Project description:Rice was domesticated independently in Asia and Africa, leading to two distinct but closely related crop species, Oryza sativa and Oryza glaberrima, respectively. The two domestications lead to morphological changes, in which a higher branching complexity of the panicles, influencing seed production and crop yield. Although much emphasis was placed on changes in transcriptional regulation during rice domestication and improvement, no large-scale study of small RNA regulation changes during domestication has been reported so far. To analyze whether rice domestication has altered the expression of small RNAs, we performed deep sequencing of small RNA transcriptomes from early developmental stages of panicles from 10 genotypes of the cultivated African species and 10 genotypes of its wild-relative O. barthii. Our study shows a drastic expression change of the 21-nucleotide smallRNA population. A total of 29% of these smallRNAs are overexpressed in panicles of O. barthii vs. O. glaberrima, corresponding mainly to 21-nucleotide phased siRNAs (or phasiRNAs). We also show that these changes are associated with a differential expression of a known regulator of phased siRNAs, miR2118 during early panicle development. Finally, these changes are associated to a heterochronic alteration of phasiRNAs and miR2118 expression pattern, during panicle development with a delayed expression in the domesticated species. Our study suggests a major reshaping of the regulation network from a specific class of small RNA during African rice domestication.
Project description:Six different Solanaceae species, Potato (Solanum tubersosum), Tomato (Lycopersicum esculentum), Pepper (Capsicum annuum), Tobacco (Nicotiana tabaccum), Petunia and Nicotiana benthiamana were grown at 25C, 16h light and 8h darkness. Mature leaves were harvested after 4-6 weeks. RNA was isolated using Qiagen RNeasy. Tomato, pepper, petunia, tobacco and N. benthamiana samples were hybridized against potato samples. Keywords: Solanaceae comparative gene expression profiling
Project description:A major challenge in biology is to determine how evolutionarily novel characters originate, however, mechanistic explanations for the origin of novelties are almost completely unknown. The evolution of mammalianM-BM- pregnancy is an excellent system in which to study the origin of novelties because extant mammals preserve major stages in the transition from egg-laying to live-birth. To determine the molecular bases of this transition we characterized the pregnant/gravid uterine transcriptome from tetrapods, including species in the three major mammalian lineages, and used ancestral transcriptome reconstruction to trace the evolutionary history of uterine gene expression. We show that thousands of genes evolved endometrial expression during the origins of mammalian pregnancy, including numerous genes that mediate maternal-fetal communication and immunotolerance.Furthermore we show that thousands of regulatory elements active inM-BM- decidualized human endometrial stromal cellsM-BM- are derived from ancient mammalian transposable elements which provided binding sites for transcription factors that mediate decidualization and endometrial cell-type identity.M-BM- Our results indicate that one of the defining mammalian novelties evolved via domestication of ancient mammalian transposable elements into hormone-responsive regulatory elements throughout the genome. Examination of histone modification and DNAse hypersensitivity in decidualized dESC
Project description:A major challenge in biology is to determine how evolutionarily novel characters originate, however, mechanistic explanations for the origin of novelties are almost completely unknown. The evolution of mammalian pregnancy is an excellent system in which to study the origin of novelties because extant mammals preserve major stages in the transition from egg-laying to live-birth. To determine the molecular bases of this transition we characterized the pregnant/gravid uterine transcriptome from tetrapods, including species in the three major mammalian lineages, and used ancestral transcriptome reconstruction to trace the evolutionary history of uterine gene expression. We show that thousands of genes evolved endometrial expression during the origins of mammalian pregnancy, including numerous genes that mediate maternal-fetal communication and immunotolerance.Furthermore we show that thousands of regulatory elements active in decidualized human endometrial stromal cells are derived from ancient mammalian transposable elements which provided binding sites for transcription factors that mediate decidualization and endometrial cell-type identity. Our results indicate that one of the defining mammalian novelties evolved via domestication of ancient mammalian transposable elements into hormone-responsive regulatory elements throughout the genome.
Project description:The lack of MIRNA set and genome sequence of O. rufipogon (the ancestor of the cultivated rice) has limited to answer the role of MIRNA genes in rice domestication. In this study, a genome, three small RNA populations and a degradome of O.rufipogon were sequenced by Illumina platform and miRNA expression were investigated by miRNA chips. A de novo genome was assembled using ~55x coverage of raw sequencing data and a total of 387 MIRNAs were identified in the O. rufipogon genome based on ~5.2 million unique small RNA reads from three different tissues of O. rufipogon. Of these O. rufipogon MIRNAs, 259 were not found in the cultivated rice, suggesting loss of these MIRNAs in the cultivated rice. We also found that 48 MIRNAs were novel in the cultivated rice, suggesting that they were potential targets of domestication selection. Some miRNAs showed significant expression difference in the wild and cultivated rice, suggesting that expression of miRNA could also be a target of domestication, as demonstrated for the miR164 family. Our results illustrated MIRNA genes, like protein-coding genes, were significantly shaped during rice domestication and could be one of the driven forces contributed to rice domestication.
