Glycolipid composition of Hevea brasiliensis latex

Glycolipids of fresh latex from three clones of Hevea brasiliensis were characterized and quantified by HPLC/ESI-MS. Their fatty acyl and sterol components were further confirmed by GC/MS after saponification. The four detected glycolipid classes were steryl glucosides (SG), esterified steryl glucosides (ESG), monogalactosyl diacylglycerols (MGDG) and digalactosyl diacylglycerols (DGDG). Sterols in SG, ESG and total latex unsaponifiable were stigmasterol, β-sitosterol and Δ⁵-avenasterol. The latter was found instead of fucosterol formerly described. Galactolipids were mainly DGDG and had a fatty acid composition different from that of plant leaves as they contained less than 5% C18:3. Glycolipids, which represented 27–37% of total lipids, displayed important clonal variations in the proportions of the different fatty acids. ESG, MGDG and DGDG from clone PB235 differed notably by their higher content in furan fatty acid, which accounted for more than 40% of total fatty acids. Clonal variation was also observed in the relative proportions of glycolipid classes except MGDG (8%), with 43–51% DGDG, 30–34% SG and 7–19% ESG. When compared with other plant cell content, the unusual glycolipid composition of H. brasiliensis latex may be linked to the peculiar nature of this specialized cytoplasm expelled from laticiferous system, especially in terms of functional and structural properties.     

Molecular characterization of the pig<Emphasis Type="Italic"> C3</Emphasis> gene and its association with complement activity

The complement system catalyzes direct lysis of micro-organisms and modulates phagocytosis, inflammation, humoral and cellular immune responses. Since the complement protein C3 is the central component within all pathways of complement activation, C3 is a candidate gene for complement activity and also for improved protection against many pathogens. The pig C3 gene was sequenced, screened for polymorphisms, and analyzed for association with hemolytic complement activity of the alternative and classical pathway (AH(50), CH(50)). C3c serum levels and haptoglobin (HP) serum concentrations were measured before and after vaccination against Mycoplasma hyopneumoniae, Aujeszky virus, and porcine reproductive and respiratory syndrome virus in F2 animals of a pig resource population based on crossbreeding of Duroc and Berlin Miniature Pig. The genomic C3 sequence covers 444 bp of promoter region, 41 exons and 40 introns, as well as 881 bp of the 3'-flanking region. The cDNA codes for a 1,661-amino acid precursor C3. Five polymorphic sites were detected in the 5'-UTR, intron 13, exon 15, exon 30, and the 3'-UTR. Within the resource population two haplotypes were found to segregate. Analysis of variance applying a repeated measures model revealed a significant effect of the interaction of C3 genotype and time of measurement relative to immunization on CH(50), AH(50,)and C3c that is likely to be due to variation of C3 expression. In contrast, the time course of the HP acute-phase reaction is not associated with C3 genomic variation. The association of C3 with complement activity indicates the importance of C3 as a candidate gene for natural resistance to micro-organisms, although the causative polymorphism modulating the expression of C3 remains to be delineated.     

Mapping of ESTs derived from pre-implantation stage cattle embryos to allocate 16 new additions to the ordered comparative map of cattle and human

Twenty expressed sequence tags (ESTs) derived from cDNA libraries of different developmental stages of embryos were mapped using a whole genome bovine hamster radiation hybrid panel. These include 14 markers representing genes, most of which have not so far been mapped in cattle, with another three being novel in both cattle and human. The markers were placed on specific chromosomes with high LOD scores and except two all localizations fit the current human and cattle comparative map. The assignment of these genes further enriches the cattle genome map and also contributes to the international effort of generating comparative maps.     

Analysis of non‐synonymous SNPs of the porcine SERPINA6 gene as potential causal variants for a QTL affecting plasma cortisol levels on SSC7

Recently, the SERPINA6 gene encoding corticosteroid‐binding globulin (CBG) has been proposed as a candidate gene for a quantitative trait locus (QTL) affecting cortisol level on pig chromosome 7. The QTL was repeatedly detected in different lines, including a Piétrain × (German Landrace × German Large White) cross (PiF1) and purebred German Landrace (LR). In this study, we investigated whether the known non‐synonymous polymorphisms c.44G>T, c.622C>T, c.770C>T, c.793G>A, c.832G>A and c.919G>A of SERPINA6 are sufficient to explain the QTL in these two populations. Our investigations revealed that SNPs c.44G>T, c.622C>T, c.793G>A and c.919G>A are associated with cortisol level in PiF1 (P < 0.01). Haplotype analysis showed that these associations are largely attributable to differences between a major haplotype carrying SNPs c.793G>A and c.919G>A and a haplotype carrying SNPs c.44G>T and c.622C>T. Furthermore, some SNPs, particularly c.44G>T and c.622C>T and the carrier haplotype, showed association with meat quality traits including pH and conductivity (P < 0.05). In LR, the non‐synonymous SNPs segregate at very low frequency (<5%) and/or show only weak association with cortisol level (SNPs c.832G>A and c.919G>A; P < 0.05). These findings suggest that the non‐synonymous SNPs are not sufficient to explain the QTL across different breeds. Therefore, we examined whether the expression of SERPINA6 is affected by cis‐regulatory polymorphisms in liver, the major organ for CBG production. We found allelic expression imbalance of SERPINA6, which suggests that its expression is indeed affected by genetic variation in cis‐acting elements. This represents candidate causal variation for future studies of the molecular background of the QTL.