Integumental lesions caused by ectoparasites in a wild population of the side-blotched lizard (Uta stansburiana)

Histopathological effects of ectoparasites on integument were examined for a wild population of the side-blotched lizard Uta stansburiana. These included the trombiculid Neotrombicula californica, the pterygosomatid mite Geckobiella texana; the macronyssid mite Ophionyssus natricis (Macronyssidae) and the ixodid tick Ixodes pacificus. A diffuse inflammatory response occurred at the site of chigger and tick attachment which consisted of histiocyte, heterophil, fibroblast and lymphocyte infiltration that often extended into the dermis. Granuloma formation also was noted. The most prevalent parasite was N. californica which frequently occurred in large aggregations above the eyelids. Ectoparasites were most abundant from February through April.     

The microanatomy of the compound eye of Munida irrasa (Decapoda: Galatheidae)

The compound eye of Munida irrasa differs in several respects from the typical decapod eye. The proximal pigment is found only in retinula cells. The eccentric cell is extremely large and expanded to fill the interstices of the crystalline tract area; thus, a typical "clear-zone" is absent. Six retinula cells course distally to screen two sides of the crystalline cone. There are approximately 12,500 ommatidia in each compound eye. There are several similarities to the typical decapod eye. Each ommatidium is composed of a typical cornea, corneagenous cells, crystalline cone cells, crystalline cone, crystalline cone tract and eight retinula cells. Distal pigment cells are present and surround the crystalline cone. The distal processes of the retinula cells also contain pigment. The retinula cell processes penetrate the basement membrane as fascicles composed of processes from adjacent retinulae.     

Immunohistochemistry in the evaluation of neovascularization in tumor xenografts

Angiogenesis, or neovascularization, is known to play an important role in the neoplastic progression leading to metastasis. CD31 or Factor VIII-related antigen (F VIII RAg) immunohistochemistry is widely used in experimental studies for quantifying tumor neovascularization in immunocompromised animal models implanted with transformed human cell lines. Quantification, however, can be affected by variations in the methodology used to measure vascularization including antibody selection, antigen retrieval (AR) pretreatment, and evaluation techniques. To examine this further, we investigated the microvessel density (MVD) and the intensity of microvascular staining among five different human tumor xenografts and a mouse syngeneic tumor using anti-CD31 and F VIII RAg immunohistochemical staining. Different AR methods also were evaluated. Maximal retrieval of CD31 was achieved using 0.5 M Tris (pH 10) buffer, while maximum retrieval of F VIII RAg was achieved using 0.05% pepsin treatment of tissue sections. For each optimized retrieval condition, anti-CD31 highlighted small vessels better than F VIII RAg. Furthermore, the MVD of CD31 was significantly greater than that of F VIII RAg decorated vessels (p<0.001). The choice of antibody and AR method has a significant affect on immunohistochemical findings when studying angiogenesis. One also must use caution when comparing studies in the literature that use different techniques and reagents.     

Atractis marquezi n. sp. (Nematoda: Atractidae) and a revision of Atractis dujardin, 1845, sensu Baker, 1987

Atractis marquezi n. sp. from the large intestine of the tortoise Geochelone nigrita is described and illustrated. Atractis Dujardin, 1845, sensu Baker, 1987, is revised to contain only those atractids having a lagonoid spicule. The remaining species of Atractis sensu Baker, 1987, are assigned to Cyrtosomum, Pseudatractis, and Klossinemella. A. marquezi represents the 12th species to be assigned to this genus and is distinguished from other Neotropical species by the distribution pattern of caudal papillae of the male: 2 pairs precloacal, 2 pairs adcloacal, and 6 pairs postcloacal.     

Spauligodon loboi n. sp. (Nematoda: Pharyngodonidae) parasite of Liolaemus spp. (Iguania: Liolaemidae) from northwestern Argentina

Three-hundred and forty-nine specimens of Spauligodon loboi n. sp. (Nematoda, Pharyngodonidae) were found in the large intestines of 55 of 225 adult specimens representing 5 species of Liolaemus collected in 11 localities of northwestern Argentina. Prevalence of infection was 24% (mean intensity = 6.3 +/- 3.4, range = 2-28). Spauligodon loboi n. sp. differs from other neotropical species in that the filamentous portion of the tail of males is spiny, whereas that of females is smooth. A key to the species of Spauligodon in the Neotropical Realm is provided.     