Project description:Domestication caused significant differences in morphology and behavior between wild and domestic animals, and gene expression changes played an important role in this event. circRNA is a class of non-coding RNA that exerts a wide range of functions in biological processes through the regulation of gene expression. However, the regulatory role of circRNA in the process of domestication is still unclear. Here, we analyzed circRNA expression patterns in the prefrontal cortices of wild boar and domestic pig to determine the potential role of circRNAs in domestication. We identified a total of 11,375 circRNAs and found that 349 and 354 circRNAs were up-regulated in wild boar and Rongchang pig, respectively. This study lays the groundwork for exploring the regulatory role of circRNA in the process of domestication and provides new insights that contribute to further investigation of the molecular mechanism of pig domestication.
Project description:The ability of the yeast Saccharomyces cerevisiae to convert glucose, even in the presence of oxygen, via glycolysis and the fermentative pathway to ethanol has played an important role in its domestication. Despite the extensive knowledge on these pathways in S. cerevisiae, relatively little is known about these pathways in other industrially-relevant Saccharomyces yeast species. In this study we explore the diversity of the glycolytic and fermentative pathways within the Saccharomyces genus using S. cerevisiae, S. kudriavzevii and S. eubayanus as paradigms. Sequencing data revealed a highly conserved genetic makeup of the glycolytic and fermentative pathways in the three species in terms of number of paralogous genes. Although promoter regions were less conserved between the three species as compared to coding sequences, binding sites for Rap1, Gcr1 and Abf1, main transcriptional regulators of glycolytic and fermentative genes, were highly conserved. Transcriptome profiling of these three strains grown in aerobic batch cultivation in chemically defined medium with glucose as carbon source, revealed a remarkably similar expression of the glycolytic and fermentative genes across species, and the conserved classification of genes into major and minor paralogs. Furthermore, transplantation of the promoters of major paralogs of S. kudriavzevii and S. eubayanus into S. cerevisiae demonstrated not only the transferability of these promoters, but also the similarity of their strength and response to various environmental stimuli. The relatively low homology of S. kudriavzevii and S. eubayanus promoters to their S. cerevisiae relatives makes them very attractive alternatives for strain construction in S. cerevisiae, thereby expanding S. cerevisiae molecular toolbox.
Project description:Gossypium barbadense is widely cultivated because of its extra-long staple cotton with superior luster, silkiness and high yield. These economically important traits were selected during initial domestication of an agronomically inferior wild ancestor, followed by millennia of human- mediated selection. To reveal the effects of this history on the cotton fiber transcriptome, we conducted comparative expression profiling on mechanically isolated fiber cells at three different stages encompassing early, mid, and late fiber elongation in wild (K101) and domesticated (Pima S-7) accessions, using a microarray platform that interrogates 42,429 unigenes. The distribution of differentially expressed genes across developmental stages was different in the two accessions, with a shift toward greater change earlier in cultivated than in wild G. barbadense. Approximately 4200 genes were differentially expressed between wild and domesticated accessions at one or more of the stages studied. Domestication appears to have led to enhanced modulation of cellular redox levels and the avoidance or delay of stress-like processes. Prolonged fiber growth in cultivated relative to wild G. barbadense is associated with upregulation of signal transduction and hormone signaling genes and down-regulation of cell wall maturation genes. Clues are provided into the processes and genes that may unwittingly have been selected by humans during domestication and development of modern elite lines. Several of the transcriptomic differences between wild and domesticated G. barbadense described here appear to have parallels in a second domesticated cotton species, Gossypium hirsutum, suggesting that replicated domestication of two different species has resulted in overlapping, parallel, metabolic transformations. Two accessions of G. barbadense were studied, the elite cultivar, Pima S-7, and a wild accession from Bolivia, K101. Seeds of both accessions were sown in sterilized potting mix in the Pohl Conservatory at Iowa State University, Ames, IA, and three biological replicates were grown for 3-5 months. Flowers were tagged at anthesis and harvested at three time points, 2, 10, and 20 days postanthesis. For each of three biological replicates, ovules were excised, frozen in liquid nitrogen, and stored at -80C.