子囊菌石耳目同源生物系统学

生物系统学亦即演化生物学或生物分类学,其目的在于为人类可持续发展中的生物资源研发提供生物信息。以单基因和多基因片段为基础的系统树分析难以获得同一祖先后代的单系类群。同源生物系统学是以共同祖先遗传的基因型和表型为基础进行的分析,是探明单系类群的最佳途径。同源性分析结果表明,石耳亚纲具有一条同源序列S及6种彼此相近的子囊顶器结构,其中包括石耳目以及未定位的5个属。石耳目包括一条同源序列O及石耳型子囊顶器结构。石耳科具有一条同源序列F及脐叶型地衣体。其中疱脐衣属具有一条同源序列L及疱状脐叶体与单孢子囊,石耳属具有一条同源序列U与非疱状脐叶体和八孢子囊。边缘种宾州疱脐衣除具有疱脐衣属同源序列L及疱状脐叶体内含单孢子囊以外,还兼具石耳属同源序列U以及疱狀脐叶体下表偶见气生根;而边缘种卡罗里石耳除具有石耳属同源序列U及非疱状脐叶体内含八孢子囊以外,还兼具疱脐衣属同源序列L以及疱脐衣属特有的砖壁型子囊孢子。     

石耳科(子囊菌门)的新种和新分布

本文报导了石耳科的八个种,其中新种四个,即阿尔泰石耳,鳞芽石耳、亚石耳及太白石耳;三个种是中国的新分布,即皱石耳、亚光石耳及淡腹疤脐衣;一个种即白根石耳为中国及蒙古的新分布。     

中国地衣型子囊菌石耳科纲要

该纲要为东亚地衣型子囊菌石耳科研究的一部分.对于该科一些种的子囊盘进行了研究.     

石耳科(子囊菌亚门)的间断分布和替代现象

本文报道了石耳科的两个亚洲的,也是美洲以外的新记录种,即角石耳与深色石耳。进一步证实了单果石耳在南大西洋的,即南美洲和南部非洲的间断分布。对于上述种类以及本科其它一些种类的间断分布和替代现象进行了分析讨论。     

八角属植物的分类学订正

根据对18个国家和地区120个标本馆收藏的万余份八角属植物标本的研究,提出3个新组合,对13个种、6个亚种、3个变种和2个变型作了归并,确认全世界现有八角属植物34种3亚种和1变种。     

五味子属植物的分类学订正

根据对12个国家53个标本馆收藏的5,000余份五味子属Schisandra植物标本的研究,结合野外调查和采集,对世界范围的五味子属种类作了分类学订正。在五味子属中,10个种被确认,22个种、7个亚种、14个变种和1个变型的名称被作为新异名。文中附有分种检索表。     

地衣型真菌石果衣(疣孢菌科，子囊菌门)次级代谢产物的多样性

地衣能够产生大量的新型次级代谢产物,但以往对石果衣Endocarpon pusillum的研究中未能检测出任何次级代谢产物。然而,对其共生菌进行基因组测序发现其中含有14个沉默的PKS基因和2个沉默的NRPS基因。在此研究中,为激活其途径,使用了优化马铃薯培养基和大米培养基对石果衣共生真菌进行了培养。从优化马铃薯培养物中分离得到9个次级代谢产物,包括2个新的异吲哚-1-酮类化合物(1, 2)。而从大米培养物中分离到3个已知化合物和1个新的萘醌类化合物(9)。通过核磁共振和质谱数据确定了新化合物的结构。研究结果表明,大量地衣中未能检测出任何次级代谢产物,或仅能检测出少量次级代谢产物,可能与其基因组中的沉默基因有关。因此,通过对沉默基因的激活方法为地衣次级代谢产物资源的研究与开发开辟了有效途径。     

悬钩子属部分类群的分类订正

根据野外调查和查阅标本的结果, 对悬钩子属部分类群做了修订。将红毛悬钩子(R.pinfaensis Lévl.et Vant.)并入椭圆悬钩子(R.ellipticus Smith), 栽秧泡(R.ellipticus Smithvar.obcordatus (Franch.)Focke)提升为种(R.obcordatus (Franch.)Focke);棱枝细瘦悬钩子(R.macilentus Camb.var.angulatus Delav.)并入细瘦悬钩子(R.macilentus Camb.);毛叶插田泡(R.coreanus Miq.var.tomentosus Card.)并入插田泡(R.coreanus Miq.);狭叶绢毛悬钩子(R.lineatus Reinw.var.angustifolius Hook.)并入绢毛悬钩子(R.lineatus Reinw.)。对针刺悬钩子(R.pungens Camb.)及其各变种做了订正。     

悬钩子属部分类群的分类订正

根据野外调查和查阅标本的结果, 对悬钩子属部分类群做了修订。将红毛悬钩子(R.pinfaensis Lévl.et Vant.)并入椭圆悬钩子(R.ellipticus Smith), 栽秧泡(R.ellipticus Smithvar.obcordatus (Franch.)Focke)提升为种(R.obcordatus (Franch.)Focke);棱枝细瘦悬钩子(R.macilentus Camb.var.angulatus Delav.)并入细瘦悬钩子(R.macilentus Camb.);毛叶插田泡(R.coreanus Miq.var.tomentosus Card.)并入插田泡(R.coreanus Miq.);狭叶绢毛悬钩子(R.lineatus Reinw.var.angustifolius Hook.)并入绢毛悬钩子(R.lineatus Reinw.)。对针刺悬钩子(R.pungens Camb.)及其各变种做了订正。     

