Glucose-6-phosphate dehydrogenase deficiency in northern Mexico and description of a novel mutation

Glucose-6-phosphate dehydrogenase deficiency (G6PD) is the most common enzyme pathology in humans; it is X-linked inherited and causes neonatal hyperbilirubinaemia, chronic nonspherocytic haemolytic anaemia and drug-induced acute haemolytic anaemia. G6PD deficiency has scarcely been studied in the northern region of Mexico, which is important because of the genetic heterogeneity described in Mexican population. Therefore, samples from the northern Mexico were biochemically screened for G6PD-deficiency, and PCR-RFLPs, and DNA sequencing used to identify mutations in positive samples. The frequency of G6PD deficiency in the population was 0.95% (n = 1993); the mutations in 86% of these samples were G6PD A^?202A/376G , G6PD A^?376G/968C and G6PD Santamaria^376G/542T . Contrary to previous reports, we demonstrated that G6PD deficiency distribution is relatively homogenous throughout the country (P = 0.48336), and the unique exception with high frequency of G6PD deficiency does not involve a coastal population (Chihuahua: 2.4%). Analysis of eight polymorphic sites showed only 10 haplotypes. In one individual we identified a new G6PD mutation named Mexico DF^193A>G (rs199474830), which probably results in a damaging functional effect, according to PolyPhen analysis. Proteomic impact of the mutation is also described.     

Inter‐specific competition and competition‐free space in the tephritid parasitoids Utetes anastrephae and Doryctobracon areolatus (Hymenoptera: Braconidae: Opiinae)

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Nektaspid arthropods from the Lower Cambrian Emu Bay Shale Lagerstätte,South Australia,with a reassessment of lamellipedian relationships

Abstract: The lower Cambrian Emu Bay Shale on Kangaroo Island, South Australia, contains the only known Cambrian Burgess Shale‐type biota in Australia. Two new lamellipedian arthropods, Emucaris fava gen. et sp. nov. and Kangacaris zhangi gen. et sp. nov., from the Emu Bay Shale Lagerstätte are described as monotypic genera that are resolved cladistically as a monophyletic group that is sister to Naraoiidae + Liwiidae and classified within the Nektaspida as a new family Emucarididae. Shared derived characters of Emucarididae involve a bipartite, elongate hypostome and elongation of the pygidium relative to the cephalic shield and very short thorax. A monophyletic Liwiidae is composed of Liwia and the Ordovician Tariccoia + Soomaspis but excludes Buenaspis, and even the membership of Buenaspis in Nektaspida is contradicted amongst the shortest cladograms. New morphological interpretations favour affinities of Kwanyinaspis with Conciliterga rather than with Aglaspidida, and Phytophilaspis with Petalopleura.     

Lessons from a complex biogeographical scenario: morphological characters match mitochondrial lineages within Iberian Coronella austriaca (Reptilia: Colubridae)

Molecular evidence suggests that climatic fluctuations in the peninsulas of southern European during the Miocene and Pleistocene resulted in considerable genetic differentiation of organisms, probably following a ‘refugia within refugia’ model. We examined morphometric and meristic characters in museum specimens from the three Iberian clades of the smooth snake Coronella austriaca, previously described by molecular markers. We found sexual and interclade differences in scale counts and head shape. Sexes were dimorphic in the number of ventral and subcaudal scales, although sexual disparities in scale counts differed among clades. Moreover, discriminant and canonical analyses showed higher interclade differences in males than in females. The results obtained in the present study match those from molecular markers and confirm the population structure identified within Iberian C. austriaca. The observed sex discrepancy in this pattern suggests that males and females are subjected to different selective pressures along their Iberian distribution. In light of the above, C. austriaca may offer a useful model system in which to explore phylogeographical patterns in southern Europe, as well as the conflicts between processes driving morphological sexual divergence. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106 , 210–223.     

Neotropical Copestylum (Diptera,Syrphidae) breeding in Agavaceae and Cactaceae including seven new species

We studied 42 species of saprophagous, Neotropical Copestylum (Diptera, Syrphidae) reared from decaying Cactaceae and Agavaceae. Thirty‐three species were reared during fieldwork in Bolivia, Costa Rica, Ecuador, Mexico, Peru, and Trinidad from 1998–2007. Nine species came from museum and private collections. Seven were new species. We describe these new species and the third stage larva and/or puparium and breeding sites of 40 species. Not described are two apparent species related to Copestylum apicale (Loew, 1866) reared from Cactaceae. Resolution of their status was beyond the scope of this paper but reference is made to their distinctive larval morphology. Based on early stage characters all reared species can be placed in ten species groups, all but three of which have been recognized previously on the basis of adult characters. A high level of congruence was found between adult and larval characters in terms of these species groups. Eight of the groups appear to be related closely and may represent a monophyletic lineage within Copestylum that has diversified in xeric habitats. Early stage morphology varied within and amongst groups but two trends in functional morphology are recognizable. One trend is towards feeding in watery decay and the other towards feeding in firmer decay. The latter trend is characterized by species that scoop food and use grinding mills in their head skeletons to break it up. They also have armoured thoraces with varying arrangements of sclerotized spicules or stiffened setae for gripping and protection during tunnelling, a short anal segment, and a short posterior breathing tube for protecting the openings. The former trend is characterized by species with opposite and contrasting features. They filter food and have well‐developed pre‐oral setal filters but they lack grinding mills or only have poorly developed grinding mills. They have reduced thoracic armature, elongate anal segments, and posterior breathing tubes which facilitates simultaneous feeding and respiration. Comparison with 23 Copestylum species reared from bromeliads (Bromeliaceae) suggests a common pattern of diversification in that species groups with the largest body sizes are more specialized.     

