ABSTRACT
Living organisms well adapt themselves to changes in the environment and are robust to potential damage such as mutations. The epigenetic mechanism whereby the suppression of phenotypic variation is achieved has been dubbed canalization. This paper summarizes results of research that employed experimental and theoretical approaches to uncover the mechanisms of canalization of variation in expression of segmentation genes.
Subject(s)
Drosophila/embryology , Embryonic Development/genetics , Epigenesis, Genetic , Gene Expression Regulation, Developmental , Models, Biological , Animals , Blastoderm/embryology , Blastoderm/metabolism , Drosophila/genetics , Genes, Insect , Genetic VariationABSTRACT
In this review we summarize original methods for the extraction quantitative information from the confocal images of gene expression patterns. These methods include image segmentation, extraction of quantitative numerical data on gene expression, removal of background signal and spatial registration. Finally it is possible to construct a spatiotemporal atlas of gene expression form individual images obtained at each developmental stage. Initially all methods were developed to extract quantitative numerical information form confocal images of segmentation gene expression in Drosophila melanogaster. Application of these methods to Drosophila images makes it possible to reveal new mechanisms of formation of segmentation gene expression domains, as well as to construct the quantitative atlas of segmentation gene expression. Most image processing procedures can be easily adapted to process a wide range of biological images.
Subject(s)
Gene Expression Profiling/methods , Gene Expression , Microscopy, Confocal , Animals , Drosophila Proteins/genetics , Drosophila melanogaster/embryology , Drosophila melanogaster/genetics , Drosophila melanogaster/ultrastructure , Embryo, Nonmammalian/ultrastructure , Gene Expression Regulation, Developmental , Genes, Insect , Image EnhancementABSTRACT
An analysis of the quantitative data obtained by processing the confocal images showed that the early variability of expression patterns of zygotic segmentation genes in Drosophila drastically decreases by the time of the onset of gastrulation. The following components of variability were examined: the scatter of the levels of gene expression in different embryos, the time and sequence of the formation of expression domains, the type of their formation, and the domain positioning. It was found that the positioning error at the level of zygotic genes is dynamically filtered with time.
