Project description:Body temperature is maintained in a narrow range in mammals, primarily controlled by sweating. In humans, the dynamic thermoregulatory organ, comprised of 2-4 million sweat glands distributed over the body, can secrete up to 4 liters of sweat per day1, thereby making it possible to withstand high temperatures and run long distances. The genetic basis for sweat gland function, however, is largely unknown. We find that a forkhead transcription factor, FoxA1, is required to generate mouse sweating capacity. When FoxA1 is ablated, mice are otherwise healthy and sweat gland morphogenesis occurs, but no sweating ensues, with the Nkcc1 sodium/potassium/chloride co-transporter and a specialized Ca2+-activated bicarbonate channel protein, Best2, both sharply down-regulated, and glycoprotein accumulating in gland lumens and ducts. Furthermore, Best2 knockout mice display comparable anhidrosis and glycoprotein accumulation. These findings link earlier observations that both sodium/potassium/chloride exchange and Ca2+ are required for sweat production. FoxA1 is inferred to regulate two corresponding features of sweat secretion. One, via Best2, catalyzes a bicarbonate gradient that could help to drive calcium-associated ionic transport; the other, requiring Nkcc1, facilitates monovalent ion exchange into sweat. These mechanistic components can be pharmaceutical targets to defend against hyperthermia and alleviate defective thermoregulation in the elderly2, and may provide a model relevant to more complex secretory processes.
Project description:Body temperature is maintained in a narrow range in mammals, primarily controlled by sweating. In humans, the dynamic thermoregulatory organ, comprised of 2-4 million sweat glands distributed over the body, can secrete up to 4 liters of sweat per day1, thereby making it possible to withstand high temperatures and run long distances. The genetic basis for sweat gland function, however, is largely unknown. We find that a forkhead transcription factor, FoxA1, is required to generate mouse sweating capacity. When FoxA1 is ablated, mice are otherwise healthy and sweat gland morphogenesis occurs, but no sweating ensues, with the Nkcc1 sodium/potassium/chloride co-transporter and a specialized Ca2+-activated bicarbonate channel protein, Best2, both sharply down-regulated, and glycoprotein accumulating in gland lumens and ducts. Furthermore, Best2 knockout mice display comparable anhidrosis and glycoprotein accumulation. These findings link earlier observations that both sodium/potassium/chloride exchange and Ca2+ are required for sweat production. FoxA1 is inferred to regulate two corresponding features of sweat secretion. One, via Best2, catalyzes a bicarbonate gradient that could help to drive calcium-associated ionic transport; the other, requiring Nkcc1, facilitates monovalent ion exchange into sweat. These mechanistic components can be pharmaceutical targets to defend against hyperthermia and alleviate defective thermoregulation in the elderly2, and may provide a model relevant to more complex secretory processes. For expression profiling of FoxA1, hairless fore footpad skin (6) was collected from FoxA1 knockouts and wild-type littermates at P10, P14 and P31. Three skin samples from 3 embryos for each genotype at each time point were used for biological replicates. Total RNAs were isolated with Trizol (Invitrogen), precipitated by 7.5M LiCl (Ambion), and cyanine-3-labeled cRNAs were hybridized to the NIA Mouse 44K Microarray v3.0 (Agilent Technologies). Triplicate data were analyzed by ANOVA (6). Genes with FDR<0.05, fold difference>1.5 and mean log intensity>2.0 were considered to be significant.
Project description:Evaporation of sweat on the skin surface is the major mechanism for dissipating heat in humans. The secretory capacity of sweat glands (SWGs) declines during aging, leading to heat intolerance in the elderly, but the mechanisms responsible for this decline remain incompletely understood. We investigated the molecular changes accompanying SWG aging in mice, where sweat tests confirmed a significant reduction of active SWGs in old mice relative to young mice. We first identified SWG-enriched mRNAs by comparing the transcriptome of Eda mutant Tabby mice, which lack SWGs, with that of wild-type control mice by RNA-sequencing analysis. This comparison revealed 171 mRNAs enriched in SWGs, including 47 mRNAs encoding core secretory proteins such as transcription factors, ion channels, ion transporters, and trans-synaptic signaling proteins. Among these, 28 SWG-enriched mRNAs showed significantly altered abundance in the aged footpad skin, and 11 of them, including Foxa1, Best2, Chrm3, and Foxc1 mRNAs belonged to the ‘core secretory’ category. Consistent with the changes in mRNA expression, immunohistology revealed that higher numbers of secretory cells from old SWGs express FOXC1 protein, the product of Foxc1 mRNA. In sum, our study identified mRNAs enriched in SWGs, including those that encode core secretory proteins, and changes in these mRNAs and proteins with SWG aging in mice.
