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Abdominal wall closure in pediatric solid organ recipients may be confounded by donor size discrepancy and structural insults from previous surgery. Here we describe the novel use of vascularized donor abdominal wall posterior rectus sheath fascia, as a composite tissue allotransplant (CTA), to achieve abdominal wall closure in a liver and double kidney pediatric recipient who could not be closed primarily due to donor/recipient size mismatch. The posterior rectus sheath fascia was procured in continuity with the liver and falciform ligament. Blood supply was achieved using the single hepatic artery anastomosis as part of the standard liver transplantation procedure. Specimens of posterior rectus sheath fascia taken on postoperative days 3 and 30 showed no signs of acute rejection. The patient succumbed to an overwhelming fungal infection on day 51, with no signs of intraabdominal involvement. The patient received no additional immunosuppression in conjunction with the posterior rectus sheath fascia allotransplant.

TATP gives rise to two separable conformations because the barrier for interconversion between them is relatively high at room temperature. This kind of behavior is rare in cyclic organic systems and is the result of poor overlap in the “flip-flop” transition state. The crystal structure of the analogous tricyclohexanone triperoxide also indicates the presence of two conformers.

Abstract: Spent Saccharomyces cerevisiae cells from a beer fermentation process were evaluated for lead cation sorption. The crude biomass was washed with water and acetone prior to any other treatment. Although the washed biomass showed substantial lead ion sorption it was susceptible to microbial spoilage. Different aldehydes were tested as chemical fixation agents; however, most of them caused drastic lowering of the metal uptake capacity. However, benzaldehyde was not only an excellent fixation agent, but the biomass treated with it also retained its original lead sorption capacity. A mechanism for the fixation process is suggested.

The gene encoding a cytosolic isozyme of phosphoglucose isomerase (PGI, EC 5.3.1.9) was isolated from Clarkia lewisii, a wild flower native to California, and the structure and sequence of the entire coding region determined. PGI catalyzes an essential step in glycolysis and carbohydrate biosynthesis in plants. Spanning about 6 kb, the gene has 23 exons and 22 introns, the highest number yet reported in plants. The exons range in size from 43 to 156 nt and encode a protein of 569 amino acids. The protein is about 44–46% identical to the inferred protein sequences of pig, Escherichia coli and Saccharomyces cerevisiae. All of the introns are bordered with the consensus 5'-GT...AG-3' dinucleotides. The longest intron includes a large stem-loop structure bounded by a perfect 9 nt direct repeat. We cloned the PGI gene from a genomic library prepared from a single plant of known PGI genotype. The locus and allele of the clone were identified by matching restriction fragments to fragments from genetically defined genomic DNAs by Southern hybridization.

Electrophoretic variation in isozymes coded by 40 loci was examined in two self-pollinating populations, one with white and the other with pink flowering plants, and four outcrossing populations ofClarkia xantiana (Onagraceae) native to California. The study was carried out to test theMoore & Lewis (1965) hypothesis that the pink selfer originated from the sympatric outcrossing population and then gave rise to the white selfer. The hypothesis could be rejected if one or the other selfer was more similar genetically to an allopatric population than to the sympatric one. Both selfers were monomorphic at all loci whereas the outcrossing populations were polymorphic at nearly half of them. The two selfers had the same genes at 32 loci but had different ones at eight loci. The pink selfer was not more similar to the allopatric populations than to the sympatric one, consistent with theMoore & Lewis model. The evidence also supported their proposal that the white selfer originated from the pink one and not independently. The electrophoretic evidence was valuable because it permitted qualitative comparisons (presence versus absence of particular alleles) between the selfer and the several outcrossing populations; such analysis was not previously possible because the latter populations are morphologically and cytologically similar.

