Banna Mini-pig Inbred-line: an inbred pig-line with high individual similarity evaluated with minisatellite DNA fingerprinting
Introduction The pure-line large mammal animal is of great important in medical research, while a pure-line pig will be much more useful duo two the biological compatibility between pig and human. However, no pure-line large mammal animal is reported in the world so far. Banna Mini-pig Inbred-line (BMI), an inbred pig-line that will reach the 19th inbreeding generation in 2001, was reported in Yunnan, South-west China. In this paper, DNA fingerprinting assays were conducted with human derived minisatellite probe to evaluate the individual similarity among 4 BMI sublines and 5 generations.
Materials and methods Blood were collected from BMI subline JB805, JS111, JS133 and JS151 from 13 to 16 inbreeding generations. DNA samples were extracted with genomic blood DNA purification kit (Amersham Pharmacia Biotech, USA) and digested with restrictive endonuclease Hinf I, and then processed following routine electrophoreses. Southern blotting. Hybridization with 33.6 probe (Cellmark Diagnostics, UK) and color development were conducted following the instruction. The DNA fingerprint similarity efficient (DFSE) was determined following the formula as DFSE = Nab/(Na + Nb) by comparing the hybridization bands with the size bigger than 2kb.
Results and discussion DFSE values of BMI were from 0.83 to 0.93 depends on the inbreeding generation. The two highest DFSEs were observed in the F16 of JS111 and F15 of JS151 as 0.925 and 0.923, respectively. Though the assay is only a rough estimate to the pig, the result clearly indicated that BMI had reached a very high individual similarity after almost 20 years inbreeding. Further more, this pig-line will very close to pure line animal after a few generation of inbreeding as the DFSE values will reach to 1 for monozygotic twins and pure-line mice according to the principle of the method. Intensive experiments are conducting on the 17-18 inbreeding generations of the pig line to evaluate its potential in medical application.