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SummaryAlthough hundreds of genetic male sterility (GMS) mutants have been identified in maize, few are commercially used due to a lack of effective methods to produce large quantities of pure male‐sterile seeds. Here, we develop a multicontrol sterility (MCS) system based on the maize male sterility 7 (ms7) mutant and its wild‐type Zea mays Male sterility 7 (ZmMs7) gene via a transgenic strategy, leading to the utilization of GMS in hybrid seed production. ZmMs7 is isolated by a map‐based cloning approach and encodes a PHD‐finger transcription factor orthologous to rice PTC1 and Arabidopsis MS1. The MCS transgenic maintainer lines are developed based on the ms7‐6007 mutant transformed with MCS constructs containing the (i) ZmMs7 gene to restore fertility, (ii) α‐amylase gene ZmAA and/or (iii) DNA adenine methylase gene Dam to devitalize transgenic pollen, (iv) red fluorescence protein gene DsRed2 or mCherry to mark transgenic seeds and (v) herbicide‐resistant gene Bar for transgenic seed selection. Self‐pollination of the MCS transgenic maintainer line produces transgenic red fluorescent seeds and nontransgenic normal colour seeds at a 1:1 ratio. Among them, all the fluorescent seeds are male fertile, but the seeds with a normal colour are male sterile. Cross‐pollination of the transgenic plants to male‐sterile plants propagates male‐sterile seeds with high purity. Moreover, the transgene transmission rate through pollen of transgenic plants harbouring two pollen‐disrupted genes is lower than that containing one pollen‐disrupted gene. The MCS system has great potential to enhance the efficiency of maize male‐sterile line propagation and commercial hybrid seed production.

Previous studies have shown that haploinsufficiency of the splanchnic and septum transversum mesoderm Forkhead Box (Fox) f1 transcriptional factor caused defects in lung and gallbladder development and that Foxf1 heterozygous (؉/؊) mice exhibited defective lung repair in response to injury. In this study, we show that Foxf1 is expressed in hepatic stellate cells in developing and adult liver, suggesting that a subset of stellate cells originates from septum transversum mesenchyme during mouse embryonic development. Because liver regeneration requires a transient differentiation of stellate cells into myofibroblasts, which secrete type I collagen into the extracellular matrix, we examined Foxf1 ؉/؊ liver repair following carbon tetrachloride injury, a known model for stellate cell activation. We found that regenerating Foxf1 ؉/؊ liver exhibited defective stellate cell activation following CCl 4 liver injury, which was associated with diminished induction of type I collagen, ␣-smooth muscle actin, and Notch-2 protein and resulted in severe hepatic apoptosis despite normal cellular proliferation rates. Furthermore, regenerating Foxf1 ؉/؊ livers exhibited decreased levels of interferon-inducible protein 10 (IP-10), delayed induction of monocyte chemoattractant protein 1 (MCP-1) levels, and aberrantly elevated expression of transforming growth factor ␤1. T he Forkhead Box (Fox) family of transcription factors shares homology in the winged helix DNA binding domain, 1 and its members play important roles in cellular proliferation, differentiation, and metabolic homeostasis. [2][3][4][5][6] Haploinsufficiency of the Foxf1 gene (previously known as HFH-8 or Freac-1) in heterozygous (ϩ/Ϫ) mice causes perinatal lethality from pulmonary hemorrhage and severe defects in alveolarization, vascularization, and fusion of lung lobes. 7-9 Lung hemorrhage was observed in one half of newborn Foxf1 ϩ/Ϫ mice that had an 80% reduction in pulmonary Foxf1 levels (low Foxf1 ϩ/Ϫ) and reduced expression of genes involved in lung morphogenesis. 7 Interestingly, expression of these lung developmental genes was unchanged in 40% of the newborn Foxf1 ϩ/Ϫ mice that had near wildtype (WT) pulmonary levels of Foxf1 messenger RNA (mRNA) (high Foxf1 ϩ/Ϫ mice) without pulmonary hemorrhage, but they exhibited diminished alveolar septation. 7 Moreover, the high Foxf1 ϩ/Ϫ mice had normal life spans and adult lung morphology, suggesting that these mice compensated for the alveolar septation defect but exhibited defective lung repair in response to injury. 10 Liver development initiates at 9 days postcoitum (dpc) of mouse embryogenesis, when the cardiac mesenchyme induces the hepatic primordium to emerge from the foregut endoderm that invades the septum transversum mesenchyme. 6 Previous expression studies have shown