The structural gene locus specifying subunits of the cytoplasmic isozymes of phosphoglucose isomerase (PGI) is present in duplicate in many diploid species of Clarkia (Onagraceae), a genus of annual plants native to California. We studied the kinetic properties and molecular weights of a large number of genetically defined and highly purified PGIs in C. xantiana, a species with the duplication, as a means of examining the biochemical consequences of the evolution of a new gene locus. This species is primarily outcrossing, but also includes several previously described predominantly self-pollinating populations. Both cytoplasmic PGI loci in the outcrossing populations are polymorphic and their enzyme products are readily separated by electrophoresis. The PGIs from the outcrossing populations were generally closely similar in molecular weight, pH optimum, heat sensitivity, energy of activation, and apparent Km (fructose-6-phosphate). The PGI loci in the selfing populations are monomorphic and specify enzymes having identical electrophoretic mobilities to those coded by the most frequent alleles of the outcrosser. The PGI isozymes in the selfers differed fivefold in Km, suggesting that they have a very different catalytic effectiveness. The high Km of the PGI-3A' isozyme (1.1mm) was anomalous among the examined and would likely be disadvantageous in a species which lacked other more normally functioning PGIs. But in the cytoplasm of the selfing plants, it is present with other PGIs that have low Km values. The PGI-3A' enzyme is a good candidate for a gene product coded by a “forbidden” mutation that could not have been established in the absence of the duplication. The rationale for this suggestion is described and it is also pointed out that the divergence of duplicated genes is influenced by many factors such as the breeding system and other population factors as well as the effect of particular mutations.

This study demonstrates that homoeologous genes in two diploid plant species that specify different amounts of an enzyme maintain the same relative level of expression in an allotetraploid derivative. The three predominant alcohol dehydrogenase (ADH) isozymes (DD, DP, PP) in seeds of the recently evolved allotetraploid plant Tragopogon miscellus (Compositae) are dimers specified by Adh3-D and Adh3-P genes derived from its diploid progenitors T. dubius and T. pratensis. Seeds of T. pratensis contain twice as much ADH activity as those of T. dubius, while T. miscellus is intermediate. The three isozymes were similar in a number of catalytic properties; the densitometric ratio of the isozymes purified from T. miscellus was 1 DD:4DP:4PP for both ADH activity and protein; and dissociation-reassociation of the DP enzyme gave a 1:2:1 ratio of the three isozymes. Therefore, the enzymes were similar in specific activity, but twice as many P as D subunits were present in active enzymes in T. miscellus, precisely the difference in activity between the parents. In T. miscellus, the specific activity of ADH and its activity per mg tissue are intermediate to those of the diploids, because relative expression of the Adh gene in each genome is not influenced by the presence of the other genome.

SummaryThe number of structural genes coding for a sample of electrophoretically detectable enzymes was determined for seven diploid species of Crepis which previously had been shown to vary in DNA/nucleus by seven-fold and to have chromosome numbers ranging from 2N = 6 to 2N = 12. The number of structural genes coding these enzymes was approximately 19 in all of the species examined, suggesting that gene number is conserved.Heredity (1978) 40, 159–163; doi:10.1038/hdy.1978.15

The apparent molecular weight of cytosolic phosphoglucose isomerase (PGI) subunits was evaluated in 18 species of Clarkia which have or do not have duplicated genes specifying this glycolytic enzyme. Species that lack the duplication had subunits of 59,000 or 60,400 whereas species with the duplication generally possessed two types of PGI subunits with these or closely similar molecular weights. The additive pattern in the species with the duplication suggests that the molecular weight divergence preceded the origin of the duplication, and that the duplication arose following hybridization between taxa that represented different lineages within Clarkia.

We report here the complete nucleotide sequence of the E. coli triose phosphate isomerase gene. The gene encodes a polypeptide of 255 amino acids which is approximately 46% homologous to eukaryotic triose phosphate isomerases, and approximately 38% homologous to the enzyme from a thermophilic bacterium, Bacillus stearothermophilus. The nucleotide sequence is 55% homologous to that of the corresponding gene in the yeast Saccharomyces cerevisiae. To our knowledge, this is the first report of the sequence of a gene coding a glycolytic enzyme from a prokaryotic organism.

Hybrid enzymes composed of subunits of oligomeric isozymes present in different subcellular compartments have never been observed in vivo, even though their precursors are commonly synthesized in the same cytosol. To investigate this problem, we examined in plants the dimeric enzyme triose phosphate isomerase, which is present as two nuclear-coded isozymes, one in the plastids and the other in the cytosol. We dissociated both purified isozymes from several unrelated species into subunits, and then reassociated the unlike subunits into active hybrid enzymes. Since such hybrid enzymes are not observed in vivo, but can be formed in vitro, a specific mechanism must prevent either their formation or their accumulation in the cell. Possible mechanisms are discussed.

