Field evaluation of transgenic wheat plants stably expressing the HVA1 gene for drought tolerance

The barley HVA1 gene, encoding a member of the group 3 late embryogenesis abundant (LEA) proteins, has previously been introduced into spring wheat cv. Hi-Line to determine its effect on drought tolerance (Sivamani E, Bahieldin A, Wraith JM, Al-Niemi T, Dyer WE, Ho T-HD, Qu R (2000) Improved biomass productivity and water use efficiency under water deficit conditions in transgenic wheat constitutively expressing the barley HVA1 gene. Plant Sci 155, 1–9). T4 progeny from six independent transgenic events (lines 111/1, 1/1, 11/2, 84, 765 and 1201) were tested in nine field experiments over six cropping seasons. In the first two seasons, the total biomass per plot and the grain yield per plot of line 111/1 were higher than those of line 1/1, and higher than those of the wild-type control in the second season. The grain yield per plot of line 11/2 was significantly lower than that of the transgenic lines 111/1 and 1/1 in the third season, and this line was not tested further. In the fourth season, the plant height and grain yield per plot of line 111/1 were significantly higher than those of the wild-type control. Under dryland conditions in the fifth season, line 111/1 showed significantly greater plant height, total biomass per plot and grain yield per plot than the wild-type control in at least two of the four locations, as well as across locations. In the sixth season, newly developed transgenic lines 1201 and 765 significantly overyielded the two original transgenic lines 111/1 and 1/1, the non-expressing transgenic line 84 as well as the wild-type control in the three yield attributes and leaf water measurement, namely relative water content (RWC). This result coincided with the rate of HVA1 transgene expression of the different genotypes. Differences in total seed storage protein concentrations between the transgenic lines and the wild-type control within or across environmental conditions were insignificant. These field trials show that the HVA1 gene has the potential to confer drought stress protection in transgenic spring wheat.     

Content and composition of fatty acids in normal and inflamed gingival tissues

The balance of essential fatty acid is important for good health and normal development. Essential fatty acids (EFA) are the precursors of prostaglandins (PGs), thromboxanes and leukotrienes (LT). The aim of this clinical study was to determine the total fatty acid level of polyunsaturated fatty acids (PUFA), monounsaturated fatty acids (MUFA), saturated fatty acids (SFA) and each fatty acids level of inflamed and normal gingival tissues. Twenty-seven subjects were included the present study. Nineteen samples of inflamed human gingival tissue (nine of fibrous hyperplasia (FH), ten of peripheral giant cell granuloma (PGCG) and eight samples of normal human gingival tissue were analyzed. The characteristics of inflammation were assessed histologically. Variance analyses were performed to assess the differences among tissues. The total cellular fatty acid profiles of the tissues in inflamed human gingival tissue and in eight samples of normal human gingival tissue were determined by gas chromatography using Sherlock microbial identification system (MIS) software (Microbial ID, Newark, DE, USA) with a database of FAME profiles for eukary. PUFAs, MUFAs, and SFAs were quantified by Sherlock microbial identification system (MIS) or database gas chromatography (DGC). There were statistically significant differences between the concentrations in inflamed (FH, PGCG) and healthy gingival tissues for PUFA and MUFA (P<0.001, P<0,011, respectively). There were statistically significant differences among the concentrations in FH, PGCG, and healthy gingival tissues for SFA (P<0.0001). Arachidonic acid, docosahexaenoic acid, linoleic acid were increased in inflamed tissue. The results of this study showed that unsaturated fatty acids (PUFA and MUFA) significantly increased in inflamed gingival tissues.     

