抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

中枢神経系疾患の治療は正常細胞（ニューロン）の機能維持を目的とするが，脳血管障害のように機能障害の原因が細胞の死滅に基づくことは多い．一方，脳腫瘍の治療においては薬物療法や放射線療法といった腫瘍細胞の死滅を目標とするものが大きな位置を占める．いずれの場合にも，細胞死の機序を理解することは各種病態や治療法の理解のうえで重要である．現在のところ最も研究の進んでいる細胞死の型はアポトーシスである．そのなかで重要な位置を占めるミトコンドリアにおける反応および抗アポトーシス因子について概要を紹介する．

Neuroscience 細胞死：最近の知見

Nutrient requirements of dairy cattle , Nutrient requirements of dairy cattle , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

Nutrient requirements of dairy cattle

We describe the draft genome of the microcrustacean Daphnia pulex, which is only 200 megabases and contains at least 30,907 genes. The high gene count is a consequence of an elevated rate of gene duplication resulting in tandem gene clusters. More than a third of Daphnia's genes have no detectable homologs in any other available proteome, and the most amplified gene families are specific to the Daphnia lineage. The coexpansion of gene families interacting within metabolic pathways suggests that the maintenance of duplicated genes is not random, and the analysis of gene expression under different environmental conditions reveals that numerous paralogs acquire divergent expression patterns soon after duplication. Daphnia-specific genes, including many additional loci within sequenced regions that are otherwise devoid of annotations, are the most responsive genes to ecological challenges.

/pdf/the-ecoresponsive-genome-of-daphnia-pulex-bywdhwk6v1.pdf

The ecoresponsive genome of Daphnia pulex

For 10,000 years pigs and humans have shared a close and complex relationship. From domestication to modern breeding practices, humans have shaped the genomes of domestic pigs. Here we present the assembly and analysis of the genome sequence of a female domestic Duroc pig (Sus scrofa) and a comparison with the genomes of wild and domestic pigs from Europe and Asia. Wild pigs emerged in South East Asia and subsequently spread across Eurasia. Our results reveal a deep phylogenetic split between European and Asian wild boars ∼1 million years ago, and a selective sweep analysis indicates selection on genes involved in RNA processing and regulation. Genes associated with immune response and olfaction exhibit fast evolution. Pigs have the largest repertoire of functional olfactory receptor genes, reflecting the importance of smell in this scavenging animal. The pig genome sequence provides an important resource for further improvements of this important livestock species, and our identification of many putative disease-causing variants extends the potential of the pig as a biomedical model.

/pdf/analyses-of-pig-genomes-provide-insight-into-porcine-3emf6a6q4o.pdf

Analyses of pig genomes provide insight into porcine demography and evolution

Objective Recently, indigenous Korean grass Sasa quelpaertensis Nakai (SQ) has garnered much interest as a roughage source for livestock to mitigate its adverse effects on habitat diversity. Thus, the objective of the present study was to evaluate the ruminal fermentation, palatability, and nutrient digestibility of SQ for Korean native beef cattle (Hanwoo) using in vitro rumen fermentation, in situ rumen degradability, and in vivo feeding trials. Methods Using in vitro tests with rumen fluid as the inoculum for 48 h, ruminal fermentation of SQ was evaluated and compared with that of other roughage sources commonly used in Korea (i.e., rice straw, Timothy hay, and Italian ryegrass [IRG]). Additionally, an in situ trial 96 h was performed using three cannulated Hanwoo steers. Further, an in vivo trial was performed using eight Hanwoo steers to compare the palatability of SQ with rice straw in total mixed ration (TMR) and forage-concentrate separate feeding conditions. Finally, an in vivo digestibility trial of SQ fed as TMR of two particle sizes was performed with four Hanwoo steers. Results In vitro and in situ trials revealed that SQ was comparable or superior to rice straw in terms of the ruminal fermentation characteristics of pH, gas production, total volatile fatty acid content, and effective ruminal dry matter digestibility (DMD), although its fermentability was lower than that of Timothy hay and IRG. In the palatability test, steers showed a greater preference for SQ when given as TMR. The total tract DMD of SQ fed as TMR was 75.9%±1.37%, and it did not differ by particle size. Conclusion The feed value of SQ as a roughage source for Hanwoo steers is comparable or superior to that of rice straw, particularly when provided as TMR.

/pdf/evaluating-feed-value-of-native-jeju-bamboo-sasa-t4c4st11.pdf

Evaluating feed value of native Jeju bamboo (Sasa quelpaertensis Nakai) for beef cattle

Accurate estimation of milk production cost is very important for dairy farmers in establishing strategies for business management (e.g. planning a program for milk production, deciding the size of business and investment, determining the milk price for sale). Since the estimated cost of milk production is used as an important index to determine the basal price of milk in Korea, there has been much interest and debate on the method used to estimate milk production cost among the stakeholder. This study was thus carried out to identify problems in the current methodology for estimating cost of milk production, and to find a better way to improve it. We propose several alternatives and better ways to improve the current method for estimating cost of milk production. Estimation of the income and cost per head should be based on the number of cattle converted to grown cows. Cost estimation per liter of milk should be made for both whole milk and 3.4% milk fat corrected milk. The value of purchased cows and raised replacement heifers should be the same as their market value. The productive life span of cows should be less 4 years, and the terminal or salvage value of cows needs to be 30 to 40% less than her initial value. When calculating depreciation of cows over the productive life span, however, the salvage value should be 0 or 1 Korean won. On calculating labor costs, the farm labor wage corresponding to the average wage of nonfarm industrial workers should be assumed. Beside of these, better estimation procedures for other items are also given. The proposed methods from this study should improve the accuracy of estimation of milk production cost and help to achieve consensus among the stakeholder.

/pdf/problems-in-methodology-for-estimating-cost-of-milk-3c4vxa04vs.pdf

Seongwon Seo

Papers

Evaluating feed value of native Jeju bamboo (Sasa quelpaertensis Nakai) for beef cattle

Problems in methodology for estimating cost of milk production and its improvement