We examined structural and functional properties of the recently duplicated cytosolic isozymes of phosphoglucose isomerase (PGI) (EC 5.3.1.9) of the wild plant Clarkia xantiana and related species. A new purification protocol yielded PGIs with high specific activities. The duplicated PGI isozymes showed similar substrate affinities (apparent Km) in both catalytic directions. A newly devised competitive enzyme-linked immunosorbent assay (ELISA), using polyclonal antibodies, distinguished sodium dodecyl sulfate (SDS)-denatured PGIs coded by the duplicated loci but did not discriminate between allelic products of one of the loci. In vitro dissociation and reassociation experiments revealed that the duplicated subunits differed in their efficiency of reassociation. The difference was closely correlated with differences between the isozymes in their in vivo accumulation. In contrast, allelic subunits in species with or without the duplication were able to reassociate with similar efficiency. The duplicated PGI isozymes have diverged more in structural properties than kinetic ones. The total evidence suggests that mechanisms have evolved which reduce the potential consequences of the duplication.

The different electrophoretic patterns of dimeric phosphoglucoisomerases extracted from haploid pollen and diploid somatic tissues of plants may be used to distinguish allozymes and isozymes. The analysis depends on the presence of two alleles at each locus in somatic tissues but only one or the other allele in pollen grains. Consequently, in heterozygotes, heterodimeric allozymes can be identified because they are formed in stems and leaves but not in pollen. The procedure is described in enzymes extracted from the diploid annual plant Clarkia dudleyana, which possesses three gene loci for PGI subunits. Comparison of the electrophoretic patterns of stem and pollen extracts makes it possible in many cases to identify allelic state without breeding tests. The technique also is likely to be useful in the interpretation of zymograms of other multimeric enzymes coded by more than one gene locus.

Genetic variability was examined in nine sexual and three apogamous natural populations of the homosporous fern Pellaea andromedifoliaby electrophoretic analysis of enzymes specified by eight loci. Genetic interpretations of heterozygous banding patterns were determined by segregational analysis of gametophytes. High levels of segregating heterozygosity characterized the sexually reproducing populations, and genotype frequencies at the five polymorphic loci were consistent with those expected under conditions of random intergametophytic mating. Multiple‐banded patterns in the apogamously reproducing populations resembled those of heterozygous sexual individuals, but did not segregate. The results suggest that genetic variation in sexual homosporous vascular plants is produced by cross fertilization of genetically different gametes and may not result from pairing between homoeologous chromosomes carrying duplicated loci as previously thought.

The annual diploid plant species Stephanomeria malheurensisis known only from a single locality where it grows interspersed with its progenitor S. exiguassp. coronaria. S. malheurensisis thought to have originated recently at its present site and, consequently, serves as a model to study how the phenotype of a species is assembled following its origin. The following were examined in the present study: dry matter allocation, growth parameters, net photosynthesis, and dark respiration of seedlings under three temperatures in order to identify specific features of the new species that might relate to its ecological properties. Under each test condition, S. malheurensishad leaves with a significantly smaller surface area, greater dry weight per unit area, heavier roots, and a higher root/shoot ratio. Both species had similar relative growth rates during the measured period of rosette growth, but in S. malheurensisthis resulted from the combination of a lower leaf area ratio and a higher net assimilation rate, whereas in ssp. coronariait resulted from the opposite combination. The mean rates of apparent net photosynthesis and dark respiration were similar in both species. The differences between the species may reflect the establishment of genes in S. malheurensiswhich still are present in ssp. coronaria. The implications of this and the possible ecological significance are discussed.

Genetic analysis of isozyme segregation patterns in Layia(Compositae) showed that cytosolic phosphoglucomutase isozymes are encoded by duplicated genes, and that the cytosolic NADP‐dependent isocitrate dehydrogenase isozymes are encoded by duplicated genes in species with haploid chromosome numbers of n =7 and triplicated genes in those with n= 8. The duplicated genes specifying both isozymes assorted independently in all species tested. An electrophoretic survey of phosphoglucomutase in diploid species representing six additional genera of Madiinae, the subtribe to which Layiais assigned, revealed that Achyrachaena, Calycadenia, Hemizonia, Holocarpha, and Madiaall possessed duplicated genes. In Lagophylla, one species also had duplicated genes for the isozyme but a second species did not, a loss probably resulting from mutation or chromosomal deletion. The phosphoglucomutase duplication characterizes nearly the entire subtribe and may prove useful to identify phylogenetic relationships between the Madiinae and other subtribes.

