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M J Iqbal

Publications and source records attributed to M J Iqbal.

At least 19 recordsLinked to original sources
PubMed2006

Genomic analysis of the rhg1 locus: candidate genes that underlie soybean resistance to the cyst nematode.

The rhg1 gene or genes lie at a recessive or co-dominant locus, necessary for resistance to all Hg types of the soybean (Glycine max (L.) Merr.) cyst nematode (Heterodera glycines I.). The aim here was to identify nucleotide changes within a candidate gene found at the rhg1 locus that were capable of altering resistance to Hg types 0 (race 3). A 1.5 +/- 0.25 cM region of chromosome 18 (linkage group G) was shown to encompass rhg1 using recombination events from four near isogenic line populations and nine DNA markers. The DNA markers anchored two bacterial artificial chromosome (BAC) clones 21d9 and 73p6. A single receptor like kinase (RLK; leucine rich repeat-transmembrane-protein kinase) candidate resistance gene was amplified from both BACs using redundant primers. The DNA sequence showed nine alleles of the RLK at Rhg1 in the soybean germplasm. Markers designed to detect alleles showed perfect association between allele 1 and resistance to soybean cyst nematode Hg types 0 in three segregating populations, fifteen additional selected recombination events and twenty-two Plant Introductions. A quantitative trait nucleotide (QTN) [corrected] in the RLK at rhg1 was inferred that alters A87 to V87 in the context of H274 rather than N274. [corrected] Contiguous DNA sequence of 315 kbp of chromosome 18 (about 2 cM) contained additional gene candidates that may modulate resistance to other Hg-types including a variant laccase, a hydrogen-sodium ion antiport and two proteins of unknown function. A molecular basis for recessive and co-dominant resistance that involves interactions among paralagous disease-resistance genes was inferred that would improve methods for developing new nematode-resistant soybean cultivars.

Animals↗
PubMed2006

An updated 'Essex' by 'Forrest' linkage map and first composite interval map of QTL underlying six soybean traits.

DNA marker maps based on single populations are the basis for gene, loci and genomic analyses. Individual maps can be integrated to produce composite maps with higher marker densities if shared marker orders are consistent. However, estimates of marker order in composite maps must include sets of markers that were not polymorphic in multiple populations. Often some of the pooled markers were not codominant, or were not correctly scored. The soybean composite map was composed of data from five separate populations based on northern US germplasm but does not yet include 'Essex' by 'Forrest' recombinant inbred line (RIL) population (E x F) or any southern US soybean cultivars. The objectives were, to update the E x F map with codominant markers, to compare marker orders among this map, the Forrest physical map and the composite soybean map and to compare QTL identified by composite interval maps to the earlier interval maps. Two hundred and thirty seven markers were used to construct the core of the E x F map. The majority of marker orders were consistent between the maps. However, 19 putative marker inversions were detected on 12 of 20 linkage groups (LG). Eleven marker distance compressions were also found. The number of inverted markers ranged from 1 to 2 per LG. Thus, marker order inversions may be common in southern compared to northern US germplasm. A total of 61 QTL among 37 measures of six traits were detected by composite interval maps, interval maps and single point analysis. Seventeen of the QTL found in composite intervals had previously been detected among the 29 QTL found in simple interval maps. The genomic locations of the known QTL were more closely delimited. A genome sequencing project to compare Southern and Northern US soybean cultivars would catalog and delimit inverted regions and the associated QTL. Gene introgression in cultivar development programs would be accelerated.

Chromosome Mapping↗
PubMed2006

The digestive fate of Escherichia coli glutamate dehydrogenase deoxyribonucleic acid from transgenic corn in diets fed to weanling pigs.

