Degenerative encephalopathy in a coastal mountain kingsnake (Lampropeltis zonata multifasciata) due to adenoviral-like infection

In March 2000, an approximately 30-yr-old, male coastal mountain kingsnake (Lampropeltis zonata multifasciata) presented with disequilibrium and unresponsiveness to stimuli that ultimately lead to euthanasia. Histologically, there were foci of gliosis primarily within the caudal cerebrum, brainstem, and cervical spinal cord. Several glial cells and endothelial cells contained magenta, intranuclear inclusion bodies. Electron microscopy of the inclusions revealed paracrystalline arrays of 79-82 nm, viral-like particles. DNA in situ hybridization of sections of formalin-fixed brain using a mixture of two digoxigenin-end-labeled, adenovirus specific, oligonucleotide probes at low and high stringency was positive for adenovirus.     

Multilocus phylogeographic assessment of the California Mountain Kingsnake (Lampropeltis zonata) suggests alternative patterns of diversification for the California Floristic Province

Phylogeographic inference can determine the timing of population divergence, historical demographic processes, patterns of migration, and when extended to multiple species, the history of communities. Single‐locus analyses can mislead interpretations of the evolutionary history of taxa and comparative analyses. It is therefore important to revisit previous single‐locus phylogeographic studies, particularly those that have been used to propose general patterns for regional biotas and the processes responsible for generating inferred patterns. Here, we employ a multilocus statistical approach to re‐examine the phylogeography of Lampropeltis zonata. Using nonparametic and Bayesian species delimitation, we determined that there are two well‐supported species within L. zonata. Ecological niche modelling supports the delimitation of these taxa, suggesting that the two species inhabit distinct climatic environments. Gene flow between the two taxa is low and appears to occur unidirectionally. Further, our data suggest that gene flow was mediated by females, a rare pattern in snakes. In contrast to previous analyses, we determined that the divergence between the two lineages occurred in the late Pliocene (c. 2.07 Ma). Spatially and temporally, the divergence of these lineages is associated with the inundation of central California by the Monterey Bay. The effective population sizes of the two species appear to have been unaffected by Pleistocene glaciation. Our increased sampling of loci for L. zonata, combined with previously published multilocus analyses of other sympatric species, suggests that previous conclusions reached by comparative phylogeographic studies conducted within the California Floristic Province should be reassessed.     

How snakes eat snakes: the biomechanical challenges of ophiophagy for the California kingsnake, Lampropeltis getula californiae (Serpentes: Colubridae)

In this study we investigated how ophiophagous snakes are able to ingest prey snakes that equal or exceed their own length. We used X-ray video, standard video, dissection, and still X-rays to document the process of ophiophagy in kingsnakes (Lampropeltis getula) feeding on corn snakes (Elaphe guttata). Most kingsnakes readily accepted the prey snakes, subdued them by constriction, and swallowed them head first. In agreement with previous observations of ophiophagy, we found that the predator snake forces the vertebral column of the prey snake to bend into waves. These waves shorten the prey's body axis and allow it to fit inside the gastrointestinal (GI) tract and body cavity of the predator. Dissection of a kingsnake immediately following ingestion revealed extensive longitudinal stretching of the anterior portion of the GI tract (oesophagus and stomach), and no visible incursion of the prey into the intestine. X-ray video of ingestion showed that the primary mechanism of prey transport was the pterygoid walk, with some contribution from concertina-like compression and extension cycles of the predator's vertebral column in two out of three observations. Complete digestion was observed in only one individual, as others regurgitated before digestion was finished. X-ray stills taken every 4 days following ingestion revealed that the corn snakes were about half digested within the first 4 days, and digestion was complete within 15 days.     

Ultrastructure of the fetal membranes of the oviparous kingsnake,Lampropeltis getula (Colubridae) as revealed by scanning electron microscopy

