Identification and genetic mapping of Xenopus TAP2 genes

The amphibian Xenopus laevis is one non-mammalian vertebrate in which the major histocompatibility complex (MHC) has been analyzed extensively. Class IIbeta, class Ia, LMP2, LMP7, HSP70, C4, Factor B, and Ring3 genes have been identified and mapped to the MHC. Here, we report the isolation of a transporter associated with antigen processing (TAP) gene, TAP2, and demonstrate its linkage to the MHC. While the ATP-binding region of Xenopus TAP2 is highly conserved in evolution, amino acid identity to other vertebrate TAP proteins was not detected in the N-terminal region. Segregation analysis of 34 individuals from two families showed exact restriction fragment length polymorphism matching between the MHC class Ia gene and the one TAP2 gene demonstrating linkage conservation since the mammalian/amphibian divergence approximately 350 million years ago. In addition, one non-MHC-linked TAP2-hybridizing fragment was detected in approximately half of the individuals tested. Interestingly, TAP2 allelic lineages appear to match those of LMP7 and classical class I, which previously were categorized into two highly divergent groups that emerged at least 60 million years ago. Similar to LMP7 and class Ia,TAP2 is expressed ubiquitously with highest levels in intestine and spleen.     

Physical mapping and characterization of 5S rRNA genes in Douglas-fir

A critical mass of Internet users will soon enable wide diffusion of electronic communication within medical practice. E-mail between physicians and patients offers important opportunities for better communication. Linking patients and physicians through e-mail may increase the involvement of patients in supervising and documenting their own health care, processes that may activate patients and contribute to improved health. These new linkages may have profound implications for the patient-physician relationship. Although the federal government proposes regulation of telemedicine technologies and medical software, communications technologies are evolving under less scrutiny. Unless these technologies are implemented with substantial forethought, they may disturb delicate balances in the patient-physician relationship, widen social disparities in health outcomes, and create barriers to access to health care. This paper seeks to identify the promise and pitfalls of electronic patient-physician communication before such technology becomes widely distributed. A research agenda is proposed that would provide data that are useful for careful shaping of the communications infrastructure. The paper addresses the need to 1) define appropriate use of the various modes of patient-physician communication, 2) ensure the security and confidentiality of patient information, 3) create user interfaces that guide patients in effective use of the technology, 4) proactively assess medicolegal liability, and 5) ensure access to the technology by a multicultural, multilingual population with varying degrees of literacy.     

Synteny mapping of four genes from the short arm of human chromosome 19 to bovine chromosome 7

Four genes on the short arm of human chromosome 19 (HSA 19p) were assigned to bovine chromosome 7 (BTA 7) using a bovine x rodent somatic hybrid cell panel. These four genes were cartilage oligomeric matrix protein (COMP), lymphoblastic leukemia derived sequence 1 (LYL1), lysosomal alpha-mannosidase (MANB), and RAS oncogene family member RAB3A. Bovine sequence tagged sites were developed for the four genes and used for screening a bovine x rodent somatic cell panel. All four genes were mapped to bovine synteny group U22 (BTA 7) with a correlation coefficient of 0.901-1.000. This study confirms that the centromeric region of BTA 7 is conserved with HSA 19p.     

Molecular mapping and tagging of genes in crop plants

In India, molecular mapping and tagging of agronomically important genes using RFLP and RAPD markers have been carried out in three different crops: rice, mustard and chickpea. In rice, tagging of genes for resistance to gall midge and blast has been accomplished. Molecular mapping of cooking quality traits in rice is in progress. For fingerprinting rice cultivars, suitable probe enzyme combinations have been identified. In mustard, a partial RFLP linkage map has been constructed and one of the yellow seed-coat colour loci has been mapped. Significant associations of RFLP markers with quantitative traits have also been established. Potential use of RAPD markers to identify heterotic groups among mustard accessions has been demonstrated. In chickpea, the occurrence of considerable interspecific DNA polymorphism as revealed by RAPD analysis has facilitated construction of a partial linkage map.     

