Endocrine Abstracts

Searching for novel endocrine markers involved in gestational disease (e.g. pre-eclampsia, foetal growth restriction, pre-term labour) remains a challenge. Nonetheless, the placenta is a very useful target tissue as it provides a repository of gene expression transcripts that are uniquely expressed during pregnancy. Here, we have used bio-informatic approaches to identify expressed sequence tag (EST) clusters differentially expressed between 1st trimester and term placentae. This offers an attractive starting point to monitor expression of potential markers as pregnancy advances. The National Centre for Biotechnology’s UniGene database was found to contain 24 placental cDNA libraries, out of which 4 were from early gestation (8–9 weeks) and 3 from term. Each of these libraries contain thousands of ESTs and by using the data-mining tool digital differential display, EST clusters from 1st trimester and term placentae were analysed for differential gene expression. For identified known genes, their functions and relationship to gestation were explored using Online Mendelian Inheritance in Man and PubMed. An electronic expression profile and chromosomal map position of each hit EST’s was generated from the UniGene database. A total of 27 EST clusters showed differential expression, out of which 16 were up regulated in early gestation and 11 were preferentially expressed in term placentae. The clusters were categorised into major classes of genes including those with haemopoetic function, tissue remodelling, growth regulation, cell surface molecules and membrane proteins. Some genes like kisspeptin-1 (KISS-1), a metastasis suppressor and H19, an imprinted maternally expressed transcript could have special roles as markers of trophoblast implantation. Profiling the normal pattern of placental gene expression during gestation serves as a powerful tool for identifying and characterising novel endocrine markers that could prove important in the diagnosis and management of gestational disease.