Corn containing genetically engineered plasmid DNA encoding an Escherichia coli glutamate dehydrogenase (gdhA) was fed to 19-d-old weanling swine to trace the digestive fate of the transgenic DNA. Eight pens of 8 pigs were fed a commercial (nongdhA) starter for 2 wk. One pig was randomly selected from each pen for 0-h control samples. The remaining 56 pigs were transitioned onto a corn-soybean meal diet and fed a diet containing 58% gdhA corn for approximately 1 wk; immediately thereafter, liver, 10th rib muscle, white blood cells, and plasma from the hepatic portal vein and ingesta from the stomach, distal ileum, and large intestine were collected. The DNA was extracted and the concentration determined via spectrophotometry. Polymerase chain reaction and gel electrophoresis were performed with primers designed to amplify 490 bp that included the plasmid's ligation site between the maize ubiquitin and the gdhA genes. The gdhA corn-derived DNA and diet served as positive assay controls, and conventional corn DNA and distilled water acted as negative assay controls. Detection limits were 0.99 fg of target DNA confounded with 500 ng of conventional corn DNA per each 20 &L reaction. Transgenic DNA was detected in 71.43% of the stomach and 1.79% of the ileal ingesta samples from treatment animals but was not detected in the large intestine, white blood cells, plasma, liver, or muscle samples. Transgenic DNA was not detected in any sample from 0-h control animals. Stomach and ileal ingesta samples were further analyzed using real-time PCR. With an estimated limit of detection of 1.049 ag/microL, 89.29% of the stomach ingesta samples were positive (average 1.56 fg target DNA). The proportion of transgenic DNA to total DNA differed between diet and stomach ingesta samples (P < 0.001). Despite the greater sensitivity of real-time PCR, target DNA was detected in only 1.79% of ileal ingesta. These data suggest that the gdhA transgene began degradation in the stomach and was nondetectable in the large intestine.

Animal Feed↗
PubMed2005

Root response to Fusarium solani f. sp . glycines: temporal accumulation of transcripts in partially resistant and susceptible soybean.

Sudden death syndrome (SDS) of soybean is a complex of root rot disease caused by the semi-biotrophic fungus Fusarium solani f. sp. glycines (Fsg) and a leaf scorch disease caused by toxins produced by the pathogen in the roots. Development of partial rate-reducing resistance in roots to SDS was studied. The recombinant inbred line 23 (RIL23) that carried resistance conferred by six quantitative trait loci (QTL) derived from cultivars 'Essex' x 'Forrest' was compared to the susceptible cultivar Essex. Roots of RIL23 and its susceptible parent Essex were inoculated with Fsg. Transcript abundance (TA) of 191 ESTs was studied at five time points after inoculation. For most of the genes, there was an initial decrease in TA in the inoculated roots of both genotypes. By days 7 and 10 the inoculated roots of Essex failed to increase expression of the transcripts of defense-related genes. In RIL23 inoculated roots, the TA of 81 genes was increased by at least two-fold at day 3 (P=0.004), 88 genes at day 7 (P=0.0023) and 129 genes at day 10 (P=0.0026). A set of 35 genes maintained at least a two-fold higher abundance at all three time points. The increase in TA in RIL23 was in contrast to that observed in Essex where most of the ESTs showed either no change or a decreased TA. The ESTs with an increased TA had homology to the genes involved in resistance (analogs), signal transduction, plant defense, cell wall synthesis and transport of metabolites. Pathways that responded included the protein phosphorylation cascade, the phospholipase cascade and the phenolic natural products pathways, including isoflavone and cell wall synthesis.

Crosses, Genetic↗
PubMed2005

Soy protein influences the development of the metabolic syndrome in male obese ZDFxSHHF rats.

Previous investigations have demonstrated a marked effect of soy protein on the metabolic syndrome (MS). The purpose of this preliminary study was to identify the effects of soy-based diets on male obese ZDFxSHHF (fa/ fa-cp/?) rats. Animals were randomly assigned to one of four diets: control, casein (C); low-isoflavone (LIS) soy protein; high-isoflavone (HIS) soy protein; or casein + rosiglitazone (CR). Physiological, biochemical, and molecular parameters were determined at sacrifice. Body weight (p < 0.01) and food intake (p < 0.05) were lower in LIS-fed rodents. Rosiglitazone-treated animals had higher body weight and adiposity (p < 0.05). LIS and CR groups exhibited better glycemic control (p < 0.05), but with a limited effect in rosiglitazone-treated animals. HIS fed rats had higher glucose and triacylglyceride levels (p < 0.01), and lower plasma insulin (p < 0.01). Renal function parameters with the exception of an increase in systolic blood pressure (p < 0.05) were all suppressed in the LIS group (p < 0.01). The CR group had twofold PPARalpha and PPARgamma mRNA abundance (p < 0.01). LIS-fed animals also exhibited greater abundance of PPARgamma mRNA (p < 0.001), and nearly threefold FAS and CPT-1 mRNA levels (p < 0.05). HIS-fed rats also had higher abundance of CPT-1 mRNA, as well as a lower abundance of ACC mRNA (p < 0.05). Soy-based diets, influenced by isoflavone content and distinct from rosiglitazone, improved several metabolic parameters in obese ZDFxSHHF rats.

