Project description:The HH16/17 chicken proepicardium (PE) gives rise to the embryonic epicardium (Epi) which significantly contributes formation of the coronary vasculature during cardiac development. In contrast to explanted Epi cells, explanted PE cells can undergo differentiation into a cardiac myocyte phenotype. In order to assess which genes are associated with PE differentiation into distinc cellular lineages, two interconnented microarray gene-expression series were performed. 1: Gene-expression profiles at 12, 24, 36, 48, 60, 72 and 120 hours during cardiac myocyte differentiation from including the HH16/17 PE (t0h) were determined by hybridizing Cy3 and Cy5 labelled amplified RNA to the ArkGen 20K oligo arrays in a 2-color looped experiment design, i.e., hybridization of successive time-points per array, including dye swaps, resulting in four technical replicates for each time point. 2: Gene expression changes during normal embryonic Epi maturation were assess by hybridizing Epi from stages HH25, HH29, HH32 and HH37 in all possible pair-wise combinations, including dye-swaps, leading to 6 replicates per time point. To allow for valid comparisons between the Epi and untreated PE differentiation, these two array series were connected via hybridization of both Epi stage HH25 and HH29 with the PE explant at 48 hours in culture, with dye swaps. Keywords: time course, cardiac myocyte differentiation, embryonic coronary vessel formation, cell type comparison, mRNA expression Proepicardium to cardiac myocyte differentiation: 16 arrays for 8 time points [t0h,t12h,t24h,t36h,t48h,t60h,t72h,t120h]; successive time points hybridized per array in a loop design with dye swaps + Embryonic epicardium dfferentiation: 12 arrays for 4 time points [HH25,HH29,HH32,HH37]; all possible sample combination were hybridized with dye swaps + Epicardium to Proepicardium data connection: 4 arrays; comparing HH25 and HH29 Epicardium to t48h Proepicardium with dye swaps.
Project description:Gene duplication enables the emergence of new functions by lowering the general evolutionary pressure. Previous studies have highlighted the role of specific paralog genes during cell differentiation, e.g., in chromatin remodeling complexes. It remains unexplored whether similar mechanisms extend to other biological functions and whether the regulation of paralog genes is conserved across species. Here, we analyze the expression of paralogs across human tissues, during development and neuronal differentiation in fish, rodents and humans. While ~80% of paralog genes are co-regulated, a subset of paralogs shows divergent expression profiles, contributing to variability of protein complexes. We identify 78 substitutions of paralog pairs that occur during neuronal differentiation and are conserved across species. Among these, we highlight a substitution between the paralogs Sec23a and Sec23b subunits of the COPII complex. Altering the ratio between these two genes via RNAi-mediated knockdown is sufficient to influence the differentiation of immature neuron. We propose that remodeling of the vesicular transport system via paralog substitutions is an evolutionary conserved mechanism enabling neuronal differentiation.
Project description:Gene duplication enables the emergence of new functions by lowering the general evolutionary pressure. Previous studies have highlighted the role of specific paralog genes during cell differentiation, e.g., in chromatin remodeling complexes. It remains unexplored whether similar mechanisms extend to other biological functions and whether the regulation of paralog genes is conserved across species. Here, we analyze the expression of paralogs across human tissues, during development and neuronal differentiation in fish, rodents and humans. While ~80% of paralog genes are co-regulated, a subset of paralogs shows divergent expression profiles, contributing to variability of protein complexes. We identify 78 substitutions of paralog eggNOG pairs that occur during neuronal differentiation and are conserved across species. Among these, we highlight a substitution between the paralogs Sec23a and Sec23b subunits of the COPII complex. Altering the ratio between these two genes via silencing-RNA knockdown was able to influence neuronal differentiation in different ways. We propose that remodeling of the vesicular transport system via paralog substitutions is an evolutionary conserved mechanism enabling neuronal differentiation.
Project description:Gene duplication enables the emergence of new functions by lowering the general evolutionary pressure. Previous studies have highlighted the role of specific paralog genes during cell differentiation, e.g., in chromatin remodeling complexes. It remains unexplored whether similar mechanisms extend to other biological functions and whether the regulation of paralog genes is conserved across species. Here, we analyze the expression of paralogs across human tissues, during development and neuronal differentiation in fish, rodents and humans. While ~80% of paralog genes are co-regulated, a subset of paralogs shows divergent expression profiles, contributing to variability of protein complexes. We identify 78 substitutions of paralog eggNOG pairs that occur during neuronal differentiation and are conserved across species. Among these, we highlight a substitution between the paralogs Sec23a and Sec23b subunits of the COPII complex. Altering the ratio between these two genes via silencing-RNA knockdown was able to influence neuronal differentiation in different ways. We propose that remodeling of the vesicular transport system via paralog substitutions is an evolutionary conserved mechanism enabling neuronal differentiation.