Project description:Diverse populations of natural killer cells, which exert critical early cytolytic functions against virally infected cells, have recently been uncovered, raising issues of lineage relationships. We used expression of the transcription factor PLZF to identify the developmental intermediates of ILC1s, a subset of natural killer-like cells that are particularly abundant in the liver, and demonstrated a distinct precursor but parallel development and partial overlap with established classical NK stages. Using microarray analysis, we defined a set of PLZF-dependent genes that contributed to the lineage divergence between ILC1s and classical NK cells. Liver lymphocytes from pools of PLZF+/+ or PLZF-/- mice were sorted into ILC1s and cNKs for RNA isolation and Illumina expression profiling.
Project description:Diverse populations of natural killer cells, which exert critical early cytolytic functions against virally infected cells, have recently been uncovered, raising issues of lineage relationships. We used expression of the transcription factor PLZF to identify the developmental intermediates of ILC1s, a subset of natural killer-like cells that are particularly abundant in the liver, and demonstrated a distinct precursor but parallel development and partial overlap with established classical NK stages. Using microarray analysis, we defined a set of PLZF-dependent genes that contributed to the lineage divergence between ILC1s and classical NK cells.
Project description:PURPOSE: To provide a detailed gene expression profile of the normal postnatal mouse cornea. METHODS: Serial analysis of gene expression (SAGE) was performed on postnatal day (PN)9 and adult mouse (6 week) total corneas. The expression of selected genes was analyzed by in situ hybridization. RESULTS: A total of 64,272 PN9 and 62,206 adult tags were sequenced. Mouse corneal transcriptomes are composed of at least 19,544 and 18,509 unique mRNAs, respectively. One third of the unique tags were expressed at both stages, whereas a third was identified exclusively in PN9 or adult corneas. Three hundred thirty-four PN9 and 339 adult tags were enriched more than fivefold over other published nonocular libraries. Abundant transcripts were associated with metabolic functions, redox activities, and barrier integrity. Three members of the Ly-6/uPAR family whose functions are unknown in the cornea constitute more than 1% of the total mRNA. Aquaporin 5, epithelial membrane protein and glutathione-S-transferase (GST) omega-1, and GST alpha-4 mRNAs were preferentially expressed in distinct corneal epithelial layers, providing new markers for stratification. More than 200 tags were differentially expressed, of which 25 mediate transcription. CONCLUSIONS: In addition to providing a detailed profile of expressed genes in the PN9 and mature mouse cornea, the present SAGE data demonstrate dynamic changes in gene expression after eye opening and provide new probes for exploring corneal epithelial cell stratification, development, and function and for exploring the intricate relationship between programmed and environmentally induced gene expression in the cornea. Keywords: other
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:The precise lineage relationships between innate lymphoid cells (ILC) and the lymphoid tissue inducer (LTi) are poorly understood. Using single-cell multiplex transcriptional analysis of 100 lymphoid genes and single-cell cultures of fetal liver precursor cells, we identified the common proximal precursor to these lineages and showed that its bifurcation was precisely marked by the differential induction of the transcription factors PLZF and TCF1. Acquisition of individual ILC1/2/3-specific effector programs was initiated later, at the common ILC precursor (ILCP) stage, by transient expression of mixed ILC1/2/3 transcriptional patterns whereas, in contrast, LTi development did not go through multilineage priming. These findings provide novel insights into divergent mechanisms of ILC and LTi lineage differentiation and establish a high-resolution map of their development.
Project description:The transcription factor PLZF (promyelocytic leukemia zinc finger) is encoded by the BTB domain-containing 16 (Zbtb16) gene. Its repressor function regulates specific transcriptional programs. During the development of invariant natural killer T (NKT) cells, PLZF is expressed and directs their effector program but the detailed mechanisms underlying PLZF regulation of multi-stage NKT cell developmental program are not well understood. This study investigated the role of acetylation-induced PLZF activation on NKT cell development by analyzing mice expressing a mutant form of PLZF mimicking constitutive acetylation (PLZFON mice). NKT populations in PLZFON mice were reduced in proportion and numbers of cells, and the cells present were blocked at the transition from developmental stage 1 to stage 2. NKT cell subset differentiation was also altered, with T-bet+ NKT1 and RORt+ NKT17 subsets dramatically reduced, and the emergence of a T-bet-RORt- NKT cell subset with features of cells in early developmental stages rather than mature NKT2 cells. Preliminary analysis of DNA methylation patterns suggested that activated PLZF acts on the DNA methylation signature to regulate NKT cells’ entry into the early stages of development, while repressing maturation. In wild-type NKT cells, deacetylation of PLZF is possible, allowing subsequent NKT cell differentiation. Interestingly, development of other innate lymphoid and myeloid cells, that are dependent on PLZF for their generation, is not altered in PLZFON mice highlighting lineage specific regulation. Overall, we propose that specific epigenetic control of PLZF through acetylation levels is required to regulate normal NKT cell differentiation. Key points: Constitutive acetylation of PLZF (PLZFON) blocks NKT cell development. PLZFON might act on the DNA methylation signature to control gene expression. PLZF acetylation levels regulate normal NKT cell differentiation.
Project description:Cellular binary fate decisions require the progeny to silence genes associated with the alternative fate. The major subsets of alpha:beta T cells have been extensively studied as a model system for fate decisions. While the transcription factor RUNX3 is required for the initiation of Cd4 silencing in CD8 T cell progenitors, it is not required to maintain the silencing of Cd4 and other helper T lineage genes. The other runt domain containing protein, RUNX1, silences Cd4 in an earlier T cell progenitor, but this silencing is reversed whereas the gene silencing after RUNX3 expression is not reverse. Therefore, we hypothesized that RUNX3 and not RUNX1 recruits other factors that maintains the silencing of helper T lineage genes in CD8 T cells. To this end, we performed a proteomics screen of RUNX1 and RUNX3 to determine candidate silencing factors.
Project description:The transcription factor PLZF (promyelocytic leukemia zinc finger) is encoded by the BTB 42 domain-containing 16 (Zbtb16) gene. Its repressor function regulates specific transcriptional 43 programs. During the development of invariant natural killer T (NKT) cells, PLZF is 44 expressed and directs their effector program but the detailed mechanisms underlying PLZF 45 regulation of multi-stage NKT cell developmental program are not well understood. This 46 study investigated the role of acetylation-induced PLZF activation on NKT cell development 47 by analyzing mice expressing a mutant form of PLZF mimicking constitutive acetylation (PLZFON mice). NKT populations in PLZFON 48 mice were reduced in proportion and numbers 49 of cells, and the cells present were blocked at the transition from developmental stage 1 to stage 2. NKT cell subset differentiation was also altered, with T-bet+ NKT1 and RORJt + 50 NKT17 subsets dramatically reduced, and the emergence of a T-bet - RORJt - 51 NKT cell subset 52 with features of cells in early developmental stages rather than mature NKT2 cells. Analysis 53 of DNA methylation patterns indicated that activated PLZF establishes a unique DNA 54 methylation signature to regulate NKT cells’ entry into the early stages of development, while 55 repressing maturation. In wild-type NKT cells, deacetylation of PLZF alleviates this 56 repression and allows subsequent NKT cell differentiation. Interestingly, development of 57 other innate lymphoid and myeloid cells, that are dependent on PLZF for their generation, is not altered in PLZFON 58 mice highlighting lineage specific regulation. Overall, we propose that 59 specific epigenetic control of PLZF through acetylation levels is required to regulate normal 60 NKT cell differentiation.