In reptilian sauropsids, fetal (extraembryonic) membranes that line the eggshell sustain developing embryos by providing for gas exchange and uptake of water and eggshell calcium. However, a scarcity of morphological studies hinders an understanding of functional specializations and their evolution. In kingsnakes (Lampropeltis getula), scanning electron microscopy reveals two major fetal membranes: the chorioallantois and yolk sac omphalopleure. In early development, the chorioallantois contains tall chorionic epithelial cells, avascular connective tissue, and enlarged allantoic epithelial cells. During its maturation, the chorionic and allantoic epithelia thin dramatically and become underlain by a rich network of allantoic capillaries, yielding a membrane ideally suited for respiratory gas exchange. Yolk sac development initially is like that of typical lizards and snakes, forming an avascular omphalopleure, isolated yolk mass (IYM), and yolk cleft. However, unlike the situation in most squamates studied, the omphalopleure becomes transformed into a “secondary chorioallantois” via three asynchronous events: flattening of the epithelium, regression of the IYM, and vascularization by the allantois. Progressive expansion of chorioallantois parallels growing embryonic needs for gas exchange. In early through mid‐development, external surfaces of both the chorionic and omphalopleure epithelium show an abundance of irregular surface protrusions that possibly increase surface area for water absorption. We postulate that the hypertrophied allantoic epithelial cells produce allantoic fluid, a viscous substance that facilitates water uptake and storage. Our findings are consistent with a previous study on the corn snake Pantherophis guttatus, but include new observations and novel functional hypotheses relevant to a reconstruction of basal squamate patterns. J. Morphol. 276:1467–1481, 2015. © 2015 Wiley Periodicals, Inc.     

Molecular phylogeography of common garter snakes (Thamnophis sirtalis) in western North America: implications for regional historical forces

Complete ND2 and partial ND4 and cytochrome b mitochondrial DNA (mtDNA) sequences were analysed to evaluate the phylogeographic patterns of common garter snakes (Thamnophis sirtalis) in western North America. This species is widely distributed throughout North America, and exhibits extensive phenotypic variation in the westernmost part of its range. The overall phylogeographic pattern based on mtDNA sequences is concordant with results from studies of other species in this region, implicating historical vicariant processes during the Pleistocene and indicating bottleneck effects of recent dispersal into postglacial habitat. Indeed, the topology is statistically consistent with the hypothesis of both southern (Great Basin and California) and northern (Haida Gwaii) refugia. Specifically, we identified genetic breaks among three major clades: Northwest Coastal populations, Intermountain populations, and all California populations. The California clade contained the only other well-supported branching patterns detected; relationships among populations within the two northern clades were indistinguishable. These molecular splits contrast sharply with all prior geographical analyses of phenotypic variation in T. sirtalis in this region. Our results suggest that the extensive phenotypic variation in western T. sirtalis has been shaped more by local evolutionary forces than by shared common ancestry. Consequently, we consider all morphologically based subspecies designations of T. sirtalis in this region invalid because they do not reflect reciprocal monophyly of the mtDNA sequences.     

Mitochondrial DNA sequence variation and phylogeography of the scarlet kingsnake (Lampropeltis elapsoides)

BACKGROUND AND AIMS. With the goal of assessing population structure and geographic distribution of haplotype lineages among Lampropeltis elapsoides, we sequenced the ND4 mitochondrial DNA locus from 96 specimens of this snake across its area of distribution. MATERIALS AND METHODS. We relied heavily on formalin-fixed museum specimens to accomplish this analysis. RESULTS. The sequence alignment consisted of 491 bp of the selected gene, with 28% missing data. A simulation used to assess the effect of missing data on population genetic and phylogenetic resolution indicated increased character conflict, but with minimal loss of phylogenetic structure. CONCLUSION. This limited dataset suggests that L. elapsoides constitutes a largely unstructured population, with both widespread haplotypes and large number of private haplotypes, a moderate level of nucleotide diversity, and a low, but significant, degree of north-south population differentiation. Haplotype structure and frequency, nucleotide frequency, and values for Tajima's D and Fu's F(S) indicate a recent range or population expansion following a historic bottleneck.     

Comparative phylogeography of woodland reptiles in California: repeated patterns of cladogenesis and population expansion

The ultimate goal of comparative phylogeographical analyses is to infer processes of diversification from contemporary geographical patterns of genetic diversity. When such studies are employed across diverse groups in an array of communities, it may be difficult to discover common evolutionary and ecological processes associated with diversification. In order to identify taxa that have responded in a similar fashion to historical events, we conducted comparative phylogeographical analyses on a phylogenetically and ecologically limited set of taxa. Here, we focus on a group of squamate reptiles (snakes and lizards) that share similar ecological requirements and generally occupy the same communities in the western USA. At a gross level, deep genetic division in Contia tenuis, Diadophis punctatus, Elgaria multicarinata, the Charina bottae complex, and Lampropeltis zonata are often concordant in the Transverse Ranges, the Monterey Bay and Sacramento-San Joaquin Delta region, and the southern Sierra Nevada in California. Molecular clock estimates suggest that major phyletic breaks within many of these taxa roughly coincide temporally, and may correspond to important geological events. Furthermore, significant congruence between the phylogeographies of E. multicarinata and L. zonata suggests that the succession of vicariance and dispersal events in these species progressed in concert. Such congruence suggests that E. multicarinata and L. zonata have occupied the same communities through time. However, across our entire multi-taxon data set, the sequence of branching events rarely match between sympatric taxa, indicating the importance of subtle differences in life history features as well as random processes in creating unique genetic patterns. Lastly, coalescent and noncoalescent estimates of population expansion suggest that populations in the more southerly distributed clades of C. tenuis, D. punctatus, E. multicarinata, and L. zonata have been stable, while populations in more northerly clades appear to have recently expanded. This concerted demographic response is consistent with palaeontological data and previous phylogeographical work that suggests that woodland habitat has become more restricted in southern California, but more widespread in the North during Holocene warming. Future phylogeographical work focusing on allied and ecologically associated taxa may add insight into the ecological and evolutionary processes that yield current patterns of genetic diversity.     