Genic male sterility (GMS) is very useful for hybrid vigor utilization and hybrid seed production. Although a large number of GMS genes have been identified in plants, little is known about the roles of GDSL lipase members in anther and pollen development. Here, we report a maize GMS gene, ZmMs30, which encodes a novel type of GDSL lipase with diverged catalytic residues. Enzyme kinetics and activity assays show that ZmMs30 has lipase activity and prefers to substrates with a short carbon chain. ZmMs30 is specifically expressed in maize anthers during stages 7-9. Loss of ZmMs30 function resulted in defective anther cuticle, irregular foot layer of pollen exine, and complete male sterility. Cytological and lipidomics analyses demonstrate that ZmMs30 is crucial for the aliphatic metabolic pathway required for pollen exine formation and anther cuticle development. Furthermore, we found that male sterility caused by loss of ZmMs30 function was stable in various inbred lines with different genetic background, and that it didn't show any negative effect on maize heterosis and production, suggesting that ZmMs30 is valuable for crossbreeding and hybrid seed production. We then developed a new multi-control sterility system using ZmMs30 and its mutant line, and demonstrated it is feasible for generating desirable GMS lines and valuable for hybrid maize seed production. Taken together, our study sheds new light on the mechanisms of anther and pollen development, and provides a valuable male-sterility system for hybrid breeding maize.

Amelogenin expression is ameloblast-specific and developmentally regulated at the temporal and spatial levels. In a previous transgenic mouse analysis, the expression pattern of the endogenous amelogenin gene was recapitulated by a reporter gene driven by a 2.2-kilobase mouse amelogenin proximal promoter. To understand the molecular mechanisms underlying the spatiotemporal expression of the amelogenin gene during odontogenesis, the mouse amelogenin promoter was systematically analyzed in mouse ameloblast-like LS8 cells. Deletion analysis identified a minimal promoter (؊70/؉52

The forkhead box f1 (Foxf1) transcription factor is expressed in the visceral (splanchnic) mesoderm, which is involved in mesenchymal-epithelial signaling required for development of organs derived from foregut endoderm such as lung, liver, gall bladder, and pancreas. Our previous studies demonstrated that haploinsufficiency of the Foxf1 gene caused pulmonary abnormalities with perinatal lethality from lung hemorrhage in a subset of Foxf1؉/؊ newborn mice. During mouse embryonic development, the liver and biliary primordium emerges from the foregut endoderm, invades the septum transversum mesenchyme, and receives inductive signaling originating from both the septum transversum and cardiac mesenchyme. In this study, we show that Foxf1 is expressed in embryonic septum transversum and gall bladder mesenchyme. Foxf1؉/؊ gall bladders were significantly smaller and had severe structural abnormalities characterized by a deficient external smooth muscle cell layer, reduction in mesenchymal cell number, and in some cases, lack of a discernible biliary epithelial cell layer. This Foxf1؉/؊ phenotype correlates with decreased expression of vascular cell adhesion molecule-1 (VCAM-1), ␣ 5 integrin, plateletderived growth factor receptor ␣ (PDGFR␣) and hepatocyte growth factor (HGF) genes, all of which are critical for cell adhesion, migration, and mesenchymal cell differentiation.At 9-days postcoitum (dpc) 1 during mouse embryogenesis, the liver primordium emerges from the foregut endoderm, invades the septum transversum mesenchyme, and receives bone morphogenetic protein 4 (Bmp-4) and fibroblast growth factor 2 (Fgf2) signaling originating from the septum transversum and cardiac mesenchyme, respectively (1, 2). This hepatic specification is associated with expression of the Foxa2 (HNF-3␤) and Gata4 transcription factors (3). Liver morphogenesis involves a proliferative expansion period and development of the bipotential hepatoblasts that begin to differentiate into hepatocytes and bile duct epithelial cells of the intrahepatic bile ducts (IHBD) at 13.5 dpc (3,4). Interestingly, targeted disruption of either the homeodomain Hex gene or the Hgf gene allows normal development of the mouse hepatic diverticulum, but these cells fail to migrate into the septum transversum and undergo liver morphogenesis (5-7).In the adult liver, bile is synthesized in hepatocytes from cholesterol, secreted into the bile canaliculi and transported through the intrahepatic and extrahepatic biliary system to the gall bladder, where it is stored for secretion into the digestive tract to emulsify lipids (8). The gall bladder and extrahepatic bile ducts (EHBD) develop from the caudal portion of the liver primordium at 10 dpc of mouse embryogenesis (9). However, little is known regarding visceral (splanchnic) mesoderm transcription factors that regulate expression of genes involved in mesenchymal-epithelial induction of gall bladder development from the liver primordium. Visceral mesenchymal expression of the homeodomain Hlx gene is required for the proli...