Issues in mapping genes for eating disorders

The purpose of this study was to obtain information about the prevalence of depressive symptoms in a representative sample of elderly subjects aged 85 years and over. The study was carried out as a population-based interview study in the City of Vantaa in Finland. The Zung Depression Status Inventory (DSI) was used to evaluate various depressive symptoms in this study population. The DSI scores range from 20 to 80; the higher the score, the more severe the disturbance. In subjects interviewed (n = 467, 362 women, 105 men), the prevalence estimates of depression with cutoff scores used in earlier studies (40 and 48) were very low: 5.2% and 1.1%. Also, the mean DSI score (SD) was very low, 27.9 (6.4). The scores tended to decrease with age, although the differences were not statistically significant. The DSI means were 28.0 (6.1) for women and 27.3 (7.2) for men (p = .0349). Women had a greater risk of being classified as depressed on the DSI (odds ratio: 1.60, 95% confidence interval: 1.00-2.57, p = .049). Feelings of emptiness, personal devaluation, and depressive mood were the most common depressive symptoms. In conclusion, the present population-based study shows that subjective experience of depression is very rare in Finnish people aged 85+. Our results suggest that optimistic mood might give some protection against death.     

Genetic mapping of the human and mouse phospholipase C genes

To determine chromosome positions for 10 mouse phospholipase C (PLC) genes, we typed the progeny of two sets of genetic crosses for inheritance of restriction enzyme polymorphisms of each PLC. Four mouse chromosomes, Chr 1, 11, 12, and 19, contained single PLC genes. Four PLC loci, Plcb1, Plcb2, Plcb4, and Plcg1, mapped to three sites on distal mouse Chr 2. Two PLC genes, Plcd1 and Plcg2, mapped to distinct sites on Chr 8. We mapped the human homologs of eight of these genes to six chromosomes by analysis of human x rodent somatic cell hybrids. The map locations of seven of these genes were consistent with previously defined regions of conserved synteny; Plcd1 defines a new region of homology between human Chr 3 and mouse Chr 8.     

Chromosomal mapping of three human LAMMER protein-kinase-encoding genes

The eukaryotic LAMMER protein kinase family is encoded by at least three loci in the human genome, designated CLK1, 2, and 3. We have mapped these loci to 2q33, 1q21, and 15q24, respectively, by fluorescent in situ hybridization. Additionally, a CLK2 pseudo-gene has been located to 7p15-21.     

Abundance, polymorphism and genetic mapping of microsatellites in rice

Dinucleotide microsatellites have been characterized and used as genetic markers in rice. Screening of a rice genomic library with poly(dG-dA).(dC-dT) and poly(dG-dT).(dC-dA) probes indicated that (GA)n repeats occurred, on average, once every 225 kb and (GT)n repeats once every 480 kb. DNA sequencing of ten randomly selected microsatellites indicated that the numbers of repeats ranged from 12 to 34 and that the patterns of microsatellites in rice were similar to those of humans and other mammals. Primers to these microsatellite loci as well as to four published microsatellite-containing sequences have been designed and degrees of polymorphism has been examined with 20 rice accessions. Multiple alleles, ranging from 5 to 11, have been observed at all the microsatellite loci in 20 rice accessions. Alleles specific to two cultivated subspecies, indica and japonica, were found in some microsatellite loci. Heterozygosity values of all the microsatellite markers were significantly higher than those of RFLP markers, based upon a parallel comparison. Ten microsatellite loci have been genetically mapped to four rice chromosomes. The genomic distribution of microsatellites appears to be random in rice.     

Methods of analysis and resources available for genetic trait mapping

Stones can be spilled from the gallbladder during laparoscopic cholecystectomy. These stones can be left in the peritoneal cavity or trapped at the trocar site. The potential late sequel and associated morbidity are not well documented. We reviewed the records of four patients who underwent laparoscopic cholecystectomy at Mount Sinai Medical Center in New York City who suffered from late complications attributed to gallstones left in the peritoneal cavity or abdominal wall. Four patients presented 1-14 months after laparoscopic cholecystectomy with intraabdominal and abdominal wall abscesses. The spillage of gallstones was noticed during the initial operation only in one of the patients. Three patients required laparotomy and open drainage of intraabdominal abscesses with drainage of pus and gallstones after failed attempts at percutaneous drainage. Two patients underwent local exploration of an abdominal wall abscess containing stones. Stones left in the abdominal cavity or trapped in trocar sites after laparoscopic cholecystectomy can cause serious late complications requiring repeated surgical interventions. Every effort should be made in order to avoid spillage of stones during dissection of the gallbladder and cystic duct and during retrieval of the gallbladder through the abdominal wall.     

