Molecular Cloning, Expression Analysis And Chromosomal Localization Of Porcine Bone Morphogenetic Protein 11 (BMP11) Gene

The length of body is one of the economically important traits in pig breeding. BMP11, also called growth differentiation factor 11 (GDF11), identified by McPherron and Gamer( 1999), is a negative regulator of thoracic and lumbar vertebrae formation in mice. Targeted deletion leads to an increase in the number of thoracic and lumbar vertebrae. As is known, Landrace and Licha pigs are characteristic of having more vertebrae, especially more thoracic vertebrae than other pig breeds. BMP11 is, therefore, selected as a candidate for elucidating the mechanism of variations in the length of pig body. The result will be helpful for improving carcass trait by using DNA markers.The present study cloned part of the porcine BMP11, analyzed its expression in porcine embryos of several stages and determined its chromosomal location. We selected a degenerate forward primer from human and mouse exon2 and a specific primer from porcine exon3 and successfully amplified intron2. Porcine exon2 was acquired by use of RT-PCR approach. With the Rapid Amplification of cDNA ends(RACE) method, partial exonl of the pig BMP11 was cloned and sequenced. Expression of porcine BMP11 on mRNA level was determined by RT-PCR approach. The chromosomal location of porcine BMP11 was determined with RH panel.The results were as follows:1. The coding region of porcine BMP11, which includes part of exonl, exon2 and intron2 were obtained. All the sequences of porcine BMP11 had been submitted to GenBank. Accession numbers are AY722391 (exon2), AY722392 (intron2) and AY874870 (partial exonl). Porcine BMP11 cDNA has 95.7, 94.0 and 93.5% nucleotide identity in the coding region with human, mouse and rat cDNA respectively. Pig BMP11 codes for a protein of 327 amino acids with 99.4% identity to mouse, human and rat proteins respectively. The porcine BMP11 intron2 was also obtained and found to be in agreement with the splicing principle of GT / AG.2. The porcine BMP11 mRNA were expressed in many tissues and organsincluding forelimb, hindlimb, gingiva, brain, eye, liver, heart, lung, kidney, cervical vertebra, thoracic vertebra, lumbar vertebra and caudal vertebra. The expression profile at embryonic stages and 72hr after birth are different. For embryos, the expression in brain is higher than in kidney. Conversely, after birth, the expression in kidney is higher than in other organs.3. We determined the chromosomal location of the porcine BMP11 using a whole genome porcine radiation hybrid (RH) panel (IMpRH). The result indicated that: there are goal band in the BMP11 and have no background. The INRA-University of Minnesota porcine radiation hybrid(IMpRH) panel was employed to determine the precise location of the BMP11 gene. Statistical analysis revealed that the gene is located to the pig chromosome 5p12-q11 and closed to DK marker with LOD score of 13.8.