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Biomedical subjects

T H Ellis

Publications and source records attributed to T H Ellis.

At least 37 records · Page 2Linked to original sources
PubMed1996

The pea early nodulin gene PsENOD7 maps in the region of linkage group I containing sym2 and leghaemoglobin.

The early nodulin gene, PsENOD7, is expressed in pea root nodules induced by Rhizobium leguminosarum bv. viciae, but not in other plant organs. In situ hybridization showed that this gene is transcribed during nodule maturation in the infected cells of the proximal part of the prefixation zone II. At the transition of zone II into interzone II-III, the level of PsENOD7 mRNA drops markedly. PsENOD7 has no significant homology to other genes. RFLP mapping studies have shown that PsENOD7 is located in linkage group I between the leghaemoglobin genes and sym2.

Amino Acid Sequence↗
PubMed1996

Isolation by PCR of a cDNA clone from pea petals with similarity to petunia and wheat zinc finger proteins.

The C2H2 TFIIIA/Krüppel class of zinc finger proteins are an important group of regulatory nucleic acid binding factors and have been extensively studied in humans, Drosophila and yeast. We have employed 3' RACE PCR, using a highly degenerate oligonucleotide primer, for the facile isolation of a C2H2 zinc finger protein cDNA (Pszf1) from pea petals. The Pszf1 cDNA open reading frame potentially encodes a protein with two widely separated zinc fingers similar to zinc finger proteins from petunia and wheat. This class of two-fingered zinc finger proteins, possessing a wide and variable linker sequence, appears to be unique to plants. Three regions outside the zinc finger domains are also conserved between the members of the plant zinc finger protein family and one of these regions is a candidate nuclear localisation signal. The Pszf1 amino acid sequence is most similar to that of the petunia Epf1 protein, they possess an interfinger linker sequence of approximately the same length and they have a similar expression pattern with maximal transcript accumulation in mature petals, suggesting that Pszf1 may be the pea homologue of the petunia Epf1 zinc finger gene.

Amino Acid Sequence↗
PubMed1994

Bicycle safety equipment.

It is important for the physician to understand bicycle safety equipment in order to prevent and treat bicycle-related injuries effectively. The physician should understand (1) the basic design and function of bicycles, (2) the relationship of improper bicycle fit to injuries, (3) the potential of the various forms of serious riding and racing for injury, and (4) bicycle safety equipment and the standards involved in its fit, manufacture, and care. A decision to use bicycle safety equipment is a decision to control the risk of injury. Physicians should accept a share of the responsibility for decreasing bicycling-related injuries, because they are viewed by the public as credible sources of information regarding the prevention of accidents and injuries.

Bicycling↗
PubMed1993

Genetic aspects of the organization of legumin genes in pea.

We have compared physical and genetic maps of the region around the legJ gene in pea. In this vicinity there are four B-type legumin genes, arranged as two close pairs. The detection of a recombination event within this gene cluster allows the orientation of this group of genes within the surrounding linkage group to be determined. The relationship between physical and genetic distances in this region is discussed, as are the implications of this for relating physical and genetic maps elsewhere in the pea genome.

Alleles↗
PubMed1993

Repeated sequences as genetic markers in pooled tissue samples.

We show, using the PDR1 element of pea, that dispersed repeated sequences of moderate copy number can be used simply and efficiently to generate markers linked to a trait of interest. Inspection of hybridization patterns of repeated sequences to DNA mixtures of pooled genotypes is a sensitive way of detecting such markers. The large number of bands in tracks of digests of these mixtures allows the simultaneous sampling of loci at many places in the genome, and the many unlinked loci serve as internal controls. It is also shown that intensity ratios calculated from these band differences can be used to give a rough estimate of linkage distance.

Chromosome Mapping↗
PubMed1992

Linkage maps in pea.

We have analyzed segregation patterns of markers among the late generation progeny of several crosses of pea. From the patterns of association of these markers we have deduced linkage orders. Salient features of these linkages are discussed, as is the relationship between the data presented here and previously published genetic and cytogenetic data.

