Description of a new genus and three new species of Otothyrinae (Siluriformes,Loricariidae)

The genus Hisonotus was resurrected as a member of the tribe Otothyrini (actually subfamily Otothyrinae). However, phylogenetic studies based on morphological and molecular data showed that Hisonotus is not monophyletic and independent lineages can be identified, such as the group composed of the species Hisonotus insperatus, Hisonotus luteofrenatus, Hisonotus oliveirai, Hisonotus paresi and Hisonotus piracanjuba, a lineage unrelated to that containing the type species of the genus Hisonotus (Hisonotus notatus). Herein, based in molecular and morphological data, a new genus is described to accommodate the lineage mentioned above, into which are also added three new species. This new genus can be distinguished from other genera of Otothyrinae by the following combination of characters: (1) a pair of rostral plates at the tip of the snout; (2) two large pre-nasal plates just posterior to the rostral plates; (3) a supra-opercular plate that receives the laterosensory canal from the compound pterotic before the preopercle; (4) a well developed membrane at anal opening in females; and (5) a V-shaped spinelet. A key to species of Curculionichthys is provided.     

Re-establishment of Carabus (Cathoplius) aliai Escalera, 1944 as a separate valid species (Coleoptera,Carabidae)

Carabus (Cathoplius) aliai was described as a separate species by Escalera in 1944 but since the 1950–60s it has been considered as a subspecies of Carabus (Cathoplius) stenocephalus Lucas, 1866. This downgrading was adopted after examining only a few specimens, due to their rarity in collections. In recent years, an important population of this taxon was rediscovered in the Tan-Tan area in southern Morocco. By combining field observations with laboratory breeding experiments including hybridization trials, and through the morphological examination of a representative number of individuals, it is confirmed that Carabus aliai is indeed a valid species. Despite close geographic distribution, the morphological and biological characteristics of Carabus aliai and Carabus stenocephalus ifniensis Zarco, 1941, its northern substitutive taxon, are very different. Carabus aliai adults are characterized by a smaller size, a slender silhouette, a more brilliant aspect, a narrower pronotum, a coarser elytral sculpture, longer legs, and a wider and a little more curved apex of the median lobe of the aedeagus. Carabus aliai larvae are also characterized by a much smaller size and the Carabus aliai pupa has a narrower thoracic area and a different chaetotaxy compared to that of Carabus stenocephalus ifniensis. Contrary to this, Carabus aliai has a life cycle belonging to the annual univoltine winter semelparous type. Moreover, the duration of its development cycle is shorter. Carabus aliai is a sabulicolous steppe-wandering species with an intensive running activity, while Carabus stenocephalus ifniensis is a more sedentary taxon. Crossbreeding experiments showed a marked reproductive isolation between Carabus aliai and Carabus stenocephalus ifniensis. When F1 hybrids were crossed with one another, a very high mortality rate during embryonic, larval and pupal development was evident and no vital F2 neo-adults were obtained. Morphological and biological differences, together with the reproductive failure in Carabus aliai × Carabus stenocephalus ifniensis hybrids, clearly indicate that Carabus aliai is a separate Cathoplius species that is distributed in an area south of the Anti-Atlas chain, from Plage Blanche (Guelmim) to Lemsid and Bou Kra (south of Laâyoune). Carabus aliai is therefore both a Saharan desert endemic and an Atlantic resident. Moreover, it is the southernmost Carabus species of the western Palaearctic region.     

Change in State following Transposition of a Regulatory Element of the Enhancer System in Maize

From an original A2 allele (colored aleurone), a mutable allele, a2-m-4 1629, that changes from a2 to A2 is described. Mutability is expressed as a very distinct pattern limited to the last cell division.—The mutability of a2-m-4 1629 is autonomously controlled by an En at the a2 locus. This En, inactive on standard a testers for En, is partially active on a2-m-1, an a2 tester for En, and expresses varied levels of activity from limited to nearly full suppression of the a2-m-1 color phenotype.—When the En of the a2-m-4 1629 allele transposes from the a2 locus, it behaves, at the new position, like a standard En in triggering a2-m-1, a-m-1 and a-m(r), which express colored spots on a colorless background. The activity of En is therefore different following the change in chromosome location. This finding supports the "position" hypothesis that has been proposed to explain diverse patterns observed among controlling elements. In this case mutation is related to the terminal cell state and not to tissue differences as shown with some phase-variation regulatory elements.     

