Observations on the morphology, systematics, and biogeography of the genus Truttaedacnitis (Nematoda:Cucullanidae)

All species of Truttaedacnitis Petter, 1974, were examined for a phylogenetic analysis. Morphological studies showed that Truttaedacnitis truttae (Fabricius, 1794) from North America possessed a reduced button-shaped or nipple-shaped caudal mucron that is in contrast to the sharp spike-shaped mucron commonly reported in Eurasian specimens. Histological studies showed that the excretory pore in Truttaedacnitis sphaerocephala (Rudolphi, 1809) was situated near the level of the pseudobuccal capsule between the 2 parts of the ventral cephalic ridge. Cucullanus heterodonti Johnston and Mawson, 1943 is transferred to Truttaedacnitis based on the presence of prominent cephalic plates separated by sutures. An hypothesis regarding interrelationships among Truttaedacnitis spp. was developed using phylogenetic systematics. The anterior excretory pore is a synapomorphy supporting the monophyly of Truttaedacnitis clitellarius (Ward and Magath, 1917) and T. sphaerocephala parasitizing sturgeons. The arrangement of cephalic plates indicates that Truttaedacnitis pybusae Anderson, 1992 and T. truttae may form a monophyletic group and further supports the monophyly of T. clitellarius and T. sphaerocephala. Using unordered character states of different cephalic plates produced a cladogram that suggested that species in holarctic/circumboreal families (Acipenseridae, Salmonidae, Petromyzontidae) may be monophyletic. The systematics and biogeography of the various species of Truttaedacnitis and their host specificity indicate that associations in this parasite genus are very ancient and of a relictual nature, determined largely by past continental and oceanic configurations, and a combination of vicariance and dispersal.     

A proposal for a new (third) genus within the family Adenoviridae

This article presents a proposal for the establishment of a new adenovirus genus to accommodate certain bovine, ovine, and avian adenoviruses with special characteristics which differentiate them from members of the existing genera Mastadenovirus and Aviadenovirus. This proposal has been developed from earlier versions with advice from the Adenovirus Study Group of the International Committee on Taxonomy of Viruses (ICTV).     

Cross-species amplification of soybean (Glycine max) simple sequence repeats (SSRs) within the genus and other legume genera: implications for the transferability of SSRs in plants

We investigated the transferability of 31 soybean (Glycine max) simple sequence repeat (SSR) loci to wild congeners and to other legume genera. Up to 65% of the soybean primer pairs amplified SSRs within Glycine, but frequently, the SSRs were short and interrupted compared with those of soybeans. Nevertheless, 85% of the loci were polymorphic within G. clandestina. Cross-species amplification outside of the genus was much lower (3%-13%), with polymorphism restricted to one primer pair, AG81. AG81 amplified loci in Glycine, Kennedia, and Vigna (Phaseoleae), Vicia (Vicieae), Trifolium (Trifolieae), and Lupinus (Genisteae) within the Papilionoideae, and in Albizia within the Mimosoideae. The primer conservation at AG81 may be explained by its apparent proximity to the seryl-tRNA synthetase gene. Interspecific differences in allele size at AG81 loci reflected repeat length variation within the SSR region and indels in the flanking region. Alleles of identical size with different underlying sequences (size homoplasy) were observed. Our findings and the emerging patterns in other plant studies suggest that in contrast to animals, successful cross-species amplification of SSRs in plants is largely restricted to congeners or closely related genera. Because mutations in both the SSR region and the flanking region contribute to variation in allele size among species, knowledge of DNA sequence is essential before SSR loci can be meaningfully used to address applied and evolutionary questions.     

DNA, morphology and fossils: phylogeny and evolutionary rates of the gastropod genus Littorina

Using data from the direct sequencing of fragments of three mitochondrial genes (12S and 16S ribosomal RNA, and cytochrome-b; total length 1469 b.p.) we have reconstructed a gene phylogeny for all 19 living species of the gastropod genus Littorina. Members of the closely related genera Nodilittorina, Littoraria and Mainwaringia have been used as outgroups, and it appears that Littorina is monophyletic. An earlier morphological phylogeny has been revised, and its topology found to be almost entirely consistent with that from the molecular data. The fossil record is sparse, but likewise consistent. A consensus tree is presented, showing clear resolution of basal and terminal branches, and a central unresolved polychotomy. We have used fossil evidence and geological events to estimate the ages of some clades, and thus to calculate average rates of molecular evolution, which in turn provide approximate dates for all branches of the molecular phylogeny. The central polychotomy may be explained by a burst of rapid speciation in the northwestern Pacific during the Middle Miocene, perhaps driven by climatic fluctuation. Our results support the hypothesis that the two clades of Littorina in the northern Atlantic originated from Pacific ancestors which took part in the Pliocene trans-Arctic migration of marine organisms.     

