Comparative Analysis of Fatty Acid Desaturases in Cyanobacterial Genomes

Fatty acid desaturases are enzymes that introduce double bonds into the hydrocarbon chains of fatty acids. The fatty acid desaturases from 37 cyanobacterial genomes were identified and classified based upon their conserved histidine-rich motifs and phylogenetic analysis, which help to determine the amounts and distributions of desaturases in cyanobacterial species. The filamentous or N-2-fixing cyanobacteria usually possess more types of fatty acid desaturases than that of unicellular species. The pathway of acyl-lipid desaturation for unicellular marine cyanobacteria Synechococcus and Prochlorococcus differs from that of other cyanobacteria, indicating different phylogenetic histories of the two genera from other cyanobacteria isolated from freshwater, soil, or symbiont. Strain Gloeobacter violaceus PCC 7421 was isolated from calcareous rock and lacks thylakoid membranes. The types and amounts of desaturases of this strain are distinct to those of other cyanobacteria, reflecting the earliest divergence of it from the cyanobacterial line. Three thermophilic unicellular strains, Thermosynechococcus elongatus BP-1 and two Synechococcus Yellowstone species, lack highly unsaturated fatty acids in lipids and contain only one Delta 9 desaturase in contrast with mesophilic strains, which is probably due to their thermic habitats. Thus, the amounts and types of fatty acid desaturases are various among different cyanobacterial species, which may result from the adaption to environments in evolution. Copyright (c) 2008 Xiaoyuan Chi et al.

蓝藻与绿藻类胡萝卜素合成酶基因的比较基因组学及代谢调控研究

类胡萝卜素在生物体内具有重要的生理功能，其中虾青素是一类高附加值值的类胡萝卜素。本文通过比较基因组学和实验手段，探索了类胡萝卜素相关基因的转录调控，为类胡萝卜素的代谢工程奠定的了基础。 1、对已测序的18种蓝藻的类胡萝卜素合成基因进行了比较基因组学研究，发现除了Gloeobacter violaceus PCC 7421的类胡萝卜素合成途径是细菌型外，其余的蓝藻类胡萝卜合成途径均属于植物型。序列比对发现蓝藻中参与合成途径上游的酶基因在进化中保守性较高。研究还发现，一些类胡萝卜素合成酶在结构和功能上存在趋同或趋异进化，揭示它们进化上的多样性。 2、 通过比较基因组学分析，发现在集胞藻Synechocystis sp.PCC6803等几种蓝藻中，没有典型的番茄红素环化酶基因的同源基因，而存在着与绿硫细菌中的γ-carotene环化酶基因相似的基因,例如集胞藻中的sll0147和sll0659。但是研究结果显示sll0147和sll0659的突变对番茄红素环化过程影响不明显，提示在这些蓝藻中可能有其他基因参与环化过程，而sll0659基因可能参与了细胞的分裂过程。 3、 从经济绿藻雨生红球藻中克隆了参与类胡萝卜素合成途径的八氢番茄红素合成酶基因（psy）和八氢番茄红素脱氢酶基因（pds）的cDNA和基因组序列。通过基因组步移的方法克隆了这两个基因的5’侧翼序列，以本实验室建立的lacZ为报告基因的瞬间表达体系研究了这两个基因上游区域的启动子活性。 4、 通过ABA、 N饥饿和高光诱导雨生红球藻积累虾青素，利用半定量RT-PCR方法分析了在相同环境因子诱导下雨生红球藻中类胡萝卜素合成基因的表达调控模式，结果显示在虾青素积累过程中，除了番茄红素环化酶基因变化不明显，其他一些基因均存在明显的转录上调。 本研究首次利用比较基因组学的方法分析了类胡萝卜素基因的进化，发现大部分蓝藻的类胡萝卜合成途径属于植物型，一些类胡萝卜合成酶存在结构和功能的多样性。同时分离了雨生红球藻中类胡萝卜素相关基因八氢番茄红素合成酶基因（psy）和八氢番茄红素脱氢酶基因（pds）的5’上游侧翼序列，验证了它们的启动子功能，研究了雨生红球藻虾青素合成酶基因在相同环境因子诱导下的表达调控模式。本文将基础研究与实验验证相结合，为下一步研究类胡萝卜素合成的代谢工程提供了线索。