Project description:Evaporation of sweat on the skin surface is the major mechanism for dissipating heat in humans. The secretory capacity of sweat glands (SWGs) declines during aging, leading to heat intolerance in the elderly, but the mechanisms responsible for this decline remain incompletely understood. We investigated the molecular changes accompanying SWG aging in mice, where sweat tests confirmed a significant reduction of active SWGs in old mice relative to young mice. We first identified SWG-enriched mRNAs by comparing the transcriptome of Eda mutant Tabby mice, which lack SWGs, with that of wild-type control mice by RNA-sequencing analysis. This comparison revealed 171 mRNAs enriched in SWGs, including 47 mRNAs encoding core secretory proteins such as transcription factors, ion channels, ion transporters, and trans-synaptic signaling proteins. Among these, 28 SWG-enriched mRNAs showed significantly altered abundance in the aged footpad skin, and 11 of them, including Foxa1, Best2, Chrm3, and Foxc1 mRNAs belonged to the ‘core secretory’ category. Consistent with the changes in mRNA expression, immunohistology revealed that higher numbers of secretory cells from old SWGs express FOXC1 protein, the product of Foxc1 mRNA. In sum, our study identified mRNAs enriched in SWGs, including those that encode core secretory proteins, and changes in these mRNAs and proteins with SWG aging in mice.
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.
Project description:Olfaction is one of the most crucial senses for vertebrates regarding foraging and social behavior. Therefore, it is of particular interest to investigate the sense of smell, its function on a molecular level, the signaling proteins involved in the process and the mechanism of required ion transport. In recent years, the precise role of the ion transporter NKCC1 in olfactory sensory neuron (OSN) chloride accumulation has been a controversial subject. NKCC1 is expressed in OSNs and is involved in chloride accumulation of dissociated neurons, but it had not been shown to play a role in mouse odorant sensation. To characterize transporter gene expression in NKCC1-/- mice, we examined the OE gene profile (Supplementary Table 1) using Illumina RNA-Seq to generate OE transcriptomes from NKCC1-/- and wild type mice. We analyzed RNA from OEs of male and female NKCC1+/+ (12 ± 1 weeks) and NKCC1-/- mice (16.5 ± 3.5 weeks, NMRI background); each RNA sample was prepared from an OE pool of 4 (mixed-gender pool RNA isolation) or 2 (gender RNA pool) different mice for each condition. Our data demonstrated the absence of a highly expressed ion transporter that could compensate for NKCC1. The Illumina RNA-Seq protocol was utilized. In total, we amplified and sequenced up to 38 million 101 nt-long fragments from murine NKCC1+/+ and NKCC1-/- adult OEs.
Project description:To understand the mechanisms through which JunB regulates Tregs-mediated immune regulation, we examined the global gene expression profiles in the JunB WT and KO Tregs by performing RNA sequencing (RNA-seq) analysis.
Project description:The SLICK1 mutation confers thermotolerance to cattle inheriting one or two copies of the gene. Results are unclear as to whether the mutation changes capacity of animals to undergo sweating during heat stress. Accordingly, differences in characteristics of sweat glands between slick and wildtype Holstein heifers was determined. There were no differences in the proportion of skin occupied by sweat glands but sweat glands from slick heifers had higher amounts of immunoreactive FOXA1 than wildtype heifers. FOXA1 is a transcription factor important for sweating. While results do not support the idea that the SLICK1 mutation changes the abundance of sweat glands in skin, it did affect functional properties of sweat glands, as indicated by increased abundance of immunoreactive FOXA1.
Project description:Olfaction is one of the most crucial senses for vertebrates regarding foraging and social behavior. Therefore, it is of particular interest to investigate the sense of smell, its function on a molecular level, the signaling proteins involved in the process and the mechanism of required ion transport. In recent years, the precise role of the ion transporter NKCC1 in olfactory sensory neuron (OSN) chloride accumulation has been a controversial subject. NKCC1 is expressed in OSNs and is involved in chloride accumulation of dissociated neurons, but it had not been shown to play a role in mouse odorant sensation. To characterize transporter gene expression in NKCC1-/- mice, we examined the OE gene profile (Supplementary Table 1) using Illumina RNA-Seq to generate OE transcriptomes from NKCC1-/- and wild type mice. We analyzed RNA from OEs of male and female NKCC1+/+ (12 ± 1 weeks) and NKCC1-/- mice (16.5 ± 3.5 weeks, NMRI background); each RNA sample was prepared from an OE pool of 4 (mixed-gender pool RNA isolation) or 2 (gender RNA pool) different mice for each condition. Our data demonstrated the absence of a highly expressed ion transporter that could compensate for NKCC1.