Morphological and morphometric study of crustacean parasites within the genus Lernaeocera

Two species of Lernaeocera are present in the southeastern North Sea. Lernaeocera lusci infects bib Trisopterus luscus, dragonet Callionymus lyra and sand goby Pomatoschistus minutas. L. minuta is a junior synonym of L. lusci. The second valid species, L. branchialis, infects whiting Merlangius merlangus. The two species can be morphologically separated by the antennary processes, which are present in L. lusci and absent in L. branchialis. Discriminant functions allow complete separation between L. lusci and L. branchialis. There is high intraspecific, host-dependent variability within L. lusci. Length of L. lusci is significantly influenced by host size, and body form is influenced by the site of attachment of L. lusci on at least one host (bib). It is suggested that L. lusci consists of 3 forms: f. lusci, f. minuta and f. lyra.     

The genus Myxidium (Protozoa: Myxosporida) in macrourid fishes

A physical model approach was used to investigate cholesterol gallstone dissolution kinetics in simulated bile. Critical experimental and theoretical investigations simulating in vivo conditions showed that, in the bile acid-lecithin solutions, there is a significant interfacial barrier for both cholesterol gallstone and cholesterol monohydrate pellet dissolution. In the present study, the rotating-disk dissolution method and the accompanying Levich theory were applied to assess the contributions of the diffusion convection mass transfer resistance and of the interfacial barrier to the overall kinetics. Cholesterol dissolution rates in bile acid solutions were about 2-20 times slower than diffusion-controlled rates depending upon the degree of agitation. As found in previous studies, these rates in the presence of sufficient concentrations of dissolution accelerators approached the theoretical diffusion-convection-controlled rates. To account for the much slower dissolution rates in bile acid-lecithin solutions, two possible kinetic interpretations were investigated. The first is based upon slow crystal-micellar solution interfacial kinetics, and the second is based upon a slow rate of cholesterol solubilization in the aqueous diffusion layer. For the latter, an analytical mathematical solution was obtained.     

Phylogenetic analysis of parthenogenesis-inducing Wolbachia in the genus Aphytis (Hymenoptera: Aphelinidae)

Well differentiated squamous cell carcinoma of the nasal septum developed in a 55-year old man with Wegener's granulomatosis. It is suggested that the malignancy was induced by immunosuppressive state from an increased and prolonged use of cyclophosphamide and corticosteroids. Although the efficacy of the therapeutic concept using cyclophosphamide and corticosteroids is well established, there have been some few reports that cyclophosphamide could be implicated in the genesis of malignancies. The pathophysiology of Wegener's granulomatosis should be better understood, and effective and less toxic alternative protocol should be established.     

Taxonomy of ticks of the genus Microtimyobia (Acariformes: Myobiidae: Radfordia) and their distribution on voles (Rodentia: Cricetidae: Arvicolinae)