The phylogenetic relationships and generic limits of finches (Fringillidae)

Phylogenetic relationships among the true finches (Fringillidae) have been confounded by the recurrence of similar plumage patterns and use of similar feeding niches. Using a dense taxon sampling and a combination of nuclear and mitochondrial sequences we reconstructed a well resolved and strongly supported phylogenetic hypothesis for this family. We identified three well supported, subfamily level clades: the Holoarctic genus Fringilla (subfamly Fringillinae), the Neotropical Euphonia and Chlorophonia (subfamily Euphoniinae), and the more widespread subfamily Carduelinae for the remaining taxa. Although usually separated in a different family-group taxon (Drepanidinae), the Hawaiian honeycreepers are deeply nested within the Carduelinae and sister to a group of Asian Carpodacus. Other new relationships recovered by this analysis include the placement of the extinct Chaunoproctus ferreorostris as sister to some Asian Carpodacus, a clade combining greenfinches (Carduelis chloris and allies), Rhodospiza and Rhynchostruthus, and a well-supported clade with the aberrant Callacanthis and Pyrrhoplectes together with Carpodacus rubescens. Although part of the large Carduelis-Serinus complex, the poorly known Serinus estherae forms a distinct lineage without close relatives. The traditionally delimited genera Carduelis, Serinus, Carpodacus, Pinicola and Euphonia are polyphyletic or paraphyletic. Based on our results we propose a revised generic classification of finches and describe a new monotypic genus for Carpodacus rubescens.     

Molecular phylogeny of the genus Dicronocephalus (Coleoptera,Scarabaeidae, Cetoniinae) based on mtCOI and 16S rRNA genes

The seven species belonging to the genus Dicronocephalus are a very interesting group with a unique appearance and distinct sexual dimorphism. Only one species among them, Dicronocephalus adamsi, has been known in the Korean fauna. This species is recognized as having a wide distribution from Tibet to Korean Peninsula and is currently represented by two subspecies that have separated geographical ranges. The phylogenetic relationships of Dicronocephalus adamsi were still unclear. The phylogeny of Dicronocephalus is reconstructed with a phylogenetic study of five species including four subspecies based on a molecular approach using mitochondrial COI and 16S rRNA genes. Our results are compared with the results obtained by previous authors based on morphological characters. They show that the tested taxa are divided into two major clades. Clade A consists of two species (Dicronocephalus adamsi + Dicranocephalus yui) and Clade B includes the others (Dicronocephalus dabryi + Dicranocephalus uenoi + Dicranocephalus wallichii). This result generally supports Kurosawa’s proposal except that Dicronocephalus dabryi and Dicranocephalus uenoi are newly recognized as members of a monophyletic group. We propose that Dicronocephalus adamsi drumonti is a junior subjective synonym of Dicronocephalus adamsi adamsi. These results show that three members of the Dicranocephalus wallichii group should be treated as species rather than subspecies. However, further research including analyses of different genetic markers is needed to reconfirm our results.     

Molecular-based estimate of species number,phylogenetic relationships and divergence times for the genus Stenotaenia (Chilopoda,Geophilomorpha) in the Italian region

Stenotaenia is one of the largest and most widespread genera of geophilid centipedes in the Western Palearctic, with a very uniform morphology and about fifteen species provisionally recognized. For a better understanding of Stenotaenia species-level taxonomy, we have explored the possibility of using molecular data. As a preliminary assay, we sampled twelve populations, mainly from the Italian region, and analyzed partial sequences of the two genes COI and 28S. We employed a DNA-barcoding approach, complemented by a phylogenetic analysis coupled with divergence time estimation. Assuming a barcoding gap of 10–16% K2P pairwise distances, we found evidence for the presence of at least six Stenotaenia species in the Italian region, which started diverging about 50 million years ago, only partially matching with previously recognized species. We found that small-sized oligopodous species belong to a single clade that originated about 33 million years ago, and obtained some preliminary evidence of the related genus Tuoba being nested within Stenotaenia.     

