Detecting signatures of inter‐regional and inter‐specific hybridization among the Chinese rhesus macaque specific pathogen‐free (SPF) population using single nucleotide polymorphic (SNP) markers

Background While rates of gene flow between rhesus and longtail macaque populations near their hybrid zone in Indochina have been quantified elsewhere, this study demonstrates that the inter‐specific introgression is not limited to the Indochinese hybrid zone but is more geographically widespread. Methods Twelve rhesus and longtail macaque populations were analyzed using single nucleotide polymorphic (SNP) loci. Results There is evidence for inter‐specific admixture between Chinese rhesus and mainland longtails, with implications for genetic diversity both in the Chinese super‐SPF population at the California National Primate Research Center and in other primate facilities. Eastern Chinese rhesus appeared more highly derived than western Chinese rhesus, and allele sharing between longtails and Chinese rhesus was not random with regard to geographic distance, but no significant nuclear genetic differences between eastern and western Chinese rhesus were detected among the 245 genic SNPs assayed. Conclusion The implications of this inter‐specific admixture for the use of Chinese rhesus and mainland longtail in biomedical research should be considered.     

Phylogeny of Local Sheep Breeds in East Asia, Focusing on the Bayanbulak Sheep in China and the Sipsu Sheep in Bhutan

The phylogenetic positions of the Bayanbulak sheep in China and the Sipsu sheep in Bhutan in the northern Asian sheep group were determined on the basis of allele frequency data for five informative and polymorphic loci of blood protein and nonproteins, such as transferrin (TF), arylesterase (ES), hemoglobin-β (HB-β), X-protein (XP), and potassium transport (KE), using different electrophoretic and ion-densitometric techniques. Based on Nei’s genetic distance, clustering analysis by the UPGMA method showed that the Bayanbulak sheep is clustered in the northern Asian sheep group. Furthermore, the Bayanbulak sheep belongs to a subgroup containing the Khalkhas and Hu sheep of the Mongolian sheep group, which is distinguished from another subgroup of the small-tailed Han, Tan, Tong, and Wadi sheep. The Bayanbulak sheep was closest to the Hu sheep, despite a morphological difference in the fat deposits. In addition to these findings, the Sipsu sheep was verified to belong to the Baruwal sheep.     

Mechanisms for asporin function and regulation in articular cartilage

Osteoarthritis (OA), the most prevalent form of skeletal disease, represents a leading cause of disability following middle age. OA is characterized by the loss of articular cartilage; however, the details of its etiology and pathogenesis remain unclear. Recently, we demonstrated a genetic association between the cartilage extracellular matrix protein asporin and OA (Kizawa, H., Kou, I., Iida, A., Sudo, A., Miyamoto, Y., Fukuda, A., Mabuchi, A., Kotani, A., Kawakami, A., Yamamoto, S., Uchida, A., Nakamura, K., Notoya, K., Nakamura, Y., and Ikegawa, S. (2005) Nat. Genet. 37, 138-144). Furthermore, we showed that asporin binds to transforming growth factor-beta (TGF-beta), a key cytokine in OA pathogenesis, and inhibits TGF-beta-induced chondrogenesis. To date, functional data for asporin have come primarily from mouse cell culture models of developing cartilage rather than from human articular cartilage cells, in which OA occurs. Here, we describe mechanisms for asporin function and regulation in human articular cartilage. Asporin blocks chondrogenesis and inhibits TGF-beta1-induced expression of matrix genes and the resulting chondrocyte phenotypes. Small interfering RNA-mediated knockdown of asporin increases the expression of cartilage marker genes and TGF-beta1; in turn, TGF-beta1 stimulates asporin expression in articular cartilage cells, suggesting that asporin and TGF-beta1 form a regulatory feedback loop. Asporin inhibits TGF-beta/Smad signaling upstream of TGF-beta type I receptor activation in vivo by co-localizing with TGF-beta1 on the cell surface and blocking its interaction with the TGF-beta type II receptor. Our results provide a basis for elucidating the role of asporin in the molecular pathogenesis of OA.     

鲤鱼肌肉生长抑制素基因(MSTN)的克隆及其组织表达特征

肌肉生长抑制素(Myostatin,MSTN)是动物肌肉发育和生长过程中的负调控因子,对MSTN的研究将有助于促进动物生产。鲤鱼是我国的主要淡水养殖对象之一。因此,我们采用RT-PCR方法克隆了鲤鱼MSTN cDNA(No.EF551058)的部分序列,长度为921bp,编码306个氨基酸残基。鲤鱼MSTN具有MSTN的共同特征,有蛋白酶水解位点RIRR和9个保守的半胱氨酸残基。多重序列比较发现其与斑马鱼GDF8有极近的亲缘关系,96.7%的氨基酸序列同源。不同组织的RT-PCR分析发现鲤鱼MSTN主要在肌肉和脑部表达,而其他所检测组织未见表达。鲤鱼MSTN不仅在肌肉生长发育中发挥作用,可能在神经系统发育中也有其作用。     

