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Self-incompatibility (SI) is a crucial mechanism that prevents self-fertilization and inbreeding in flowering plants. Citrus exhibits SI regulated by a polymorphic S -locus containing an S-RNase gene and multiple S -locus F-box (SLF) genes. It has been documented that S-RNase functions as the pistil S determinant, but there is no direct evidence that the SLF genes closely linked with S-RNase function as pollen S determinants in Citrus. This study assembled the genomes of two pummelo (Citrus grandis) plants, obtained three novel complete and well-annotated S -haplotypes, and isolated 36 SLF or SLF-like alleles on the S -loci. Phylogenetic analysis of 138 SLFs revealed that the SLF genes were classified into 12 types, including six types with divergent or missing alleles. Furthermore, transformation experiments verified that the conserved S6-SLF7a protein can lead to the transition of SI to self-compatibility by recognizing non-self S8-RNase in 'Mini-Citrus' plants (S 7 S 8 and S 8 S 29 , Fortunella hindsii), a model plant for citrus gene function studies. In vitro assays demonstrated interactions between SLFs of different S haplotypes and the Skp1–Cullin1–F-box subunit CgSSK1 protein. This study provides direct evidence that SLF controls the pollen function in Citrus , demonstrating its role in the 'non-self recognition' SI system. [ABSTRACT FROM AUTHOR]

Abstract Background Seedlessness is an important agronomic trait for citrus, and male sterility (MS) is one main cause of seedless citrus fruit. However, the molecular mechanism of citrus seedlessness remained not well explored. Results An integrative strategy combining suppression subtractive hybridization (SSH) library with cDNA microarray was employed to study the underlying mechanism of seedlessness of a Ponkan mandarin seedless mutant (Citrus reticulata Blanco). Screening with custom microarray, a total of 279 differentially expressed clones were identified, and 133 unigenes (43 contigs and 90 singletons) were obtained after sequencing. Gene Ontology (GO) distribution based on biological process suggested that the majority of differential genes are involved in metabolic process and respond to stimulus and regulation of biology process; based on molecular function they function as DNA/RNA binding or have catalytic activity and oxidoreductase activity. A gene encoding male sterility-like protein was highly up-regulated in the seedless mutant compared with the wild type, while several transcription factors (TFs) such as AP2/EREBP, MYB, WRKY, NAC and C2C2-GATA zinc-finger domain TFs were down-regulated. Conclusion Our research highlighted some candidate pathways that participated in the citrus male gametophyte development and could be beneficial for seedless citrus breeding in the future.

Objective: To observe and quantitatively analyze the effect of glucagon like peptide-1 (GLP-1) on the alveolar capillary basal lamina in spontaneous type 2 diabetes mellitus animal model Otsuka Long-Evans Tokushima Fatty (OLETF) rats., Methods: Experimental rats were divided into three groups: OLETF group, GLP-1-treated group (OLETF/G group), and Long-Evans Tokushima Otsuka group (LETO group) as control. The ultrastructure and thickness of the alveolar capillary basal lamina in the rats were examined by transmission electron microscopy and morphometry methods., Results: The fused basal lamina (F-BL) of the alveolar capillary endothelium and type I epithelial basal lamina, and the alveolar capillary endothelium basal lamina (Cap-BL) were thickened in OLETF rats than those of LETO rats [(110.60+/-14.14) nm vs (57.30+/-11.08) nm, and (118.40+/-19.12) nm vs (66.80+/-8.63) nm, P<0.01]. F-BL and Cap-BL were thinned in the OLETF/G group as compared with OLETF group [(79.70+/-5.44) nm vs (110.60+/-14.14) nm and (69.80 +/-3.32) nm vs (118.40+/-19.12) nm, P<0.01]., Conclusion: Our studies suggest the existence of ultrastructural changes of alveolar capillary basal lamina in OLETF rats. GLP-1 intervention decreases the damage of alveolar capillary basal lamina in OLETF rats.

Objective: To investigate the pathologic features and diagnostic algorithm of light chain nephropathy (LCN)., Methods: Seven cases of LCN were studied by light microscopy, electron microscopy and immunolabeling of light chains (kappa, lambda) by immunofluorescence and immunoelectron microscopy., Results: The histopathology of 7 cases by light microscopy was variable, with 3 cases showing nodular glomerulosclerosis, 1 case showing mild to moderate mesangial proliferation, and 3 cases showing cast nephropathy with minimal glomerular change. Immunofluorescence study revealed positive staining of a single type of light chain in mesangium (nodular pattern) or along glomerular basement membrane (linear), along tubular basement membrane and around arteriolar walls in all the 7 cases. Ultrastructurally, electron-dense granular deposits were identified in mesangium, subendothelial aspect of glomerular basement membrane, outer aspect of tubular basement membrane and arteriolar walls. Immunogold labeling of light chains showed distinct labeling of a single type light chain in the granular electron-dense materials (5 cases being kappa-positive and 2 being lambda-positive)., Conclusions: LCN typically shows nodular glomerulosclerosis. The ultrastructural change is characteristic and important for diagnosis. Immunolabeling of light chains by immunofluorescence and immunoelectron microscopy carries further diagnostic value, especially in cases with minimal light microscopic change.