Trueness-To-Type and Yield Components of the Banana Hybrid Cultivar FHIA-18 Plants Regenerated Via Somatic Embryogenesis in a Bioreactor     

Rafael Gómez Kosky  Luis Antonio Barranco  Borys Chong Pérez  Dion Daniels  Maritza Reyes Vega  Manuel de Feria Silva 《Euphytica》2006,150(1-2):63-68

Summary A population of 1,500 plants of the banana hybrid ‘FHIA-18’ (AAAB), regenerated from somatic embryos, which were multiplied in bioreactors, showed similar characteristics to plants propagated from shoot tip cultures both in the acclimatization stage and in field experiments carried out in Cuba. The plants originating from somatic embryos were similar to the plants obtained from shoot tips with respect to plant height, diameter of the pseudostem and number of suckers. Both groups of plants obtained from in vitro cultures were significantly different to the plants obtained from suckers during the flowering period of the mother plants, which was shortened by two months. The greater plant height and diameter of the pseudostem in the plants coming from somatic embryos and shoot tip is due to the effect of in vitro culture, and this was observed in different banana and plantain cultivars. During the second cycle of evaluation, the plants coming from the three propagation methods studied in this work had similar growth habits without significant differences in the majority of the morphological parameters evaluated. These results confirm that the difference obtained during the first cycle between the distinct populations is attributed to temporary changes. The original characteristics of the cultivar were evident from the second cycle of culture. Only 0.13% somaclonal variant was observed in the plants coming from somatic embryogenesis. These percentages are low taking into consideration that other propagated methods accept up to 5% variants in field conditions.  相似文献   

Sclerosing peritoneal mesothelioma in a dog evaluated by electron microscopy and immunoperoxidase techniques.     

P Schoning  C E Layton  W D Fortney  L H Willard  J E Cook 《Journal of veterinary diagnostic investigation》1992,4(2):217-220

  相似文献   

Autosomal dominant mutations affecting X inactivation choice in the mouse     

Percec I  Plenge RM  Nadeau JH  Bartolomei MS  Willard HF 《Science (New York, N.Y.)》2002,296(5570):1136-1139

X chromosome inactivation is the silencing mechanism eutherian mammals use to equalize the expression of X-linked genes between males and females early in embryonic development. In the mouse, genetic control of inactivation requires elements within the X inactivation center (Xic) on the X chromosome that influence the choice of which X chromosome is to be inactivated in individual cells. It has long been posited that unidentified autosomal factors are essential to the process. We have used chemical mutagenesis in the mouse to identify specific factors involved in X inactivation and report two genetically distinct autosomal mutations with dominant effects on X chromosome choice early in embryogenesis.  相似文献   

Horse species symposium: a novel approach to monitoring pathogen progression during uterine and placental infection in the mare using bioluminescence imaging technology and lux-modified bacteria     

Ryan PL  Christiansen DL  Hopper RM  Walters FK  Moulton K  Curbelo J  Greene JM  Willard ST 《Journal of animal science》2011,89(5):1541-1551

Uterine and placental infections are the leading cause of abortion, stillbirth, and preterm delivery in the mare. Whereas uterine and placental infections in women have been studied extensively, a comprehensive examination of the pathogenic processes leading to this unsatisfactory pregnancy outcome in the mare has yet to be completed. Most information in the literature relating to late-term pregnancy loss in mares is based on retrospective studies of clinical cases submitted for necropsy. Here we report the development and application of a novel approach, whereby transgenically modified bacteria transformed with lux genes of Xenorhabdus luminescens or Photorhabdus luminescens origin and biophotonic imaging are utilized to better understand pathogen-induced preterm birth in late-term pregnant mares. This technology uses highly sensitive bioluminescence imaging camera systems to localize and monitor pathogen progression during tissue invasion by measuring the bioluminescent signatures emitted by the lux-modified pathogens. This method has an important advantage in that it allows for the potential tracking of pathogens in vivo in real time and over time, which was hitherto impossible. Although the application of this technology in domestic animals is in its infancy, investigators were successful in identifying the fetal lungs, sinuses, nares, urinary, and gastrointestinal systems as primary tissues for pathogen invasion after experimental infection of pregnant mares with lux-modified Escherichia coli. It is important that pathogens were not detected in other vital organs, such as the liver, brain, and cardiac system. Such precision in localizing sites of pathogen invasion provides potential application for this novel approach in the development of more targeted therapeutic interventions for pathogen-related diseases in the equine and other domestic species.  相似文献   

