A Y‐chromosomal comparison of the Madjars (Kazakhstan) and the Magyars (Hungary)

The Madjars are a previously unstudied population from Kazakhstan who practice a form of local exogamy in which wives are brought in from neighboring tribes, but husbands are not, so the paternal lineages remain genetically isolated within the population. Their name bears a striking resemblance to the Magyars who have inhabited Hungary for over a millennium, but whose previous history is poorly understood. We have now carried out a genetic analysis of the population structure and relationships of the Madjars, and in particular have sought to test whether or not they show a genetic link with the Magyars. We concentrated on paternal lineages because of their isolation within the Madjars and sampled males representing all extant male lineages unrelated for more than eight generations (n = 45) in the Torgay area of Kazakhstan. The Madjars show evidence of extensive genetic drift, with 24/45 carrying the same 12‐STR haplotype within haplogroup G. Genetic distances based on haplogroup frequencies were used to compare the Madjars with 37 other populations and showed that they were closest to the Hungarian population rather than their geographical neighbors. Although this finding could result from chance, it is striking and suggests that there could have been genetic contact between the ancestors of the Madjars and Magyars, and thus that modern Hungarians may trace their ancestry to Central Asia, instead of the Eastern Uralic region as previously thought. Am J Phys Anthropol 2009. © 2009 Wiley‐Liss, Inc.     

Central lactate metabolism suppresses food intake via the hypothalamic AMP kinase/malonyl-CoA signaling pathway

Previous studies showed that centrally administered glucose and fructose exert different effects on food intake - glucose decreasing and fructose increasing food intake. Because of the uncertainty of whether fructose can cross the blood-brain-barrier, the question is raised; can dietary fructose directly enter the CNS? Evidence is presented that fructose administered by intraperitoneal (ip) injection to mice is rapidly (<10 min) converted to lactate in the hypothalamus. Thus, fructose can cross the blood-brain-barrier to enter the CNS/hypothalamus for conversion to lactate without prior (slower) conversion to glucose in the liver. Fructose-derived hypothalamic lactate is not, however, responsible for the orexigenic effect of fructose. Ip lactate administered at a level equivalent to that of fructose generates a higher level of hypothalamic lactate, which rapidly triggers dephosphorylation/inactivation of AMP-kinase. Thereby, ACC — a substrate of AMP-kinase that catalyzes malonyl-CoA formation — is dephosphorylated and activated. Consistent with these findings, ip or centrally (icv) administered lactate rapidly increases (<10 min) hypothalamic malonyl-CoA. Increasing hypothalamic malonyl-CoA suppresses the expression of the orexigenic and increases the expression of the anorexigenic neuropeptides, which decrease food intake. All downstream effects of hypothalamic lactate are blocked by icv administered oxamate, a potent inhibitor of lactate dehydrogenase, thus verifying the central action of lactate.     

A Computationally Guided Protein-Interaction Screen Uncovers Coiled-Coil Interactions Involved in Vesicular Trafficking

Mapping protein-protein interactions at a domain or motif level can provide structural annotation of the interactome. The α-helical coiled coil is among the most common protein-interaction motifs, and proteins predicted to contain coiled coils participate in diverse biological processes. Here, we introduce a combined computational/experimental screening strategy that we used to uncover coiled-coil interactions among proteins involved in vesicular trafficking in Saccharomyces cerevisiae. A number of coiled-coil complexes have already been identified and reported to play important roles in this important biological process. We identify additional examples of coiled coils that can form physical associations. The computational strategy used to prioritize coiled-coil candidates for testing dramatically improved the efficiency of discovery in a large experimental screen. As assessed by comprehensive yeast two-hybrid assays, computational prefiltering retained 90% of positive interacting pairs and eliminated > 60% of negatives from a set of interaction candidates. The coiled-coil-mediated interaction network elucidated using the combined computational/experimental approach comprises 80 coiled-coil associations between 58 protein pairs, among which 21 protein interactions have not been previously reported in interaction databases and 26 interactions were previously known at the protein level but have now been localized to the coiled-coil motif. The coiled-coil-mediated interactions were specific rather than promiscuous, and many interactions could be recapitulated in a green fluorescent protein complementation assay. Our method provides an efficient route to discovering new coiled-coil interactions and uncovers a number of associations that may have functional significance for vesicular trafficking.     