Animals↗
PubMed2005

Genomic analysis of a region encompassing QRfs1 and QRfs2: genes that underlie soybean resistance to sudden death syndrome.

Candidate genes were identified for two loci, QRfs2 providing resistance to the leaf scorch called soybean (Glycine max (L.) Merr.) sudden death syndrome (SDS) and QRfs1 providing resistance to root infection by the causal pathogen Fusarium solani f.sp. glycines. The 7.5 +/- 0.5 cM region of chromosome 18 (linkage group G) was shown to encompass a cluster of resistance loci using recombination events from 4 near-isogenic line populations and 9 DNA markers. The DNA markers anchored 9 physical map contigs (7 are shown on the soybean Gbrowse, 2 are unpublished), 45 BAC end sequences (41 in Gbrowse), and contiguous DNA sequences of 315, 127, and 110 kbp. Gene density was high at 1 gene per 7 kbp only around the already sequenced regions. Three to 4 gene-rich islands were inferred to be distributed across the entire 7.5 cM or 3.5 Mbp showing that genes are clustered in the soybean genome. Candidate resistance genes were identified and a molecular basis for interactions among the disease resistance genes in the cluster inferred.

Contig Mapping↗
PubMed2004

Endophyte-infected tall fescue diet alters gene expression in heifer luteal tissue as revealed by interspecies microarray analysis.

Cattle consuming endophyte-infected tall fescue grass have an associated reduction in circulating progesterone and reduced reproductive rates. In this study, commercially available rat microarrays were used to analyze the gene expression in luteal tissues from heifers fed endophyte-free fescue, endophyte-infected fescue, or endophyte-infected fescue supplemented with the dopamine (DA) antagonist, domperidone. The number of hybridized spots represented approximately 40% of the total 10,000 rat genes/ESTs evaluated. Each luteal sample was analyzed in triplicate, resulting in within treatment correlation coefficients of >/=0.98. Median values of mRNA abundance from luteal tissue taken from the endophyte-infected fed heifers revealed 598 genes and ESTs that were down regulated and 56 genes and ESTs that were upregulated compared with luteal mRNA values from the endophyte-free treatment. There were fewer comparative differences between median values from luteal mRNA from the endophyte-free versus feeding endophyte-infected plus domperidone treated heifers. Only 19 genes and ESTs were upregulated and two were down-regulated.

Animal Feed↗
PubMed2003

Gene expression in cloned bovine fetal liver.

Nuclear transfer (NT) is a method of animal reproduction that bypasses fertilization and propagates known combinations of genes. Currently NT is an inefficient process. Attempts have been made to increase the efficiency of this procedure, but most have been deemed unsuccessful. Some problems associated with NT are unusually large birth weights, and physical abnormalities in developing liver, heart, and brain. Despite numerous studies performed on NT animals, the factors behind the anomalies remain unknown. It is possible that nuclear reprogramming is the basis of poor development rates, meaning, when the donor cells are fused with enucleated eggs the nuclei may not regain the full ability to direct cell differentiation in subsequent mitotic divisions. If reprogramming is not carried out precisely, then some genes may not be correctly expressed in NT animals. The purpose of this study was to determine if differential gene expression between the livers of NT fetuses when compared to an embryo transfer (ET) derived fetus could be detected and the genes identified. An Angus fetus at 45 d of gestation was collected and a non-clonal cell line established for use as NT donor cells. Two NT fetuses were propagated and compared to the original. Differential Display Reverse Transcription Polymerase Chain Reaction (ddRT-PCR) was used to identify genes that were differentially expressed. Differentially abundant cDNAs were subcloned, sequenced and their corresponding mRNAs were verified by semi-quantitative RT-PCR. Twenty-three Expressed Sequence Tags (ESTs) were sequenced in Bos taurus and submitted to GenBank. The results of ddRT-PCR identified 39 genes/ESTs that were potentially differentially expressed. Fifteen of the genes were tested by semi-quantitative RT-PCR, but no significant differences were detected.

Animals↗
PubMed2002

Differentially abundant mRNAs in rat liver in response to diets containing soy protein isolate.

