Project description:Induced pluripotent stem cells generated from patients with geographic atrophy as well as healthy individuals were differentiated to retinal pigment epithelium (RPE) cells. By integrating transcriptional profiles of 127,659 RPE cells generated from 43 individuals with geographic atrophy and 36 controls with genotype data, we identified 439 expression Quantitative Trait (eQTL) loci in cis that were associated with disease status and specific to subpopulations of RPE cells. We identified loci linked to two genes with known associations with geographic atrophy - PILRB and PRPH2, in addition to 43 genes with significant genotype x disease interactions that are candidates for novel genetic associations for geographic atrophy. On a transcriptome-only level, we identified molecular pathways significantly upregulated in geographic atrophy-RPE including in mitochondrial functions, metabolic pathways, and extracellular cellular matrix reorganisation. We subsequently implemented a large-scale proteomics analysis, confirming modification in proteins associated with these pathways. We also identified six significant protein (p) QTL that regulate protein expression in the RPE cells and in geographic atrophy - two of which share variants with cis-eQTL, including proteins involve in mitochondrial biology and neuodegeneration. Investigation of mitochondrial functions in the two cohorts confirmed a modification of respiration etc…. This study provides strong proof of concept of the validity of using iPSC for the modeling of complex diseases. It is the first to use a large scale patient -derived iPSC cohort to uncover important differences in RPE homeostasis associated with geographic atrophy. It clearly identifies mitochondrial activity as a core constitutive difference of the RPE from patients with geographic atrophy, and could be a target of potential therapies for this condition (STACEY/MATT).
Project description:Plumage color plays a prominent role in reproductive isolation and thus understanding the genetic basis of pigmentation patterns can provide critical insight into speciation. Subspecies of the dark-eyed junco (Junco hyemalis) show marked differences in melanic plumage coloration known to have evolved rapidly since the Last Glacial Maximum just 18,000 years ago. To understand this rapid radiation we studied the pigment composition and the genetic basis of coloration in two divergent subspecies, the slate-colored and Oregon juncos. We used HPLC and light microscopy to investigate pigment deposition patterns in feathers from four body areas. RNA-seq data generated under common garden experimental conditions were then used to compare the relative roles of differential gene expression in growing feathers and sequence divergence in loci expressed during feather development. Junco feathers were found to differ in eumelanin and pheomelanin content and distribution, producing a range of black, gray and brown colors. Transcriptomic data revealed marked regulatory differences among subspecies and among body-parts within subspecies in known melanin-pathway genes (including PMEL, TYR, TYRP1, OCA2, MLANA), but also in several novel or poorly known loci (EDAR, VPS33B, HPS1). Within subspecies, lighter feathers expressed less melanin synthesis genes, more ASIP, and showed differential expression of Wnt signaling genes. Feathers from different body regions also showed differential expression of Hox genes. The two subspecies differed in expression of ASIP and three other genes (MFSD12, KCNJ13, HAND2) previously associated with color development. Sequence variation in the expressed genes was not related to color differences between junco subspecies. Our findings suggest that differential expression of a few genes can account for marked differences in plumage color and pattern, a mechanism that can account for the rapid diversification of juncos. Several novel candidate pigmentation genes found in juncos may contribute to the expression of melanic coloration in other vertebrates.
Project description:In order to reveal the candidate genes related to yellow plumage in Chinese chicken, a hybrid population of Huiyang Bearded chicken and White Leghorn chicken, and transcriptome data were generated from the yellow and white feather follicle of F3 population in two periods (7 and 11weeks) respectively, using RNA-seq. 127 common different expressed genes were obtained(DEGs) between two periods, these DEGs were mainly enriched in the Gene Ontology classes ‘developmental pigmentation’, ‘melanin biosynthetic process’, ‘melanosome organization’, ‘melanosome membrane’ and ‘melanosome’all related to the pigmentation process. And involved genes were considered as pigment genes that play important roles in melanogenesis. The results reveal key functional genes and possible molecular mechanisms for the elucidation of yellow plumage formation in Chinese indigenous chickens.
Project description:The present study was designed to test the hypothesis of a widespread photochemical trait in fruiting body-forming fungal species. The biomaterial was selected based on Gill and Steglich's classification of fungal pigments, which focuses on their biosynthetic origin. With the aim to cover most described pigment types, 48 different species were selected. Second, dried and ground fruiting bodies were extracted and subjected to UPLC-HRMS/MS measurement.
Project description:Tissue tolerance is a sexually dimorphic trait. Here, we investigated the role of BCL6 in establishing hepatic chromatin landscape promoting sexually dimorphic tissue tolerance during E.Coli infection.
