A review of the global ecology,genomics, and biogeography of the toxic cyanobacterium,Microcystis spp.

This review summarizes the present state of knowledge regarding the toxic, bloom-forming cyanobacterium, Microcystis, with a specific focus on its geographic distribution, toxins, genomics, phylogeny, and ecology. A global analysis found documentation suggesting geographic expansion of Microcystis, with recorded blooms in at least 108 countries, 79 of which have also reported the hepatatoxin microcystin. The production of microcystins (originally “Fast-Death Factor”) by Microcystis and factors that control synthesis of this toxin are reviewed, as well as the putative ecophysiological roles of this metabolite. Molecular biological analyses have provided significant insight into the ecology and physiology of Microcystis, as well as revealed the highly dynamic, and potentially unstable, nature of its genome. A genetic sequence analysis of 27 Microcystis species, including 15 complete/draft genomes are presented. Using the strictest biological definition of what constitutes a bacterial species, these analyses indicate that all Microcystis species warrant placement into the same species complex since the average nucleotide identity values were above 95%, 16S rRNA nucleotide identity scores exceeded 99%, and DNA–DNA hybridization was consistently greater than 70%. The review further provides evidence from around the globe for the key role that both nitrogen and phosphorus play in controlling Microcystis bloom dynamics, and the effect of elevated temperature on bloom intensification. Finally, highlighted is the ability of Microcystis assemblages to minimize their mortality losses by resisting grazing by zooplankton and bivalves, as well as viral lysis, and discuss factors facilitating assemblage resilience.     

Development of the aphid parasitoid,Aphidius ervi, in asexual and sexual females of the pea aphid,Acyrthosiphon pisum, and the blackberry-cereal aphid,Sitobion fragariae

The aphid parasitoid,Aphidius ervi Haliday, overwinters in larval diapause. The possibility that the parasitoid might prefer sexual (oviparae) rather than asexual females (virginoparae) as overwintering hosts (oviparae predominate in autumn when host numbers are generally declining) was tested by comparing these aphid morphs as potential hosts. Two host species were also examined, the pea aphid,Acyrthosiphon pisum (Harris), and the blackberry aphid,Sitobion fragariae (Walker). The parasitoids took longer to develop inS. fragariae than inA. pisum but the development of non-diapausingA. ervi was similar in sexual and asexual females. This observation, together with the greater variation in the duration of the different parasitoid stadia inS. fragariae, indicated that the parasitoid is specialized on the pea aphid. In photophases of 12 h and longer, the proportion ofA. ervi entering diapause inA. pisum oviparae was higher than in virginoparae. The critical daylength (where 50% of parasitoids entered diapause) was therefore longer in oviparae (12.6 h) than in virginoparae (11.7 h) with the inference that parasitoids developing in the oviparae would enter diapause earlier in the field. InS. fragariae, critical day-lengths were similar in both aphid morphs. The duration of diapause was unaffected by host morph and emergence in short days (10:14 L:D) occurred over a long period (c. 60 days).     

Genetic Redundancy,Proximity, and Functionality of lspA,the Target of Antibiotic TA,in the Myxococcus xanthus Producer Strain

We recently showed that type II signal peptidase (SPaseII) encoded by lspA is the target of an antibiotic called TA (myxovirescin), which is made by Myxococcus xanthus. SPaseII cleaves the signal peptide during bacterial lipoprotein processing. Bacteria typically contain one lspA gene; however, strikingly, the M. xanthus DK1622 genome contains four (lspA1 to lspA4). Since two of these genes, lspA3 and lspA4, are located in the giant TA biosynthetic gene cluster, we hypothesized they may play a role in TA resistance. To investigate the functions of the four M. xanthus lspA (lspA^Mx) genes, we conducted sequence comparisons and found that they contained nearly all the conserved residues characteristic of SPaseII family members. Genetic studies found that an Escherichia coli ΔlspA mutation could be complemented by any of the lspA^Mx genes in an lpp mutant background, but not in an E. coli lpp⁺ background. Because Lpp is the most abundant E. coli lipoprotein, these results suggest the M. xanthus proteins do not function as efficiently as the host enzyme. In E. coli, overexpression of each of the LspA^Mx proteins conferred TA and globomycin resistance, although LspA3 conferred the highest degree of resistance. In M. xanthus, each lspA^Mx gene could be deleted and was therefore dispensable for growth. However, lspA3 or lspA4 deletion mutants each exhibited a tan phase variation bias, which likely accounts for their reduced-swarming and delayed-development phenotypes. In summary, we propose that all four LspA^Mx proteins function as SPaseIIs and that LspA3 and LspA4 might also have roles in TA resistance and regulation, respectively.     

