THE INCREASEMENT OF INDIVIDUAL GENETIC SIMILARITY AMONG AN INBRED CHINESE PORCINE BREEDING

Abstract

P1048 Aims: To evaluate the genetic similarity between individuals among the inbred porcine breeding, Banna Minipigs Inbred line (BMI), with DNA fingerprint techniques. Methods: 81 blood samples from four BMI sublines (JB805, JS111, JS133 and JS151) (inbred generation from 13 to 18) were investigated. A commercial multi-locus human minisatellite probe 33.15 (Cellmarker, UK) was used to produce DNA fingerprints (DFPs) following the routine protocoles as blood DNA extraction, restriction endonuclease (Hinf I) digestion, sample electrophoresis on 1% agarose gels, Southern blotting and probe 33.15 hybridization. DNA segment bands were calculated and the similarity coefficient (F) between individuals were estimated by the formulation as F=2×(shared bands)/(bands of A+ bands of B). Results: Human minisatellite probe 33.15 has been used to estimate the genetic similarity in poultries and mammals. In this study, clearly and highly polymorphic DNA fingerprints for BMI were obtained, and the number of distinct bands ranged from 21 to 32. The results of DFPs for 81 individuals of BMI substrains among 13-18 generations is shown in the table.Figure Conclusions: DNA fingerprint technique with multi-locus human minisatellite 33.15 allowed a unique identification of genetic similarity among different sublines of BMI by the configuration of DNA-patterns. It was demonstrated that this was an effective method to estimate the inbreeding level of line. Individual genetic similarities increased following the increase of inbreeding generation in the four BMI sublines. The similarity coefficients have reached a relative high level 0.857-0.935 among 13-18 generations. Using similar method, some previous studies of other non-inbred Chinese pig breedings were conducted by Meng Anming, Sun Zongyan, et al. Comparatively, DFPs similarity coefficients of Neijiang pig (closed clony), Guizhou minipig (closed clony) were 0.50, 0.48 respectively, which evidenced the higher inbreeding degree of BMI. Traced back to one couple of ancestors, BMI has divided into two major sublines, including JB (with larger body size) and JS (with smaller body size) after the 7th generation. Since a small size pig is easier to breed and manipulate, the JS lines will be more suitable for medicine application.