The nucleotide sequence of the gene encoding the glycolytic enzyme phosphoglucose isomerase (PGI) from Escherichia coli is presented. The gene encodes a polypeptide of 549 amino acids. The transcriptional start point of the gene was determined and found to lie within a consensus promoter region. The amino acid sequence derived from the E. coli PGI gene can be aligned without insertions or deletions to the predicted amino acid sequence of a nuclear-encoded chloroplast isozyme of PGI from a higher plant, and the two sequences have a similarity of 87.6%. The amino acid sequence similarity between E. coli and that predicted from cDNA sequences for mouse and pig PGI is approximately 65%.

The mechanism of lead cation biosorption by acetone-washed biomass of Saccharomyces uvarum was investigated by chemical modifications and spectroscopic monitoring of the cell components. Reacting the carboxyl groups with propylamine, which neutralizes these anions, considerably decreased the metallic ion uptake, indicating that negatively charged carboxyl groups play an important role in lead bisorption due to electrostatic attraction. After lead biosorption the photoacoustic Fourier transform infrared spectroscopy showed a change in the symmetrical stretch of the carboxylate groups of the acetone-washed yeast biomass, and the X-ray photoelectron spectroscopy oxygen peak was also found to be shifted. These findings support the hypothesis that lead uptake occurs mainly through binding to the carboxyl group. In X-ray photoelectron spectroscopy the nitrogen peak decreased after the biosorption of lead, suggesting that nitrogen-containing groups are also involved in the biosorption process. Acylation of amino groups was shown to increase the lead biosorption capacity. The acylation reaction converts the positively charged amino group to an amide capable of coordination to lead cations. Deproteination by boiling the biosorbent with NaOH increased the lead uptake. The acetone-washed biomass uptake of lead from an aqueous solution at ph 5.5 was 48.9 mg/g dry weight. Pure chitin adsorbed 48.8 mg lead/g dry weight. Mannan isolated from S. uvarum did not adsorb lead at all. Electrostatic attraction of the carboxyl groups and other anions present in the acetone-washed biomass, and complexation with nitrogen atoms, especially in chitin, appear to be the main mechanisms involved in lead cation biosorption. © 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 55: 1–10, 1997.

Phenotypic variation in 33 quantitative characters was analyzed in Stephanomeria exiguassp. coronaria(Greene) Gottlieb and its recent derivative species, presently called “Malheurensis,” grown in a series of experimental environments. The study was made to determine whether their high genetic identity, previously revealed by electrophoresis of a sample of their enzymes, was correlated with a high similarity in quantitative traits of morphology, size, growth rates, and fecundity. The electrophoretic evidence provided correct information about the relative variability, similarity, and phylogenetic relationship of the two taxa. Thus, 90% of the between‐plant variance components from the analysis of variance were higher in ssp. coronariaand, therefore, concordant with its higher genetic variability. The between‐environment variance components in the two species were similar in magnitude and when ordered, from smallest to largest, were nearly identical in ranking. The quantitative study provided important additional evidence. Ssp. coronariagrew more rapidly and produced more florets than Malheurensis in all of the growth conditions and also was found to grow larger than Malheurensis in their native habitat in eastern Oregon where they grow sympatrically. These and other results indicate that the persistence of Malheurensis in nature cannot depend on advantages of size, growth rates, or number of flowers produced per individual. The large differences between the taxa in the size of their seeds was used as the basis for a model to account for the continued persistence of Malheurensis.

