Isolation and characterization of 2S cocoa seed albumin storage polypeptide and the corresponding cDNA

The amine pool of cocoa is known to be an essential component for the development of the typical cocoa flavor. To better understand and to produce an intense in vitro cocoa flavor, identification of the polypeptides that are the source of the amine flavor precursor pool is essential. Chromatographic analysis of the polypeptide profile of unfermented cocoa resulted in identification of a novel storage polypeptide of M(r) 8515. The N-terminal sequence of the first 34 residues of the purified polypeptide shows similarity to 2S storage albumins of cotton and Brazil nut and sweet protein, Mabinlin. To identify the corresponding cDNA of the putative cocoa 2S albumin, 18 randomly chosen clones from the cDNA library of immature Theobroma cacao seed mRNA were sequenced, and a full-length cDNA clone encoding a protein harboring the N-terminal sequence of the novel polypeptide was selected. The open reading frame of the clone encodes a polypeptide of M(r) 17125. Comparison of the translated amino acid sequence of the precursor protein or the mature polypeptide against the Swiss-Prot and TrEMBL databases shows high sequence similarity (>52%) and identity (>38%) to many plant 2S albumins. Tryptic peptide mass fingerprinting of the purified polypeptide by high-performance liquid chromatography-electrospray ionization mass spectrometry shows 10 masses that match the expected tryptic peptides of the deduced sequence. Together with the published work on plant 2S albumin processing, the results presented here suggest that post-translational processing yields a 73-residue polypeptide (residue positions 78-150) corresponding to the 9 kDa subunit of the mature cocoa 2S albumin protein.     

Characterization of peptides formed during fermentation of cocoa bean.

Analysis by SDS-PAGE and GPC-MS of fermented cocoa extracts shows changes in the amount and composition of the major proteins, accompanied by formation of complex distributions of peptides. MS/MS studies and application of SEQUEST sequencing software have allowed identification of two related peptides, a hexapeptide and a nonapeptide, formed from vicilin, one of the cocoa storage proteins. Time course studies of the two peptides show different abundance profiles and indicate, in part, production of the hexapeptide from the nonapeptide.     

Potential impacts of non‐native fish on the threatened mahseer (Tor) species of the Indian Himalayan biodiversity hot spot

1. Mahseer (Tor) fish species are critical components of locally adapted freshwater food webs across the Indian Himalayan biodiversity hotspot; however, multiple human stressors compounded by climate change have significantly depleted their populations over recent decades.
2. Mahseer species are now considered locally vulnerable or endangered in many regions. Hydropower projects in particular have fragmented populations, impairing genetic exchange, obstructing migratory paths, and changing the structure and functioning of riverine habitats, especially of formerly fast‐flowing rivers.
3. Worryingly, a literature survey and group discussions reveal that the increasing spread of non‐native fish species further compounds threats to mahseer and overall freshwater ecology. A better understanding of the current distribution, habitat requirement, and dispersal of non‐native fish is therefore essential to manage the growing threats to mahseer in the Indian Himalayan region.

     

生物学技术衍生动物的标识和追溯展望

可靠的动物标识方法是追溯体系成功的关键,可用于动物家系、动物健康和食品安全追溯.在繁殖技术多样化和遗传传播模式存在的情况下,生物技术衍生动物(BDAS)及其后代的追踪依然面临很多挑战,一个重要的问题是如何将这些通过传统技术或繁殖技术选育而成的动物与转基因动物进行区分,例如体细胞核转移(SCNT)形成的克隆动物.尽管可选择的动物标识很多,但是不是所有的都可用于生物技术衍生动物的标识,需要将分子学技术和其他物理学标识方法联合起来进行应用.