Haptoglobin in various diseases]

The clinical significance of haptoglobin (Hp) can be seen in the fact that its serum concentration shows a specific pattern in certain diseases and under various therapeutic measures. The determination of Hp is not only indicated in haemolytic anaemias, but also in liver and kidney diseases, infections, diseases of the connective tissue, malignant tumours, and under certain therapeutic conditions.     

Blood group assignment--a genetic marker of hepatic hemangiomatosis]

There is no single point of view on pathogenesis of hemangiomas. The authors investigated the ABO blood types in 52 patients with hepatic hemangiomas (Group 1) and 1000 control patients (Group 2). The study demonstrated 61.5% of the A blood type among the patients of Group 1. This was significantly higher than in the Group 2 and representative groups from literature (P less than 0.001). Taking into account that the cells of both blood and blood vessels are formed in embryos through the mesenchyma and the heritability of blood group antigens, it is supposed that the results obtained support the genetic determination theory of pathogenesis of hepatic hemangiomas.     

Polymorphism of untranscribed spacer rDNA as a molecular genetic marker in population studies of cattle]

Variable polymorphic patterns were detected using EcoRI-SalI fragment of bovine rDNA, including 3'-end of 28S rRNA gene with the adjacent portion of the transcribed spacer, as a probe for hybridization. Some features of these polymorphic patterns are similar to DNA fingerprints detected with the M13 probe. Bovine rDNA spacer polymorphism was used as a molecular genetic marker for population analysis of individual specific patterns of 4 cattle breeds with the help of the Jeffreys' method. It was supposed that the probability of identical fingerprints appearance could be the characteristics of heterogeneity of cattle populations. The observed length of polymorphic gragments ranged from 2000 to 6000 bp. The mean number of fragments per individual for all breeds was 15.05. The probability of identical patterns appearance was very high: from 1.18 x 10(-5) in ajshir's breed to 1.43 x 10(-7) in "white and black"s' breed. So, high probability seems to be dependent on the high allelic frequency and the way of breeding.     

遗传标记的研究进展

遗传图谱的构建依赖于各种遗传标记 ,在基因组织中可作为标记的特征繁多 ,本文对不同遗传标记的应用和发展作一综述。1　蛋白质标记蛋白质标记是在蛋白多态性基础上发展的一种分子标记 ,最常用是蛋白质电泳及其配套的专一性染色。在具有大量形态标记和细胞学标记定位的物种中 ,可通过两点或三点测交将编码同工酶基因定位于特定的染色体上。即使没有已被定位的标记基因 ,同样可以测定编码酶的基因间的连锁关系。由于编码同工酶的等位基因是共显性的 ,通过产生多个酶座位处于杂合状态的Ｆ1,就可以同时确定这些同工酶座位的连锁关系。随着已定…     

Haptoglobin study of sheep during the development process]

The development of haptoglobin blood system was studied in the sheeps during intrauterine development and early postnatal period. The haptoglobin content was shown to decrease with the foetus age, two peaks of its reliable increase having been, however, noted -- on the 55th and 105th days of development. After the birth the haptoglobin concentration in blood is relatively low, increases gradually and attains by the 8th month of life that in adult animals. In the blood serum of 45--120 days old foetuses two phenotypes of fetal haptoglobin were found; the adult haptoglobin is present only beginning from the 1st month of life.     

Cost-efficient selection of a marker panel in genetic studies

Genetic techniques are frequently used to sample and monitor wildlife populations. The goal of these studies is to maximize the ability to distinguish individuals for various genetic inference applications, a process which is often complicated by genotyping error. However, wildlife studies usually have fixed budgets, which limit the number of genetic markers available for inclusion in a study marker panel. Prior to our study, a formal algorithm for selecting a marker panel that included genotyping error, laboratory costs, and ability to distinguish individuals did not exist. We developed a constrained nonlinear programming optimization algorithm to determine the optimal number of markers for a marker panel, initially applied to a pilot study designed to estimate black bear abundance in central Georgia. We extend the algorithm to other genetic applications (e.g., parentage or population assignment) and incorporate possible null alleles. Our algorithm can be used in wildlife pilot studies to assess the feasibility of genetic sampling for multiple genetic inference applications. © 2011 The Wildlife Society.     

Dual selection of a genetic switch by a single selection marker

Forward engineering of synthetic genetic circuits in living cells is expected to deliver various applications in biotechnology and medicine and to provide valuable insights into the design principles of natural gene networks. However, lack of biochemical data and complexity of biological environment complicate rational design of such circuits based on quantitative simulation. Previously, we have shown that directed evolution can complement our weakness in designing genetic circuits by screening or selecting functional circuits from a large pool of nonfunctional ones. Here we describe a dual selection strategy that allows selection of both ON and OFF states of genetic circuits using tetA as a single selection marker. We also describe a successful demonstration of a genetic switch selection from a 2000-fold excess background of nonfunctional switches in three rounds of iterative selection. The dual selection system is more robust than the previously reported selection system employing three genes, with no observed false positive mutants during the simulated selections.     

