Characterization of quantitative trait loci controlling genetic variation for preharvest sprouting in synthetic backcross-derived wheat lines

Aegilops tauschii, the wild relative of wheat, has stronger seed dormancy, a major component of preharvest sprouting resistance (PHSR), than bread wheat. A diploid Ae. tauschii accession (AUS18836) and a tetraploid (Triticum turgidum L. ssp. durum var. Altar84) wheat were used to construct a synthetic wheat (Syn37). The genetic architecture of PHS was investigated in 271 BC(1)F(7) synthetic backcross lines (SBLs) derived from Syn37/2*Janz (resistant/susceptible). The SBLs were evaluated in three environments over 2 years and PHS was assessed by way of three measures: the germination index (GI), which measures grain dormancy, the whole spike assay (SI), which takes into account all spike morphology, and counted visually sprouted seeds out of 200 (VI). Grain color was measured using both Chroma Meter- and NaOH-based approaches. QTL for PHSR and grain color were mapped and their additive and epistatic effects as well as their interactions with environment were estimated by a mixed linear-model approach. Single-locus analysis following composite interval mapping revealed four QTL for GI, two QTL for SI, and four QTL for VI on chromosomes 3DL and 4AL. The locus QPhs.dpiv-3D.1 on chromosome 3DL was tightly linked to the red grain color (RGC) at a distance of 5 cM. The other locus on chromosome 3D, "QPhs.dpiv-3D.2" was independent of RGC locus. Two-locus analysis detected nine QTL with main effects and 18 additive x additive interactions for GI, SI, and VI. Two of the nine main effects QTL and two epistatic QTL showed significant interactions with environments. Both additive and epistatic effects contributed to phenotypic variance in PHSR and the identified markers are potential candidates for marker-assisted selection of favorable alleles at multiple loci. SBLs derived from Ae. tauschii proved to be a promising tool to dissect, introgress, and pyramid different PHSR genes into adapted wheat genetic backgrounds. The enhanced expression of PHS resistance in SBLs enabled us to develop white PHS-resistant wheat germplasm from the red-grained Ae. tauschii accession.     

Construction of Adipogenic ceRNA Network Based on lncRNA Expression Profile of Adipogenic Differentiation of Human MSC Cells

Biochemical Genetics - The Long non-coding RNA (lncRNA) expression profile data of ten samples including human Mesenchymal Stem Cell (MSC) adipogenic differentiation 0, 3, and 6 days from...     

Efficient non-viral reprogramming of myoblasts to stemness with a single small molecule to generate cardiac progenitor cells

The current protocols for generation of induced pluripotent stem (iPS) cells involve genome integrating viral vectors which may induce tumorgenesis. The aim of this study was to develop and optimize a non-viral method without genetic manipulation for reprogramming of skeletal myoblasts (SMs) using small molecules.

Methods and Results

SMs from young male Oct3/4-GFP⁺ transgenic mouse were treated with DNA methyltransferase (DNMT) inhibitor, RG108. Two weeks later, GFP⁺ colonies of SM derived iPS cells (SiPS) expressing GFP and with morphological similarity of mouse embryonic stem (ESCs) were formed and propagated in vitro. SiPS were positive for alkaline phosphatase activity, expressed SSEA1, displayed ES cell specific pluripotency markers and formed teratoma in nude mice. Optimization of culture conditions for embryoid body (EBs) formation yielded spontaneously contracting EBs having morphological, molecular, and ultra-structural similarities with cardiomyocytes and expressed early and late cardiac markers. miR profiling showed abrogation of let-7 family and upregulation of ESCs specific miR-290-295 cluster thus indicating that SiPS were similar to ESCs in miR profile. Four weeks after transplantation into the immunocompetent mice model of acute myocardial infarction (n = 12 per group), extensive myogenesis was observed in SiPS transplanted hearts as compared to DMEM controls (n = 6 per group). A significant reduction in fibrosis and improvement in global heart function in the hearts transplanted with SiPS derived cardiac progenitor cells were observed.

Conclusions

Reprogramming of SMs by DNMT inhibitor is a simple, reproducible and efficient technique more likely to generate transgene integration-free iPS cells. Cardiac progenitors derived from iPS cells propagated extensively in the infarcted myocardium without tumorgenesis and improved cardiac function.