Choline status in newborns, infants, children, breast-feeding women, breast-fed infants and human breast milk

This study assessed the choline status in newborns, infants, children, breast-feeding women, breast milk, infant formula, breast-fed and formula-fed infants. The serum free choline level was 35.1+/-1.1 micromol/L at birth and decreased to 24.2+/-1.6, 18.1+/-0.8, 16.3+/-0.9, 14.3+/-0.8, 12.9+/-0.6 or 10.9+/-0.6 micromol/L at 22-28, 151-180, 331-365, 571-730, 731-1095 or 4016-4380 days after birth, respectively. The serum phospholipid-bound choline level was 1997+/-75 micromol/L at birth and increased gradually to 2315+/-190 or 2572 +/-100 micromol/L at 571-730 or 4016-4380 days after birth, respectively. In breast-feeding women, serum free and phospholipid-bound choline levels were doubled at 12-28 days after birth, they decreased toward the control values with time. Free choline, phosphocholine and glycerophosphocholine were major choline compounds in breast milk. Their concentrations in mature milk were much greater than in colostrum and serum. Choline contents of breast milk varied greatly between mothers, and milk free choline levels were correlated with serum free choline (r=.541; P<.001), phospholipid-bound choline (r=.527; P<.001) and glycerophosphocholine (r=.299; P<.01) concentrations and lactating days (r=.520; P<.001). In breast-fed infants, serum free choline concentrations were correlated with free choline (r=.47; P<.001), phosphocholine (r=.345; P<.002), glycerophosphocholine (r=.311; P<.01) and total choline (r=.306; P<.01) contents of breast milk. Serum free choline concentration in formula-fed infants was lower than breast-fed infants. These data show that (a) circulating choline status is elevated during infancy and lactation, (b) choline contents of breast milk vary between mothers and milk free choline contents are influenced by maternal circulating choline status, and (c) the choline contents of breast milk can influence infants' circulating choline status.     

A computational investigation of kinetoplastid trans-splicing

Trans-splicing is an unusual process in which two separate RNA strands are spliced together to yield a mature mRNA. We present a novel computational approach which has an overall accuracy of 82% and can predict 92% of known trans-splicing sites. We have applied our method to chromosomes 1 and 3 of Leishmania major, with high-confidence predictions for 85% and 88% of annotated genes respectively. We suggest some extensions of our method to other systems.     

Using co-occurrence network structure to extract synonymous gene and protein names from MEDLINE abstracts

Background  

Text-mining can assist biomedical researchers in reducing information overload by extracting useful knowledge from large collections of text. We developed a novel text-mining method based on analyzing the network structure created by symbol co-occurrences as a way to extend the capabilities of knowledge extraction. The method was applied to the task of automatic gene and protein name synonym extraction.     

Triticum durum metallothionein. Isolation of the gene and structural characterization of the protein using solution scattering and molecular modeling

A novel gene sequence, with two exons and one intron, encoding a metallothionein (MT) has been identified in durum wheat Triticum durum cv. Balcali85 genomic DNA. Multiple alignment analyses on the cDNA and the translated protein sequences showed that T. durum MT (dMT) can be classified as a type 1 MT. dMT has three Cys-X-Cys motifs in each of the N- and C-terminal domains and a 42-residue-long hinge region devoid of cysteines. dMT was overexpressed in Escherichia coli as a fusion protein (GSTdMT), and bacteria expressing the fusion protein showed increased tolerance to cadmium in the growth medium compared with controls. Purified GSTdMT was characterized by SDS- and native-PAGE, size exclusion chromatography, and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. It was shown that the recombinant protein binds 4 +/- 1 mol of cadmium/mol of protein and has a high tendency to form stable oligomeric structures. The structure of GSTdMT and dMT was investigated by synchrotron x-ray solution scattering and computational methods. X-ray scattering measurements indicated a strong tendency for GSTdMT to form dimers and trimers in solution and yielded structural models that were compatible with a stable dimeric form in which dMT had an extended conformation. Results of homology modeling and ab initio solution scattering approaches produced an elongated dMT structure with a long central hinge region. The predicted model and those obtained from x-ray scattering are in agreement and suggest that dMT may be involved in functions other than metal detoxification.     