A phylogenetic system of the subgenus Microtimyobia (Myobiidae: Radfordia) elaborated for the first time by means of the software HENNIG-86 is proposed. The subgenus Microtimyobia including three species groups, lemnina, hylandi and zibethicalis, was divided for a cladistic analysis into 6 operation units based mainly on a male genital shield structure. The analysis shows, that the zibethicalis group is a polyphyletic, while the hylandi and lemnina groups are monophyletic. Host-parasite associations of myobiid mite taxa with vole taxa (Arvicolinae) and some peculiarities of mite and host taxa distribution are analysed. The zibethicalis group is represented by two species, associated with the North American rodents of the genera Ondatra and Phenacomys respectively. The hylandi group are most widely distributed among Arvicolinae taxa, both in Eurasia and North America. However, R. hylandi occurs on those vole species of the genera Microtus and Pitymys, which are distributed only in central and southern parts of North America and represent descendants of the earlier migration wave of Microtus from the Eurasia. As far as R. hylandi is also found in the pleistocenus of the Yakutia, that means that its areal was wider than in recent period. The lemnina group lives on hosts of 2 subtribes of the tribe Arvicolini (Arvicolina and Clethrionomyina) and is restricted to Eurasian range, except R. lemnina. This species is also mainly distributed on Eurasian vole species, however it occurs on vole species distributed in Alaska and being decendants of the later wave of Microtus migration. As far as R. lemnina and R. hylandi are associated with representatives of different migration waves of Microtus from the Euroasia, it is suggested that mites of the hylandi group are the original myobiid fauna of the Microtus voles. The species of the lemnina group had apparently originated on voles of the subtribe Clethrionomyina and then migrated onto phylogenetically young hosts of the subtribe Arvicolina (Euroasian species of the Microtus and related genera), where they probably eliminated mites of the hylandi group from these hosts in Euroasia. The recent pattern of myobiid species distribution on vole species is a result of both a mite cospeciation with their hosts and a shift of hosts. Five new myobiid mite species are described and distinguished by characters as follows. R. (M.) abramovi sp. n. from Phodopus roborovskii (Cricetidae) is closely related to R. (M.) triton Fain et Lukoschus, 1977. In both sexes of the new species setae cxI 1, 2 are scale-shaped, while in R. (M.) triton these setae (cxI 1, 2) are hair-like. R. (M.) stekolnikovi sp. n. from Chionomys nivalis (type host) and Ch. gud is similar to R. (M.) lemnina (Koch, 1841). Females of new species have setae ra with 2 apical processes; female tritonymphs with long whip-like setae ic4. R. (M.) lemnina females have setae ra with 3 processes; female tritonymphs with short hair-like setae ic4. R. (M.) stenocrani sp. n. from Microtus gregalis is also closely related to R. (M.) lemnina. Females of the new species have setae ra with 2 processes; female tritonymphs with whip-like setae ic3. R. (M.) lemnina females have seate ra with 3 processes, female tritonymph with short hair-like setae ic3. R. (M.) synaptomysi sp. n. (ABSTRACT TRUNCATED)     

Phylogenetic relationships within the genus Equus and the evolution of alpha and theta globin genes

Sequences of the alpha1, alpha2 and theta globin genes from six equid species have been determined to investigate relationships within the genus Equus. Analyses using standard phylogenetic methods, or an approach designed to account for the effects of gene conversion between the alpha genes, gave broadly similar results and show that the horses diverged from the zebra/ass ancestor approximately 2.4 million years ago and that the zebra and ass species arose in a rapid radiation approximately 0.9 million years ago. These results from the alpha genes are corroborated by theta gene data and are in contrast to mitochondrial DNA studies of the phylogeny of this genus, which suggest a more gradual set of speciation events.     

Families of repeated DNA in the oomycete Phytophthora infestans and their distribution within the genus

Paclitaxel (Taxol) is a new class of anti-tumor agents which act by promoting the assembly and inhibiting the disassembly of microtubules. Single-agent studies have shown its significant activity for advanced cancers in various organs including ovary, lung, breast, and head and neck. Combination therapies with other anticancer agents have been extensively investigated in these cancers. Paclitaxel combined with cisplatin is now considered to be the standard treatment for advanced ovarian cancer. In other cancers, promising results have been obtained in several studies of paclitaxel-based chemotherapy. Major toxicities of paclitaxel-monotherapy are hypersensitivity reaction, neutropenia, and peripheral neuropathy. Combination of other cytotoxic agents sometimes leads to severer toxicities such as neurotoxicity with cisplatin and cardiotoxicity with anthracycline. Although further evaluation is needed, paclitaxel will be a main agent in the treatment of advanced solid tumors.     

Isozyme polymorphism of esterases in the genus Lanistes (Mollusca:Prosobranchiata) and genetic analysis of populations

Esterases from the digestive gland of the snails Lanistes carinatus and Lanistes bolteni collected from Egyptian governorates were extracted and analyzed using starch gel electrophoresis and five substrates. Twelve esterase bands were detected in both Lanistes species. The esterase bands were distributed in three main zones, which could be classified as acetylesterases, carboxylesterases, and cholinesterases. Depending on the substrates specificity, inhibition properties, and relative mobility of esterase bands, the three zones of esterase activity could be traced to eight genetic loci. Locality-specific loci were found. Inter- and intrapopulation variations are discussed. There is an absence of equilibria at all esterase loci in all populations studied, and a high proportion of genetic diversity in different esterase loci. The absence of interspecific variations proves that Lanistes snails in Egypt belong to one species.     