Review and cladistic analysis of the Neotropical tarantula genus Ephebopus Simon 1892 (Araneae : Theraphosidae) with notes on the Aviculariinae

The tarantula genus Ephebopus Simon 1892 is reviewed and includes the type species, E. murinus (Walckenaer 1837), and E. uatuman Lucas, Silva & Bertani 1992, E. cyanognathus West & Marshall 2000, E. rufescens West & Marshall 2000 and Ephebopus foliatus, sp. nov., from Guyana. Ephebopus violaceus Mello-Leitao 1930 is transferred to Tapinauchenius Ausserer, where it is a senior synonym of Tapinauchenius purpureus Schmidt 1995 new synonymy. Ephebopus fossor Pocock 1903 is considered a nomen dubium. Ephebopus occurs in northeastern South America where it is known only from Brazil, Guyana, Suriname, and French Guiana. Spiders of the genus are generally fossorial; however, Ephebopus murinus has a developmental stage that is arboreal. A cladistic analysis of the Theraphosidae retrieves the Aviculariinae as monophyletic, including Avicularia Lamarck, Iridopelma Pocock 1901, Pachistopelma Pocock 1901, Tapinauchenius, Psalmopoeus Pocock, Ephebopus, Stromatopelma Karsch and Heteroscodra Pocock, having as a synapomorphy the well-developed scopulae on tarsi and metatarsi I-II that is very laterally extended.

Illusions vary because of the types of decorations at bowers, not male skill at arranging them, in great bowerbirds

Many animals use extended phenotypes to attract mates, but the availability of suitable resources in the environment can affect the size and form of these signals, with unknown consequences for honest signalling. In some populations of the great bowerbird, Ptilonorhynchus nuchalis, males arrange decorations by size, with smaller decorations placed closer to the bower entrance than larger decorations. This may create a more even background pattern from the female's viewpoint within the bower than if decorations were arranged randomly. Males show consistent, individual variation in the size-distance gradient, which could reflect variation among males in the cognitive skills needed to arrange decorations. We examined whether individual consistency in gradient characteristics is related to a male's skill at decoration arrangement or the types of decorations at bowers. We paired 18 males and switched bower decorations between pairs. We measured gradient characteristics before switching and 4 and 8 days after switching. Gradient characteristics after switching were related to those of the bower from which decorations were received, not to those of the male's own bower before switching. Gradient characteristics were also related to the types of decorations received, including bones and snail shells. These results suggest that variation among males in the size-distance gradient is explained by differences in the availability of decorations at bowers, not the cognitive skills required to arrange decorations. Although variation in gradient characteristics could indicate the male's ability to locate and transport particular decorations, it could also reflect local availability of objects, with no relationship to male quality.

Feeding habits of the blue shark (Prionace glauca) off the coast of Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Feeding habits of the atlantic spotted dolphin, Stenella frontalis, in southeastern Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Male and female interactions during courtship of the Neotropical damselfly Mnesarete pudica (Odonata: Calopterygidae)

The courtship behavior in calopterygid damselflies is well documented; however, the behavior of the large Neotropical genus Mnesarete is still unknown. Thus, here we present the first description of male-female interactions in Mnesarete pudica, a common damselfly in the Neotropical Savanna. The male-female interactions were composed of courtship displays, mounting, and chasing. The courtship behavior lasted 5.23 +/- 1.65 s and is very different from other calopterygids, consisting of hovering flights and the cross display made in front of females rather than on the oviposition site. The arrival and presence of females on a male territory are not sufficient to initiate sexual interactions; the male usually interacts with the female only after a patrolling flight. The females may present three distinct behaviors in response to male approach: (a) warding off signal (31.53%), (b) escape (28.83%), (c) and wing flipping (39.64%), which seems to stimulate male courtship. Females also may sit still, which induces males to react as if females were signaling they are willing to mate. In this paper, we also suggest that male courtship behavior is mediated by female signals.

