Project description:The Sex-linked orange mutation in domestic cats causes variegated patches of reddish/yellow hair and is a defining signature of random X-inactivation in female tortoiseshell and calico cats. Unlike the situation for most coat color genes, there is no apparent homolog for Sex-linked orange in other mammals. We show that Sex-linked orange is caused by a 5 kb deletion that leads to ectopic and melanocyte-specific expression of the Rho GTPase Activating Protein 36 (Arhgap36) gene. Single cell RNA-seq studies from fetal cat skin reveal that red/yellow hair color is caused by reduced expression of melanogenic genes that are normally activated by the Melanocortin 1 receptor (Mc1r)—cyclic adenosine monophosphate (cAMP)—protein kinase A (PKA) pathway, but Mc1r and its ability to stimulate cAMP accumulation is intact. Instead, we show that expression of Arhgap36 in melanocytes leads to reduced levels of the PKA catalytic subunit (PKAC); thus, Sex-linked orange is genetically and biochemically downstream of Mc1r. Our findings resolve a longstanding comparative genetic puzzle, provide in vivo evidence for the ability of Arhgap36 to inhibit PKA, and reveal a molecular explanation for a charismatic color pattern with a rich genetic history.
Project description:The Sex-linked orange mutation in domestic cats causes variegated patches of reddish/yellow hair and is a defining signature of random X-inactivation in female tortoiseshell and calico cats. Unlike the situation for most coat color genes, there is no apparent homolog for Sex-linked orange in other mammals. We show that Sex-linked orange is caused by a 5 kb deletion that leads to ectopic and melanocyte-specific expression of the Rho GTPase Activating Protein 36 (Arhgap36) gene. Single cell RNA-seq studies from fetal cat skin reveal that red/yellow hair color is caused by reduced expression of melanogenic genes that are normally activated by the Melanocortin 1 receptor (Mc1r)—cyclic adenosine monophosphate (cAMP)—protein kinase A (PKA) pathway, but Mc1r and its ability to stimulate cAMP accumulation is intact. Instead, we show that expression of Arhgap36 in melanocytes leads to reduced levels of the PKA catalytic subunit (PKAC); thus, Sex-linked orange is genetically and biochemically downstream of Mc1r. Our findings resolve a longstanding comparative genetic puzzle, provide in vivo evidence for the ability of Arhgap36 to inhibit PKA, and reveal a molecular explanation for a charismatic color pattern with a rich genetic history.
Project description:BACKGROUND: MicroRNAs negatively regulate gene expression and play a pivotal role in the pathogenesis of human type 2 diabetes mellitus (T2DM). As the domestic cat presents a spontaneous animal model for human T2DM, the purpose of this study was to investigate whether microRNAs are detectable in feline serum and whether microRNA expression profiles differ between healthy and diabetic cats. METHODS: Total RNA was extracted from 400 µl serum of healthy lean (HL) and newly diagnosed diabetic (D) cats. MicroRNA microarrays representing 1079 distinct mouse miRNA targets were used to measure miRNA expression in samples from eight HL and eight D cats. RESULTS: By microarray, 227 distinct microRNAs were identified. Nineteen miRNAs were differentially expressed in diabetic cats, but only two reached statistical significance after correction for multiple comparisons. In qRT-PCR, miR-122* was found to be upregulated in diabetic cats more than 40-fold compared to HL cats, while miR-193b was upregulated about 10-fold. MiR-483* showed a 6- fold increase in diabetic cats compared to HL cats. CONCLUSIONS: Small volumes of serum samples yield sufficient material to detect altered microRNA expression profiles in diabetic cats. The domestic cat may be considered a useful animal model for studying miRNAs involved in human T2DM.
2013-04-11 | GSE37177 | GEO
Project description:What determines plant species diversity along the Silk Road in the East?
Project description:The silk gland (SG) of the domesticated silkworm Bombyx mori, an economically important insect that has been used for silk production for over 5000 years, is a remarkable organ that produces vast amounts of silk with exceptional properties . Little is known about which SG cells execute silk protein synthesis and its precise spatiotemporal control. Here, we used single-cell RNA-seq to build a comprehensive cell atlas of the B. mori SG, consisting of 14,972 high-quality cells representing 10 distinct cell types, in three early developmental stages. We annotated all 10 cell types and determined their distributions in each region of the SG, decoded their developmental trajectory and gene-switch status, and discovered marker genes involved in the regulation of SG development and silk protein synthesis. Our study reveals the high heterogeneity of B. mori SG cells and their gene expression dynamics for the first time, affording a deeper understanding of silk-producing organs at the single-cell level .
Project description:Chronic kidney disease (CKD) is the leading cause of mortality in aged cats. After injury, feline kidneys undergo extensive metabolic reprogramming, but a comprehensive evaluation is lacking. Integration of serum metabolome from early stages, late stages CKD and healthy control cats with renal cortex and medulla transcriptome and proteome can reveal spatiotemporal patterns of gene and protein expression changes. In this study, we conducted mass spectrometry (MS)-based proteomic analysis of kidney (cortex and medulla) tissues from cats with CKD and control cats, euthanized for humane reasons unrelated to the study.
Project description:BACKGROUND: MicroRNAs negatively regulate gene expression and play a pivotal role in the pathogenesis of human type 2 diabetes mellitus (T2DM). As the domestic cat presents a spontaneous animal model for human T2DM, the purpose of this study was to investigate whether microRNAs are detectable in feline serum and whether microRNA expression profiles differ between healthy and diabetic cats. METHODS: Total RNA was extracted from 400 M-BM-5l serum of healthy lean (HL) and newly diagnosed diabetic (D) cats. MicroRNA microarrays representing 1079 distinct mouse miRNA targets were used to measure miRNA expression in samples from eight HL and eight D cats. RESULTS: By microarray, 227 distinct microRNAs were identified. Nineteen miRNAs were differentially expressed in diabetic cats, but only two reached statistical significance after correction for multiple comparisons. In qRT-PCR, miR-122* was found to be upregulated in diabetic cats more than 40-fold compared to HL cats, while miR-193b was upregulated about 10-fold. MiR-483* showed a 6- fold increase in diabetic cats compared to HL cats. CONCLUSIONS: Small volumes of serum samples yield sufficient material to detect altered microRNA expression profiles in diabetic cats. The domestic cat may be considered a useful animal model for studying miRNAs involved in human T2DM. Blood was drawn from two groups of cats: 8 healthy cats and 8 cats suffering from diabetes. After clotting, samples were centrifuged and total mRNA was extracted from serum. These 16 serum samples were analyzed and the groups were compared. Due to technical problems during hybridization (leaking chamber), sample 1_4_B (Serum_diabetic_8) was not included into analysis.