Paving the way of systems biology and precision medicine in allergic diseases: the MeDALL success story: Mechanisms of the Development of ALLergy; EU FP7-CP-IP; Project No: 261357; 2010-2015.

MeDALL (Mechanisms of the Development of ALLergy; EU FP7-CP-IP; Project No: 261357; 2010-2015) has proposed an innovative approach to develop early indicators for the prediction, diagnosis, prevention and targets for therapy. MeDALL has linked epidemiological, clinical and basic research using a stepwise, large-scale and integrative approach: MeDALL data of precisely phenotyped children followed in 14 birth cohorts spread across Europe were combined with systems biology (omics, IgE measurement using microarrays) and environmental data. Multimorbidity in the same child is more common than expected by chance alone, suggesting that these diseases share causal mechanisms irrespective of IgE sensitization. IgE sensitization should be considered differently in monosensitized and polysensitized individuals. Allergic multimorbidities and IgE polysensitization are often associated with the persistence or severity of allergic diseases. Environmental exposures are relevant for the development of allergy-related diseases. To complement the population-based studies in children, MeDALL included mechanistic experimental animal studies and in vitro studies in humans. The integration of multimorbidities and polysensitization has resulted in a new classification framework of allergic diseases that could help to improve the understanding of genetic and epigenetic mechanisms of allergy as well as to better manage allergic diseases. Ethics and gender were considered. MeDALL has deployed translational activities within the EU agenda.

Genetic analysis of testis weight and fertility in an interspecies hybrid congenic strain for Chromosome X.

A hybrid congenic strain, C57BL/6J.SPRET-Hprt(a), carrying 17 map units of Chromosome (Chr) X from Mus spretus on a background of C57BL/6J. has the novel phenotype of low fertility associated with small testis weight. In histological cross-section, many of the tubules in the testes of these congenic mice are empty except for Sertoli cells, while the other tubules appear to be normal. The gene, interspecific hybrid testis weight 1 (Ihtw1) causing this phenotype, has been fine mapped by using the strategy of generating subcongenic strains from recombinants within the congenic region. Genetic and phenotypic analysis of the subcongenic strains has defined a critical region of 1.8 map units for Ihtw1. This region of the genetic map is orthologous to the region on human Chr X containing the gene for the Borjeson-Forssman-Lehman syndrome, an inherited disease in which males show microorchidism.

A radiation hybrid map of mouse chromosome 13.

A mouse radiation hybrid (RH) panel was used to make a framework map for the entire length of mouse chromosome (Chr) 13. Forty-one loci were typed, and while most used primers flanking simple sequence repeats, some genes were included. The most proximal and distal loci are D13Mit132 and D13Mit35. The estimate of map length for Chr 13 is 1328 cR. The map is compared with the same set of loci from the consensus map for Chr 13, which is 70 cM in length, and also with a recombinational map derived from an intraspecies cross typed for many of the same loci. The mouse RH panel gave good resolution for Chr 13 and at the distal end allowed separation of previously nonrecombinant markers that are present on a single 620-kb YAC clone. Data analysis was performed using the RH option for Map Manager QT. This framework RH map of Chr 13 is the second of a series of RH maps for mouse chromosomes.

Genetic analysis of colon cancer susceptibility in mice.

Mouse models may aid in the identification of genes involved in colon cancer. Our mating scheme involved mouse strains selected for maximum differences in susceptibility to DMH-induced colon tumors. Tumors were found in 40 of 122 progeny from a backcross to the resistant strain. We examined progeny animals for segregation of 177 genetic markers distributed at intervals of 5-30 cM on all mouse chromosomes. Multiple loci contribute to the phenotype, with significant linkage to a novel locus, Ccs1, between D12Mit5 and D12Mit6 on mouse Chr 12. Comparative maps suggest that the human homologue of Ccs1 is near FOS on human chromosome 14q.

DNA sequence variation within the beta-glucuronidase gene complex among inbred strains of mice.

Tightly linked to the gene that encodes murine beta-glucuronidase (GUS) are three GUS-specific regulatory elements. Together, these elements define the GUS gene complex. Specific alleles of each regulatory element are associated with a specific GUS structural allele. These associations define the three common forms (haplotypes) of the GUS gene complex, designated A, B, and H. As an initial step in defining the DNA determinants of each regulatory element and to develop DNA markers for the common haplotypes, we have identified several DNA variants by blot hybridization analysis of restricted genomic DNA using GUS-specific cDNA probes. Of 30 tested restriction endonucleases, 24 reveal DNA polymorphisms that distinguish B- and H-haplotype DNA from that of the A haplotype. Of these 24, 18 uncover a restriction fragment length polymorphism in which the polymorphic fragment of A-haplotype DNA is 200-300 bp larger than the corresponding fragment of B- or H-haplotype DNA. DNA sequence analysis of this polymorphic region reveals the presence of a short, interspersed repetitive element of the B2 family within A-haplotype DNA which is absent in DNAs of B- or H-haplotype mice. None of the DNA variations revealed by these analyses can be associated at this time with variation in the regulatory or structural properties of GUS among the common haplotypes. Nevertheless, they do provide useful haplotype-specific markers within the GUS gene complex which are of critical importance for DNA transfer experiments in transgenic mice and in cultured cells.

Identification and characterization of functional genes encoding the mouse major urinary proteins.

Mouse Ltk- cells were stably transfected with cloned genes encoding the mouse major urinary proteins (MUPs). C57BL/6J MUP genomic clones encoding MUP 2 (BL6-25 and BL6-51), MUP 3 (BL6-11 and BL6-3), and MUP 4 (BL6-42) have been identified. In C57BL/6J mice, MUP 2 and MUP 4 are known to be synthesized in male, but not female, liver, and MUP 3 is known to be synthesized in both male and female liver and mammary gland. A BALB/c genomic clone (BJ-31) was shown to encode a MUP that is slightly more basic than MUP 2 and was previously shown to be synthesized in both male and female liver of BALB/c but not C57BL/6 mice. Comigration on two-dimensional polyacrylamide gels of the MUPs encoded by the transfecting gene provides a basis for tentative identification of the tissue specificity and mode of regulation of each gene. DNA sequence analysis of the 5' flanking region indicates that the different MUP genes are highly homologous (0.20 to 2.40% divergence) within the 879 base pairs analyzed. The most prominent differences in sequence occur within an A-rich region just 5' of the TATA box. This region (from -47 to -93) contains primarily A or C(A)N nucleotides and varies from 15 to 46 nucleotides in length in the different clones.

Mapping the gene for LTW-4, a 26,000 molecular weight major protein of mouse liver and kidney.

The polypeptide LTW-4 has previously been shown by 2D electrophoresis to be a major soluble protein of mouse liver. We now show that it is a major soluble polypeptide of mouse kidney. The Ltw-4 locus has been mapped on Chromosome 1 using the BXD, AKXL and BXH recombinant inbred strains. The gene order is Dip-1 Rnr - (Sas-1, ald) - Ltw-4 - Mls. The map distance between (Dip-1, Rnr) and Ltw-4 is estimated to be 12.2 +/- 4.2 cM, between Sas-1 and Ltw-4 5.4 +/- 2.6, between ald and Ltw-4 7.1 +/- 4.6 cM, and between Ltw-4 and Mls 4.3 +/- 2.0 cM. The strain distribution pattern of Ltw-4 is reported for the SWXL recombinant inbred strains and for a large number of inbred strains of mice.