The Application of Nutrimetabolomics to Investigating the Bioaccessibility of Nutrients in Ham Using a Batch <i>in Vitro</i>Digestion Model

Delivering high quality dietary protein at an affordable price is a major aim of the EU-funded CHANCE project. Foods have been formulated with this aim and as part of their nutritional assessment;the bioaccessbility of nutrients following simulated gastroduodenal digestion is being investigated. Nutrimetabolomics approaches can be used to comprehensively and quantitatively analyse nutrients and metabolites. They have been applied to monitor nutrient release from ham, formulated in the CHANCE project, during in vitro digestion. SDS-PAGE analysis shows that constituent ham proteins were broken down to lower molecular weight polypeptides (Mr ≤ 10 kDa) after 120 min simulated gastric digestion which was digested further by subsequent duodenal digestion. Digestion of porteins resulted in the appearance of coalesced lipid droplets associated with the loss of the muscle protein matrix of the ham. Important nutrients, such as choline, creatine, carnosine, sucrose, cholesterol, triacylglyceride and fatty acids (saturated and unsaturated) were identified using 1H NMR. Chance ham is a good source of dietary protein and the combined approach can provide representative data on the bioaccessibility of all detectable nutrients contained in CHANCE ham to human digestive system.

Three-dimensional solution structure of ω-conotoxin SO_(3) determined by ^(1)H NMR

Cone snails (Conus) elaborate a series of conotoxin (CTX) peptides in their venoms to paralyze their prey. Among these toxins, w-CTX抯 specifically target to presynaptic voltage-gated calcium channel subsets, causing inhibition of neurotransmitter release. w-CTX SO3 was isolated from the venom of Conus striatus, which is the only available fish-hunting snail near the coast of the South China Sea. The three-dimensional solution structure of w-CTX SO3, a peptide which is the only w-conotoxin reported to show high homology with another w-CTX (MVIIA from C. Magus), has been determined by 1H NMR techniques. The molecular structure of w-CTX SO3 is stabilized by three disulfide bridges and a short triple-stranded antiparallel b-sheet with four turns. A comprehensive comparison suggested that the backbone conformation of w-CTXs was quite conserved, while the length of b-sheet and the type of some turns might have minor differences.

Genome Editing Enables Next-Generation Hybrid Seed Production Technology

The next-generation hybrid seed technology enables the successful production of sortable hybrid seeds from genic male sterile(GMS)lines and maintainers;however,it requires multiple laborious and complicated steps.Here,we designed a simple next-generation hybrid seed production strategy that takes advantage of the CRISPR/Cas9 technology to create a Manipulated GMS Maintainer(MGM)system via a single transformation.Under this schema,the maize male fertility gene ZmMS26 was nullified by removal of its fifth exon using the CRISPR/Cas9 system on a vector,and a second vector carrying a functional ZmMS26 cDNA was co-transformed to restore fertility.The second vector also contains a male gametophyte inactivation gene(ZmAA1)encoding maizeα-amylase driven by the pollen-specific promoter PG47 and an endosperm fluorescent marker(DsRED)driven by the barley endosperm aleurone-specific promoter Ltp2.The derived single-copy hemizygous MGM lines bore a mutated MS26 gene,leading to complete male sterility but normal vegetative growth and grain yield.The MGM system could prevent genetic transmission of the MGM elements via male gametophytes,providing an efficient method for sorting maintainer seeds labeled by DsRED.This strategy can be extended to any GMS gene and to hybrid crops other than maize.