Seasonal changes in a cactus‐hoverfly (Diptera: Syrphidae) network

1. We analysed a cacti‐syrphid community focusing on the exploitation of decaying cacti resources by the flies, i.e. if exploitation exhibited a nested topology as a structural pattern, or whether it was temporally random. If availability of cactus resources was predictable during the rainy season, it would then be exploited by a more structured community, or as resource availability would be unpredictable during the dry season, we should expect it to be exploited by a random community. 2. We registered 12 Copestylum species (9 in dry and 11 in rainy season). Four cactus species were recorded per season, three were shared between seasons. 3. The community of Copestylum larvae in the rainy season was not randomly assembled but highly nested, revealing a highly structured pattern of resource use. It exhibited a random organization for the dry season. The high nestedness value obtained for the rainy season suggests that factors along with competition must play a major role in determining community structure. 4. Succession in the cacti‐syrphid community mediated by microorganisms involved in necrosis is an important factor structuring nested subsets. The studied networks were small, which may limit the power of the analysis, and strong conclusions could also be limited.     

Selection of low investment in sex in a cyclically parthenogenetic rotifer

Cyclical parthenogens, which combine asexual and sexual reproduction, are good models for research into the ecological and population processes affecting the evolutionary maintenance of sex. Sex in cyclically parthenogenetic rotifers is necessary for diapausing egg production, which is essential to survive adverse conditions between planktonic growing seasons. However, within a planktonic season sexual reproduction prevents clonal proliferation. Hence, clones with a low propensity for sex should be selected, becoming dominant in the population as the growing season progresses. In this context, we studied the dynamics of the heritable variation in propensity for sexual reproduction among clones of a Brachionus plicatilis rotifer population in a temporary Mediterranean pond during the period the species occurred in plankton. Clonal isolates displayed high heritable variation in their propensity for sex. Moreover, the frequency of clones with low propensity for sex increased during the growing season, which supports the hypothesized short‐term selection for low investment in sex within a growing season. These results demonstrate (1) the inherent instability of the cyclical parthenogenetic life cycle, (2) the cost of sexual reproduction in cyclical parthenogens where sex produces diapausing eggs and (3) the role of the association between sexual reproduction and diapause in maintaining sex in these cyclical parthenogens.     

A NEW TEMNOSPONDYL FROM THE PERMO-TRIASSIC BUENA VISTA FORMATION OF URUGUAY

Abstract:  A partial skull recovered from conglomerates of the Permo-Triassic Buena Vista Formation in Uruguay belongs to a new species, Uruyiella liminea gen. et sp. nov. This species is characterized by a broadly triangular skull with laterally projecting posterior corners, rhytidosteid-like dermal sculpturing, and orbits positioned close to the skull margin. Uruyiella liminea is distinguished from other temnospondyls by a combination of primitive and derived character states, such as the anterior extent of the palatine ramus of the pterygoid, which excludes the ectopterygoid and most of the palatine from the lateral border of the interpterygoid vacuity, and the absence of both tabular horns and otic notches. A phylogenetic analysis places Uruyiella and the enigmatic Early Triassic Laidleria in a clade to which we attach the family name Laidleriidae. The Plagiosauridae and the Laidleriidae form a clade at the base of Dvinosauria, which is the sister group of a clade that includes Stereospondyli and Archegosauroidea. This result is unexpected because Laidleria and Plagiosauridae are nested deeply within Stereospondyli in most phylogenies. The sister-group relationship of Uruyiella and Laidleria suggests that a ghost lineage for the latter genus extends down into the earliest Triassic and perhaps even into the Late Permian, which in turn would suggest survivorship of the Laidleriidae through the Permo-Triassic extinction event.     

New chromosome counts in the genus Centaurea (Asteraceae) from Turkey

Twenty‐two chromosome counts are reported in 16 species, four subspecies and two varieties of the genus Centaurea. These are mostly Turkish local endemics of section Cheirolepis, a complicated group from the Eastern clade of the Jacea group. Twenty‐one reports are new. Prevalence of the basic chromosome number x = 9 among the eastern sections of the Jacea group is confirmed. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 280–286.