Production of l-lactic acid with immobilized Lactobacillus delbrueckii

Summary Living Lactobacillus delbrueckii cells were entrapped in calcium alginate gel beads and employed both in recycle batch and continuous column reactors to produce l-lactic acid from glucose. The substrate contained l% (w/v) yeast extract as nutrient and 4.8% (w/v) solid calcium carbonate as buffer. The maxiumum lactic acid yield obtained was 97%, of which more than 90% was l-lactic acid. The biocatalyst activity half-life in continuous operation was about 100 d, and only about 10% of the activity was lost during intermittent storage of the bioreactor at +7°C for about 5 months.     

Molecular anatomy of the cytoplasmic domain of bovine growth hormone receptor, a quantitative trait locus

Quantitative trait loci (QTL) studies have indicated growth hormone receptor (GHR) as a candidate gene affecting cattle milk yield and composition. In order to characterize genetic variation at GHR in cattle, we studied European and East African breeds with different histories of selection, and Bos grunniens, Ovis aries, Sus scrofa, Bison bison and Rangifer tarandus as references. We sequenced most of the cytoplasmic domain (900 bp of exon 10), 89 bp of exon 8, including the putative causative mutation for the QTL effect, and 390 bp of intron 8 for comparison. In the cytoplasmic domain, seven synonymous and seven non-synonymous single nucleotide polymorphisms (SNP) were identified in cattle. Three non-synonymous SNPs were found in sheep and one synonymous SNP in yak, while other studied species were monomorphic. Three major haplotypes were observed, one unique to African breeds, one unique to European breeds and one shared. Bison and yak haplotypes are derivatives of the European haplotype lineage. Most of the exon 10 non-synonymous cattle SNPs appear at phylogenetically highly conserved sites. The polymorphisms in exon 10 cluster around a ruminant-specific tyrosine residue, suggesting that this site may act as an additional signalling domain of GHR in ruminants. Alternative explanations for the persistent polymorphism include balancing selection, hitch-hiking, pleiotropic or sexually antagonistic fitness effects or relaxed functional constraints.     

Full Likelihood Analysis of Genetic Risk with Variable Age at Onset Disease—Combining Population-Based Registry Data and Demographic Information

Background

In genetic studies of rare complex diseases it is common to ascertain familial data from population based registries through all incident cases diagnosed during a pre-defined enrollment period. Such an ascertainment procedure is typically taken into account in the statistical analysis of the familial data by constructing either a retrospective or prospective likelihood expression, which conditions on the ascertainment event. Both of these approaches lead to a substantial loss of valuable data.

Methodology and Findings

Here we consider instead the possibilities provided by a Bayesian approach to risk analysis, which also incorporates the ascertainment procedure and reference information concerning the genetic composition of the target population to the considered statistical model. Furthermore, the proposed Bayesian hierarchical survival model does not require the considered genotype or haplotype effects be expressed as functions of corresponding allelic effects. Our modeling strategy is illustrated by a risk analysis of type 1 diabetes mellitus (T1D) in the Finnish population-based on the HLA-A, HLA-B and DRB1 human leucocyte antigen (HLA) information available for both ascertained sibships and a large number of unrelated individuals from the Finnish bone marrow donor registry. The heterozygous genotype DR3/DR4 at the DRB1 locus was associated with the lowest predictive probability of T1D free survival to the age of 15, the estimate being 0.936 (0.926; 0.945 95% credible interval) compared to the average population T1D free survival probability of 0.995.

Significance

The proposed statistical method can be modified to other population-based family data ascertained from a disease registry provided that the ascertainment process is well documented, and that external information concerning the sizes of birth cohorts and a suitable reference sample are available. We confirm the earlier findings from the same data concerning the HLA-DR3/4 related risks for T1D, and also provide here estimated predictive probabilities of disease free survival as a function of age.     

Serial duplication of 10 (q21→q22) in a mentally retarded boy with congenital malformations

Summary A boy with congenital malformations and a serial duplication of 10(q21q22) is reported. His clinical picture is compared with that of a previously reported patient with a similar karyotype.     