Checklist of the Braulidae,Camillidae, Diastatidae and Drosophilidae of Finland (Diptera,Ephydroidea)

A checklist of the Braulidae (1 species), Camillidae (3 spp.), Diastatidae (10 spp.) and Drosophilidae (67 spp.) of Finland is presented. Campichoetinae is included as a subfamily of Diastatidae.     

Review of subtribe Singilina Jeannel, 1949, of the Middle East and Central Asia (Coleoptera, Carabidae, Lebiini)

Species of the genus Singilis Rambur, 1837 (Phloeozeteus Peyron, 1856, syn. n., Agatus Motschulsky, 1845, syn. n.), occurring in the Middle East and Central Asia are reviewed, with 24 species now recognized in the region, including ten species described as new: Singilis makarovi sp. n. (Tajikistan), Singilis jedlickai sp. n. (Afghanistan), Singilis kolesnichenkoi sp. n. (Iran), Singilis kabakovi sp. n. (Afghanistan, Iran), Singilis timuri sp. n. (Uzbekistan), Singilis klimenkoi sp. n. (Iran), Singilis saeedi sp. n. (Iran), Singilis felixi sp. n. (UAE), Singilis kryzhanovskii sp. n. (Iran, Turkmenistan), and Singilis timidus sp. n. (Iran); Singilis libani (Sahlberg, 1913) is recognized as a valid species; and Singilis solskyi nom. n. is proposed as a replacement name for Agatus bicolor (Solsky, 1874, not Rambur 1837), now placed in Singilis as junior homonym. New synonymies include: Singilis cingulatus (Gebler, 1843) = Singilis jakeschi Jedlička, 1967, syn. n.; Singilis mesopotamicus Pic, 1901 = Singilis apicalis Jedlička, 1956, syn. n. A key to species is provided. Habitus and aedeagal illustrations are provided for all species. Distributional data include many new country records.     

The New World whirligig beetles of the genus Dineutus Macleay, 1825 (Coleoptera,Gyrinidae, Gyrininae,Dineutini)

All New World members of the whirligig beetle genus Dineutus Macleay, 1825 are treated. The New World Dineutus are found to be composed of 18 species and 6 subspecies: one species, Dineutus mexicanus Ochs, 1925, stat. n. is elevated from subspecies to species rank, and the subspecies Dineutus carolinus mutchleri Ochs, 1925, syn. n. is synonymized here with the typical form. Lectotypes are designated for Dineutus discolor Aubé, 1838, Dineutes metallicus Aubé, 1838, Dineutus solitarius Aubé, 1838, Dineutes analis Régimbart, 1883, and Gyrinus longimanus Olivier, 1795. Each taxonomic unit is provided with a taxonomic history, type locality, diagnosis, distribution, habitat information, and a discussion section. The aedeagus and male mesotarsal claws are illustrated, and dorsal and ventral habitus images of both sexes, for each species and subspecies are provided. General distribution maps are provided for all taxonimc units. A key to the genera of New World Gyrinidae, as well as all the New World Dineutus species is provided. General Dineutus anatomy as well as a clarification of homology and anatomical terms is included.     

Resolution of the long-standing controversy over the type species of the genus Pseudotypotherium (Notoungulata,Typotheria, Mesotheriidae)

Mesotheres (Notoungulata: Typotheria) are among the most common mammals found in upper Miocene to Pliocene deposits of central Argentina, including the classic type Monte Hermoso locality, which defines the Montehermosan South American Land Mammal “Age”. Nevertheless, the correct name for the mesothere species from this site has been shrouded in uncertainty for well over a century due to questions of taxonomic priority, specimen provenance, and ontogenetic changes in dental formula. Since the mesotheres from Monte Hermoso were named, three distinct species have been formally considered as the type species of the genus: (1) Pseudotypotherium bravardi; (2) “Pseudotypotherium” maendrum; and (3) Pseudotypotherium exiguum. However, none of these species is a nominal species of the Pseudotypotherium genus; all three were originally referred to Typotherium. Article 67.2 of the International Code of Zoological Nomenclature (ICZN, 1999) indicates that only species considered as nominal species are eligible to set the type; in the case of Pseudotypotherium, these include: P. pulchrum, P. carlesi, P. hystatum, and P. carhuense. We conclude that Pseudotypotherium pulchrum F. Ameghino, 1904 (holotype MACN A 10299, Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”, Ameghino Collection), is the type species of the mesotheriid notoungulate genus from Monte Hermoso. According to Article 68.2, F. Ameghino fixed the type by original designation in 1904 when he described P. pulchrum and included “n. g., n. sp.”. Two of the other species previously considered species P. (= T.) bravardi and P. (= T.) exiguum are invalid as type species according to Article 70.2, since their designations overlooked the previous type fixation. The third species (M. (= T.) maendrum) represents a different mesothere genus (Mesotherium) that only occurs in younger (Pleistocene) deposits. Our analysis puts an end to a historical debate that has been ongoing for more than a century regarding the identity of this well-represented late Miocene–Pliocene mesotheriine genus (Pseudotypotherium). This study provides a solid taxonomic foundation for future studies on intraspecific and ontogenetic variation of Pseudotypotherium pulchrum.     

