Classical genetic markers and DNA markers: A commensal marriage

In this paper, we present an overview of classical genetic markers in nonhuman primates and then contrast the discriminatory powers of these markers with DNA markers. We have restricted the scope of our discussion to genetic markers found in blood, since they have been studied most extensively over the past 30 years. For example, immunoglobulin allotypes, complement markers, transferrins, and other protein markers can be identified using serum or plasma. Lymphocytes carry the major histocompatibility complex (MHC) markers, which are very polymorphic in most nonhuman primates. Lymphocytes are also used as a source of DNA. Finally, red blood cells carry an enormous array of blood group as well as isozyme markers. Our discussion will be limited to three species: rhesus monkeys (Macaca mulatta), baboons (Papio hamadryas), and chimpanzees (Pan troglodytes), although the principles are applicable to all nonhuman primates.     

Conversion of AFLP markers to sequence-specific PCR markers in barley and wheat

 Conversion of amplified fragment length polymorphisms (AFLPs) to sequence-specific PCR primers would be useful for many genetic-linkage applications. We examined 21 wheat nullitetrasomic stocks and five wheat-barley addition lines using 12 and 14 AFLP primer combinations, respectively. On average, 36.8% of the scored AFLP fragments in the wheat nullitetrasomic stocks and 22.3% in the wheat-barley addition lines could be mapped to specific chromosomes, providing approximately 461 chromosome-specific AFLP markers in the wheat nullitetrasomic stocks and 174 in the wheat-barley addition lines. Ten AFLP fragments specific to barley chromosomes and 16 AFLP fragments specific to wheat 3BS and 4BS chromosome arms were isolated from the polyacrylamide gels, re-amplified, cloned and sequenced. Primer sets were designed from these sequences. Amplification of wheat and barley genomic DNA using the barley derived primers revealed that three primer sets amplified DNA from the expected chromosome, five amplified fragments from all barley chromosomes but not from wheat, one amplified a similar-sized fragment from multiple barley chromosomes and from wheat, and one gave no amplification. Amplification of wheat genomic DNA using the wheat-derived primer sets revealed that three primer sets amplified a fragment from the expected chromosome, 11 primer sets amplified a similar-sized fragment from multiple chromosomes, and two gave no amplification. These experiments indicate that polymorphisms identified by AFLP are often not transferable to more sequence-specific PCR applications. Received: 30 June 1998 / Accepted: 26 October 1998     

Molecular markers and plant breeding

The achievements of modern biotechnology allow to modernize significantly the traditional plant breeding. The use of molecular codominant markers reduces considerably the quantity of breeding material and promotes the selection of genotypes, which posses desirable genes in the homozygous state. Molecular marking systems of agronomically important simple and quantitative traits have been developed using mono- and multiloci systems. Markers of the plant type and development rate, alleles of the storage protein genes, Wx-genes, short-stem genes, etc., have been created and tested at the South Biotecnology Center, National Academy of Agricultural Sciences. The technology of the application of DNA-typing for the identification and registration of varieties that has been developed in the South Biotecnology Center is of great importance for the systematization of germplasm sources and the protection of the rights of breeders.     

土壤水分对不同专用小麦后期光合特性及产量的影响

采用盆栽方法,研究了土壤水分对专用小麦生育后期光合特性及产量的影响.结果表明,强筋小麦豫麦34旗叶叶绿素计读数(SPAD值)、PSⅡ活性(Fv/Fo)和PSⅡ最大光能转换效率(Fv/Fm)在土壤相对含水量60%(FC)的条件下最高,光化学猝灭系数(qP)、非光化学猝灭系数(qN)、有效电子传递速率(ETR)和传递的量子产率(Φ2)在80%FC下最高;高产小麦豫麦49旗叶SPAD值、qP、qN、ETR均以80%FC下最高,Fv/Fo、Fv/Fm和φ2受土壤水分影响不大;弱筋小麦豫麦0,除qN在80%FC下最低外,其余光合特性参数均以80%FC的条件下最高.豫麦34产量和蛋白质含量均以60%FC最高,且产量达极显著差异;豫麦49和豫麦0籽粒蛋白质含量以40%FC最高,籽粒产量以80%FC最高,且豫麦49产质差异均达显著水平,而豫麦0的产量差异达极显著水平.     