Polymorphisms of the gene encoding cholesterol ester transfer protein and serum lipoprotein levels in subjects with and without coronary heart disease

Summary We determined TaqI-A, TaqI-B and EcoNI genotypes at the cholesteryl ester transfer protein (CETP) locus in 111 healthy volunteers and in 187 hyperlipidemic men of whom 72 had suffered a myocardial infarction. There were no significant differences in the allele distributions at these polymorphic loci either between the population sample and the hyperlipidemic subjects, or between patients with and without previous myocardial infarction. To detect the associations between the CETP polymorphisms and serum lipid and apoprotein levels, we determined the serum concentrations of total cholesterol, triglycerides, high density lipoprotein (HDL)-cholesterol, apoA-I, apoA-II and apoB in the subjects studied and correlated them to the 3 RFLPs. No significant differences were observed in the serum levels of apoproteins and lipid parameters between subjects with different genotypes in any of these polymorphic CETP loci, either in the population sample or in hyperlipidemic men. Multivariate analyses did not reveal a significant independent role for any of the 3 polymorphisms in determining serum HDL-cholesterol or apoA-I levels after adjusting for triglyceride and low density lipoprotein cholesterol concentrations. This was evident for the group of healthy volunteers and for hyperlipidemic subjects, including those who had survived a myocardial infarction. We conclude that, in Finns, the CETP RFLPs are not useful markers for the risk of coronary heart disease.     

Phylogeny of Mysis (Crustacea, Mysida): history of continental invasions inferred from molecular and morphological data

We studied the phylogenetic history of opossum shrimps of the genus Mysis Latreille, 1802 (Crustacea: Mysida) using parsimony analyses of morphological characters, DNA sequence data from mitochondrial (16S, COI and CytB) and nuclear genes (ITS2, 18S), and eight allozyme loci. With these data we aimed to resolve a long‐debated question of the origin of the non‐marine (continental) taxa in the genus, i.e., “glacial relicts” in circumpolar postglacial lakes and “arctic immigrants” in the Caspian Sea. A simultaneous analysis of the data sets gave a single tree supporting monophyly of all continental species, as well as monophyly of the taxa from circumpolar lakes and from the Caspian Sea. A clade of three circumarctic marine species was sister group to the continental taxa, whereas Atlantic species had more distant relationships to the others. Small molecular differentiation among the morphologically diverse endemic species from the Caspian Sea suggested their recent speciation, while the phenotypically more uniform “glacial relict” species from circumpolar lakes (Mysis relicta group) showed deep molecular divergences. For the length‐variable ITS2 region both direct optimization and a priori alignment procedures gave similar topologies, although the former approach provided a better overall resolution. In terms of partitioned Bremer support (PBS), mitochondrial protein coding genes provided the largest contribution (83%) to the total tree resolution. This estimate however, appears to be partly spurious, due to the concerted inheritance of mitochondrial characters and probable cases of introgression or ancestral polymorphism. © The Willi Hennig Society 2005.     

A medium-density genetic linkage map of the bovine genome

A cattle genetic linkage map was constructed which covers more than 95 percent of the bovine genome at medium density. Seven hundred and forty six DNA polymorphisms were genotyped in cattle families which comprise 347 individuals in full sibling pedigrees. Seven hundred and three of the loci are linked to at least one other locus. All linkage groups are assigned to chromosomes, and all are orientated with regards to the centromere. There is little overall difference in the lengths of the bull and cow linkage maps although there are individual differences between maps of chromosomes. One hundred and sixty polymorphisms are in or near genes, and the resultant genome-wide comparative analyses indicate that while there is greater conservation of synteny between cattle and humans compared with mice, the conservation of gene order between cattle and humans is much less than would be expected from the conservation of synteny. This map provides a basis for high-resolution mapping of the bovine genome with physical resources such as Yeast and Bacterial Artificial Chromosomes as well as providing the underpinning for the interpolation of information from the Human Genome Project. Received: 15 August 1996 / Accepted: 15 September 1996