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Bone tissue engineering (BTE) is a complex biological process involving the repair of bone tissue with proper neuronal network and vasculature as well as bone surrounding soft tissue. Synthetic biomaterials used for BTE should be biocompatible, support bone tissue regeneration, and eventually be degraded in situ and replaced with the newly generated bone tissue. Recently, various forms of bone graft materials such as hydrogel, nanofiber scaffolds, and 3D printed composite scaffolds have been developed for BTE application. Decellularized extracellular matrix (DECM), a kind of natural biological material obtained from specific tissues and organs, has certain advantages over synthetic and exogenous biomaterial-derived bone grafts. Moreover, DECM can be developed from a wide range of biological sources and possesses strong molding abilities, natural 3D structures, and bioactive factors. Although DECM has shown robust osteogenic, proangiogenic, immunomodulatory, and bone defect healing potential, the rapid degradation and limited mechanical properties should be improved for bench-to-bed translation in BTE. This review summarizes the recent advances in DECM-based BTE and discusses emerging strategies of DECM-based BTE.

The glume is an organ of the maize spikelet and plays important roles in anther and kernel development. Vestigial glume1(Vg1) is a classic mutant associated with ligule and glume development. Here we report the phenotypic characterization, fine mapping, and candidate gene analysis of the Vg1mutant. Vg1is a semi-dominant and pleiotropic gene, and also affects plant height, ear height, and tassel length. Vg1ligule degeneration begins at the first leaf, and the Vg1tassel and ear can be distinguished from those of wild-type plants when their lengths reach respectively 55 mm and 51 mm. Using a BC3mapping population of 11,445 plants, we delimited the Vg1functional site to an interval of 7.4 kb, flanked by the markers InDelLMand CRM6. A putative cyclopropane fatty-acid synthase gene (ZmCPA-FAS1) was hypothesized to underlie the mutant phenotype. We detected a Helitroninsertion in the sixth intron of ZmCPA-FAS1. Its presence caused abnormal alternative splicing of ZmCPA-FAS1that conferred new characteristics on the Vg1mutant. These findings are a basis for further discovery of the molecular mechanism underlying glume development and a potential guide for maize breeding of small-glume varieties, especially sweet corn breeding.

Elucidating the correlations among maize (Zea maysL.) brace-root traits and identifying the quantitative trait loci (QTL) that control the traits are important for genetic improvement of brace-root traits. Two maize inbred lines, Yi17 (well-developed root system) and Yi16 (poorly developed root system), an F2population derived from their cross containing 276 individuals, and an F2:3population containing 241 families were used to analyze the correlations among brace-root traits and determine the QTL for brace-root traits at Xiema and Hechuan in 2014 and 2015. All brace-root traits were highly significantly correlated with each other. In particular, brace-root diameter was highly correlated with brace-root fresh weight (r= 0.730), brace-root dry weight (r= 0.729), root fresh weight (r= 0.734), and root dry weight (r= 0.754). A total of 212 simple sequence repeat (SSR) markers were used to develop a genetic map based on the F2population. The total length of the genetic map was 1558.9 cM, with a mean interval of 7.35 cM between adjacent markers. Ninety-three QTL controlling the brace-root traits were detected in generations F2at Xiema in 2014 and F2:3at Xiema and Hechuan in 2015. However, only two consistent major QTL were identified in F2:3generation—qBRTN8b for brace-root tier number and qBRD8b for brace-root diameter. The qBRTN8b was located in the mmc0181 to bnlg1031 interval (bin 8.06) on chromosome 8, which explained 32.64% (at Xiema) and 16.18% (at Hechuan) of phenotypic variation. The qBRD8b was mapped in the umc2367 to umc1846 interval (bin 8.05) on chromosome 8, which explained 14.28% (at Xiema) and 10.41% (at Hechuan) of phenotypic variation. Moreover, three new important chromosomal regions harboring QTL for brace-root traits were detected—bins 5.04, 6.06, and 8.05 to 8.06. These results could provide a very important reference for evaluating root traits under field conditions and for fine mapping QTL of brace-root traits in maize.

ZAG2has been identified as a maternally expressed imprinted gene in maize endosperm. Our study revealed that paternally inherited ZAG2alleles were imprinted in maize endosperm and embryo at 14days after pollination (DAP), and consistently imprinted in endosperm at 10, 12, 16, 18, 20, 22, 24, 26, and 28 DAP in reciprocal crosses between B73 and Mo17. ZAG2alleles were also imprinted in reciprocal crosses between Zheng 58 and Chang 7-2 and between Huang C and 178. ZAG2alleles exhibited differential imprinting in hybrids of 178×Huang C and B73×Mo17, while in other hybrids ZAG2alleles exhibited binary imprinting. The tissue-specific expression pattern of ZAG2showed that ZAG2was expressed at a high level in immature ears, suggesting that ZAG2plays important roles in not only kernel but ear development.