Evaluating the competence of the primary vector,Culex tritaeniorhynchus,and the invasive mosquito species,Aedes japonicus japonicus,in transmitting three Japanese encephalitis virus genotypes

Japanese encephalitis virus (JEV) is maintained in an enzootic cycle between swine, water birds, and mosquitoes. JEV has circulated indigenously in Asia, with Culex tritaeniorhynchus as the primary vector. In some areas where the primary vector is scarce or absent, sporadic cases of Japanese encephalitis have been reported, with Aedes japonicus japonicus presumed to have the potential as a secondary vector. As one of the world’s most invasive culicid species, Ae. j. japonicus carries a considerable health risk for spreading diseases to wider areas, including Europe and North America. Thus, evaluation of its competency as a JEV vector, particularly in a native population, will be essential in preventing potential disease spread. In this study, the two mosquito species’ vector competence in transmitting three JEV genotypes (I, III, and V) was assessed, with Cx. tritaeniorhynchus serving as a point of reference. The mosquitoes were virus-fed and the infection rate (IR), dissemination rate (DR), and transmission rate (TR) evaluated individually by either RT-qPCR or focus forming assay. Results showed striking differences between the two species, with IR of 95% (261/274) and 9% (16/177) in Cx. tritaeniorhynchus and Ae. j. japonicus, respectively. Both mosquitoes were susceptible to all three JEV genotypes with significant differences in IR and mean viral titer. Results confirm the primary vector’s competence, but the fact that JEV was able to establish in Ae. j. japonicus is of public health significance, and with 2%–16% transmission rate it has the potential to successfully transmit JEV to the next host. This may explain the human cases and infrequent detection in primary vector-free areas. Importantly, Ae. j. japonicus could be a relevant vector spreading the disease into new areas, indicating the need for security measures in areas where the mosquito is distributed or where it may be introduced.     

Regulation of the expression of the nod box-independent nodulation gene, nolX, in Sinorhizobium fredii, a nitrogen-fixing symbiont of legume plants

nolX, a nod box-independent nodulation gene from the nitrogen-fixing symbiont, Sinorhizobium fredii, regulates cultivar-specific nodulation of soybean. Expression of this gene is triggered by isoflavonoid cues from host roots but is not mediated by a typical cis-acting nod box promoter. We have found that two isoflavonoids, daidzein and coumestrol, induce expression of a nolX-lacZ gene fusion at pH values between 5.5 and 8.5, with an optimum at 6.5. Expression of nolX is highly dependent on nutritional status but insensitive to salinity. Methionine and casamino acids, amendments that enhance expression of hrpF, a homologous gene from the plant pathogen Xanthomonas campestris biovar vesicatoria, have no and strongly negative effects, respectively, on expression of nolX. Growth of S. fredii on rhamnose, galactose, xylose, or myo-inositol as carbon source greatly elevates inducibility in comparison to a standard yeast extract-mannitol medium. None of the tested variables, however, released nolX from its dependence on isoflavonoids as inducers.     

A case of mistaken identity,Opuntia abjecta,long-lost in synonymy under the Caribbean species,O. triacantha,and a reassessment of the enigmatic O. cubensis

Opuntia abjecta and O. militaris have been placed in synonymy under the Caribbean species O. triacantha for the past 30 years. Recent molecular phylogenetic evidence has shown, however, that O. abjecta and O. triacantha are actually in two very different clades suggesting that the Floridian endemic O. abjecta should be recognized as a distinct species. Here, we summarize major morphological differences between O. abjecta and O. triacantha. We also include new sequence data from the rare Cuban taxon, O. militaris, in a molecular phylogenetic analysis to determine its relationship to O. triacantha and O. abjecta. We discuss the putative hybrid taxa O. cubensis and O. ochrocentra, which currently are treated as synonyms. We also show through analysis of morphological and molecular characters that these two taxa were derived from two independent origins from divergent maternal progenitors, confirming that O. ochrocentra should not be treated as synonymous with O. cubensis. A key is provided for identifying these taxonomically confusing taxa and their close relatives. This study emphasizes the distinctions among O. abjecta, O. militaris, and O. triacantha and illustrates that extreme caution must be employed when using herbarium specimens for identifying species of Opuntia. It also indicates that broad phytogeographic assumptions regarding species’ relationships in Opuntia may sometimes be misleading. Hybridization and polyploidy are common in Opuntia and have played a role in the formation of new species in this group as well. A neotype is here designated for O. triacantha.     