Qfhi.nau-5A is a major quantitative trait locus (QTL) against Fusarium graminearum infection in the resistant wheat germplasm Wangshuibai. Genetic analysis using BC(3)F(2) and BC(4)F(2) populations, derived from selfing two near-isogenic lines (NIL) heterozygous at Qfhi.nau-5A that were developed, respectively, with Mianyang 99-323 and PH691 as the recurrent parent, showed that Qfhi.nau-5A inherited like a single dominant gene. This QTL was thus designated as Fhb5. To fine map it, these two backcross populations and a recombinant inbred line (RIL) population derived from Nanda2419 × Wangshuibai were screened for recombinants occurring between its two flanking markers Xbarc56 and Xbarc100. Nineteen NIL recombinants were identified from the two backcross populations and nine from the RIL population. In the RIL recombinant selection process, selection against Fhb4 present in the RIL population was incorporated. Genotyping these recombinant lines with ten markers mapping to the Xbarc56-Xbarc100 interval revealed four types of Mianyang 99-323-derived NIL recombinants, three types of PH691-derived NIL recombinants, and four types of RIL recombinants. In different field trials, the percentage of infected spikes of these lines displayed a distinct two-peak distribution. The more resistant class had over 55% less infection than the susceptible class. Common to these resistant genotypes, the 0.3-cM interval flanked by Xgwm304 and Xgwm415 or one of these two loci was derived from Wangshuibai, while none of the susceptible recombinants had Wangshuibai chromatin in this interval. This interval harboring Fhb5 was mapped to the pericentromeric C-5AS3-0.75 bin through deletion bin mapping. The precise localization of Fhb5 will facilitate its utilization in marker-assisted wheat breeding programs.

Ameloblast-specific amelogenin gene expression is spatiotemporally regulated during tooth development. In a previous study, the CCAAT/enhancer-binding protein ␣ (C/EBP␣) was identified as a transcriptional activator of the mouse amelogenin gene in a cell typespecific manner. Here, Msx2 is shown to repress the promoter activity of amelogenin-promoter reporter constructs independent of its intrinsic DNA binding activity. In transient cotransfection assays, Msx2 and C/EBP␣ antagonize each other in regulating the expression of the mouse amelogenin gene. Electrophoresis mobility shift assays demonstrate that Msx2 interferes with the binding of C/EBP␣ to its cognate site in the mouse amelogenin minimal promoter, although Msx2 itself does not bind to the same promoter fragment. Proteinprotein interaction between Msx2 and C/EBP␣ is identified with co-immunoprecipitation analyses. Functional antagonism between Msx2 and C/EBP␣ is also observed on the stably transfected 2.2-kilobase mouse amelogenin promoter in ameloblast-like LS8 cells. Furthermore, the carboxyl-terminal residues 183-267 of Msx2 are required for protein-protein interaction, whereas the amino-terminal residues 2-97 of Msx2 play a less critical role. Among three family members tested (C/EBP␣, -␤, and -␥), Msx2 preferentially interacts with C/EBP␣. Taken together, these data indicate that protein-protein interaction rather than competition for overlapping binding sites results in the functional antagonism between Msx2 and C/EBP␣ in regulating the mouse amelogenin gene expression.