Engineered biosynthesis of bacteriochlorophyll gF in Rhodobacter sphaeroides

Engineering photosynthetic bacteria to utilize a heterologous reaction center that contains a different (bacterio) chlorophyll could improve solar energy conversion efficiency by allowing cells to absorb a broader range of the solar spectrum. One promising candidate is the homodimeric type I reaction center from Heliobacterium modesticaldum. It is the simplest known reaction center and uses bacteriochlorophyll (BChl) g, which absorbs in the near-infrared region of the spectrum. Like the more common BChls a and b, BChl g is a true bacteriochlorin. It carries characteristic C3-vinyl and C8-ethylidene groups, the latter shared with BChl b. The purple phototrophic bacterium Rhodobacter (Rba.) sphaeroides was chosen as the platform into which the engineered production of BChl g_F, where F is farnesyl, was attempted. Using a strain of Rba. sphaeroides that produces BChl b_P, where P is phytyl, rather than the native BChl a_P, we deleted bchF, a gene that encodes an enzyme responsible for the hydration of the C3-vinyl group of a precursor of BChls. This led to the production of BChl g_P. Next, the crtE gene was deleted, thereby producing BChl g carrying a THF (tetrahydrofarnesol) moiety. Additionally, the bchG^Rs gene from Rba. sphaeroides was replaced with bchG^Hm from Hba. modesticaldum. To prevent reduction of the tail, bchP was deleted, which yielded BChl g_F. The construction of a strain producing BChl g_F validates the biosynthetic pathway established for its synthesis and satisfies a precondition for assembling the simplest reaction center in a heterologous organism, namely the biosynthesis of its native pigment, BChl g_F.     

Systematics of the Osteocephalus buckleyi species complex (Anura,Hylidae) from Ecuador and Peru

We present a new phylogeny, based on DNA sequences of mitochondrial and nuclear genes, for frogs of the genus Osteocephalus with emphasis in the Osteocephalus buckleyi species complex. Genetic, morphologic, and advertisement call data are combined to define species boundaries and describe new species. The phylogeny shows strong support for: (1) a basal position of Osteocephalus taurinus + Osteocephalus oophagus, (2) a clade containing phytotelmata breeding species, and (3) a clade that corresponds to the Osteocephalus buckleyi species complex. Our results document a large proportion of hidden diversity within a set of populations that were previously treated as a single, widely distributed species, Osteocephalus buckleyi. Individuals assignable to Osteocephalus buckleyi formed a paraphyletic group relative to Osteocephalus verruciger and Osteocephalus cabrerai and contained four species, one of which is Osteocephalus buckleyi sensu stricto and three are new. Two of the new species are shared between Ecuador and Peru (Osteocephalus vilmae sp. n. and Osteocephalus cannatellai sp. n.) and one is distributed in the Amazon region of southern Peru (Osteocephalus germani sp. n.) We discuss the difficulties of using morphological characters to define species boundaries and propose a hypothesis to explain them.     

Diffusible Signal Factor (DSF) Synthase RpfF of Xylella fastidiosa Is a Multifunction Protein Also Required for Response to DSF

Xylella fastidiosa, like related Xanthomonas species, employs an Rpf cell-cell communication system consisting of a diffusible signal factor (DSF) synthase, RpfF, and a DSF sensor, RpfC, to coordinate expression of virulence genes. While phenotypes of a ΔrpfF strain in Xanthomonas campestris could be complemented by its own DSF, the DSF produced by X. fastidiosa (XfDSF) did not restore expression of the XfDSF-dependent genes hxfA and hxfB to a ΔrpfF strain of X. fastidiosa, suggesting that RpfF is involved in XfDSF sensing or XfDSF-dependent signaling. To test this conjecture, rpfC and rpfF of X. campestris were replaced by those of X. fastidiosa, and the contribution of each gene to the induction of a X. campestris DSF-dependent gene was assessed. As in X. fastidiosa, XfDSF-dependent signaling required both X. fastidiosa proteins RpfF and RpfC. RpfF repressed RpfC signaling activity, which in turn was derepressed by XfDSF. A mutated X. fastidiosa RpfF protein with two substitutions of glutamate to alanine in its active site was incapable of XfDSF production yet enabled a response to XfDSF, indicating that XfDSF production and the response to XfDSF are two separate functions in which RpfF is involved. This mutant was also hypervirulent to grape, demonstrating the antivirulence effects of XfDSF itself in X. fastidiosa. The Rpf system of X. fastidiosa is thus a novel example of a quorum-sensing signal synthase that is also involved in the response to the signal molecule that it synthesizes.     

An O Antigen Capsule Modulates Bacterial Pathogenesis in Shigella sonnei

Shigella is the leading cause for dysentery worldwide. Together with several virulence factors employed for invasion, the presence and length of the O antigen (OAg) of the lipopolysaccharide (LPS) plays a key role in pathogenesis. S. flexneri 2a has a bimodal OAg chain length distribution regulated in a growth-dependent manner, whereas S. sonnei LPS comprises a monomodal OAg. Here we reveal that S. sonnei, but not S. flexneri 2a, possesses a high molecular weight, immunogenic group 4 capsule, characterized by structural similarity to LPS OAg. We found that a galU mutant of S. sonnei, that is unable to produce a complete LPS with OAg attached, can still assemble OAg material on the cell surface, but a galU mutant of S. flexneri 2a cannot. High molecular weight material not linked to the LPS was purified from S. sonnei and confirmed by NMR to contain the specific sugars of the S. sonnei OAg. Deletion of genes homologous to the group 4 capsule synthesis cluster, previously described in Escherichia coli, abolished the generation of the high molecular weight OAg material. This OAg capsule strongly affects the virulence of S. sonnei. Uncapsulated knockout bacteria were highly invasive in vitro and strongly inflammatory in the rabbit intestine. But, the lack of capsule reduced the ability of S. sonnei to resist complement-mediated killing and to spread from the gut to peripheral organs. In contrast, overexpression of the capsule decreased invasiveness in vitro and inflammation in vivo compared to the wild type. In conclusion, the data indicate that in S. sonnei expression of the capsule modulates bacterial pathogenesis resulting in balanced capabilities to invade and persist in the host environment.     