Helminths of two anuran species, Atelopus spurrelli (Bufonidae) and Dendrobates histrionicus (Dendrobatidae), from Colombia, South America

Two species of anurans from Colombia, South America, Atelopus spurrelli and Dendrobates histrionicus, were examined for helminths. A. spurrelli was found to harbor three species of Nematoda, adults of Cosmocerca podicipinus and larvae of Physocephalus sp. and Porrocaecum sp. D. histrionicus was found to harbor, in addition to C. podicipinus, Physocephalus sp. and Porrocaecum sp. and cystacanths of three species of Acanthocephala: Centrorhynchus sp., Onicola sp. and Polymorphus sp. A. spurrelli and D. histrionicus represent new host records for these helminths.     

Thubunaea dactyluris Sensu Fabio and Rolas, a synonym of Physalopteroides venancioi (Spirurida, Physalopteridae)

Specimens of Thubunaea dactyluris Karve, 1938 sensu Fabio and Rolas, 1974 from the lizard Ameiva ameiva of Brazil and types of Physalopteroides venancioi (Lent, Freitas, and Proen?a, 1946) from the toad Bufo paracnemis of Paraguay were re-examined. The male caudal papillae and the tooth arrangement demonstrated that these specimens were conspecific and are all assigned to P. venancioi. The occurrence of Physalopteroides dactyluris (Karve, 1938), a nematode parasite of lizards of India and Turkmenistan, is invalidated for Brazil.     

Dietary input of microbes and host genetic variation shape among-population differences in stickleback gut microbiota

To explain differences in gut microbial communities we must determine how processes regulating microbial community assembly (colonization, persistence) differ among hosts and affect microbiota composition. We surveyed the gut microbiota of threespine stickleback (Gasterosteus aculeatus) from 10 geographically clustered populations and sequenced environmental samples to track potential colonizing microbes and quantify the effects of host environment and genotype. Gut microbiota composition and diversity varied among populations. These among-population differences were associated with multiple covarying ecological variables: habitat type (lake, stream, estuary), lake geomorphology and food- (but not water-) associated microbiota. Fish genotype also covaried with gut microbiota composition; more genetically divergent populations exhibited more divergent gut microbiota. Our results suggest that population level differences in stickleback gut microbiota may depend more on internal sorting processes (host genotype) than on colonization processes (transient environmental effects).     

Caspase-mediated cleavage of the exosome subunit PM/Scl-75 during apoptosis

Recent studies have implicated the dying cell as a potential reservoir of modified autoantigens that might initiate and drive systemic autoimmunity in susceptible hosts. A number of subunits of the exosome, a complex of 3'→5' exoribonucleases that functions in a variety of cellular processes, are recognized by the so-called anti-PM/Scl autoantibodies, found predominantly in patients suffering from an overlap syndrome of myositis and scleroderma. Here we show that one of these subunits, PM/Scl-75, is cleaved during apoptosis. PM/Scl-75 cleavage is inhibited by several different caspase inhibitors. The analysis of PM/Scl-75 cleavage by recombinant caspase proteins shows that PM/Scl-75 is efficiently cleaved by caspase-1, to a smaller extent by caspase-8, and relatively inefficiently by caspase-3 and caspase-7. Cleavage of the PM/Scl-75 protein occurs in the C-terminal part of the protein at Asp369 (IILD³⁶⁹↓G), and at least a fraction of the resulting N-terminal fragments of PM/Scl-75 remains associated with the exosome. Finally, the implications of PM/Scl-75 cleavage for exosome function and the generation of anti-PM/Scl-75 autoantibodies are discussed.     

New genus, new species of Cestoda (Anoplocephalidae), new species of Nematoda (Cosmocercidae) and other helminths in Cyrtodactylus louisiadensis (Sauria: Gekkonidae) from Papua New Guinea

Gekkotaenia novaeguineaensis n. gen., n. sp. (Cestoda: Anoplocephalidae) from the small intestine and Cosmocerca zugi n. sp. (Nematoda: Cosmocercidae) from the large intestine of the ring-tailed gecko, Cyrtodactylus louisiadensis (Sauria: Gekkonidae) are described and illustrated. Gekkotaenia novaeguineaensis n. gen., n. sp. is unique among the acraspedote Linstowiinae in possessing a poral female reproductory system. Cosmocerca zugi n. sp. is the 22nd species to be assigned to the genus and differs from other species in the genus by possessing 4 pairs of rosette papillae on plectanes and having a gubernaculum longer than the spicules. It is the fifth species to be described from the Australian biogeographical region. Eight additional helminth species were found: the digenean, Allopharynx macallisteri; 2 cestodes, cysticercoids of Cyclophyllidea gen. sp. and tetrathyridia of Mesocestoides sp.; 5 nematodes, larvae in cysts of Abbreviata sp., Aplectana macintoshii, Oswaldocruzia bakeri, Parapharyngodon maplestonei, and an undescribed species of Physalopteroides. Cyrtodactylus louisiadensis represents a new host record for each of these helminths.