Physical mapping of unique nucleotide sequences on identified rice chromosomes

A physical mapping method for unique nucleotide sequences on specific chromosomal regions was developed combining objective chromosome identification and highly sensitive fluorescence in situ hybridisation (FISH). Four unique nucleotide sequences cloned from rice genomic DNAs, varying in size from 1.3 to 400 kb, were mapped on a rice chromosome map. A yeast artificial chromosome (YAC) clone with a 399 kb insert of rice genomic DNA was localised at the distal end of the long arm of rice chromosome (1q2.1) and a bacterial artificial chromosome (BAC) clone (180 kb) containing the rice leaf blast-resistant gene (Pi-b) was shown to occur at the distal end of the long arm of chromosome 2 (2q2.1). A cosmid (35 kb) with the resistance gene (Xa-21) against bacterial leaf blight was mapped on the interstitial region of the long arm on chromosome 11 (11q1.3). Furthermore a single RFLP marker, 1.29 kb in size, was mapped successfully to the distal region of the long arm of rice chromosome 4 (4q2.1). For precise localisation of the nucleotide sequences within the chromosome region, image analyses were effective. The BAC clone was localised to the specific region, 2q2.1:96.16, by image analysis. The result was compared with the known location of the BAC clone on the genetic map and the consistency was confirmed. The effectiveness and reliability in physically mapping nucleotide sequences on small plant chromosomes achieved by the FISH method using a variety of probes was unequivocally demonstrated.     

Physical status and expression of HPV genes in cervical cancers

Entamoeba histolytica and Entamoeba dispar have only recently been defined as two separate species. E. histolytica, the pathogenic species, is the microorganism causing invasive intestinal amoebiasis and/or liver abscess, while the morphologically similar E. dispar is nonpathogenic and noninvasive. The gold standard for the distinction of the two species has been the isoenzyme electrophoresis of phosphoglucomutases (EC 5.4.2.2) and hexokinases (EC 2.7.1.1), but there had also been a controversy about the possibility of a conversion of isoenzyme patterns. In this study, we cloned the phosphoglucomutase (PGM) cDNAs from the pathogenic and the nonpathogenic species. The deduced amino acid sequences were only 2.4% different. The cDNAs were expressed in Escherichia coli under the control of a T7 RNA polymerase promoter. The recombinant polypeptides displayed strong phosphoglucomutase activity, each of the recombinant enzymes comigrated with its natural counterpart from E. histolytica and E. dispar in the starch gel electrophoresis. Our results give a biochemical interpretation of the PGM isoenzyme pattern and support the clear distinction between the two species.     

Physical and genetic map of the obligate intracellular bacterium Coxiella burnetii

Pulsed-field gel electrophoresis and PCR techniques have been used to construct a NotI macrorestriction map of the obligate intracellular bacterium Coxiella burnetii Nine Mile. The size of the chromosome has been determined to be 2,103 kb comprising 29 NotI restriction fragments. The average resolution is 72.5 kb, or about 3. 5% of the genome. Experimental data support the presence of a linear chromosome. Published genes were localized on the physical map by Southern hybridization. One gene, recognized as transposable element, was found to be present in at least nine sites evenly distributed over the whole chromosome. There is only one copy of a 16S rRNA gene. The putative oriC has been located on a 27.5-kb NotI fragment. Gene organization upstream the oriC is almost identical to that of Pseudomonas putida and Bacillus subtilis, whereas gene organization downstream the oriC seems to be unique among bacteria. The physical map will be helpful in investigations of the great heterogeneity in restriction fragment length polymorphism patterns of different isolates and the great variation in genome size. The genetic map will help to determine whether gene order in different isolates is conserved.     

Chromosomal mapping of genes in the RBCS family in Arabidopsis thaliana

We evaluated the usefulness of magnetic resonance angiography (MRA) for showing the topography of paraclinoid carotid artery aneurysms in 27 patients with 30 paraclinoid aneurysms undergoing conventional angiography, three-dimensional time-of-flight MRA and surgery. The anatomy shown on the axial MRA source images was consistent with that found at surgery. The neck of the aneurysm could always be identified on the source images, while it could not be analysed exactly on conventional angiography in 3 cases (10%). The optic nerves, including those displaced by the aneurysm, were recognised in all patients. The anterior clinoid process was shown as a low-intensity rim or area contiguous with the cortical bone. The source images were of great value in understanding the topography of paraclinoid carotid artery aneurysms.