October 18, 1985

Dear Mr Plant:

After re-reading some of your material I wrote to Mrs Banning regarding references to fertile second and third generation Avian Hybrids. Her reply is enclosed. I’m afraid some well meaning, highly respected individuals may have been making comments based upon phenotypic observation rather than sound genetic evidence - but then that may be only my opinion too. At any rate, a copy of her replay is attached (#1).

I told Dr Bitgood of your interest in his reading and he commented as shown in attachment (#2).

Best of luck,

John L.Skinner
Professor (Emeritus)

Memo to: John Skinner
From: Jim Bitgood

October 15, 1985

In response to our conversation of several weeks ago in regard to the possible monophyletic origin of our domestic fowl from Gallus gallus (Red Jungle Fowl), the following information is provided.

Weiss and Briggs (1972) found that the Red Jungle Fowl carried a genetically transmitted viral genome of subgroup E specificity that was indistinguishable from that found in domesticated chickens.

Frisby et al. (1979) reported that domesticated chickens carry the genome of the endogenous retrovirus RAV-O as DNA sequences that were integrated into the host chromosomes and transmitted through the cell line. Molecular hybridization of RAV-O cDNA showed 80% homology in the genomes of the domestic chicken and the Red Jungle Fowl. G. sonnerati (Grey Jungle Fowl), G. varius (Green Jungle Fowl), ring necked pheasant and Japanese quail all showed less than 10% homology. Further, restriction enzyme digests showed several distinct fragments of DNA hybridization to chick retrovirus cDNA in both the Red Jungle Fowl and domestic chicken, however no fragments related to the chicken retrovirus were found in the Grey, Green or Ceylonese Jungle Fowl (G. lafayettei). The authors theorize that the RAV-O retrovirus was introduced into the Red Jungle Fowl after speciation occurred, but before domestication, probably within the last million years.

Of further interest, using molecular hybridization on chicken chromo­somes, Tereba et al. (1981) showed that the ev-2 locus, which codes for the pro­totype RAV-O genome, is in the middle of the long arm of chromosome 2.

References

Frisby, D.P, R.A. Weiss, M. Roussel, and D. Stehelin, 1979. The distribution of endogenous chicken retrovirus sequences in the DNA of Galliform birds does not coincide with avian phylogenetic relationships. Cell 17:623-634.

Tereba, A., L.B. Crittenden, and S. M. Astrin, 1981, Chromosomal localization of three endogenous retrovirus loci associated with virus production in White Leghorn chickens. J. Virology 39:282-289.

Weiss, R.A. and P.M. Briggs, 1972. Leukosis and Marek’s disease viruses of feral Red Jungle Fowl and domestic fowl in Malaya. J. Natl. Cancer Inst. 49:1713-1725.