ETEROSIS in characteristics which are part of the reproductive process is a commonly observed result of crossing unrelated stocks in many species (e.g., GOWEN 1952). In mammals, the observed heterosis in litter size could be due to superiority of the crossbred in ovulation rate, in embryo survival, or both. The second of these parameters can be further subdivided into preand postimplantation st...

Active DNA repair pathways are crucial for preserving genomic integrity and are likely among the complex mechanisms involved in the normal development of preimplantation embryos. MicroRNAs (miRNA), short non-coding RNAs, are key regulators of gene expression through the post-transcriptional and post-translational modification of mRNA. The association of miRNA expression with infertility or poly...

Adherens junction formation is fundamental for compaction and trophectoderm differentiation during mammalian preimplantation development. We recently isolated an IQGAP-2 cDNA from a differential display-polymerase chain reaction screen of bovine preimplantation developmental stages. IQGAP-1 and -2 proteins mediate E-cadherin-based cell-to-cell adhesion through interactions with beta-catenin and...

Pregnancy loss is a serious social and medical issue, with one important cause associated with aberrant embryo implantation during early pregnancy. However, whether and how the process of embryo implantation is affected by environmental factors such as stress-induced sympathetic activation remained elusive. Here we report an unexpected, transient effect of β(2)-adrenoreceptor (β(2)-AR) activati...

Isocupressic acid (ICA) [15-hydroxylabda-8 (17), 13E-dien-19-oic acid], a labdane diterpene acid, isolated from ponderosa pine (Pinus ponderosa), Lodgepole pine (Pinus contorta), common juniper (Juniperus communis) and Monterey cypress (Cupressus macrocarpa), induces abortion in pregnant cows when ingested primarily during the last trimester. The objective of this study was to investigate the e...