Helicobacter pylori infection triggers aberrant expression of activation-induced cytidine deaminase in gastric epithelium

Infection with Helicobacter pylori (H. pylori) is a risk factor for the development of gastric cancer. Here we show that infection of gastric epithelial cells with 'cag' pathogenicity island (cagPAI)-positive H. pylori induced aberrant expression of activation-induced cytidine deaminase (AID), a member of the cytidine-deaminase family that acts as a DNA- and RNA-editing enzyme, via the IkappaB kinase-dependent nuclear factor-kappaB activation pathway. H. pylori-mediated upregulation of AID resulted in the accumulation of nucleotide alterations in the TP53 tumor suppressor gene in gastric cells in vitro. Our findings provide evidence that aberrant AID expression caused by H. pylori infection might be a mechanism of mutation accumulation in the gastric mucosa during H. pylori-associated gastric carcinogenesis.     

Neuroendocrine ductal carcinoma in situ of the breast: cytological features in 32 cases

T. Kawasaki, S. Nakamura, G. Sakamoto, T. Kondo, H. Tsunoda‐Shimizu, Y. Ishii, T. Nakazawa, K. Mochizuki, T. Yamane, M. Inoue, S. Inoue and R. Katoh
Neuroendocrine ductal carcinoma in situ of the breast: cytological features in 32 cases Objective: The purpose of this study was to clarify the cytological features of neuroendocrine ductal carcinoma in situ (NE‐DCIS) of the breast. Methods: We analysed the cytopathological findings in 22 fine needle aspiration (FNA) smears and 17 nipple discharge smears obtained from 32 Japanese patients with NE‐DCIS. Results: The background of the FNA smears was clear (59%), mucoid (23%), haemorrhagic (14%) or necrotic (5%). Most of the FNA smears (95%) showed high cellularity. Characteristically, NE‐DCIS cells were loosely arranged in three‐dimensional solid clusters or singly dispersed. Well‐developed vascular cores with or without malignant cells were occasionally recognized. The tumour cells were polygonal or spindle‐shaped with a fine granular, abundant cytoplasm. Nuclei with finely granular chromatin were round or oval and often eccentrically located (plasmacytoid appearance). Mitotic figures were infrequent. Nuclear grade was estimated to be low in 86%. Most nipple discharge smears had fairly low cellularity with poorly preserved cell clusters in a markedly haemorrhagic background, although two (12%) were extremely cellular with cytological characteristics similar to those of the FNA smears. Pre‐operative cytological malignant diagnoses were made in 42% of FNA smears and 0% of nipple discharge smears. Immunohistochemistry for neuroendocrine markers (chromogranin A and synaptophysin) confirmed the neuroendocrine nature of this tumour in adequate cytological specimens. Conclusions: NE‐DCIS has distinctive cytological features and can therefore be diagnosed as a neuroendocrine tumour in most FNAs and some nipple discharge smears by cytological examination employing immunohistochemical techniques. We emphasize that a breast lesion with these features may be in situ and not invasive, and also that there is a risk of under‐diagnosis.     

Regulation of lipid metabolism by palmitoleate and eicosapentaenoic acid (EPA) in mice fed a high-fat diet

We investigated whether oral administration of palmitoleate ameliorates disorders of lipid metabolism to clarify the effects of one of the components of fish oil. Lipid levels in the liver and plasma were significantly decreased by palmitoleate and by EPA administration. These results suggest that palmitoleate, in addition to EPA, plays a role in the regulation of lipid metabolism by fish oil.     

CO2浓度升高和施氮条件下小麦根际呼吸对土壤呼吸的贡献

依托FACE技术平台,采用稳定13C同位素技术,通过将小麦(C3作物)种植于长期单作玉米(C4作物)的土壤上,研究了大气CO2浓度升高和不同氮肥水平对土壤排放CO2的δ13C值及根际呼吸的影响.结果表明:种植小麦后土壤排放CO2的δ13C值随作物生长逐渐降低,CO2浓度升高200 μmol·mol-1显著降低了孕穗、抽穗期(施氮量为250 kg·hm-2,HN)与拔节、孕穗期(施氮量为150 kg·hm-2,LN)土壤排放CO2的δ13C值,显著提高了孕穗、抽穗期的根际呼吸比例.拔节至成熟期,根际呼吸占土壤呼吸的比例在高CO2浓度下为24％～48％ (HN)和21％ ～48％ (LN),在正常CO2浓度下为20％ ～36％ (HN)和19％～32％(LN).不同CO2浓度下土壤排放CO2的δ13C值和根际呼吸对氮肥增加的响应不同,CO2浓度与氮肥用量在拔节期对根际呼吸的交互效应显著.