Project description:Purple carrots can accumulate large quantities of anthocyanins in their roots. Depending on the genetic background, anthocyanin pigmentation can be expressed in the entire root, or it can display tissue specific-patterns, confined to the root phloem or xylem tissues. Within the phloem, the tissue usually contributing most of the overall anthocyanin concentration in the carrot root, purple pigmentation can be found in the outer phloem (OP) (also called cortex) and inner phloem (IP) tissues, or it can be confined exclusively to the OP. The latter is a fairly-common phenotype in many purple carrot cultivars. In this work, the genetic control underlying tissue-specific anthocyanin pigmentation in the carrot root OP and IP tissues was investigated by means of linkage mapping, transcriptome (RNA-seq), phylogenetic, and gene expression (RT-qPCR) analyses in two genetic backgrounds; an F2 mapping population (3242) and the inbred line B7262. Genetic mapping of the ‘root outer phloem anthocyanin pigmentation’ (ROPAP) and inner phloem pigmentation (RIPAP) revealed co-localization of ROPAP with the P1 and P3 genomic regions previously known to condition pigmentation in different genetic stocks, whereas RIPAP co-localized with P3 only. Transcriptome analysis of purple OP (POP) vs. non-purple IP (NPIP) tissues, along with linkage and phylogenetic data, allowed an initial identification of 28 candidate genes, 19 of which were further evaluated by RT-qPCR in independent root samples of 3242 and B7262, revealing 15 genes consistently upregulated in the POP in both genetic backgrounds, and two genes upregulated in the POP in specific backgrounds. These include seven transcription factors (4 MYBs, 1 bHLH, 1 MADS-box, 1 ERF), seven anthocyanin structural genes, and two genes involved in cellular transport. Altogether, our results point at DcMYB7, DcMYB113, and a MADS-box (DCAR_010757) as the main candidate genes conditioning ROPAP in 3242, whereas DcMYB7 and MADS-box condition RIPAP in this background. In 7262, which roots present purple pigmentation only in the outer phloem, DcMYB113 conditions ROPAP
2021-10-27 | GSE181611 | GEO
Project description:Anthocyanin transcriptional profile and pigmentation pattern in the purple tomato fruit in response to light
Project description:The effects of low and high light intensities on transcriptome of purple non sulfur bacterium R. capsulatus were investigated by comparing expression profiles of dark and low light intensity (2000 lux), and by comparing high light intensity (10,000 lux) with low light intensity (2000 lux).
Project description:Purple-grain wheat are caused by anthocyanin accumulation in the seed coat. The anthocyanin biosynthesis and accumulation were affected by light in purple-grain wheat. The spikes of purple-grain wheat Luozhen No.1 were bagged with four-layer Kraft paper bags after pollination. To identify genes involved in the anthocyanin biosynthesis, we sequenced two pericarp cDNA libraries, D20 (20 DAP) of shading treatment, and L20 (20 DAP) of untreated control using an Illumina HiSeqTM 2000.
Project description:O. rhodostigmatus are non-obligative cave dwellers, whose tadpoles keep albinistic phenotype in caves but rapidly darken in light within 24 hours. Their coloration system is an excellent model for exploring the processes and mechanisms of light-induced pigmentation and revealing the genetic adaptation for non-obligative cave dwelling due to complicated life history. Using comparative transcriptomics, we found that melanocyte MCC (including melanogenesis and melanocytes proliferation) was responsible for the rapid skin darkening in was activated in O. rhodostigmatus. Light exposure induced robust activation of growth signals (including growth factor signals, MAPK signal pathways and PIK3-Akt signal pathways) at transcriptional levels, which were likely the upstream activation signals of melanocyte MCC in O. rhodostigmatus tadpoles. These results evidenced that amphibians and mammals likely share similar regulatory signals for light-induced melanocyte MCC. The conservation of pigmentation mechanisms across lower vertebrates and mammals imply that knowledge based on simpler models could also provide implications for causations and therapies of human pigmentation disorders and pigmented tumors. In aspect of genetic adaptation, an in-frame deletion of four amino acids in the membrane/extracellular junctions of the second and third transmembrane domains of O. rhodostigmatus MC1R, the receptor for melanogenesis signal, was identified. This mutation increases the negative charge of the ligand pocket of MC1R and results stereo-tandem of three aspartate residues aligning towards its ligand pocket. The ligand pocket of O. rhodostigmatus MC1R resembles a trap for positively charged ligands (α-MSH and ACTH) and likely increases the ligands-dependent activity of MC1R, providing an explanation for the rapid MCC of O. rhodostigmatus in light. Meanwhile, increased negative charge of ligand pocket likely decreased the constitutive activity of MC1R, in in supporting the albinistic phenotype of cave dwelling tadpoles. Therefore, genetic change of MC1R explains, at least to some extent, how the pigmentation system of O. rhodostigmatus coordinates the capacity of rapid melanogenesis (or other types of pigment production) and pigment regression, a couple of seemingly contradictory coloration requirements. To our knowledge, this is the first study reporting the association between pigmentation phenotype adaptation and MC1R mutations in amphibians or in non-obligative cave dwellers.
2018-06-07 | GSE106622 | GEO
Project description:BSR-seq of maize purple midribs
Project description:During the long history of chicken domestication, eyelid color, like skin color and shank color, has been one of the unique physical traits of Chinese indigenous chickens that influence consumer behavior. In China, the Lindian chicken, which has colored feathers, is renowned for the appetizing flavor of its meat and eggs, and its eyelid colors varies from deep to light shades, including black, gray, red, and light yellow. To identify the genes controlling eyelid pigmentation, the expression profiles of black and light-yellow eyelids of Lindian chickens were analyzed with transcriptome sequencing. We detected 13,466 genes expressed in the eyelids, among which 14 were differentially expressed. A KEGG pathway analysis showed that tyrosine metabolism and melanogenesis genes were significantly enriched among these DEGs (corrected P < 0.05). Therefore, we infer that melanin metabolism is one of main factors affecting Lindian chicken eyelid pigmentation. In summary, we have identified the melanin genes responsible for eyelid pigmentation of the Lindian chicken, and also provide a valuable resource for the future study of the physical traits of chickens.
Project description:This research identifies a novel protein required for paramutation at the maize purple plant1 locus. This 'required to maintain repression2' (RMR2) protein represents the founding member of a plant-specific clade of hypothetical proteins. We show that RMR2 is required for transcriptional repression at the Pl1-Rhoades haplotype, for accumulation of 24 nt RNA species, and for maintenance of a 5-methylcytosine pattern distinct from that maintained by RNA polymerase IV. Genetic tests indicate that RMR2 is not required for paramutation occurring at the red1 locus. These results distinguish the paramutation-type mechanisms operating at specific haplotypes. The RMR2 clade of proteins provides a new entry point for understanding the diversity of epigenomic control operating in higher plants.
Project description:Differential expression of microRNAs was studied in maize leaves after an 8-h-exposure under UV-B light. As a control, plants were kept in the greenhouse in the absence of UV-B