Psoriasis vulgaris and genetic markers

Summary In a sample of n=160 nonrelated male and female patients suffering from psoriasis vulgaris, blood, serum protein, and enzyme group typings have been carried out and compared with healthy controls from the same area (Rheinland-Pfalz). Marked statistically significant differences between patients and controls were found in none of the genetic blood polymorphisms considered here. However, combining previously published data from various authors with our own, significant associations between this skin disease and genetic polymorphisms such as MN, Gc, Gm(2), red cell acid phosphatase, and red cell phosphoglucomutase (PGM₁) were seen. The possible reasons for these associations are discussed.     

Progestins and cardiovascular risk markers

Several risks are attributed to progestins as a class-effect; however, the progestins used in hormone replacement therapy (HRT) have varying pharmacologic properties and do not induce the same side effects. Natural progesterone (P) and some of its derivatives, such as the 19-norprogesterones, do not exert any androgenic effect and, hence, have no negative effect on the lipids. On the other hand, the 19-nortestosterone derivatives and even some 17-hydroxyprogesterones have a partial androgenic effect, which may explain some of the negative effects observed on surrogate markers of cardiovascular risk. The relevance of the lipid changes induced by sex steroids has been questioned, and studies in the female cynomolgous monkey have not shown a direct relationship to atherosclerosis. Results suggest that estrogens (E) have antiatherogenic effects and that P does not reverse the beneficial effect of estradiol. Also, sex hormones modulate the vasomotor response of the main arteries. E preserves the normal endothelium-mediated dilation of coronary arteries, and P does not reverse this potential cardioprotective mechanism. In the same animal model, the addition of cyclic or continuous medroxyprogesterone acetate (MPA) to E inhibited vasodilatation by 50%, while nomegestrol acetate did not diminish the E-induced vasodilatation. Not all progestins act similarly on vasomotion or affect cardiovascular risk factors in the same way. Progestins, such as MPA or norethisterone acetate (NETA), exert a partial detrimental effect on the beneficial actions of estrogens with regard to lipid changes, atheroma development, or vasomotion. In contrast, progesterone itself does not have this inhibitory effect on lipid changes and vascular reactivity in animal models or on exercise-induced myocardial ischemia in humans. Nonandrogenic molecules of P itself and of derivatives, such as 19-norprogesterones, would appear neutral on the vessels. Several ongoing randomized controlled trials of HRT are focusing on primary or secondary prevention of coronary heart disease. Unfortunately, most of these large trials have selected the same HRT regimen for their study design. Further studies with other treatment regimens are thus needed and should consider the various steroids used in different countries.     

Analysis of tetraploid Elymus species using wheat microsatellite markers and RAPD markers.

An analysis of Amplification fragment polymorphism of DNA from 27 accessions of 19 tetraploid Elymus species was carried out using 18 wheat microsatellite (WMS) primer pairs and 10 decamer primers. Ten WMS primer pairs produced multiple polymorphism on all accessions tested. Two independent phenograms, one based on WMS-PCR and one on RAPDs, separated the 19 tetraploid species into two main groups, viz., the SH genome species group and the SY genome species group. The results coincide with the genomic classification of these species and hence support previous studies showing that Elymus is not a monophyletic genus. The assays indicated that accessions within a species cluster together, which concurs with the morphological classification. Interspecific and intraspecific polymorphisms were detected by the WMS-PCR and RAPD analyses. Variation was observed among accessions of Elymus caninus. The WMS-PCR detected a much higher level of polymorphism than the RAPD analysis. WMSs seem to be more efficient markers than RAPD markers for studying the population diversity of Elymus species. The potential of cross-species amplification of microsatellite markers as an additional source for genetic analysis and applications in Elymus is discussed in the context of these results.     