The diploid annual plants Stephanomeria exiguassp. coronariaand S. malheurensisare related as progenitor and derivative. Stephanomeria malheurensisis known only from a single locality in eastern Oregon where it grows alongside (cohabits) its parent. Although the species are morphologically similar, they can be distinguished under uniform garden conditions by differences in root/shoot ratio, duration of rosette growth, branch structure and number of flower heads, seed weight, and other characters. The species were grown in pure and mixed cultures at several densities in two experiments to test the hypothesis that the distinctive phenotype of S. malheurensiscould have evolved to reduce competition with its parent. The experiment revealed that the expression of the S. malheurensisphenotype did not change when it was grown alone or in mixed cultures with ssp. coronaria. Stephanomeria malheurensisneither gained nor lost an advantage. Since the measured characters related directly to fitness components, this suggests that the phenotype of the derivative probably did not evolve as a result of character displacement brought about by interference with ssp. coronaria. The consequence of sympatry between a newly arisen species and its parent appears to depend on the nature of the environment at the time of its origin. In an open habitat such as the Oregon locality of S. malheurensis, competition with the progenitor need not be a primary factor influencing the evolution of a new species.

Layia glandulosa (Compositae) and L. discoidea are self-incompatible annual plants native to California which are completely interfertile and appear to be related as progenitor and recent derivative. L. glandulosa has sunflower-like heads (capitula) with showy female rays, each subtended by an involucral bract which enfolds the ovary. L. discoidea lacks both rays and enfolding bracts. We describe the results of a breeding programme to identify specific genes that control these and associated morphological traits. The differences in capitulum type are governed primarily by two genes, partially confirming the conclusions of Clausen, Keck and Hiesey (1947). Recombination of these genes produced a novel phenotype with “gibbous” florets in place of rays. Gibbous florets have aspects of both ray and disk florets as well as unique traits. They are fertile and consistent in expression, demonstrating that new combinations of developmental processes may be assimilated without evident adverse effects. Another recombinant genotype confers on ray florets traits such as ovary pubescence and pappus, normally found only on disk florets. Despite the absence of ray florets, L. discoidea has a polymorphism that affects ray presence/absence and additional genes modifying ray floret number, size, shape and colour. Thus, differences in floral morphology between the species depend on a complex assemblage of genes with significant and specific morphological consequences.Heredity (1990) 64, 29–44; doi:10.1038/hdy.1990.5

Differences in the gametic chromosome numbers (n= 4, 5, 9) of species in the Astereae tribe of the Compositae have been variously interpreted. One hypothesis proposes that n= 9 was the original base number of the group and that the lower numbers resulted from aneuploid reduction. The alternative hypothesis asserts that the ancestral base number was n= 4 or n= 5 and that species in which n= 9 are allotetraploids derived by hybridization between taxa with the lower numbers. Electrophoretic analysis of 17 enzyme systems in five species of Machaeranthera, in which n= 4, 5, and 9, and two species of Asterin which n= 5 and 9, demonstrates that all of these species have the same number of gene loci specifying the tested enzymes. The absence of isozyme multiplicity in the species in which n= 9 suggests that they did not arise by polyploidy.

Electrophoretic variability was examined in six species of Layia(Compositae), native to California, which have previously been studied by Clausen, Keck, and Hiesey, and are regarded as a classic example of geographic speciation in plants. The study was carried out to test the hypothesis that the extent of divergence in structural genes coding enzymes is concordant with divergence in morphological characteristics, ecological traits, and reproductive isolation. Eleven enzymes specified by 17 loci were analyzed. The genetic identity values were consistent with those expected on the model that the species diverged gradually as they adapted to geographically separate habitats. Thus, the values between the three species complexes proposed by Clausen, Keck, and Hiesey (L. chrysanthemoides/L. fremontii; L. jonesii/L. leucopappa/L. munzii; L. platyglossa)were substantially lower than the values between species within the complexes. The results provide an important contrast to the very high genetic identities between species which originated rapidly from their progenitors. The electrophoretic results also provided evidence that the cytosolic isozyme of phosphoglucomutase and the cytosolic NADP‐dependent isocitrate dehydrogenase in the six species are coded by duplicate genes.