Chromosome Mapping↗
PubMed1991

Evidence for the presence of hairpin chloroplast DNA molecules in barley cultivars.

Total DNA was extracted from young green and etiolated barley leaf shoots and run on 2D neutral/alkaline agarose gels. This technique showed the presence of molecules which behaved as though their single-stranded length was twice their double-stranded length. This behaviour was sensitive to S1 nuclease. Our conclusion is that these DNAs are hairpin molecules. They are homologous to sequences found throughout the barley chloroplast genome. This type of molecule is present in uncut DNA with a continuous range of sizes varying between 0.5 and 15 kbp in our experimental conditions. The origin and possible biological function of these molecules is discussed.

Blotting, Southern↗
PubMed1991

Sports protective equipment.

It is important for the primary care and team physician to become more involved and better informed regarding the athletic equipment process. With the increase in litigation related to sport participation and caused by athletic protective equipment misuse or malfunction, the primary care and team physician can not afford to be an uninformed bystander. Primary care and team physicians serve a very necessary role in the protection of an athlete because they are usually able to serve independently of the school or sponsoring group, thus keeping the athlete's safety and health the primary consideration. Many athletic injuries occur as "unavoidable" accidents, but many others are "preventable." One of the variables involved in preventing injuries is to follow high standards of quality, fitting, use, and maintenance of athletic protective equipment. When we obtain athletic protective equipment, we have made a decision to control the risk of injury. The primary care and team physicians should accept a share of the responsibility in decreasing risk of sports injuries. Diverse public opinion has been generated over catastrophic injuries resulting from sport participation. Most of those injuries involve either the head or neck and may be either permanently disabling or lethal. Any part of the body may be subjected to injury. Sports protective equipment is available for many different sports, with many different injury risks, and for any part of the body. Many involved in the athletic health care delivery system continue to struggle with the "noncompliant" athletic patient. Not surprisingly, the "noncompliant" athletic patient. Not surprisingly, the noncompliant athletes have a higher recurrence rate of injury than do those who are compliant. Anything that the primary care and team physicians can do to decrease the desire of the athletic patient to resist orders for modification of activities to allow an injury to heal is important.

Athletic Injuries↗
PubMed1990

The wrinkled-seed character of pea described by Mendel is caused by a transposon-like insertion in a gene encoding starch-branching enzyme.

We describe the cloning of the r (rugosus) locus of pea (Pisum sativum L.), which determines whether the seed is round or wrinkled. Wrinkled (rr) seeds lack one isoform of starch-branching enzyme (SBEI), present in round (RR or Rr) seeds. A major polymorphism in the SBEI gene between near-isogenic RR and rr lines shows 100% cosegregation with the r locus, establishing that the SBEI gene is at the r locus. An aberrant transcript for SBEI is produced in rr embryos. In rr lines the SBEI gene is interrupted by a 0.8 kb insertion that is very similar to the Ac/Ds family of transposable elements from maize. Failure to produce SBEI has complex metabolic consequences on starch, lipid, and protein biosynthesis in the seed.

1,4-alpha-Glucan Branching Enzyme↗
PubMed1990

A copia-like element in Pisum demonstrates the uses of dispersed repeated sequences in genetic analysis.

A DNA sequence between two legumin genes in Pisum is a member of the copia-like class of retrotransposons and represents one member of a polymorphic and heterogeneous dispersed repeated sequence family in Pisum. This sequence can be exploited in genetic studies either by RFLP analysis where several markers can be scored together, or the segregation of individual elements can be followed after PCR amplification of specific members.

Base Sequence↗
PubMed1990

Identification and genetic regulation of the chalcone synthase multigene family in pea.

