| host stadium specificity in the gregarine assemblage parasitizing tenebrio molitor. | reciprocal cross-stadia experimental infections were used to demonstrate stadium specificity within the gregarine assemblage parasitizing tenebrio molitor, the yellow mealworm. gregarina cuneata, gregarina polymorpha, and gregarina steini are characteristic parasites of larval t. molitor. gregarina niphandrodes is a characteristic parasite of adult t. molitor. experimental infections were produced in all homologous host-parasite combinations. no infection was produced in heterologous or cross-st ... | 1992 | 1556647 |
| the response of gregarina niphandrodes (apicomplexa: eugregarinida: septatina) to host starvation in tenebrio molitor (coleoptera: tenebrionidae) adults. | numerous studies of host starvation have emphasized pathological effects of parasites on their insect host, but little attention has been focused on the effects of host starvation on the parasites. this study addressed the possibility that parasite life-cycle events could be manipulated by withholding food from the host. the system used was gregarina niphandrodes (apicomplexa: eugregarinida) in tenebrio molitor (coleoptera: tenebrionidae) adults. gregarine gametocyst formation and shedding cease ... | 2001 | 11426724 |
| diversity of extracellular proteins during the transition from the 'proto-apicomplexan' alveolates to the apicomplexan obligate parasites. | the recent completion of high-coverage draft genome sequences for several alveolate protozoans - namely, the chromerids, chromera velia and vitrella brassicaformis; the perkinsid perkinsus marinus; the apicomplexan, gregarina niphandrodes, as well as high coverage transcriptome sequence information for several colpodellids, allows for new genome-scale comparisons across a rich landscape of apicomplexans and other alveolates. genome annotations can now be used to help interpret fine ultrastructur ... | 2016 | 26585326 |
| ultrastructure of the gregarina niphandrodes nucleus through stages from unassociated trophozoites to gamonts in syzygy and the syzygy junction. | in gregarina niphandrodes, an apicomplexan parasite, the sexual stage of its life cycle begins with the association of 2 gamonts. here, we describe the ultrastructure of the syzygy junction and the nucleus during the transition from unassociated trophozoites to paired gamonts to gamonts in syzygy. throughout this process, the folds within the syzygy junction undergo changes that correspond to changes of the epicytic folds. the nucleus goes through dramatic changes from multiple spheres of conden ... | 2007 | 17626337 |
| cryptosporidium is more closely related to the gregarines than to coccidia as shown by phylogenetic analysis of apicomplexan parasites inferred using small-subunit ribosomal rna gene sequences. | the phylogenetic placement of gregarine parasites (apicomplexa: gregarinasina) within the apicomplexa was derived by comparison of small-subunit ribosomal rna gene sequences. gregarine sequences were obtained from gregarina niphandrodes clopton, percival, and janovy, 1991, and monocystis agilis stein, 1848 (eugregarinorida léger 1900), as well as from ophriocystis elektroscirrha mclaughlin and myers, 1970 (neogregarinorida grassé 1953). the sequences were aligned with several other gregarine and ... | 1999 | 10540950 |
| individual and population effects of eugregarine, gregarina niphandrodes (eugregarinida: gregarinidae), on tenebrio molitor (coleoptera: tenebrionidae). | gregarines are single-celled parasites in the phylum apicomplexa that infect invertebrates. they are highly abundant on three levels: among a large diversity of invertebrates, in the proportion of population of organisms they infect, and within individually infected organisms. because of their remarkable prevalence, we hypothesize that they play an important role in support of their hosts. however, studies done to date on the impact of gregarines on their host are conflicting. therefore, we stud ... | 2007 | 17716459 |
| gregarina niphandrodes (eugregarinorida: septatorina): oocyst surface architecture. | the surface architecture of oocysts produced by gregarina niphandrodes (eugregarinorida) from tenebrio molitor adults (coleoptera: tenebrionidae) as revealed by scanning electron microscopy is reported. gametocysts were allowed to dehisce on 15-mm, round cover glasses; the cover glasses with their oocysts chains were then mounted on stubs without further processing, and sputter-coated with 20-nm gold palladium. scanning electron microscopy was performed at 10-15 kv with a hitachi 3000n sem. oocy ... | 2007 | 17626372 |
| gregarina niphandrodes may lack both a plastid genome and organelle. | gregarines are early diverging apicomplexans that appear to be closely related to cryptosporidium. most apicomplexans, including plasmodium, toxoplasma, and eimeria, possess both plastids and corresponding plastid genomes. cryptosporidium lacks both the organelle and the genome. to investigate the evolutionary history of plastids in the apicomplexa, we tried to determine whether gregarines possess a plastid and/or its genome. we used pcr and dot-blot hybridization to determine whether the gregar ... | 2007 | 17300522 |