Project description:Transposable elements (TEs) are genomic parasites that constitute the most abundant portions of higher plant genomes. However, whether TE selection occurred during crop domestication remains unknown. HUO is active under normal growth conditions, present at low copy numbers, inserts preferentially into regions capable of transcription, but absent in almost all modern varieties, indicating its removal during rice domestication and modern rice breeding. HUO triggers genomic immunity and dramatically alters genome-wide methylation levels and small RNA biogenesis, as well as global gene expression. Its presence specifically affects agronomic traits by decreasing yield performance and disease resistance but enhancing salt tolerance, which mechanistically explains its domestication removal. Thus, our study reveals a unique retrotransposon as a negative target for maintaining genetic and epigenetic stability during crop domestication and selection.
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:This SuperSeries is composed of the following subset Series: GSE16889: Domestication causes large-scale effects on gene expression in rainbow trout: Analysis of the brain transcriptome GSE16897: Domestication causes large-scale effects on gene expression in rainbow trout: Analysis of the liver transcriptome GSE16901: Domestication causes large-scale effects on gene expression in rainbow trout: Analysis of the muscle transcriptome Refer to individual Series
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: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:Domestication of wild animals induces a set of phenotypic characteristics collectively known as the domestication syndrome. However, how this syndrome emerges is still not clear. Recently, the neural crest cell deficit hypothesis proposed that it is generated by a mildly disrupted neural crest cell developmental program, but clear support is lacking due to the difficulties of distinguishing pure domestication effects from preexisting genetic differences between farmed and wild mammals and birds. Here, we use a farmed fish as model to investigate the role of persistent changes in DNA methylation (epimutations) in the process of domestication.We show that early domesticates of sea bass, with no genetic differences with wild counterparts, contain epimutations in tissues with different embryonic origins. About one fifth of epimutations that persist into adulthood are established by the time of gastrulation and affect genes involved in developmental processes that are expressed in embryonic structures, including the neural crest. Some of these genes are differentially expressed in sea bass with lower jaw malformations, a key feature of domestication syndrome. Interestingly, these epimutations significantly overlap with cytosine-to-thymine polymorphisms after 25 years of selective breeding. Furthermore, epimutated genes coincide with genes under positive selection in other domesticates. We argue that the initial stages of domestication include dynamic alterations in DNA methylation of developmental genes that affect the neural crest. Our results suggest a role for epimutations during the beginning of domestication that could be fixed as genetic variants and suggest a conserved molecular process to explain Darwin’s domestication syndrome across vertebrates.