南五味子属(五味子科)一些种类的分类学订正

根据对12个国家54个标本馆所收藏的5000余份南五味子属植物标本的研究,结合野外调查和采集,对南五味子属的一些种类作了分类学订正:将仁昌南五味子归并入狭叶南五味子,将菲律宾南五味子和盘柱南五味子归并入异型南五味子,将长梗南五味子、城口南五味子、少齿南五味子、麦克氏南五味子和峨嵋南五味子归并入南五味子,将苏拉威西南五味子归并入南洋南五味子,将史氏南五味子归并入柄果南五味子。在南五味子属中,11个种被确认。     

The hyoid arch and braincase anatomy of Acanthodes support chondrichthyan affinity of ‘acanthodians’

Solving the evolutionary relationships of the acanthodians is one of the key problems in reconstructing ancestral anatomical conditions for the jawed vertebrates (gnathostomes). Current debate concerns whether acanthodians are an assemblage of stem chondrichthyans, or a more generalized grade encompassing some early stem osteichthyans. The skull anatomy of Acanthodes bronni has been pivotal in these debates, owing to tension between chondrichthyan- and osteichthyan-like models of reconstruction. We use computed tomography scanning and traditional palaeontological techniques to resolve the long-standing debate about the anatomy of the jaw suspension. We establish the correct length of the hyomandibula and show that it attaches to a process on the ventrolateral angle of the braincase below the jugular vein groove. This condition corresponds precisely to that in chondrichthyans. This character represents an unambiguously optimized synapomorphy with chondrichthyans given current gnathostome phylogenies, corroborating the growing consensus of the chondrichthyan affinity of acanthodians.     

Functional Characteristics of Heteromeric Cx40-Cx43 Gap Junction Channel Formation

Cx40:Cx43 expression ratio in A7r5 cells is augmented in growth stimulated vs. growth arrested conditions. To determine the impact of changing Cx40:Cx43 expression ratio on gap junction function, we have developed A7r5 cell lines that display Cx40:Cx43 ratios of 1:1 (6B5n) and 10:1 (A7r540C3). When Rin43 cells were paired with these coexpressing cells, there was an increasing asymmetry of voltage dependent gating as the Cx40:Cx43 ratio increased in the coexpressing cell. This asymmetry was opposite to that which is predicted by Cx40/Cx43 heterotypic channels. In addition, when Rin43 cells were paired with coexpressing cells there was a shift toward smaller single channel event amplitudes with increasing Cx40:Cx43 ratio in the coexpressing cell. Again, this is opposite to that which is predicted by Cx40/Cx43 heterotypic channels. In dye coupling experiments, 6B5N, A7r5, and A7r540C3 cells displayed charge and size selectivity that increased with increasing Cx40:Cx43 expression ratio. These data indicate that although the electrophysiological properties of heteromeric/heterotypic channels are not directly related to the proportions of Cx constituents that comprise the channel, the dye permeability data fit what would be predicted by an increase in Cx40:Cx43 ratio.     

New Studies of Enamel Microstructure in Mesozoic Mammals: A Review of Enamel Prisms as a Mammalian Synapomorphy

Characters from enamel microstructure have not been used in recent phylogenetic analyses of Mesozoic Mammalia. Reasons are that enamel characters have been perceived as (A) variable without regard to systematic position of taxa, (B) inconsistently reported within the literature, and (C) simply scored as either prismatic or not prismatic in earlier mammals. Our work on Mesozoic mammals such as Sinoconodon, Gobiconodon, Triconodontidae, Docodon, Laolestes, and others suggests that synapsid columnar enamel (SCE) structure was easily transformed into plesiomorphic prismatic enamel (PPE) and that PPE may be described with at least five independent character states. Two PPE characters—a flat, open prism sheath and a planar prism seam—were present in the cynodont Pachygenelus and in several Jurassic and Cretaceous mammals. We propose that appearance of a prism sheath transforms SCE into PPE and that reduction and loss of a prism sheath reverse PPE into SCE, in both phylogeny and ontogeny. We further propose that no amniote vertebrates other than the trithelodontid cynodont, Pachygenelus, plus Mammalia have ever evolved an ameloblastic Tomes process capable of secreting PPE and that the genetic potential to secrete PPE is a synapomorphy of Pachygenelus plus Mammalia, whether or not all lineages of the clade have expressed that potential.     

Velvet worm development links myriapods with chelicerates

Despite the advent of modern molecular and computational methods, the phylogeny of the four major arthropod groups (Chelicerata, Myriapoda, Crustacea and Hexapoda, including the insects) remains enigmatic. One particular challenge is the position of myriapods as either the closest relatives to chelicerates (Paradoxopoda/Myriochelata hypothesis), or to crustaceans and hexapods (Mandibulata hypothesis). While neither hypothesis receives conclusive support from molecular analyses, most morphological studies favour the Mandibulata concept, with the mandible being the most prominent feature of this group. Although no morphological evidence was initially available to support the Paradoxopoda hypothesis, a putative synapomorphy of chelicerates and myriapods has recently been put forward based on studies of neurogenesis. However, this and other morphological characters remain of limited use for phylogenetic systematics owing to the lack of data from an appropriate outgroup. Here, we show that several embryonic characters are synapomorphies uniting the chelicerates and myriapods, as revealed by an outgroup comparison with the Onychophora or velvet worms. Our findings, thus provide, to our knowledge, first morphological/embryological support for the monophyly of the Paradoxopoda and suggest that the mandible might have evolved twice within the arthropods.