Soy diets influence cell growth, regulate lipid metabolism to lower blood cholesterol, and prevent bone losses. These biological effects are most likely due to effects of soy phytochemicals on the expression of genes. In this study, we fed 12 female obese Zucker rats (fa/fa) with a low- or a high-isoflavone soy protein diet and compared the gene expression with animals on a casein diet. Rat livers were compared by differential display of mRNA, and 62 unique sequences were identified. The change in mRNA abundance of these sequences was quantified by cDNA macroarray analysis. Thirty-three mRNAs showed more than twofold increase in abundance on soy diets compared with the control. The corresponding genes include carnitine palmitoyltransferase I, stromal cell-derived factor 1, a protein associated with MYC mRNA, basic transcription element binding protein, and expressed sequence tags (ESTs) of unknown function. Twenty-nine mRNAs showed a less than twofold change in abundance in the two diet treatments. For majority of the genes identified, there was not significant difference between the low- and high-isoflavone diet treatments. Therefore, the contrast between soy protein and casein caused the changes observed in mRNA abundance.

Animals↗
PubMed2002

Resistance locus pyramids alter transcript abundance in soybean roots inoculated with Fusarium solani f.sp. glycines.

Soybean Sudden Death Syndrome (SDS) is caused by Fusarium solani f.sp. glycines (Fsg). Six quantitative trait loci (QTLs), each conferring partial resistance to SDS, have been discovered in an Essex x Forrest recombinant inbred line (RIL) population, but their mode of action is not clear. This study aimed to identify genes (ESTs) whose mRNA transcripts were altered in abundance in soybean roots following inoculation of Fsg. Roots of the soybean variety Forrest (four resistance alleles) were inoculated with Fsg, and 14 days later RNA sequences that were differentially expressed relative to uninoculated roots were enriched using suppression subtraction and differential display. The abundance of these RNAs was quantified in inoculated and non-inoculated roots by macroarray hybridizations. A unigene set of 135 ESTs was identified and used in a further macroarray analysis. The abundance of 28 cDNA fragments was increased more than two-fold in inoculated compared to uninoculated roots of RIL 23 (six resistance alleles). In Forrest and Essex (two resistance alleles), the level of only one mRNA was increased two-fold in inoculated roots compared to the uninoculated roots. In Essex most of the mRNAs analyzed decreased in abundance (61/135 showed a two-fold decrease), while in Forrest most mRNA abundances did not change. Among the 28 cDNAs that revealed a two-fold or higher increase in mRNA abundance in RIL 23, 14% code for proteins known to be involved in plant defense, 21% in metabolism, 14% in cell structure and 4% in transport. Unannotated ESTs accounted for 43% of the genes, and 4% of the sequences were previously unknown. The plant defense-related genes that showed a differential response to Fsg inoculation suggested a role for the phenylproponoid pathway in soybean defense against Fsg. In Essex, genes involved in plant defense, cell wall synthesis, ethylene synthesis and metabolism were expressed at lower levels in inoculated roots. The difference in response between the 2-, 4- and 6-gene pyramids suggests that QTLs for SDS resistance serve to delay symptoms or confer resistance by maintaining or increasing the expression of specific genes after inoculation/infection.

DNA, Complementary↗
PubMed2001

Adaptation to long-term cold-girdling in genotypes of common bean (Phaseolus vulgaris L.).

The effect of long-term cold-girdling on phloem transport and resource allocation in whole plants of common bean is described. Wide differences were found between genotypes, with some maintaining translocation when cold-girdled. This provides evidence to support passive phloem transport. The possibilities that cold-girdling may physically block transport and/or disrupt root-shoot signalling are discussed.

Adaptation, Physiological↗
PubMed1998

Arthroscopic cheilectomy for hallux rigidus.

Hallux rigidus is a disabling problem especially in younger patients. Open cheilectomy or exostosectomy for treatment has been reported with satisfactory results. Analysis of a series of 15 patients who underwent arthroscopic cheilectomy for hallux rigidus has shown very satisfactory and encouraging early results without any recurrence or any need of revision surgery. This has provided rapid recovery and rehabilitation as well as maintained the pain relief with good metatarso-phalangeal joint power and motion.

Adult↗
PubMed1996

Convex spinal epiphysiodesis in the management of progressive infantile idiopathic scoliosis.