A seven-transmembrane RGS protein that modulates plant cell proliferation     

Chen JG  Willard FS  Huang J  Liang J  Chasse SA  Jones AM  Siderovski DP 《Science (New York, N.Y.)》2003,301(5640):1728-1731

G protein-coupled receptors (GPCRs) at the cell surface activate heterotrimeric G proteins by inducing the G protein alpha (Galpha) subunit to exchange guanosine diphosphate for guanosine triphosphate. Regulators of G protein signaling (RGS) proteins accelerate the deactivation of Galpha subunits to reduce GPCR signaling. Here we identified an RGS protein (AtRGS1) in Arabidopsis that has a predicted structure similar to a GPCR as well as an RGS box with GTPase accelerating activity. Expression of AtRGS1 complemented the pheromone supersensitivity phenotype of a yeast RGS mutant, sst2Delta. Loss of AtRGS1 increased the activity of the Arabidopsis Galpha subunit, resulting in increased cell elongation in hypocotyls in darkness and increased cell production in roots grown in light. These findings suggest that AtRGS1 is a critical modulator of plant cell proliferation.  相似文献   

Genomic and genetic definition of a functional human centromere   总被引：1，自引：0，他引：1  

Schueler MG  Higgins AW  Rudd MK  Gustashaw K  Willard HF 《Science (New York, N.Y.)》2001,294(5540):109-115

The definition of centromeres of human chromosomes requires a complete genomic understanding of these regions. Toward this end, we report integration of physical mapping, genetic, and functional approaches, together with sequencing of selected regions, to define the centromere of the human X chromosome and to explore the evolution of sequences responsible for chromosome segregation. The transitional region between expressed sequences on the short arm of the X and the chromosome-specific alpha satellite array DXZ1 spans about 450 kilobases and is satellite-rich. At the junction between this satellite region and canonical DXZ1 repeats, diverged repeat units provide direct evidence of unequal crossover as the homogenizing force of these arrays. Results from deletion analysis of mitotically stable chromosome rearrangements and from a human artificial chromosome assay demonstrate that DXZ1 DNA is sufficient for centromere function. Evolutionary studies indicate that, while alpha satellite DNA present throughout the pericentromeric region of the X chromosome appears to be a descendant of an ancestral primate centromere, the current functional centromere based on DXZ1 sequences is the product of the much more recent concerted evolution of this satellite DNA.  相似文献   

Cloning of human androgen receptor complementary DNA and localization to the X chromosome   总被引：55，自引：0，他引：55  

D B Lubahn  D R Joseph  P M Sullivan  H F Willard  F S French  E M Wilson 《Science (New York, N.Y.)》1988,240(4850):327-330

The androgen receptor (AR) mediates the actions of male sex steroids. Human AR genomic DNA was cloned from a flow-sorted human X chromosome library by using a consensus nucleotide sequence from the DNA-binding domain of the family of nuclear receptors. The AR gene was localized on the human X chromosome between the centromere and q13. Cloned complementary DNA, selected with an AR-specific oligonucleotide probe, was expressed in monkey kidney (COS) cells and yielded a high-affinity androgen-binding protein with steroid-binding specificity corresponding to that of native AR. A predominant messenger RNA species of 9.6 kilobases was identified in human, rat, and mouse tissues known to contain AR and was undetectable in tissues lacking AR androgen-binding activity, including kidney and liver from androgen-insensitive mice. The deduced amino acid sequence of AR within the DNA-binding domain has highest sequence identity with the progesterone receptor.  相似文献   

