苏珊·格拉斯佩尔的短篇小说《同命人审案》（A Jury of Her Peers）体现了一位女性主义者对社会和人生的思考,被认为是美国第二时期女性文学的代表作之一。作者用＂同命人＂为标题将作品中几位女性置于＂姐妹情谊＂的关系模式之中...苏珊·格拉斯佩尔的短篇小说《同命人审案》（A Jury of Her Peers）体现了一位女性主义者对社会和人生的思考,被认为是美国第二时期女性文学的代表作之一。作者用＂同命人＂为标题将作品中几位女性置于＂姐妹情谊＂的关系模式之中。＂姐妹情谊＂的抒写既体现了苏珊·格拉斯佩尔鲜明的女性意识,也传达出她对女性生存困境的思考及对女性如何摆脱困境道路的找寻。展开更多
Orderly execution of two critical events during the cell cycle––DNA replication and chromosome segregation––ensures the stable transmission of genetic materials. The cohesin complex physically connects sister chro...Orderly execution of two critical events during the cell cycle––DNA replication and chromosome segregation––ensures the stable transmission of genetic materials. The cohesin complex physically connects sister chromatids during DNA replication in a process termed sister chromatid cohesion. Timely establishment and dissolution of sister chromatid cohesion is a prerequisite for accurate chromosome segregation, and is tight regulated by the cell cycle machinery and cohesin-associated proteins. In this review, we discuss recent progress in the molecular understanding of sister chromatid cohesion during the mitotic cell cycle.展开更多
Discocephalids and pseudoamphisiellids are possibly two of the most confused groups among hypotrichous/euplotid ciliates regarding their systematic position and phylogenetic relationships.The former were often regarde...Discocephalids and pseudoamphisiellids are possibly two of the most confused groups among hypotrichous/euplotid ciliates regarding their systematic position and phylogenetic relationships.The former were often regarded as related to euplotids while the latter,in the absence of molecular data,were mostly assigned to the urostylid-like hypotrichs.In the present work,the small subunit rRNA genes of several rarely observed discocephalid and pseudoamphisiellid genera were analyzed to obtain insights into the phylogenetic relationships of these highly ambiguous Spirotrichea.Four different tree reconstruction algorithms yielded nearly identical topologies,which indicated both groups belong to the same assemblage.This assemblage is clearly isolated as a deep-branching clade and invariably positioned between Euplotida and Hypotricha.The sister group relationship of the Pseudoamphisiellidae and Discocephalidae supports the previous suggestion that they might represent an ordinal taxon,the Discocephalida.Both morphological and morphogenetic features indicate that the pseudoamphisiellids should be placed in the order Discocephalida but as a sister group to other typical discocephalids.Thus we propose establishing a new suborder,Pseudoamphisiellina subord.n.The new taxon is diagnosed by the following characteristics:(i) two distantly separated midventral rows that are morphogenetically formed with an urostylid mode;(ii) absence of the "frontoterminal row",which is formed from the posterior-most frontoventral-transverse cirral anlage in all other typical urostylids;(iii) numerous caudal cirri that derive from each of the dorsal kinety anlagen;(iv) right marginal row that has a unique de novo origin;and (v) inhabiting periphytic communities.The validity of the suborder Pseudoamphisiellina is firmly supported by molecular data.展开更多
文摘苏珊·格拉斯佩尔的短篇小说《同命人审案》（A Jury of Her Peers）体现了一位女性主义者对社会和人生的思考,被认为是美国第二时期女性文学的代表作之一。作者用＂同命人＂为标题将作品中几位女性置于＂姐妹情谊＂的关系模式之中。＂姐妹情谊＂的抒写既体现了苏珊·格拉斯佩尔鲜明的女性意识,也传达出她对女性生存困境的思考及对女性如何摆脱困境道路的找寻。
基金supported by the Welch Foundation(I-1441 to H.Y.)the Clayton Foundation,and Cancer Prevention and Research Institute of Texas(RP110465-P3 and RP120717-P2 to H.Y.)
文摘Orderly execution of two critical events during the cell cycle––DNA replication and chromosome segregation––ensures the stable transmission of genetic materials. The cohesin complex physically connects sister chromatids during DNA replication in a process termed sister chromatid cohesion. Timely establishment and dissolution of sister chromatid cohesion is a prerequisite for accurate chromosome segregation, and is tight regulated by the cell cycle machinery and cohesin-associated proteins. In this review, we discuss recent progress in the molecular understanding of sister chromatid cohesion during the mitotic cell cycle.
基金supported by the National Natural Science Foundation of China (Grant Nos. 40906065 and 31030059)
文摘Discocephalids and pseudoamphisiellids are possibly two of the most confused groups among hypotrichous/euplotid ciliates regarding their systematic position and phylogenetic relationships.The former were often regarded as related to euplotids while the latter,in the absence of molecular data,were mostly assigned to the urostylid-like hypotrichs.In the present work,the small subunit rRNA genes of several rarely observed discocephalid and pseudoamphisiellid genera were analyzed to obtain insights into the phylogenetic relationships of these highly ambiguous Spirotrichea.Four different tree reconstruction algorithms yielded nearly identical topologies,which indicated both groups belong to the same assemblage.This assemblage is clearly isolated as a deep-branching clade and invariably positioned between Euplotida and Hypotricha.The sister group relationship of the Pseudoamphisiellidae and Discocephalidae supports the previous suggestion that they might represent an ordinal taxon,the Discocephalida.Both morphological and morphogenetic features indicate that the pseudoamphisiellids should be placed in the order Discocephalida but as a sister group to other typical discocephalids.Thus we propose establishing a new suborder,Pseudoamphisiellina subord.n.The new taxon is diagnosed by the following characteristics:(i) two distantly separated midventral rows that are morphogenetically formed with an urostylid mode;(ii) absence of the "frontoterminal row",which is formed from the posterior-most frontoventral-transverse cirral anlage in all other typical urostylids;(iii) numerous caudal cirri that derive from each of the dorsal kinety anlagen;(iv) right marginal row that has a unique de novo origin;and (v) inhabiting periphytic communities.The validity of the suborder Pseudoamphisiellina is firmly supported by molecular data.