Factors affecting the efficacy of trapping system to the peach fruit fly (PFF) males,Bactrocera zonata (Saunders) (Diptera: Tephritidae)

This study was conducted in Arab-Elmadabegh region located at the Northern West part of Assiut city at the border with the Western Desert. Four types of traps; Bottle trap, Glass McPhail trap, Plastic McPhail trap, and Abdel-Kawi trap baited with different doses of methyl eugenol (ME) were used. Obtained results indicated that Abdel-Kawi trap charged with 0.5?ml ME, it was the most effective trapping system. ME seemed to be with highly attracting effect, but most of the attracted males were found on the outside surface of the trap and on the branches surround the trap. Under these conditions, the females/males ration became 1:171. Thus, the believing tactic that fruit flies populations will decline due to the lack of males in the population available to females for mating seemed to be an erroneous believing. Results proved that PFF males had the highest activity at the dawn period between 5 and 7am. We strongly recommend using the trapping system consists of Abdel-Kawi trap charged with 0.5?ml ME only at dawn period (The first appearance of light in the morning followed by sunrise).     

黄道蚜蝇螺原体的分离及其基本生物学特性

摘要：【目的】调查我国部分昆虫螺原体的存在情况,收集我国的昆虫螺原体资源,并研究它们的基本生物学特性,初步确定其分类地位。【方法】螺原体分离、培养方法,应用暗视野显微镜和透射电子显微镜观察螺原体形态,根据16S rDNA构建系统发育树研究螺原体分离菌株可能的分类地位。【结果】从黄道蚜蝇昆虫体内分离到螺原体YY0801,并对其进行了形态学、基本生物学及分子生物学特性研究。分离菌株在R2液体培养基中生长良好,能通过孔径为0.22 μm、0.45 μm的微孔滤膜;在R2固体培养基上呈颗粒状菌落;在对数期呈典型的螺旋状;能利用葡萄糖、D-果糖作为碳源;能强烈代谢精氨酸;不能利用尿素,在含氨苄青霉素钠(2000 U/mL)的R2液体培养基中生长良好。根据16S rDNA构建的系统发育树显示,分离菌株YY0801与血清组Ⅰ的Spiroplasma melliferum 聚类较近。【结论】首次在国内从食蚜蝇科中的黄道蚜蝇（Phytomia zonata）分离到螺原体,分离菌株YY0801可能是Spiroplasma melliferum,但其确切的分类地位需要进行血清学进一步分析。     

Phylogeography of the Northern Alligator Lizard (Squamata,Anguidae): Hidden diversity in a western endemic

Western North America includes the California Floristic Province and the Pacific Northwest, biologically diverse regions highlighted by a complex topography, geology, climate and history. A number of animals span these regions and show distinctive patterns of dispersal, vicariance and lineage diversification. Examining phylogeographic patterns in the fauna of this area aids in our understanding of the forces that have contributed to the generation and maintenance of regional biodiversity. Here, we investigate the biogeography and population structure of the Northern Alligator Lizard (Elgaria coerulea), a wide‐ranging anguid endemic to western North America. We sequenced two mtDNA fragments (ND2 and ND4) for 181 individuals across the range of the species and analysed these data with phylogenetic approaches to infer population and biogeographic history, and date major divergences within the taxon. We further used Bayesian clustering methods to assess major patterns of population structure and performed ecological niche modelling (ENM) to aid in our interpretation of geographic structure and diversification of E. coerulea lineages. Our phylogeographic examination of E. coerulea uncovered surprising diversity and structure, recovering 10 major lineages, each with substantial geographic substructure. While some divergences within the species are relatively old (Pliocene, 5.3–2.6 mya), most intraspecific variation appears to be of more recent origin (Pleistocene, 2.6 mya‐11,700 ya). Current diversity appears to have arisen in the Sierra Nevada Mountains and spread west and north since the Pliocene. Finally, our ENMs suggest that much of the Coast Ranges in California provided ideal habitat during the Last Glacial Maxima (LGM) that has since contracted dramatically and shifted northwards, whereas significant portions of the Sierra Nevada were unsuitable during the LGM and have since become more suitable. Interestingly, E. coerulea shares a number of genetic boundaries with other sympatric taxa, suggesting common historical events and geomorphological features have shaped the biota of this region.     