Simultaneous analysis of lymphocyte markers using triple color markers

The introduction in flow cytometry of the new reagent Streptavidin Duochrome allows the simultaneous three color analysis of biological samples. Streptavidin Duochrome is a phycoerythrin-Texas red fluorochrome complex conjugated to the protein streptavidin. This novel complex exploits the principle fluorescence energy transfer when this reagent is used with FITC, PE and biotin-conjugated monoclonal antibodies; three different emissions of fluorescence are possible simultaneously using an argon laser at 488 nm (FACScan Becton Dickinson). Using Paint-a-gate software which analyses samples and displays the three colors on a screen, antigen distribution on multiple cell populations is obtained. Single, double and triple labeled cells (up to seven combinations) are visualized and quantified quickly and easily. Using a panel of normal donors we have evaluated the following combinations: CD3/CD4/CD8 to visualize T lymphocytes and their subsets; CD3/CD19/CD16 to quantify quickly the T, B, NK populations; CD4/Leu8/Leu18 to analyse the helper subset and CD3/CD8/Leu7. Our purpose is to evaluate the importance of this new kind of analysis to study the heterogeneity of several lymphocytic populations.     

NotI-STS markers for human chromosome 3 are gene markers

Ninety four NotI-STS markers to seventy two individual NotI clones were developed basing on DNA nucleotide sequences from NotI-"jumping" and "linking" NotI-libraries of human chromosome 3. The localization of NotI-STS markers and their ordering on chromosome was established by combined data of RH-mapping (our data), contig-mapping, cytogenetic mapping and in silico mapping. Performed comparison of NotI-STS DNAs with human genome sequences revealed two gaps in the regions, 3p21.33 (marker NLI-256) and 3p21.31 (NL3-005), and segmental duplication. Identical DNA fragments are localized in the regions 12q and 3p22-21.33 (marker NL3-007). In the region 3q28-q29 (marker NLM-084) a fragment was detected with its identical copies present also on chromosomes 1, 2, 15 and 19. For 69 NotI-STSs, significant homologies with nucleotide sequences of 70 genes and two cDNAs were detected taking in consideration homologies to NotI-STS 5'- and 3'-terminal sequences. Association of NotI-STSs with genes is confirmed by high correlation of gene density distribution with the density of NotI-STS markers on the map of human chromosome 3. Obtained data evidence possibility of NotI-STS marker application as gene markers and allow considering constructed NotI-map as gene map of human chromosome 3.     

Plasmacytoma with aberrant expression of myeloid markers, T-cell markers, and cytokeratin.

Plasmacytomas are localized neoplastic proliferations of monoclonal plasma cells. When multifocal, the process is referred to as multiple myeloma. These lesions exhibit a pattern of antigen expression and cytomorphology that usually leads to a ready diagnosis. However, potentially troublesome variations in immunophenotype occur. We describe a case of a plasmacytoma from a patient who presented with sudden onset of pain and a lytic lesion of the left proximal humerus. Hematoxylin and eosin-stained sections showed a lymphoproliferative lesion composed of large lymphoid cells, some with plasmacytoid and immunoblastic features. The lesion also showed significant mitotic activity. Immunohistochemical staining was positive for CD45 (LCA), CD56 (N-CAM), CD43 (MT1), and cytokeratin CAM5.2. There was also clonal staining for lambda light chains. In addition, flow cytometric analysis showed positivity for myeloid markers such as CD13, CD33, CD38, and CD138. Significant negative markers include CD20 (L26), CD45RO (UCHL-1), and CD79alpha. The unusual phenotypic features of this plasmacytoma illustrate potential diagnostic pitfalls. It is important to fully study such lesions to correctly classify them, because this has significant impact on prognosis and management.     