STUDY DESIGN: Retrospective review of patient records with current clinical and radiographic assessment. OBJECTIVE: To evaluate the long-term result of anterior and posterior convex spinal growth arrest, with or without instrumentation, in managing infantile idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: There were 12 male and 10 female patients studied, with a mean follow-up period of 10 years, 9 months. The mean Cobb angle before surgery was 65 degrees. All had a rib vertebral angle difference more than 20 degrees. The mean age at surgery was 6 years. Nine patients had epiphysiodesis alone; nine patients also underwent Harrington instrumentation simultaneously, and four underwent Harrington instrumentation 2-4 years later. METHOD: Clinical evaluation and sequential measurements of Cobb angle were done. RESULTS: The epiphysiodesis-only group had a mean preoperative Cobb angle of 72 degrees, mean progression of curves of +12 degrees, and mean rate of progression of +2.5 degrees per year: the group's postoperative figures were 92 degrees, +15 degrees, and +3 degrees per year, respectively. The epiphysiodesis and late Harrington rod group had a mean preoperative Cobb angle of 56 degrees, mean progression of +12 degrees, and a mean rate of progression of +5 degrees per year; the group's postoperative Cobb angle averaged 62 degrees, progression +6 degrees, and rate of progression +1 degree per year. The epiphysiodesis with simultaneous Harrington rod group had a preoperative mean Cobb angle of 60 degrees, mean progression of +18 degrees, and mean rate of progression of +6 degrees per years. After surgery, these improved to 58 degrees, correction of 2 degrees, and rate of correction of 0.5 degree per year. CONCLUSION: Combined anterior and posterior convex spinal growth arrest alone does not prevent progression of deformity in infantile idiopathic scoliosis. The addition of posterior instrumentation can slow or arrest deformity progression but not reverse it.

Bone Nails↗
PubMed1987

Interactions of foetal steroid binding protein with other binding proteins in human serum.

Foetal steroid binding protein (FSBP) which is present in normal human serum sometimes exhibits unusual sex-steroid binding; its effects on steroid action are uncertain but potentially important in view of the different levels seen in populations at different risk of breast cancer. Studies of the binding of 5 alpha-dihydrotestosterone to FSBP were conducted at varying concentrations of human serum albumin (HSA) and sex hormone binding globulin (SHBG). The saturable, specific binding of purified FSBP (Ka approximately equal to 5 X 10(8) l/mol), was transformed to a rising, plateau pattern by the addition of HSA. In equilibrium dialysis, FSBP competed with HSA or SHBG in a strictly proportional way when the third protein was absent. In the presence of HSA an initial sharp shift of ligand from SHBG to FSBP was observed with increasing FSBP concentration, but this was reversed as higher levels were reached. Steroid binding by FSBP in vivo may be determined predominantly by its interactions with other binding proteins.

Blood Proteins↗
PubMed1987

Blood donation by the elderly. Clinical and policy considerations.

At present, healthy potential blood donors older than the age of 66 years often leave the donor pool for reasons of age alone, despite the fact that this demographic group is growing, is a potentially willing source of blood products, and constitutes the cohort with highest per capita use of blood and its derivatives. There is no clinical or physiological rationale for this. We performed a controlled study to measure the feasibility and safety of blood donation by healthy elderly donors aged 66 years and older, compared with a younger cohort aged 55 to 65 years of age. A study group of prior donors aged 66 years and older and a control group of prior donors between the ages of 50 and 65 were sent letters inviting them to donate blood. The volume donated did not differ between the two groups. In the older group, there were eight immediate reactions, seven mild and one moderate. The control population experienced seven immediate reactions, six mild and one severe. We conclude that it is both clinically feasible and efficient to recruit healthy prior donors older than the age of 66 years for blood donation. As a group, this population is potentially able to donate large volumes of blood and do so without any difference in immediate or short-term reactions. Further study of hemodynamic variables as more objective markers of safety is needed.

Adult↗
PubMed1987

Response to cyproterone acetate treatment in primary hepatocellular carcinoma is related to fall in free 5 alpha-dihydrotestosterone.

The male preponderance in cirrhotic patients with primary hepatocellular carcinoma (HCC) and the presence of androgen receptors in tumour tissue suggest possible benefit from anti-androgenic therapy. Twenty-five cirrhotic patients with irresectable HCC (23 male) were treated with cyproterone acetate (CPA) 300 mg daily. Hepatic ultrasound, alpha-fetoprotein and total and free sex steroid levels were monitored. Five patients had an objective response to therapy with a median duration of 8 weeks and survival in excess of 29 weeks. Median survival for all patients was 14 weeks. Apart from transient paranoia in two cases, side-effects were minimal. Total androgen levels (measured in 13 patients) had fallen significantly at 10 weeks, but free 5 alpha-dihydrotestosterone (DHT) which had fallen by 4.8 pM (median) in five responders, had risen by 5.05 pM in eight non-responders: P less than 0.025. The apparent correlation of response with reduction in free DHT suggests that hormonal manipulation may be effective in HCC if free DHT is reliably reduced. This has been achieved in other conditions by the combination of CPA with low dose oestrogen or with LHRH agonists.

Adult↗