Simulation study of territory size distributions in subterranean termites

In this study, on the basis of empirical data, we have simulated the foraging tunnel patterns of two subterranean termites, Coptotermes formosanus Shiraki and Reticulitermes flavipes (Kollar), using a two-dimensional model. We have defined a territory as a convex polygon containing a tunnel pattern and explored the effects of competition among termite territory colonies on the territory size distribution in the steady state that was attained after a sufficient simulation time. In the model, territorial competition was characterized by a blocking probability P_block that quantitatively describes the ease with which a tunnel stops its advancement when it meets another tunnel; higher P_block values imply easier termination. In the beginning of the simulation run, N=10, 20,…,100 territory seeds, representing the founding pair, were randomly distributed on a square area. When the territory density was less (N=20), the differences in the territory size distributions for different P_block values were small because the territories had sufficient space to grow without strong competitions. Further, when the territory density was higher (N>20), the territory sizes increased in accordance with the combinational effect of P_block and N. In order to understand these effects better, we introduced an interference coefficient γ. We mathematically derived γ as a function of P_block and N: γ(N,P_block)=a(N)P_block/(P_block+b(N)). a(N) and b(N) are functions of N/(N+c) and d/(N+c), respectively, and c and d are constants characterizing territorial competition. The γ function is applicable to characterize the territoriality of various species and increases with both the P_block values and N; higher γ values imply higher limitations of the network growth. We used the γ function, fitted the simulation results, and determined the c and d values. In addition, we have briefly discussed the predictability of the present model by comparing it with our previous lattice model that had been used to explain the territory size distributions of mangrove termites on the Atlantic coast of Panama.     

A Critical Component of Meiotic Drive in Neurospora Is Located Near a Chromosome Rearrangement

Neurospora fungi harbor a group of meiotic drive elements known as Spore killers (Sk). Spore killer-2 (Sk-2) and Spore killer-3 (Sk-3) are two Sk elements that map to a region of suppressed recombination. Although this recombination block is limited to crosses between Sk and Sk-sensitive (Sk^S) strains, its existence has hindered Sk characterization. Here we report the circumvention of this obstacle by combining a classical genetic screen with next-generation sequencing technology and three-point crossing assays. This approach has allowed us to identify a novel locus called rfk-1, mutation of which disrupts spore killing by Sk-2. We have mapped rfk-1 to a 45-kb region near the right border of the Sk-2 element, a location that also harbors an 11-kb insertion (Sk-2^INS1) and part of a >220-kb inversion (Sk-2^INV1). These are the first two chromosome rearrangements to be formally identified in a Neurospora Sk element, providing evidence that they are at least partially responsible for Sk-based recombination suppression. Additionally, the proximity of these chromosome rearrangements to rfk-1 (a critical component of the spore-killing mechanism) suggests that they have played a key role in the evolution of meiotic drive in Neurospora.     

Taxonomic revision of the genus Callimerus Gorham s. l. (Coleoptera,Cleridae). Part I. latifrons species-group

The latifrons species-group (=Brachycallimerus sensu Chapin 1924, Corporaal 1950; = flavofasciatus-group sensu Kolibáč 1998) of Callimerus Gorham is redefined and revised. Five species are recognized including one new species Callimerus cacuminis Yang & Yang sp. n. (type locality: Yunnan, China). Callimerus flavofasciatus Schenkling, 1902 is newly synonymized with Callimerus latifrons Gorham, 1876. Callimerus trifasciatus Schenkling, 1899a is transferred to the genus Corynommadius Schenkling, 1899a. Callimerus gorhami Corporaal, 1949 and Callimerus pallidus Gorham, 1892 are excluded from the latifrons species-group (their assignment to a species-group will be dealt with in a subsequent paper). A key to species of the latifrons species-group is given and habitus of each type specimen, male terminalia, and other diagnostic characters are illustrated.