donor PGCs from another bird into the female bird in ovo, and incubating the female bird to hatch. The female bird is raised to sexual maturity and bred to produce a plurality of eggs having a higher proportion of male eggs than in the absence of the inventive methods. In some embodiments, the donor PGCs are from a different species than the recipient bird. In preferred embodiments, endogenous PGCs are reduced using busulfan.

Abstract: A method of altering the phenotype of a bird comprises introducing a DNA sequence into somatic cells of a bird contained within an egg during in ovo incubation. The DNA sequence is selected to be effective to cause a change in phenotype, such as an increase in growth rate, feed efficiency, or both in the bird after hatch. A DNA sequence may further be selected to increase disease resistance or induce disease prevention by the expression of an antigen over a period of time.

Abstract: A method has been developed for the injection of muscle tissue of an embryonic chicken in ovo. An apparatus for such injection in a plurality of eggs simultaneously has also been developed, where the apparatus is composed of a an engaging means for the eggs, an injection means to insert an elongate needle through the eggshell to a depth of about 7/8 inch to 1.5 inch into the shoulder or breast of the embryo, and a positioning means to position the needle about 1 to 5 degrees of offset of the long axis of the egg. The apparatus can delivery a variety of substances to the muscle tissue of the embryonic chicken in ovo.