Identification Of Pork Production Trait Candidate Genes By CDNA Macroarray

Pig serves as an important source of protein for human consumption as one of the major meat animals. Swine industries have been pursuing higher lean growth rate and better meat quality in pigs as two of their highest priority goals for profitability for many years. Muscle fiber characteristics are critical for meat quality, pigs with greater muscle fiber numbers and moderate fiber size can produce better pork. The number of muscle fibers is determined at the prenatal stage, while the fiber sizes are determined in a postnatal development process. In order to make the genetic improvement in growth rate and meat quality traits of pigs by using the molecular breeding strategy, the useful approaches to identify candidate genes related to rapid muscle growth and better meat production in pigs is to understand the variation of gene expression patterns in different developmental stages together with the understanding of gene structure and it's function.The objective of this thesis was to monitor-the gene activities in different developmental stages of porcine fetal' skeletal muscle and to isolate, characterize some of those differential expression genes. The main results are as follows:1. The condition of related techniques of cDNA Macroarray was improved by trial and error; linear mixed models were used to mine the useful information of the porcine cDNA macroarry data set. 98 ESTs were revealed differential expression among the five swine developmental stages in Duroc within a total of 327 expressed-sequence tags (ESTs) in the analyses, which represents 43 known genes and 27 ESTs with no good matchs. 138 ESTs were revealed differential expression among the five swine developmental stages in Tongcheng pig within a total of 327 expressed-sequence tags (ESTs) in the analyses, which represents 58 known genes and 52 ESTs with no good macths. Browse those genes in the OMIM database, it was found that NUDT3 , ACTN2 , cavec4in-M , transferring , ribosomal protein L3, ribosomal protein S7, 60S acidic ribosomal protein PI, ribosomal protein s20, ribosomal protein, large PO, and vitamin binding protein etc. genes had differential expression in the other researcher's result.2. The fators related to the Hemoglobin function include Hemoglobin beta chain, Hemoglobin alpha chain, Beta-1-metal binding globulin, Transferrin show a significant downregulation expression during the fetal's stage from the 33thday to the 75thday.3. RP factors were found differential expression during the stage from the 33thday to the 75thday. The downregulated genes include 40S ribosomal protein S7, 40S ribosomal proteinS20, 60S acidic ribosomal protein PO, 60S ribosomal protein L37a, 40S ribosomal protein S3 A, 60S acidic ribosomal protein PI; the upregulated genes included mitochondrial ribosomal protein L42, T09551 ribosomal protein L4 and ribosomal protein L29/cell surface heparin binding protein HIP. Sus scrofa ribosomal protein L3 was first upregulated in the Tongcheng pig from the 33thd to the 55thd and then down regulated from the 55th d to the 75thd, but in Duroc, it was a downregulated gene; the gene ribosomal protein S10 shows upregulated from the 33thd to the 55thd and then downregulated from the 55.thd to the 75thd.4. Hierarchical Clustering results displayed that the EST came from Ae same gene were in a cluster, for example, 16 ESTs from UniGene Cluster (Ssc.7157) which represented the gene Chain B of Carbonmonoxy-Haemoglobin were in a cluster except one EST did not in the cluster. And the genes that had the similar function or joined the same process were most likely clustered together, for example, EST (E6 acc-d-07 (ribosomal protein L3), E2-ab-g-07(ribosomal protein S7), E2-aa-h-ll (60S acidic ribosomal protein PI), E2-ab-f-ll (ribosomal protein s20), E3-aaf-a-09(ribosomal.protein,large P0))and so on were clustered closely. This could give some clue for the understanding -the function of new genes. The results also indicated that development stages with similar gene expression action mode were clustered together. The 33thd and the...