Variations on the topic of the "histone code"

Histones are the fundamental structural proteins intimately associated with eukaryotic DNA to form a highly ordered and condensed nucleoproteic complex termed chromatin. They are the targets of various posttranslational modifications including acetylation, methylation, phosphorylation and ubiquitination that modulate the structure/function of chromatin. The combinatorial nature of histone modifications is hypothesized to define a "histone code" that considerably extends the information potential of the genetic code, giving rise to epigenetic information. Moreover, most core histones consist of several nonallelic variants that can mark specific loci and could play an important role in establishment and maintenance of epigenetic memory. Here we will briefly present our current knowledge about histone posttranslational modifications and their implications in the regulation of epigenetic information. We will next describe core histone variants, insisting on their mode of incorporation into chromatin to discuss their epigenetic function and inheritance.     

干旱草原有个"天鹅湖"

达里湖水面宽阔、食物丰富,对大天鹅来说是不可多得的理想驿站,数量最多时达到8万多只,被称为中国第三大“天鹅湖”。草原十月湛蓝而辽远的天空中,一队大天鹅远远地北飞而来。夏天吃下的水草中所蕴含的能量,正被一点点地从鼓动着的翅膀中释放出来,带着大天鹅飞越了冰原、山脉和河流,一直从西伯利亚、新疆飞到了蒙古高原。奋力飞越绵延的大兴安岭之后,出现在大天鹅视野     

Introduction: Expanding the Discourse on "Race"

In response to Mukhopadhyay and Moses's call for biological and cultural anthropologists to reestablish a dialogue on race, anthropologists from the four major subfields join colleagues from two allied disciplines to address the possible ways in which the anthropological discourse on race can become more holistic and amenable to the urgent needs and interests of the public. This essay offers an overview of the current resurgence of race-focused scholarship in anthropology, as well as a framework for an intertextual reading of the articles featured in this theme forum. Anthropologists' current conversation on race and racism is built on a rich legacy, elements of which are still being uncovered in gender- and racecognizant explorations of the discipline's past Despite the considerable hiatus since the last major juncture of race-centered debate and research, that legacy has recently inspired a promising upsurge of critical analysis which, if mobilized effectively, may contribute to the subversion of the often subtle cultural and structural logics of contemporary racism, as well as clear the ground for a new culture for multiracial democracy. Toward this end, anthropologists and others interested in using anthropological tools must cultivate more richly nuanced analyses and intervention strategies informed by insights emerging from the cross-fertilization of ideas from the various subfields along with such fields as human genetics and ethnic studies. Anthropology's unique role in interrogating, theorizing, and potentially disrupting the dynamics of racism may be dependent on understanding the conceptual and methodological significance of strategic intradisciplinary and interdisciplinary interfaces.     

Highlights on the capacities of "Gel-based" proteomics

Gel-based proteomic is the most popular and versatile method of global protein separation and quantification. This is a mature approach to screen the protein expression at the large scale, and a cheaper approach as compared with gel-free proteomics. Based on two independent biochemical characteristics of proteins, two-dimensional electrophoresis combines isoelectric focusing, which separates proteins according to their isoelectric point, and SDS-PAGE, which separates them further according to their molecular mass. The next typical steps of the flow of gel-based proteomics are spots visualization and evaluation, expression analysis and finally protein identification by mass spectrometry. For the study of differentially expressed proteins, two-dimensional electrophoresis allows simultaneously to detect, quantify and compare up to thousand protein spots isoforms, including post-translational modifications, in the same gel and in a wide range of biological systems. In this review article, the limits, benefits, and perspectives of gel-based proteomic approaches are discussed using concrete examples.