The flowers of Clarkia gracilis subsp. sonomensis have large petals each with a large, central, red-purple spot while the flowers of subsp. gracilis are small and unspotted. Other pigmentation (anthocyanin) patterns also vary within and between these subspecies. We carried out a genetic analysis of differences in floral patterns and petal size. A novel basal petal spot appeared in the F2. The analysis indicated that the novel petal spot was specified by an allele in subsp. gracilis at a locus governing spot position. This allele is not normally expressed in subsp. gracilis because of the action of a modifier gene at a second locus. The study also indicated single factor inheritance for presence versus absence of pigmentation on the hypanthium, stamens, and the lower portion of the petals. Multifactorial inheritance was observed for differences in petal length and width. Most of the possible recombinant floral patterns were recovered in the F2and F3. This system can be used to study developmental regulation of floral traits as well as ecological relationships between floral pattern and pollination system. The recovery of a normally unexpressed allele for basal petal spot points to the difficulty of extrapolating from phenotypic analysis to an understanding of morphological evolution.Heredity (1988) 60, 237–246; doi:10.1038/hdy.1988.37

RAPD analysis was carried out on 52 accessions of Solanum melongena (eggplant) and related weedy forms known as “insanum”. Twenty-two primers amplified 130 fragments. Solanum melongena exhibited 117 of the fragments, all of which were also present in insanum. Insanum displayed an additional 13 fragments not found in S. melongena. Overall, the insanum accessions were more diverse than those of S. melongena. The calculated similarity between them was 0.947. The RAPD results were closely concordant with the results of an electrophoretic isozyme survey performed on the same accessions. The concordance of the results shows that even though S. melongena and insanum are highly diverse morphologically, it is no longer appropriate to distinguish them taxonomically.

Enzyme electrophoretic studies were made in cultivated Solanum melongena L. (eggplant) and similar wild and weedy forms, several of which have been thought to be different species/taxa. Twenty-nine accessions of S. melongena, 33 accessions of weedy forms (referred to as “insanum”) and 2 accessions of wild forms (referred to as “incanum”) were surveyed for 29 isozyme loci. In S. melongena, 22 of the 29 loci were monomorphic, and nearly all of its genes were either also monomorphic or in similar frequencies in insanum and incanum. The results demonstrate that the three taxa have a very close genetic relationship. The high genetic identities between them (0.913–0.967) suggests that they are conspecific even though they include extensive morphological diversity.

1. Subcellular-compartment-specific decreased-activity mutants of phosphoglucose isomerase in Clarkia xantiana were used to analyse the control of sucrose and starch synthesis during photosynthesis. Mutants were available in which the plastid phosphoglucose isomerase complement is decreased to 75% or 50% of the wild-type level, and the cytosol complement to 64%, 36% or 18% of the wild-type level. 2. The effects on the [product]/[substrate] ratio and on fluxes to sucrose or starch and the rate of photosynthesis were studied with the use of saturating or limiting light intensity to impose a high or low flux through these pathways. 3. Removal of a small fraction of either phosphoglucose isomerase leads to a significant shift of the [product]/[substrate] ratio away, from equilibrium. We conclude that there is no ‘excess’ of enzyme over that needed to maintain its reactants reasonably close to equilibrium. 4. Decreased phosphoglucose isomerase activity can also alter the fluxes to starch or sucrose. However, the effect on flux does not correlate with the extent of disequilibrium, and also varies depending on the subcellular compartment and on the conditions. 5. The results were used to estimate Flux Control Coefficients for the chloroplast and cytosolic phosphoglucose isomerases. The chloroplast isoenzyme exerts control on the rate of starch synthesis and on photosynthesis in saturating light intensity and CO2, but not at low light intensity. The cytosolic enzyme only exerts significant control when its complement is decreased 3-5-fold, and differs from the plastid isoenzyme in exerting more control in low light intensity. It has a positive Control Coefficient for sucrose synthesis, and a negative Control Coefficient for starch synthesis. 6. The Elasticity Coefficients in vivo of the cytosolic phosphoglucose isomerase were estimated to lie between 5 and 8 in the wild-type. They decrease in mutants with a lowered complement of cytosolic phosphoglucose isomerase. 7. The implications of these results for regulation and for evolution are discussed.

A concise route is described to a Reserpine synthetic intermediate having the features of ring E and an oxygen function for constructing ring D. This involves an unusual α-diketone cleavage, the selective elaboration of the carboxylated ring in 1-naphthoic acids and selective boron halide cleavage of ester and ether groups.