Project description:To gain insight into the genetic regulation of lipid metabolism in tomato, we conducted metabolic trait loci (mQTL) analysis following the lipidomic profiling of fruit pericarp and leaf tissue of the Solanum pennellii introgression lines. To enhance mapping resolution for selected fruit-specific mQTL, we profiled the lipids in a subset of independently derived S. pennellii backcross inbred lines, as well as in a near-isogenic (sub-IL) population. We identified a putative lecithin:cholesterol acyltransferase that controls the levels of several lipids, and two members of the class III lipase family, LIP1 and LIP2, that were associated with decreased levels of diacylglycerols (DAGs) and triacylglycerols (TAGs). Lipases of this class cleave fatty acids from the glycerol backbone of acylglycerols. The released fatty acids serve as precursors of flavor volatiles. We show that LIP1 expression correlates with fatty-acid-derived volatile levels. We further confirm the function of LIP1 in TAG and DAG breakdown and volatile synthesis using transgenic plants. In summary, this study provides an extensive characterization of the genetic architecture of lipophilic compounds in tomato in addition to zooming down to the molecular level to demonstrate that release of free fatty acids from the glycerol backbone can have a major impact on downstream volatile synthesis.
Project description:Comprehensive utilization of cottonseeds is limited by the presence of pigment gland and its inclusion gossypol. The ideal cotton is glandless-seeds and glanded-plant, a trait found in only few Australian wild cotton species, including Gossypium bickii. Introgressing the trait to cultivated species is proved to be difficult. Understanding the biological processes towards pigment gland morphogenesis and the associated underlying molecular mechanisms will facilitate breeding cultivated cotton varieties with the trait of glandless-seeds and glanded-plant. Single-cell RNA sequencing (scRNA-seq) was performed on 12,222 protoplasts isolated from cotyledons of germinating G. bickii seeds 48-hours after imbibition. Clustered into 14 distinct clusters unsupervisedly, these cells could be grouped into eight cell populations with the assistance of known cell marker genes. The pigment gland cells were well separated from others, and could be separated into pigment gland parenchyma cells, secretory cells, and apoptotic cells. In this study, integrating pigment gland cells developmental trajectory, transcription factors regulatory networks, and core transcription factors functional validation, a relatively complete model was proposed for pigment gland formation. Light and gibberellin were verified to promote the formation of pigment glands. Besides, three novel genes, GbiERF114 (ETHYLENE RESPONSE FACTOR 114), GbiZAT11 (ZINC FINGER OF ARABIDOPSIS THALIANA 11) and GbiNTL9 (NAC TRANSCRIPTION FACTOR-LIKE 9), were found to affect pigment gland formation. These findings shed new insights into pigment gland morphogenesis and lay the cornerstone for future cotton scRNA-seq investigations.
Project description:Comprehensive utilization of cottonseeds is limited by the presence of pigment gland and its inclusion gossypol. The ideal cotton is glandless-seeds and glanded-plant, a trait found in only few Australian wild cotton species, including Gossypium bickii. Introgressing the trait to cultivated species is proved to be difficult. Understanding the biological processes towards pigment gland morphogenesis and the associated underlying molecular mechanisms will facilitate breeding cultivated cotton varieties with the trait of glandless-seeds and glanded-plant. Single-cell RNA sequencing (scRNA-seq) was performed on 12,222 protoplasts isolated from cotyledons of germinating G. bickii seeds 48-hours after imbibition. Clustered into 14 distinct clusters unsupervisedly, these cells could be grouped into eight cell populations with the assistance of known cell marker genes. The pigment gland cells were well separated from others, and could be separated into pigment gland parenchyma cells, secretory cells, and apoptotic cells. In this study, integrating pigment gland cells developmental trajectory, transcription factors regulatory networks, and core transcription factors functional validation, a relatively complete model was proposed for pigment gland formation. Light and gibberellin were verified to promote the formation of pigment glands. Besides, three novel genes, GbiERF114 (ETHYLENE RESPONSE FACTOR 114), GbiZAT11 (ZINC FINGER OF ARABIDOPSIS THALIANA 11) and GbiNTL9 (NAC TRANSCRIPTION FACTOR-LIKE 9), were found to affect pigment gland formation. These findings shed new insights into pigment gland morphogenesis and lay the cornerstone for future cotton scRNA-seq investigations.
Project description:Color is an important trait in nature, playing a role in selection and speciation. The most important colorants in crustaceans are carotenoids, which in complexes with carotenoid-binding proteins provide an astonishing variety of colors from red to violet. Over 350 species and subspecies of amphipods (Crustacea: Amphipoda) endemic to Lake Baikal exhibit an impressive variability of colors and coloration patterns. However, the mechanisms forming this diversity are underexplored. In this work, we analyze the coloration of two species of endemic Lake Baikal amphipods, Eulimnogammarus cyaneus and E. vittatus. These species are brightly colored and, even more importantly, characterized by intraspecific color variability. We showed that the color of either species strongly correlated with the abundance of two putative carotenoid-binding proteins (the relative abundance of these proteins was higher in blue or teal-colored animals than in the orange- or yellow-colored ones.). With LC-MS/MS, we were able to identifiy these proteins, which turned out to be similar to the pheromone/odorant-binding protein family.