Research On The Differentially Expressed Genes Between The Ovarian Tissues Of Meishan And Duroc Sows At Proestrus Stage

The fecundity of pig is a main factor of porcine production efficiency, litter size of pig is one of the main breeding objectives.Since ovulation and reproductive traits of pig is controlled by multiple genes and the heritability of quantity traits is very low (h2≤0.15), it is difficult to obtain to further improvement by using conventional breeding techniques. Compared with conventional breeding techniques, molecular biology technology shows incomparable advantages in breeding selection; but due to insufficient knowledge of molecular mechanism of porcine reproductive traits and ovμlation currently, the application of molecular biotechniques in breeding selection is restricted.DDRT-PCR was performed to detect genes differentially expressed between the ovaries of Meishan and Duroc sows for further study on the molecμlar mechanism of ovμlation regμlatory network.The main results are as follows:Three Meishan and three Duroc sows with normal estrus cycles and reproductive performance were selected. The ovarian tissues were collected at Proestrus stage, then total RNA of samples were isolated and two RNA pools were made up.DDRT-PCR reactions were performed by using 90 primers combinations of 9 anchored primers coupled with 10 arbitrary primers.Thirteen differentially expressed Expressed Sequence Tags (ESTs) were obtained and sequenced.Sequence alignments were performed using BLAST of NCBI online. Five of thirteen EST represented known genes.They were designated as EST511(216bp), EST141(495bp), EST142(104bp), EST64(202bp), EST33(244bp). EST511 showed high homology (98%) with Glutamate cysteine ligase. EST141 was homologous highly with pig ADP-ribosylation factor 3 (ARF3) gene (93%),EST142 showed high homology (97%) with pig BCL2/adenovirus E1B 19kDa interacting protein 3-like (BNIP3L),EST64 was highly homologous (99%) with pig superoxide dismutase Orgotein (Superoxide Dismutase, SOD), EST33 showed extremly high homology(100%) with pig BMP and activin membrane-bound inhibitor. Other ESTs had no significant similarity found similarity in GenBank.By semi-quantitative RT-PCR methods, we verified the different expressions of the ESTs between ovarian tissues of 2 breeds and analyzed the expression profiles of the ESTs in heart, liver, lung, kidney, muscle, fat (subcutaneous fat little legs, the same below), small intestine, brain, ovary, uterus, spleen, fallopian tubes and other tissues of the Meishan pigs. The results showed that all ESTs expressed in ovary. EST511 was expressed at a low level in kidney and small intestine, was hardly detected in the heart, liver, lung, brain, and was expressed in almost all the other tissues. EST141 was moderately expressed in kidney, was lowly expressed in fallopian tubes, uterus, spleen, and was hardly detected in brain; EST141 was moderately expressed in kidney, muscle, fat, brain, spleen, uterus, fallopian tubes, was expressed at a low level in heart, liver, and was hardly detected in lung and small intestine. EST64 was highly expressed in kidney, uterus, brain, spleen, showed a lower expression in musule. fat, and was hardly detected in heart, liver, lung, small intestine. EST33 was expressed at a low level in musule. and was hardly detected in heart, brain, kidney and was highly expressed in other tissues.