Phylogeography of the tidewater goby, Eucyclogobius newberryi (Teleostei, Gobiidae), in coastal California

The tidewater goby, Eucyclogobius newberryi, inhabits discrete, seasonally closed estuaries and lagoons along approximately 1500 km of California coastline. This species is euryhaline but has no explicit marine stage, yet population extirpation and recolonization data suggest tidewater gobies disperse intermittently via the sea. Analyses of mitochondrial control region and cytochrome b sequences demonstrate a deep evolutionary bifurcation in the vicinity of Los Angeles that separates southern California populations from all more northerly populations. Shallower phylogeographic breaks, in the vicinities of Seacliff, Point Buchon, Big Sur, and Point Arena segregate the northerly populations into five groups in three geographic clusters: the Point Conception and Ventura groups between Los Angeles and Point Buchon, a lone Estero Bay group from central California, and San Francisco and Cape Mendocino groups from northern California. The phylogenetic relationships between and patterns of molecular diversity within the six groups are consistent with repeated, and sometimes rapid, northward and southward range expansions out of central California caused by Quaternary climate change. Plio-Pleistocene tectonism, Quaternary coastal geography and hydrography, and historical human activities probably also influenced the modern geographic and genetic structure of E. newberryi. The phylogeography of E. newberryi is concordant with phylogeographic patterns in several other coastal California taxa, suggesting common extrinsic factors have had similar effects on different species. However, there is no evidence of a phylogeographic break coincident with a biogeographic boundary at Point Conception.     

Phylogeography of the mountain chickadee (Poecile gambeli): diversification, introgression, and expansion in response to Quaternary climate change

Since the late 1990s, molecular techniques have fuelled debate about the role of Pleistocene glacial cycles in structuring contemporary avian diversity in North America. The debate is still heated; however, there is widespread agreement that the Pleistocene glacial cycles forced the repeated contraction, fragmentation, and expansion of the North American biota. These demographic processes should leave genetic 'footprints' in modern descendants, suggesting that detailed population genetic studies of contemporary species provide the key to elucidating the impact of the late Quaternary (late Pleistocene-Holocene). We present an analysis of mitochondrial DNA (mtDNA) variation in the mountain chickadee (Poecile gambeli) in an attempt to examine the genetic evidence of the impact of the late Quaternary glacial cycles. Phylogenetic analyses reveal two strongly supported clades of P. gambeli: an Eastern Clade (Rocky Mountains and Great Basin) and a Western Clade (Sierra Nevada and Cascades). Post-glacial introgression is apparent between these two clades in the Mono Lake region of Central California. Within the Eastern Clade there is evidence of isolation-by-distance in the Rocky Mountain populations, and of limited gene flow into and around the Great Basin. Coalescent analysis of genetic variation in the Western Clade indicates that northern (Sierra Nevada/Cascades) and southern (Transverse/Peninsular Ranges) populations have been isolated and evolving independently for nearly 60,000 years.     

Phylogeography, hybridization and Pleistocene refugia of the kob antelope (Kobus kob)

Mitochondrial DNA control region sequences and seven microsatellites were used to estimate the genetic structuring, evolutionary history and historic migration patterns of the kob antelope (Kobus kob). Ten populations were analysed, representing the three recognized K. kob subspecies: K. k. kob in west Africa, K. k. thomasi in Uganda and K. k. leucotis in Sudan and Ethiopia. Despite being classified as K. k. thomasi and being phenotypically identical to the kob in Queen Elizabeth National Park (NP), the Murchison Falls population in Uganda showed high genetic similarity with the phenotypically distinct K. k. leucotis populations in Sudan and Ethiopia. This was regardless of marker type. Pairwise comparisons and genetic distances between populations grouped Murchison with K. k. leucotis, as did the Bayesian analysis, which failed to find any genetic structuring within the group. We propose that the divergent phenotype and life-history adaptations of K. k. leucotis reflect the isolation of kob populations in refugia in west and east Africa during the Pleistocene. Subsequent dispersal has led to secondary contact and hybridization in northern Uganda between lineages, which was supported by high levels of genetic diversity in Murchison. The reduced variability observed in Queen Elizabeth NP reflects a small founder population from west Africa and in part the decimation of Uganda's wildlife during the country's political turmoil in the 1970s. Due to similarities in phenotype and ecology, and the joint evolutionary history of their mtDNA sequences, the taxonomic status of K. k. kob and K. k. thomasi as separate subspecies is called into question.     