Postembryonic ontogeny of the spadefoot toad, Scaphiopus intermontanus (Anura: Pelobatidae): skeletal morphology

Postembryonic skeletal ontogeny of the pelobatid frog Scaphiopus intermontanus is described based on a developmental series of cleared-and-stained, whole-mount specimens. The focus is on laboratory-reared individuals fed a herbivorous diet as larvae. Although there is variation in the timing of ossification of individual skeletal elements relative to developmental stages based on external morphological criteia, the sequence of skeletal development generally is conservative. Compared with its close relative, S. bombifrons, ossifications that occur during prometamorphosis tend to be slightly delayed in S. intermontanus; however, cranial bones that ossify during late metamorphic climax in S. intermontanus are delayed until post-metamorphosis in S. bombifrons. The differences in timing between the two species are consistent, however, with differences observed between two developmental series of S. intermontanus raised at two different temperatures. Noteworthy features of skeletal development in S. intermontanus include: 1) presence of palatine ossifications that form from independent centers of ossification and soon fuse with the postnarial portion of the vomers to form the compound vomeropalatine bones; 2) compound sphenethmoid that may arise from four or more endochondral centers of ossification and one dorsal, dermal center of ossification; and 3) presence of transverse processes and vestigal prezygapophyses on the first postsacral vertebra. The morphology of the larval orbitohyoideus and interhyoideus muscles is compared. The record of skeletal ontogeny and muscle morphology presented herein for the herbivorous larval morph can serve as a baseline for comparisons with the ontogeny of the carnivorous larval morph of Scaphiopus.     

Recognition of the tick genus Anocentor Schulze, 1937 (Acari: Ixodidae) by numerical taxonomy

We report on an evaluation of the systematic position of the tick Anocentor nitens (Neumann), examining particularly whether Anocentor should be regarded as a subgenus of Dermacentor or as a separate genus. Twelve species of Ixodidae were analyzed phenetically by using 24 characters of adult ticks. A phenogram indicated 3 clusters, with Anocentor more closely related to Rhipicephalus than to Dermacentor. The results of this study endorse the validity of the monotypic genus Anocentor.     

The genus Hexidionis (Acari:Trombiculidae) with the description of a new species from Texas

Hexidionis garfieldi is described as new from specimens collected off a domestic cat. Felis silvestris f. catus Schreber, in Corpus Christi, TX. The genus Hexidionis Vercammen-Grandjean & Loomis, 1967, is rediagnosed and a key to the 11 included species given.     

Non-telomeric chromosome localization of (TTAGGG)n repeats in the genus Eulemur

Numerous dietary studies and several serum micronutrient studies have produced equivocal results on the relation of vitamins A and E to prostate cancer risk. To evaluate this association further, we conducted a nested case-control study in a cohort of 6860 Japanese-American men examined from 1971 to 1975. At the time of examination, a single blood specimen was obtained, and the serum was frozen. After a surveillance period of more than 20 years, 142 tissue-confirmed incident cases of prostate cancer were identified. Their stored sera and those of 142 matched controls were measured by high-performance liquid chromatography for the following: total carotenoids, lutein, zeaxanthin, beta-cryptoxanthin, lycopene, alpha-carotene, beta-carotene, total retinoids, retinol, total tocopherols, alpha-tocopherol, delta-tocopherol, and gamma-tocopherol. Odds ratios for prostate cancer, based on quartiles of serum micronutrient levels, were determined using conditional logistic regression analysis. The odds ratio for the highest quartiles were 1.8 (95% confidence interval, 0.9-3.9) for beta-cryptoxanthin, 1.6 (0.8-3.5) for beta-carotene, 0.8 (0.4-1.5) for retinol, and 0.7 (0.3-1.5) for gamma-tocopherol, but none of the differences was statistically significant. For the other micronutrients, the results were also unremarkable. The findings of this study indicate that none of the micronutrients is strongly associated with prostate cancer risk.     

Temporal segregation in coexisting spiny mice (genus Acomys): role of photoperiod and heterospecific odor

The distal long arm of chromosome 10 harbors genes of biomedical interest such as MXI1, a putative tumor suppressor gene, and those encoding the adrenergic receptors alpha2A (ADRA2A) and beta1 (ADRB1). As part of a physical and genetic study of this genomic region, we constructed a 1.5-Mb YAC contig mapping to 10q25 that contains MXI1 and ADRA2A as well as a number of STSs. Rare cutting restriction site analysis of overlapping YACs allowed fine mapping of these genes and markers along the contig and revealed the presence of four CpG islands. MXI1 and ADRA2A appear to be about 600 kb apart, whereas ADRB1 is separated from ADRA2A by a distance larger than previously reported.