Genetic variability within the innate immune system influences personality traits in women

Raised levels of inflammation markers have been associated with several mental disorders; however, studies regarding the relationship between inflammation or the immune system and various aspects of human behaviour are not numerous. The aim of the present study was to investigate whether an association exists between personality traits and two single nucleotide polymorphisms located in genes that are associated with the innate immune system. The studied population consisted of 42-year-old women recruited from the population registry that had been assessed by means of Karolinska Scales of Personality, a self-reported inventory. The first polymorphism, +1444C>T (rs1130864), is located in the gene coding for C-reactive protein (CRP), a marker of low-grade inflammation. The T-allele has previously been suggested to be linked to raised serum levels of CRP. The second polymorphism, Y402H (1277T>C, rs1061170), is located in the gene coding for complement factor H, an important regulator of the complement system. The C-allele has consistently been associated with age-related macular degeneration. While the +1444T allele was associated with higher scores in the personality traits impulsiveness, monotony avoidance and social desirability, the 1277C polymorphism was associated with higher scores in verbal aggression and lower scores in social desirability. In conclusion, the associations between the personality traits and the studied polymorphisms further support the possible influence of the immune system on mental functions.     

杏属（蔷薇科）一新种

发表了蔷薇科杏属的一个新种,即仙居杏(Armeniaca Xianjuxing J.Y.Zhang et Z.X.Wu),其与普通杏(Armeniaca vulgaris Lam.)的区别在于叶片两面具有短柔毛,花梗或果梗长1~1.2 cm,花瓣边缘钝锯齿或小裂片状,萼片边缘有小钝锯齿。     

MYS2多态位点在中国26个人群中分布的研究

对中国26个人群中Y染色体小卫星分位点MYS2的分布进行了研究,结果显示：MYS2*4是常见的等位基因类型,MYS2*3在中国不同人群中分布差异很大（0-32.4％）;并对该位点在不同人群中分布的频率进行了AMOVA分析,结果为：不分组、南方人群和北方人群的遗传学差异分别为7.76％、8.11％和1.42％。南北方人群间、东北和西北人群间的差异分别为4.34％和1.57％。结论：MYS2是研究中国人群遗传结构有价值的多态位点,中国不同人群之间存在一定的遗传学差异,中国南方人群间的遗传学差异较大,再次证实了中国人群的南北差异。     

Y‐chromosomal variation confirms independent domestications of swamp and river buffalo

Y‐chromosomal variation in the water buffalo was analysed by sequencing of DBY, ZFY and SRY gene segments. A clear separation of the paternal lineages of the river and swamp types parallels the differences between their maternal lineages and nuclear DNA. Sequence divergence was found to be comparable to the divergence of taurine cattle and zebu, and this divergence predated domestication, confirming that river and swamp buffalo originated from different wild populations. Within a sample of 23 Thai swamp buffaloes, we identified four haplotypes with different geographical distributions, two of which were shared by Thai wild buffaloes.     

Secondary structural and “active site” momologies between nerve growth factor and insulin

Secondary structural elements, α-helix, β-sheet and turns, of nerve growth factor (NGF) were predicted by the method of Chou and Fasman. Analysis of the prediction results showed the presence of domain structure in NGF; the second half of the polypeptide chain showed a secondary structural “pattern” very similar to the first half. Comparison of the secondary structure of NGF and proinsulin showed significant homology between the B-chain, which has the “active site”, and NGF^25–54 The homology is reinforced by the identification of a pentapeptide sequence in NGF which is very similar to the “active site” sequence of insluin essential for receptor binding and agonist activity. The present alignment of insulin and NGF is however different from that proposed earlier on the basis of sequence data alone.     

转录调控因子WRKY 超级家族: 起源、结构和功能*

WRKY 蛋白质是一个植物特有的超级转录调控因子家族, 在拟南芥和水稻基因组中分别拥有至少74 个和97 个成员。最古老的WRKY 转录调控因子拥有2 个高度保守的WRKY 结构域, 可能起源于15~ 20 亿年前的真核生物。虽然所有WRKY 蛋白质主要通过特异地结合靶基因启动子区域的W 盒序列而调控其表达, 但各家族成员基因的生物学功能存在着各自的特异性。本文详细总结了WRKY 蛋白质在调控植物发育和逆境诱导反应的信号转导途径建立等方面的分子生物学功能。     

蛋白质相互作用研究方法及其应用

过去10年来,蛋白质组学得到迅速发展,蛋白质间的相互作用作为蛋白质组学的重要内容,更是成为国内外竞相研究的重点,研究方法的快速发展为蛋白质间相互作用的研究奠定了坚实基础。着重就经典的噬菌体展示、酵母双杂交以及新近发展起来的串联亲和纯化、荧光共振能量转移技术和表面等离子共振等蛋白质相互作用研究方法的原理及应用作一综述并展望其发展前景。