The DMRT gene family in amphioxus

<div><p>Doublesex and Mab-3-related transcription factor (DMRT) gene family is widely known for its involvement in sex determination and/or differentiation among different phyla. In this study, we identify eight DMRT genes in the cephalochordate amphioxus, a protochordate holding a key phylogenetic position. The eight DMRTs can be divided into two groups based on the conserved domain: BfDM044, BfDM045, BfDM55.1, BfDM115.1, and BfDM17.1 belong to the first group which have both DM and DMA domains, while BfDM246.1, BfDM084, and BfDM175 belong to the second group which have only DM domain. Most of the first group members have same genomic structure except BfDM17.1, while no regular pattern exists in the second group. Phylogenetic analysis of the DM domain sequences shows that DMRT genes in vertebrates form seven different independent clusters, and some even contain genes from invertebrates with high bootstrap. Notably, the first group members of amphioxus cluster with vertebrate DMRTs; while the second group members cluster into a single branch, which diverge from the vertebrate classes. The results suggest that several DMRT genes in vertebrates may evolve from homologous genes in invertebrates. As in nematode, drosophila, fish, and vertebrates, DMRT genes cluster is also found in amphioxus, which may be the result of gene duplication. Interspecific differences in the amphioxus DMRTs and sea squirt DMRTs may suggest post-speciation duplication of some DMRT genes.</p> </div

Assessment of apoptotic BPCs show a higher rate of apoptotic BPCs in the wildtype retina.

<p>A–L. Representative confocal images of the central retinas from wildtype, <i>Pou4f2^−/−, Atoh7^−/−</i>, and DKO mice at P5, P10 and P15. Retinas were labeled with antibodies to Chx10 (red), cleaved Caspase-3 (green) and TOPRO-3 (blue). Scale bar  = 50 µm. M. A histogram showing the percentage of Caspase-3 and Chx10-double positive cells over the Chx10-positive cells, depicting the ratio of apoptotic bipolar cells over all bipolar cells in four different retinas.</p

The number of <i>Vsx1</i>-expressing cells supports that fewer C-BPCs are found in the <i>Atoh7^−/−</i> retina.

<p>A–F. Confocal images of cryosections showing <i>Vsx1^LacZ/+</i>-expressing C-BPCs (green) in the wildtype (<i>Atoh7^+/−;Vsx1^LacZ/+</i>) and <i>Atoh7^−/−</i> (<i>Atoh7^−/−;Vsx1^LacZ/+</i>) retinas. Green: LacZ; red: propidium iodide. Scale bar  = 50 µm. G. A histogram comparing the mean number of <i>Vsx1^LacZ</i>-positive cells in wildtype and <i>Atoh7^−/−</i> retinas.</p

Phospho-Histone-3 and BrdU labeling of the peripheral retinas show the number of proliferating cells corresponds to the existing RGC number.

<p>A–H. Representative confocal images at P0 and P4 show PH3-positive cells (green) in cryosections of wildtype and RGC-depleted retinas. I–L. Representative confocal images at P4 show PH3-positive cells in flat-mounted retinas. Dash lines mark the edge of the retina. M–T. Representative confocal images at P4 and P7 show BrdU-positive cells (green) in cryosections. Red in all panels: propidium iodide. All scale bars  = 50 µm. U–W. Histograms comparing the numbers of proliferating cells estimated by PH3-positive cells in sections (U), PH3-positive cells in flat-mounts (V), and BrdU-positive cells in sections (W). Proliferating cell numbers found in all retinas at P10 are either zero or close to zero. There is no significant difference between any two genotypes at P10.</p

Phospho-Histone-3 and BrdU labeling show unexpected proliferation dynamics in the central retinas that have varying degrees of RGC loss.