Enzyme markers in inbred rat strains: Genetics of new markers and strain profiles

Twenty-six inbred strains of the laboratory rat (Rattus norvegicus) were examined for electrophoretic variation at an estimated 97 genetic loci. In addition to previously documented markers, variation was observed for the enzymes aconitase, aldehyde dehydrogenase, and alkaline phosphatase. The genetic basis of these markers (Acon-1, Ahd-2, and Akp-1) was confirmed. Linkage analysis between 35 pairwise comparisons revealed that the markers Fh-1 and Pep-3 are linked. The strain profiles of the 25 inbred strains at 11 electrophoretic markers are given.     

Inflammatory markers and coronary heart disease

PURPOSE OF REVIEW: Despite changes in lifestyle and the use of effective pharmacologic interventions to lower cholesterol levels, coronary heart disease remains the major cause of morbidity and mortality in the developed world. Cholesterol screening fails to identify almost 50% of those individuals who will present with acute coronary syndromes. Recent evidence from laboratory and prospective clinical studies demonstrates that atherosclerosis is not simply a disease of lipid deposition, but rather is an inflammatory process with highly specific cellular and molecular responses. The clinical utility of inflammatory markers has been examined in a variety of atherothrombotic diseases. Because C-reactive protein is highly stable in stored frozen samples, and automated and robust analytical systems for its measurement are available, it has become the most widely examined inflammatory marker. RECENT FINDINGS: C-reactive protein has consistently been shown to be a useful prognostic indicator in acute coronary syndromes and is a strong predictor of future coronary events in apparently healthy individuals. In addition, C-reactive protein can identify individuals with normal lipid levels who are at increased risk for future coronary events. Because drugs such as aspirin and statins reduce inflammatory risk, C-reactive protein has the potential to guide the use of these therapies in high-risk individuals for primary prevention. SUMMARY: C-reactive protein may have a role in global risk assessment for primary prevention and in targeting those patients who will benefit from anti-inflammatory therapies. In addition, it may also be a good prognostic indicator in patients with acute coronary syndromes.     

Cellular and extracellular markers of hemangioma

Several cellular and extracellular markers that distinguish the phases of the hemangioma life cycle have been described previously. However, details of the phenotypic changes of; the various cellular elements during hemangioma development have not been fully reported, and the extracellular matrix composition, especially in the vicinity of the proliferating endothelial cells, is poorly described. This study examined the expression of cellular and extracellular molecules and cytokines in the proliferative, involuting, and involuted phases of hemangioma. Paraffin-embedded hemangioma specimens, four from each phase, were examined histochemically and immunohistochemically. Throughout the three phases, vascular endothelial cells stained positive for CD31 and von Willebrand factor, although in the involuted phase, not all vessels in the tissue expressed these endothelial markers. Proliferating cell nuclear antigen was expressed by the majority of endothelial cells and pericytes in the proliferative and early involuting phases, but its expression was negligible in the involuted phase. In addition to finding that the total number of mast cells was highest in the involuting phase, the authors observed that the proportion of chymase-positive mast cells decreased with the progression of hemangioma and that virtually all mast cells expressed the biogenic amine phenotype throughout the hemangioma life cycle. The localization of vascular endothelial growth factor predominantly to the pericytes and endothelial cells during the proliferative phase and of basic fibroblast growth factor to the endothelial cells in both the proliferative and early involuting phases is consistent with previous reports, although the latter growth factorwas also observed in mast cells. Type IV collagen and the beta chain of laminin and perlecan were detected in the basement membranes in all phases. Interestingly, collagen types I, III, and V were present in basal membranes throughout the phases and with increasing density in the stromal areas with involution, although type I collagen was less prominent during the proliferative phase. Short-chain collagen type VIII was localized extracellularly throughout the development of hemangioma but, during the early proliferative phase, it was also detected within mast cells. The expression of specific cytokines and cellular and extracellular markers may help distinguish the different clinical phases of the hemangioima life cycle. These results provide further insight into the biology of hemangioma.