Serum ferritin as a marker of affection for genetic hemochromatosis

A bivariate segregation analysis of genetic hemochromatosis with serum ferritin concentration was undertaken to examine the pleiotropic effect of the hemochromatosis locus on each of the two phenotypes, in an ascertained sample of families from Brittany, France. The gene was recessive with respect to both phenotypes, and the estimated gene frequency in the general population was 0.054. Although the ferritin concentration was corrected for the linear relationship with age among controls, there was a residual correlation with age among male family members, consistent with the progressive increase in body iron stores among hemochromatosis homozygotes. This genotype-specific relationship with age illustrates the importance of incorporating interaction effects into analytic models, and suggests that even as a better indicator of progress of disease, rather than liability to disease, serum ferritin concentration serves well to distinguish hemochromatosis homozygotes from alternate genotypes in a family study.     

NADH diaphorase as a genetic marker for sheep red cells

Three NADH diaphorase phenotypes were observed in the red cells of sheep. Breeding data indicated that this polymorphism was under the control of two autosomal co-dominant alleles, designated Dia^F and Dia^s. Phenotype Dia F had significantly lower NADH diaphorase activity than phenotype Dia S. The frzquency of Dia^F and Dia^S was determined in 9 different breeds.     

Efficient genetic transformation of Sorghum using a visual screening marker.

To transform grain sorghum (Sorghum bicolor (L.) Moench) with a visual reporter gene (gfp) and a target gene (tlp), three genotypes (two inbreds, Tx 430 and C401, and a commercial hybrid, Pioneer 8505) were used. We obtained a total of 1011 fertile transgenic plants from 61 independent callus lines, which were produced from 2463 zygotic immature embryos via Agrobacterium-mediated transformation. The reporter gene, gfp, encoding green fluorescent protein (GFP), was used as a visual screening marker, and the target gene, tlp, encoding thaumatin-like protein (TLP), was chosen for enhancing resistance to fungal diseases and drought. Both genes were under the control of the maize ubi 1 promoter in the binary vector pPZP201. A total of 320 plants showing GFP expression, derived from 45 calli, were selected and analyzed by Southern blot analysis. There was a 100% correlation between the GFP expression and the presence of the target gene, tlp, in these plants. Transgenic plants showing strong TLP expression were confirmed by Western blotting with antiserum specific for TLP. The transgene segregated in various ratios among progeny, which was confirmed by examining seedlings showing GFP fluorescence. The progeny also showed different copy numbers of transgenics. This report describes the successful use of GFP screening for efficient production of stably transformed sorghum plants without using antibiotics or herbicides as selection agents.     

D-serine deaminase is a stringent selective marker in genetic crosses.

The presence of the locus for D-serine deaminase (dsd) renders bacteria resistant to growth inhibition by D-serine and enables them to grow with D-serine as the sole nitrogen source. The two properties permit stringent selection in genetic crosses and make the D-serine deaminase gene an excellent marker, especially in the construction of strains for which the use of antibiotic resistance genes as selective markers is not allowed.     

Determining informativity of marker typing for genetic counseling in a pedigree

Summary For the situation of a Mendelian disease linked to a genetic marker, a new method is described that allows evaluating for genetic counseling the information potentially available from the linked marker before the marker data are actually obtained, that is, prior to drawing blood for marker typing. For a consultand in a family pedigree, the method determines the risk distribution (small families) or an approximation to it (larger families) and calculates the probability that the risk will deviate beyond certain limits from its a priori value, which exists without marker data, for example, that the risk will be smaller than 0.10 or larger than 0.90. The method was applied here to a pedigree of 15 individuals for which analytical calculations would be difficult to carry out.     

Insertion of a genetic marker into the ribosomal DNA of yeast

Plasmid pBR322 carrying the yeast LEU2+ gene transforms leu⁻ yeast into LEU+ at a low frequency by integration at homologous chromosomal DNA. When one-half of the yeast rDNA repeat unit (BglII-A) is inserted into the plasmid, the frequency of yeast transformation increases 100- to 200-fold, in proportion to the increased amount of homologous repetitive rDNA available for integration. When the other half of the repeat unit (BglII-B) is inserted into the plasmid, the transformation frequency increases by a factor of 10⁴, and the transformants are very unstable. It is likely that this fragment of rDNA contains a yeast origin of replication. This plasmid is a useful vector for cloning fragments of yeast DNA in yeast. We have used the LEU2+ gene, inserted into the rDNA locus, as a genetic marker for mapping the rDNA, in a procedure analogous to the use of antibiotic resistance transposons in the mapping of bacterial genes. Yeast ribosomal DNA is on chromosome XII between asp5 and ura4 as determined by mitotic linkage. Genetic analysis of markers inserted at the rDNA locus should be a useful tool for studying the conservation of sequence homology and the conservation of copy number of repeated genes.     

Haptoglobin and malaria

Haptoglobin gene knockout mice and wild-type controls were infected with Plasmodium berghei ANKA or Plasmodium chabaudi. The peak parasitaemia and parasite burden were higher in Hp-/- mice than in Hp+/+ mice. The increase in spleen weight following malaria infection was smaller in Hp-/- mice than in Hp+/+ animals. The occurrence of cerebral malaria in P. berghei ANKA infection was not different in Hp gene knockout mice and their controls.