<p>A–H. Representative confocal images at P0 and P4 show PH3-positive cells (green) in cryosections of wildtype and RGC-depleted retinas. I–L. Representative confocal images at P4 show PH3-positive cells in flat-mounted retinas. M–T. Representative confocal images at P0 and P4 show BrdU-positive cells (green) in cryosections. Red: PI. All scale bars  = 50 µm. U–W. Histograms comparing the numbers of proliferating cells estimated by PH3-positive cells in sections (U), PH3-positive cells in flat-mounts (V), and BrdU-positive cells in sections (W). No proliferating cells were found in the sampled region in all examined retinas at P7 and P10.</p

Birthdating experiments confirm fewer C-BPC and normal R-BPC production in the <i>Atoh7^−/−</i> retina.

<p>A, B. Representative confocal images of retinal cryosections from mice that received BrdU injection at P1 and harvested at P20. In the inner nuclear layer, Chx10 antibody (red) labels both R-BPCs and C-BPCs; PKCα antibody (green) labels only R-BPCs; and BrdU (blue) marks the cells born at P1. A′ and B′ show only the BrdU channel at a positions corresponding to A and B. Arrows indicate R-BPCs and arrowheads indicate C-BPCs. Scale bar  = 50 µm. Cells outside of the inner nuclear layer were not analyzed. Images of retinas with BrdU injected at other time points are not shown. C, D. Statistical analysis comparing C-BPC (C) and R-BPC (D) cell counts that were born on a specific day. Significantly fewer C-BPCs were born in the <i>Atoh7^−/−</i> retina on each examined day. In the sampling area, no C-BPCs were observed in either wildtype or <i>Atoh7^−/−</i> retinas born at P7.</p

Assessment of C-BPC and R-BPC numbers show reduced C-BPC numbers and normal R-BPC numbers in the RGC-depleted retinas.

<p>A–P. Representative confocal images from the central retinas from wildtype, <i>Pou4f2^−/−, Atoh7^−/−</i>, and DKO mice at P5, P10, P15, and P21. Samples were labeled with Chx10- (red) and PKCα- (green) to depict total BPCs and R-BPCs respectively. Nuclei were counterstained with TOPRO-3 (blue). Scale bar  = 50 µm. Q–S. Histograms comparing the mean numbers of total BPCs (Q), R-BPCs (R), and C-BPCs (S) in four different retinas with varying degrees of RGC depletion. Means of the C-BPC populations were calculated by taking the difference between Chx10- and PKCα- positive cell counts.</p

Synthesis of Trelagliptin Succinate

An improved process for the synthesis of antidiabetic drug trelagliptin succinate through unprotected (<i>R</i>)-3-aminopiperidine was described. The impurity profile with different conditions of the key substitution was illustrated, and then the best reaction condition was identified. The optimizations also included the bromination of 4-fluoro-2-methylbenzonitrile so that the process became efficient and concise

Bismuth-Induced Inactivation of Ferric Uptake Regulator from <i>Helicobacter pylori</i>

Ferric uptake regulator (Fur) of <i>Helicobacter pylori</i> is a global regulator that is important for bacterial colonization and survival within the gastric mucosa. <i>H. pylori</i> Fur (<i>Hp</i>Fur) is unique in its ability to regulate gene expression in both metal-bound (holo-Fur) and metal-free (apo-Fur) forms. Bismuth-based drugs are widely used for the treatment of <i>H. pylori</i> infection. However, the mechanism of action of bismuth drug was not fully understood. Recently, it has been reported that bismuth drugs could interfere with the bacterial ferric uptake pathway and inhibit bacterial growth, implying intrinsic correlation between bismuth drug and bacterial iron metabolism. Herein, we demonstrate that Bi­(III) binds to <i>Hp</i>Fur protein specifically at the physiologically important S1 site, which further leads to protein oligomerization and loss of DNA binding capability. The targeting of <i>Hp</i>Fur by bismuth drugs significantly reduced transcription levels of its regulated genes, which are crucial for bacterial physiology and metabolism. Our studies present direct evidence that perturbation of iron metabolism in <i>H. pylori</i> by bismuth might serve as one of the mechanisms for the antimicrobial activity of bismuth drugs

Additional file 1 of Chloroplast genome analyses of Caragana arborescens and Caragana opulens

Additional file 1: Table S1. Statistical table of sequencing data