Natural and somatic embryo development in loblolly pine: gene expression studies using differential display and DNA arrays

In production biological systems, monitoring and controlling the growth environment is possible, but assessing the metabolic competency of the organism is more difficult. Somatic embryogenesis (SE), a tissue-culture method for multiplying embryos asexually, has great potential to capture at low cost the genetic gain from breeding and genetic-engineering programs. Loblolly pine, however, has proven recalcitrant in the production of somatic embryos suitable in quality for operational use. Many similarities and differences in gene expression were uncovered. We have modified a recent technique called differential display (DD) to examine gene expression, allowing the comparison of somatic and zygotic embryos. Over 400 cDNA "bands" have been cloned and their sequences determined. These bands can serve as "expression markers," providing rapid, simple, and sensitive assessment of embryo physiology development. These techniques are applicable to many areas of research where monitoring specific levels of gene expression is important for evaluating the performance of a system.