A new species of nectar-feeding bat,genus Lonchophylla,from the Caatinga of Brazil (Chiroptera,Phyllostomidae)

We describe Lonchophylla inexpectata sp. n. from the Caatinga of Brazil. This new species can be distinguished from all known species of Lonchophylla that occur in Brazil by dental traits, cranial size, and fur colour. Specimens of Lonchophylla inexpectata have been misidentified as Lonchophylla mordax; but Lonchophylla inexpectata is a pale-venter species, similar in external appearance to Lonchophylla dekeyseri. We have found Lonchophylla inexpectata in the Caatinga of North-eastern Brazil; Lonchophylla mordax along the eastern border of the Caatinga and in the Atlantic Forest–Caatinga ecotone in North-eastern Brazil; and Lonchophylla dekeyseri in the Cerrado of Mid-western Brazil, in the Brazilian Cerrado–Caatinga ecotone, and as far west as the Cerrado of Bolivia.     

Two new species of the genus Teredorus Hancock, 1906 (Orthoptera,Tetrigidae) from China,with a key to the species of the genus

Taxonomy of a tetrigid genus Teredorus Hancock is reviewed. Two new species, Teredorus parvipulvillus sp. n. and Teredorus hunanensis sp. n. are described from China and an updated identification key to all known species of the genus is given, as well as brief comments on phylogenetic relationships, biology and ecology.     

Chemotactic attraction between hemocytes of the oyster,Crassostrea virginica,and bacteria

Experiments were conducted to ascertain whether there is chemotactic attraction by Bacillus megaterium and Micrococcus varians, both Gram-positive species, and Escherichia coli and Vibrio parahaemolyticus, both Gram-negative species, for hemocytes of the American oyster, Crassostrea virginica. It was ascertained quantitatively that oyster hemocytes are attracted to live E. coli, B. megaterium, and M. varians but not to heat-killed bacteria. Furthermore, oyster cells are not attracted to either live or heat-killed V. parahaemolyticus. It is concluded that the chemoattractant is some molecule emitted by living vegetative cells of certain Gram-positive as well as Gramnegative bacteria.     

Possible toxic effects of the marine blue-green alga, Spirulina subsalsa, on the blue shrimp, Penaeus stylirostris.

Blooms of a marine species of blue-green algae identified as Spirulina subsalsa (Cyanophyta, Oscillatoriacae) were found to be related to a particular disease syndrome in raceway-reared blue shrimp, Penaeus stylirostris. The disease was characterized by necrosis of the lining epithelium of the midgut, dorsal cecum, and hindgut gland, and a consequent hemocytic enteritis. Bacterial infections due predominately to Vibrio alginolyticus were common in affected shrimp and presumed to be a secondary condition resulting from necrosis of the gut epithelium. These bacterial infections were expressed as local abscesses near or on the gut or as fulminating septicemias.     

Megalictis,the Bone-Crushing Giant Mustelid (Carnivora,Mustelidae, Oligobuninae) from the Early Miocene of North America

We describe cranial and mandibular remains of three undescribed individuals of the giant mustelid Megalictis ferox Matthew, 1907 from the latest Arikareean (Ar4), Early Miocene mammal fauna of Nebraska, and Wyoming (USA) housed at the American Museum of Natural History (New York, USA). Our phylogenetic hypothesis indicates that Ar4 specimens assigned to M. ferox constitute a monophyletic group. We assign three additional species previously referred to Paroligobunis to Megalictis: M. simplicidens, M. frazieri, and “M.” petersoni. The node containing these four species of Megalictis and Oligobunis forms the Oligobuninae. We test the hypothesis that Oligobuninae (Megalictis and Oligobunis) is a stem mustelid taxon. Our results indicate that the Oligobuninae form the sister clade to the crown extant mustelids. Based on the cranium, M. ferox is a jaguar-size mustelid and the largest terrestrial mustelid known to have existed. This new material also sheds light on a new ecomorphological interpretation of M. ferox as a bone-crushing durophage (similar to hyenas), rather than a cat-like hypercarnivore, as had been previously described. The relative large size of M. ferox, together with a stout rostrum and mandible made it one of the more powerful predators of the Early Miocene of the Great Plains of North America.