FEEDING HABITS OF THE ATLANTIC SPOTTED DOLPHIN, Stenella frontalis, IN SOUTHEASTERN BRAZIL

This study presents new information on the feeding habits of the Atlantic spotted dolphins, Stenella frontalis, in the Western South Atlantic. Nine stomach contents of S. frontalis incidentally caught in fishing operations conducted by the gillnet fleet based on main harbour of Cananeia (25 degrees 00' S; 47 degrees 55'W), southeastern Brazil, were analyzed. These specimens were captured between 2005 and 2007. A total of 1 422 cephalopod beaks, 147 otoliths and three crustaceans were recovered from the stomach contents. The dolphins assessed preyed on at least eight different fish species of the families Trichiuridae, Carangidae, Sparidae, Merluccidae, Engraulidae, Sciaenidae, Congridae and Scombridae, five cephalopod species of the families Loliginidae, Sepiolidae, Tremoctopodidae and Thysanoteuthidae, and one shrimp species of the Penaeidae family. Based on the analysis of the Index of Relative Importance (IRI), the Atlantic cutlassfish, Trichiurus lepturus, was the most important fish species represented. Of the cephalopods, the squid Doryteuthis plei was by far the most representative species. Several items were reported for the first time as prey of the S. frontalis: Xiphopenaeus kroyeri, Tremoctopus violaceus, Semirossia tenera, Merluccius hubbsi, Pagrus pagrus and Paralonchurus brasiliensis. S. frontalis presented teuthophagous and ichthyofagous feeding habits, with apparent predominance of the first, and preyed mainly on pelagic and demersal items.

New genera and species of Neotropical Rhinotragini (Coleoptera, Cerambycidae, Cerambycinae)

Giesberteclipta and Thomasella, two new genera of Rhinotragini Thomson, 1861 (Coleoptera: Cerambycidae: Cerambycinae), are described and illustrated. Six new species are also described and illustrated: Acyphoderes violaceus from Costa Rica; Ischasioides giesberti from Ecuador, and Oxylymma pallida, Pseudagaone williamsi, Stultutragus tippmanni and S. ventriguttatus from Brazil. Keys are provided for the known species of Pseudagaone Tippmann, 1960, Giesberteclipta, and Oxylymma Pascoe, 1859 and for parts of Ischasioides Tavakilian & Penaherrera-Leiva, 2003 and Stultutragus Clarke, 2010. The following new combinations are proposed: Giesberteclipta costipennis (Giesbert, 1991); G. monteverdensis (Giesbert, 1991); Thomasella igniventris (Giesbert, 1991), and Stultutragus romani (Aurivillius, 1919). The following three new country records are reported: Oxylymma durantoni Penaherrera-Leiva & Tavakilian, 2003 (Brazil), Oxylymma sudrei Penaherrera-Leiva & Tavakilian, 2003 (Brazil), and Ommata (Eclipta) faurei Penaherrera-Leiva & Tavakilian, 2003, all from Brazil.

Feeding habits of the atlantic spotted dolphin, Stenella frontalis, in southeastern Brazil

This study presents new information on the feeding habits of the Atlantic spotted dolphins, Stenella frontalis, in the Western South Atlantic. Nine stomach contents of S. frontalis incidentally caught in fishing operations conducted by the gillnet fleet based on main harbour of Cananéia (25°00'S; 47°55'W), southeastern Brazil, were analyzed. These specimens were captured between 2005 and 2007. A total of 1 422 cephalopod beaks, 147 otoliths and three crustaceans were recovered from the stomach contents. The dolphins assessed preyed on at least eight different fish species of the families Trichiuridae, Carangidae, Sparidae, Merluccidae, Engraulidae, Sciaenidae, Congridae and Scombridae, five cephalopod species of the families Loliginidae, Sepiolidae, Tremoctopodidae and Thysanoteuthidae, and one shrimp species of the Penaeidae family. Based on the analysis of the Index of Relative Importance (IRI), the Atlantic cutlassfish, Trichiurus lepturus, was the most important fish species represented. Of the cephalopods, the squid Doryteuthis plei was by far the most representative species. Several items were reported for the first time as prey of the S. frontalis: Xiphopenaeus kroyeri, Tremoctopus violaceus, Semirossia tenera, Merluccius hubbsi, Pagrus pagrus and Paralonchurus brasiliensis. S. frontalis presented teuthophagous and ichthyofagous feeding habits, with apparent predominance of the first, and preyed mainly on pelagic and demersal items.