Nutritional modulation of immune function in broilers.

Selection for disease resistance related traits is a tool of choice for evidencing and exploring genetic variability and studying underlying resistance mechanisms. In this framework, chickens originating from a base population, homozygote for the B19 major histocompatibility complex (MHC) were divergently selected for either progression or regression of tumors induced at 4 weeks of age by a SR-D strain of Rous sarcoma virus (RSV). The first generation of selection was based on a progeny test and subsequent selections were performed on full-sibs. Data of 18 generations including a total of 2010 birds measured were analyzed for the tumor profile index (TPI), a synthetic criterion of resistance derived from recording the volume of the tumors and mortality. Response to selection and heritability of TPI were estimated using a restricted maximum likelihood method with an animal model. Significant progress was shown in both directions: the lines differing significantly for TPI and mortality becoming null in the "regressor" line. Heritability of TPI was estimated as 0.49 +/- 0.05 and 0.53 +/- 0.06 within the progressor and regressor lines respectively, and 0.46 +/- 0.03 when estimated over lines. Preliminary results showed within the progressor line a possible association between one Rfp-Y type and the growth of tumors.

/pdf/genetic-analysis-of-a-divergent-selection-for-resistance-to-5fdb4azs2b.pdf

Genetic analysis of a divergent selection for resistance to Rous sarcomas in chickens.

Selection for disease resistance related traits is a tool of choice for evidencing and exploring genetic variability and studying underlying resistance mechanisms. In this framework, chickens originating from a base population, homozygote for the B19 major histocompatibility complex (MHC) were divergently selected for either progression or regression of tumors induced at 4 weeks of age by a SR-D strain of Rous sarcoma virus (RSV). The first generation of selection was based on a progeny test and subsequent selections were performed on full-sibs. Data of 18 generations including a total of 2010 birds measured were analyzed for the tumor profile index (TPI), a synthetic criterion of resistance derived from recording the volume of the tumors and mortality. Response to selection and heritability of TPI were estimated using a restricted maximum likelihood method with an animal model. Significant progress was shown in both directions: the lines differing significantly for TPI and mortality becoming null in the "regressor" line. Heritability of TPI was estimated as 0.49 ± 0.05 and 0.53 ± 0.06 within the progressor and regressor lines respectively, and 0.46 ± 0.03 when estimated over lines. Preliminary results showed within the progressor line a possible association between one Rfp-Y type and the growth of tumors.

/pdf/genetic-analysis-of-a-divergent-selection-for-resistance-to-1iv2nwb248.pdf

Genetic analysis of a divergent selection for resistance to Rous sarcomas in chickens†. This article is dedicated to the memory of Pierrick Thoraval (1960–2000).

1. Selected aspects of differentiation in malignant neoplastic growth.- 2. Some biochemical aspects of the metastatic dissemination of tumor cells.- 3. Tumor dormant states in man.- 4. Regenerative potential, innervation and oncogenesis.- 5. Regression of neoplasms in man.- 6. Regression of neoplasms in vertebrates.- 7. Regression of neoplasms in invertebrates with special emphasis on mollusca.- 8. Tumor reversal and tumor suppression in plants.- 9. A biological approach to an understanding of regression.- 10. Preconditions in the host-tumor relationship during local recurrence.- 11. Response of the central nervous system to cancer: general features and cancer-related dementias.- 12. Increased intracranial pressure.- 13. Cardiac and pulmonary complications of cancer.- 14. Dermatologic effects of cancer.- 15. Hematologic complications of cancer from the species specific view.- 16. Endocrine and metabolic function in patients with neoplastic disease.- 17. Hormone production by tumors: ectopia or gene derepression.- 18. Immunosuppression by metastatic tumors.- 19. Abnormal variation of the immune system as related to cancer.- 20. Animal models for liver metastasis.- 21. Problems in the assessment of lung cancer risk posed by ambient air pollutants.- 22. Carcinogenic activity of drinking water as related to the tumor initiating and promoting activity of trihalomethanes.- Index of subjects.

Influence of the host on tumor development

The spontaneous neoplastic regression in non-human vertebrates is interesting from two points of view: to expand our knowledge through comparison of selected cases and to use animals as experimental models to provide the proof for our comparative assumptions in order to study the causes and mechanisms of tumor regression.

R. W. Buck

Papers

Estimates of heritability of response to Rous sarcomas of chickens.