Geographic variation in the garter snakes (Thamnophis sirtalis) of the north-central United States, a multivariate study

A study of geographic variation in three subspecies of garter snake (Thamnophis sirtalis sirtalis, T. s. parietalis, T. s. semifasciata) in the north-central United States indicates patterns of irregular non-clinal microgeographic variation for 40 characters of coloration, scalation, and internal anatomy. Multivariate analyses show that geographically close populations are not always phenetically close and that overall differentiation of the phenotype is greater in males than in females. Univariate and multivariate studies indicate that T. s. semifasciata Cope 1892, restricted to the Chicago area, is not uniform within its small range and that it has no constant distinguishing features: it is shown to be taxonomically invalid.     

Multilocus genealogies reveal multiple cryptic species and biogeographical complexity in the California turret spider Antrodiaetus riversi (Mygalomorphae, Antrodiaetidae)

Antrodiaetus riversi (Araneae, Antrodiaetidae) is a dispersal-limited, habitat specialized mygalomorph spider species endemic to mesic woodlands of northern and central California. This species occupies a disjunct distribution, with populations in the Sierra Nevada and Coast Ranges, separated by the inhospitable Central Valley. Previous studies of morphological and allozyme variation have suggested that these populations may constitute cryptic species. We investigated the phylogeography of A. riversi using both nuclear and mitochondrial DNA sequences, collected for a comprehensive population sample. These data reveal the presence of at least five species in the A. riversi complex - these species are deeply diverged, and genealogically exclusive in both nuclear and mitochondrial genomes. Each of these species is characterized by extreme population subdivision and deep phylogeographical structuring, consistent with minimal gene flow across the dissected Californian landscape. Three species are restricted to the Coast Ranges, one to high altitudes of the central Sierran Nevada, and one species is found in both ranges. These species have allopatric distributions, although species parapatry is hypothesized to occur in several areas. Species diversification appears to have pulsed in the Late Miocene/Early Pliocene, a timing consistent with biogeographical reconstructions for many Californian taxa, and a time of turbulent geological activity in the region.     

Phylogeography of a stream-dwelling frog (Pseudacris cadaverina) in southern California

Recent phylogeographic studies of animal taxa in California have revealed common geographic patterns of evolutionary divergence and genetic diversity that are generally attributable to landscape influences. However, there remains a paucity of knowledge on the evolution of freshwater taxa in southern California. Here, we investigate phylogeographic patterns in a stream-dwelling frog (Pseudacris cadaverina). Two hundred and twenty-one individuals were collected from 46 populations across the species’ range in southern California. Using 1100 bp of sequence data from cytochrome b and tRNA-Glu, we conducted phylogenetic analyses, analysis of molecular variance, and nested clade phylogeographic analysis to gain insight into the factors contributing to the distribution of genetic diversity in P. cadaverina. We tested for evidence of two putative phylogeographic breaks and tested hypotheses that genetic diversity in this species is partitioned into (1) major watersheds, (2) mountain ranges, and (3) coastal and desert regions. Our results suggest that the eastern Transverse Ranges are the center of origin for extant P. cadaverina lineages and that the observed genetic structure in this species was established during the Pleistocene Epoch. There is strong support for three major haplotype groups and a Transverse Range break in P. cadaverina that is concordant with breaks found in numerous other taxa. The distribution of genetic diversity in P. cadaverina is due in large part to the separation of populations into different major watersheds and mountain ranges. Gene flow appears to be generally limited among disjunct populations throughout the region and some desert populations have been isolated by historical habitat fragmentation.     

Morphology and taxonomic status of the grass snake, Natrix natrix (L.) (Reptilia, Squamata, Colubridae) on the island of Gotland, Sweden

The isolated population of grass snakes, Natrix natrix (L.), on the island of Gotland in die Baltic Sea is described and illustrated. Comparisons are made with the surrounding mainland grass snake. On the basis of morphological and ecological divergence, the conclusion is drawn that the Gotland population represents a new subspecies.