Assignment of the gene for myelin proteolipid protein to the X chromosome: implications for X-linked myelin disorders   总被引：32，自引：0，他引：32  

H F Willard  J R Riordan 《Science (New York, N.Y.)》1985,230(4728):940-942

Several inherited disorders in humans and in rodents result in myelin dysgenesis and a deficiency of the molecular constituents of myelin. A complementary DNA to one of the two major myelin proteins, myelin proteolipid protein (also known as lipophilin), has been used with Southern blot analysis of somatic cell hybrid DNA to map the human proteolipid protein gene to the middle of the long arm of the human X chromosome (bands Xq13-Xq22) and to assign the murine proteolipid protein gene to the mouse X chromosome. Comparison of the gene maps of the human and mouse X chromosomes suggests that myelin proteolipid protein may be involved in X-linked mutations at the mouse jimpy locus and has implications for Pelizaeus-Merzbacher disease, a human inherited X-linked myelin disorder.  相似文献   

Potato processing: Past,present and future     

Miles Willard 《American Journal of Potato Research》1993,70(5):405-418

From the time of the Incas, man has dehydrated potatoes to alleviate famine and feed its warriors. After the Spaniards brought potatoes to Europe, the same became true there. During the Industrial Revolution, drying processes emerged in Germany and England for dried pieces, extruded mash filaments and, finally, thin layers of mash on heated surfaces. During the 19th century, fermentation of potatoes for alcohol, starch manufacture and, finally, fried potato chips emerged. In the 20th century, the requirements of two world wars created a rapid increase in drying technology and led to the development of quickrehydrating dried mashed potatoes. The post-WWII era of convenience foods and development of freezing technology converted the “french fries” American GIs had seen on street corners in Belgium to the largest worldwide outlet for potatoes: retail and institutional frozen fried products. Recent trends in technology and usage are cited for dehydrated products, including dehydrated mashed potatoes (flakes, granules and agglomerates), dried dice and slices, flour, and frozen products, including specialty products made from smaller potatoes and pieces. Miscellaneous products such as pre-peeled potatoes, potato starch, alcohol and canned products are examined. The author and a number of collaborators then look toward the future. The general trends stress the importance of improvements in ecology, reduction of waste, improvement in product wholesomeness and development of new varieties with improved processing characteristics. Trends in dehydration technology include more sophisticated drying techniques, less energy use, improved flavor, better utilization and development of simpler processes for third world countries. Trends in frozen products include development of improved microwaveable products, more flexible manufacturing techniques, improved defect removal and reduction in fat content of fast-serve products.  相似文献   

Rheological and thermal properties of masa as related to changes in corn protein during nixtamalization     

Adriana Quintanar Guzmán  María Eugenia Jaramillo Flores  Javier Solorza Feria  María Guadalupe Méndez Montealvo  Ya-Jane Wang 《Journal of Cereal Science》2011

Traditional nixtamalization process produces a masa (dough) with appropriate cohesiveness and adhesiveness. Masa is considered as a network of solubilized starch polymers with dispersed, uncooked and swollen starch granules, cell fragments, proteins and lipids. In this work, the influence of proteins on the masa viscoelastic behavior was studied in corn kernels under different nixtamalization conditions. Scanning electron microscopy, SDS-PAGE, differential scanning calorimetry and rheological analysis were used to characterize the corn samples. The micrographs showed that the nixtamalization modified the shape of the starch granules and protein bodies, but no changes in appearance were observed when protein was removed. SDS-PAGE showed that corn proteins polymerized during cooking. Lime promoted both calcium–protein and protein–calcium–protein interactions mainly by calcium bridges, which were difficult to disrupt and increased the protein thermo-resistance. In the absence of lime, corn proteins polymerized mainly by disulfide bond cross-linking. Thermal analysis (DSC) indicated that the gelatinization temperature increased in lime-treated samples compared to control samples. Rheological studies showed that the corn protein exhibited greater influence on gel strength by enhancing the elastic character of the samples (G′). These results suggested that polymerized corn proteins stabilized the gel structure, which in consequence influenced the viscoelastic behavior of masa.  相似文献