Development of New Placental and Fetal Expressed Sequence Tags (EST) for Gene Discovery in Pig Reproduction

Abstract

<p>One major problem that has high economic impact on pig reproduction is the unexplained loss of potential porcine conceptuses during the first month of gestation. To better understand when and how these losses occur, it is imperative to investigate the underlying genetic regulatory mechanisms. We have recently initiated a large-scale cDNA sequencing project to provide molecular information regarding the genes expressed in female reproductive tissues. cDNA libraries are planned for ovary, hypothalamus, pituitary, placenta, uterus, and several stages of embryonic development. Sequence information will also be highly useful in developing sequence-tagged sites for physical mapping and developing comparative links between the human, mouse, and pig genome maps. We have previously reported the creation of two cDNA libraries, porcine fetal (day 20), and conceptus (day 17). Sequencing of these libraries produced 220 Expressed Sequence Tags (ESTs), with 180 sequences analyzed by clustering algorithms, and 139 clusters identified within these sequences. We now report the creation of two more libraries from porcine fetal (day 45) and placental tissues. The day 45 fetal library has 971,150 independent clones (average insert: 1.4 kb), whereas the placental library has 1,320,000 independent clones. Initial sequencing of the fetal library has produced 119 ESTs (81 clusters), whereas we have obtained 1411 ESTs (1056 clusters) from the placental library. After clustering all sequences thus far obtained, we have identified 1,233 unique clusters. Sequences obtained in this project will be deposited into Genbank dbEST, and all comparative homology</p>