Chalcone synthase (CHS) is a key enzyme in the biosynthesis of diverse flavonoids involved in disease resistance, nodulation, and pigmentation in pea. We describe a multigene family encoding CHS and the effects of two regulatory loci, a and a2, on the pattern of expression of three of its member genes. Two of the genes, CHS1 and CHS3, are expressed in both petal and root tissue, whereas expression of a third gene, CHS2, is detected only in roots. The products encoded by the a and a2 loci are required for the expression of the CHS1 gene and for wild-type levels of expression of the CHS3 gene in petal tissue. In root tissue, all three CHS genes are expressed and induced by CuCl2 regardless of the genotype at the a and a2 loci. These results show that the various members of the CHS multigene family interact in diverse ways with multiple genetic signals in the plant, providing a basis for the differential expression of these genes. Spatially specific genetic regulation of distinct members of a multigene family has been clearly demonstrated.

Acyltransferases↗
PubMed1988

The sequence of a gene encoding convicilin from pea (Pisum sativum L.) shows that convicilin differs from vicilin by an insertion near the N-terminus.

The sequence of a gene encoding convicilin, a seed storage protein in pea (Pisum sativum L.), is reported. This gene, designated cvcA, is one of a sub-family of two active genes. The transcription start of cvcA was mapped. Convicilin genes are expressed in developing pea seed cotyledons, with maximum levels of the corresponding mRNA species present at 16-18 days after flowering. The gene sequence shows that convicilin is similar to vicilin, but differs by the insertion of a 121-amino-acid sequence near the N-terminus of the protein. This inserted sequence is very hydrophilic and has a high proportion of charged and acidic residues; it is of a similar amino acid composition to the sequences found near the C-terminal of the alpha-subunit in pea legumin genes, but is not directly homologous with them. Comparison of this sequence with the 'inserted' sequence in soya-bean (Glycine max) conglycinin (a homologous vicilin-type protein) suggests that the two insertions were independent events. The 5' flanking sequence of the gene contains several putative regulatory elements, besides a consensus promoter sequence.

Amino Acid Sequence↗
PubMed1988

Two genes encoding 'minor' legumin polypeptides in pea (Pisum sativum L.). Characterization and complete sequence of the LegJ gene.

A genomic clone from pea (Pisum sativum L.) contains all of one gene encoding a 'minor' (B-type) legumin polypeptide, and most of a second very similar gene. The two genes, designated LegJ and LegK, are arranged in tandem, separated by approx. 6 kb. A complete sequence of gene LegJ and its flanking sequences is given, with as much of the sequence of gene LegK as is present on the genomic clone. Hybridization of 3' flanking sequence probes to seed mRNA, and sequence comparisons with cDNA species, suggested that gene LegJ, and probably gene LegK, was expressed. The partial amino acid sequences of 'minor' legumin alpha- and beta-polypeptides were used to confirm the identity of these genes. The transciption start in gene LegJ was mapped. The 5' flanking sequence of gene LegJ contains a sequence conserved in legumin genes from pea and other species, which is likely to have functional significance in control of gene expression. Sequence comparisons with legumin genes and cDNA species from Vicia faba and soya bean show that separation of legumin genes into A- and B-type subfamilies occurred before separation of the Viciae and Glycinae tribes.

Base Sequence↗
PubMed1988

5S rRNA genes in Pisum: sequence, long range and chromosomal organization.

We have employed a combination of techniques to examine the organization of pea 5S rRNA genes. These include the analysis of length variant interspersion patterns in cosmid clones, sequence analysis, Southern analysis of both conventional gels and field inversion gels and in situ hybridization. From these analyses we conclude that the 5S rRNA genes of pea are arranged in three major tandem arrays which are represented by three large EcoRI fragments and that these correspond to the three sites of in situ hybridization in the haploid pea complement.

Base Sequence↗
PubMed1986

A hairpin plastid genome in barley.

A linear plastid genome of a barley albino plant derived from anther culture has been characterized. The monomeric genome is 21 kb long. This molecule has a hairpin structure. We discuss the possible origins of this genome.

Journal Article↗