Roberts syndrome: study of 4 new Rgyptian cases with comparison of clinical and cytogenetic findings

Roberts syndrome is a rare autosomal recessive genetic disorder (MIM 268300). It is characterized by pre and postnatal growth retardation, severe shortening of limbs with radial defects, oligodactyly and characteristic facial features. The present study reports 4 new cases of Roberts syndrome from 3 families presenting variable phenotypes. Patients were thoroughly investigated clinically and cytogenetically. By reviewing literature, we compared our cases to those previously reported. The rating severity system proposed by Van den Berg and Francke (30) was applied to correlate the phenotypic and cytogenetics changes. We observed more severe reduction defects in the upper limbs than in the lower limbs. While the main reduction defects in the upper limbs involved the thumb and radius ranging to phocomelia, absent or severely hypoplastic fibula was the main lower limb involvement. We emphasize this finding in the present investigation. Heterochromatin repulsion of chromosomes derived from Roberts syndrome patients is a characteristic cytogenetic abnormality. It was a constant finding in our studied patients demonstrated by DABI stain which supports the possibility that mutations in Roberts syndrome lie in centromere related proteins which may also play a role in body patterning. This was proved recently by Vega et al. (31). Application of the clinical rating score and its correlation with cytogenetic changes showed negative results. Cytogenetic studies in normal obligatory heterozygotes parents showed no changes. Phenotypic variability within the same family as well as between different families was observed. The ascertainment of 4 cases with Roberts syndrome from 3 Egyptian consanguineous families during one year in our department may indicate a high frequency of the Roberts syndrome allele among Egyptians. This confirms the need for molecular studies for early and accurate prenatal diagnosis to prevent such dramatic malformation syndrome.     

Ubiquitin crosstalk connecting cellular processes

Cullin 4 (Cul4), a member of the evolutionally conserved cullin protein family, serves as a scaffold to assemble multisubunit ubiquitin E3 ligase complexes. Cul4 interacts with the Ring finger-containing protein ROC1 through its C-terminal cullin domain and with substrate recruiting subunit(s) through its N-terminus. Previous studies have demonstrated that Cul4 E3 ligase ubiquitylates key regulators in cell cycle control and mediates their degradation through the proteasomal pathway, thus contributing to genome stability. Recent studies from several groups have revealed that Cul4 E3 ligase can target histones for ubiquitylation, and importantly, ubiquitylation of histones may facilitate the cellular response to DNA damage. Therefore, histone ubiquitylation by Cul4 E3 ligase constitutes a novel mechanism through which Cul4 regulates chromatin function and maintains genomic integrity. We outline these studies and suggest that histone ubiquitylation might play important roles in Cul4-regualted chromatin function including the cellular response to DNA damage and heterochromatin gene silencing.     

Tyrosine-specific MAPK phosphatases and the control of ERK signaling in PC12 cells

Background

Spatio-temporal control of extracellular signal-regulated kinase (ERK) activity, a critical determinant of the cell's response to growth factors, requires timely dephosphorylation of its regulatory tyrosine and/or threonine residue by MAPK phosphatases. We studied the physiological role of kinase interaction motif (KIM)-containing protein tyrosine phosphatases (PTPs) in the control of EGF- and NGF-induced ERK activity in neuroendocrine PC12 cells.

Results

We found a single KIM-containing PTP to be endogenously expressed in rat PC12 cells: the transmembrane PTPRR isoform termed PCPTP1. Protein knock-down of PCPTP1, or fourfold overexpression of its mouse orthologue, PTPBR7, left EGF- and NGF-induced ERK1/2 activity in PC12 cells unaltered. Ectopic expression of cytosolic PTPRR isoforms, however, resulted in reduced EGF-induced ERK1/2 activity, an effect that was dependent on the phosphatase activity and the KIM-domain of these PTPs.

Conclusion

The finding that robust changes in tyrosine-specific MAPK phosphatase expression levels have minor effects on temporal ERK1/2 activity control in PC12 cells suggests that dual-specificity MAPK phosphatases may act as major regulators of growth factor-induced ERK1/2 signaling in these cells.