Transcription factor gene TuGTγ-3 is involved in the stripe rust resistance in Triticum urartu.

Wheat stripe rust, caused by Puccinia striiformis West. f. sp. tritici Eriks. ＆Henn. (Pst), is a serious fungal disease. Identification of new genes associate with stripe rust resistance is important for developing disease resistant wheat cultivars and studying the mechanism of disease resistance. Trihelix is a plant specific transcription factor family, which is involved in regulation of growth and development, morphogenesis, and response to stresses. So far, no study reports on the relationship between the Trihelix family and wheat stripe rust. In this study, a gene in the GTγ subfamily of Trihelix family, designated TuGTγ-3, was cloned from Triticum urartu Tum. (2n=2x=14, AA). The results of sequencing demonstrated that TuGTγ-3 gene consisted of a complete open reading frame (ORF), and its coding sequence was 1329 bp in length, which encoded a protein with 442 amino acids. The predicted molecular weight of this protein was 50.31 kDa and the theoretical isoelectric point was 6.12. Bioinformatic analysis revealed that TuGTγ-3 protein had a monopartite nuclear localization signal (GLPMQKKMRYT), and had neither transmembrane domain nor signal peptide. The conserved trihelix domain, the fourth α-helix and the CC domain were located in the regions of Q115?R187, F234?Y241 and K362?K436, respectively. Dissection of secondary structure showed that TuGTγ-3 protein comprised of 43.89% α-helix, 9.51% extended strand, 9.95% ß-turn and 36.65% random coil structures. Based on the BLAST search against the genome database of common wheat from IWGSC, TuGTγ-3 was located on the long arm of chromosome 5A. Transient expression experiment using onion inner epidermal cell showed that the fusion protein TuGTγ-3-GFP distributed mainly in nuclear and slightly in cytoplasm. Expression profiles in different organs indicated that expression level of TuGTγ-3 was much higher in leaves than that in roots or leaf sheaths, and the expression in leaves was extremely up-regulated by infection of the Pst race CYR32. Furthermore, the BSMV-VIGS experiment demonstrated that the transcription factor TuGTγ-3 positively regulated resistance to stripe rust in T. urartu.

Dysregulated Arginine Metabolism Is Linked to Retinal Degeneration in Cep250 Knockout Mice.

Purpose: Degeneration of retinal photoreceptors is frequently observed in diverse ciliopathy disorders, and photoreceptor cilium gates the molecular trafficking between the inner and the outer segment (OS). This study aims to generate a homozygous global Cep250 knockout (KO) mouse and study the resulting phenotype. Methods: We used Cep250 KO mice and untargeted metabolomics to uncover potential mechanisms underlying retinal degeneration. Long-term follow-up studies using optical coherence tomography (OCT) and electroretinography (ERG) were performed. Results: OCT and ERG results demonstrated gradual thinning of the outer nuclear layer (ONL) and progressive attenuation of the scotopic ERG responses in Cep250-/- mice. More TUNEL signal was observed in the ONL of these mice. Immunostaining of selected OS proteins revealed mislocalization of these proteins in the ONL of Cep250-/- mice. Interestingly, untargeted metabolomics analysis revealed arginine-related metabolic pathways were altered and enriched in Cep250-/- mice. Mis-localization of a key protein in the arginine metabolism pathway, arginase 1 (ARG1), in the ONL of KO mice further supports this model. Moreover, adeno-associated virus (AAV)-based retinal knockdown of Arg1 led to similar architectural and functional alterations in wild-type retinas. Conclusions: Altogether, these results suggest that dysregulated arginine metabolism contributes to retinal degeneration in Cep250-/- mice. Our findings provide novel insights that increase understanding of retinal degeneration in ciliopathy disorders.

Image-Guided Optical Coherence Tomography to Assess Structural Changes in Rodent Retinas.

Ocular diseases, such as age-related macular degeneration, glaucoma, retinitis pigmentosa, and uveitis, are always accompanied by retinal structural changes. These diseases affecting the fundus always exhibit typical abnormalities in certain cell types in the retina, including photoreceptor cells, retinal ganglion cells, cells in the retinal blood vessels, and cells in the choroidal vascular cells. Noninvasive, highly efficient, and adaptable imaging techniques are required for both clinical practice and basic research. Image-guided optical coherence tomography (OCT) satisfies these requirements because it combines fundus photography and high-resolution OCT, providing an accurate diagnosis of tiny lesions as well as important changes in the retinal architecture. This study details the procedures of data collection and data analysis for image-guided OCT and demonstrates its application in rodent models of choroidal neovascularization (CNV), optic nerve crush (ONC), light-induced retinal degeneration, and experimental autoimmune uveitis (EAU). This technique helps researchers in the eye field to identify rodent retinal structural changes conveniently, reliably, and tractably.

Peripapillary structural and microvascular alterations in early dysthyroid optic neuropathy.

BACKGROUND: To explore the changes in blood supply and structure around the optic nerve head (ONH) in thyroid-associated ophthalmopathy (TAO) patients with suspected dysthyroid optic neuropathy (DON). METHODS: TAO patients [19 with DON; 24 non-DON (NDON); 20 with equivocal DON (EDON)], and 34 control subjects were examined. Optical coherence tomography angiography (OCTA) was used to obtain peripapillary retinal nerve fiber layer (p-RNFL) and vessel density parameters, including the ONH whole image vessel density (ONH-wiVD) and the radial peripapillary capillary vessel density (RPC-VD) in early DON. RESULTS: Although there were no differences in p-RNFL thickness among the groups, there were differences in the ONH-wiVD of each grid section and the RPC-VD in all areas (P < 0.01). Compared with healthy controls, the EDON eyes had significantly lower RPC-VDs in all aeras (P < 0.05).The peripapillary region was further divided into eight sectors, and the RPC-VD in the temporal upper, superior temporal, and temporal lower sectors in the EDON group were significantly lower than in the controls. The visual impairment was closely related to the loss of peripapillary capillary vessel density. Univariate correlation analysis showed that the ONH-wiVD and RPC-VD of the TAO groups were negatively correlated with the intraocular pressure (r = - 0.296, P = 0.006; r = - 0.258, P = 0.016 respectively). CONCLUSIONS: EDON patients had significantly lower ONH-wiVD and RPC-VD than control subjects, and the temporal and upper VDs were more likely to be affected in the early stage of TAO. The combined use of spectral domain optical coherence tomography and OCTA technologies offer a new method for early diagnosis of suspected DON patients.