Spore morphotypes of Thelohania solenopsae (microsporidia) described microscopically and confirmed by PCR of individual spores microdissected from smears by position ablative laser microbeam microscopy

Abstract

Development of Thelohania solenopsae, a parasite of the red imported fire ant (Solenopsis invicta), until recently was thought to include formation of two types of spores: unicellular meiospores, maturing inside sporophorous vesicles in sets of eight (octospores); and Nosema-like binuclear free spores. Megaspores, discovered in 2001, develop primarily in alates and are morphologically distinct from the two previously known types of spores. The role of megaspores in the T. solenopsae life cycle, as well as their existence, has been questioned. The current research includes light and electron microscopic descriptions of the three major spore morphotypes characteristic of T. solenopsae development. In addition, individual octospores and megaspores were isolated into groups of 8-20 from methanol-fixed and Calcofluor-stained smears of the infected ants for subsequent PCR analysis by the laser pressure catapulting function of a position ablative laser microbeam microscope, a technique applied for the first time to research of microsporidia. The PCR-amplified SSU rDNA nucleotide sequences from octospores and megaspores were identical. This, along with the consistency with which megaspores are detected in infected ants, demonstrates that megaspores are integral to the life cycle of T. solenopsae.

Rapid and Sensitive Detection of Single Cryptosporidium Oocysts from Archived Glass Slides

“…LCM has rapidly developed over the last few years and can be used as a tool to select and recover biological material from fixed/mounted slides (12,24). Although this technology has predominantly been used as a tool for gene expression of fixed tissue section and in vitro-cultivated cell lines (12,25), recent literature indicates the possibility of using it for the recovery of single life stages of parasites (40,42,44). Previous attempts to recover oocysts from archived slides were based on washing fixed oocyst/cryptosporidial DNA from slides (2,3).…”

“…The application of molecular techniques for species identification and genotyping from archived glass slides has the potential to provide detailed epidemiological information on the cryptosporidia in circulation in each water catchment. However, until recently, few procedures were sensitive and accurate enough to recover low numbers of oocysts fixed to glass slides (42,44).…”

Transmission of Vairimorpha invictae (Microsporidia: Burenellidae) infections between red imported fire ant (Hymenoptera: Formicidae) colonies

“…This contrasts with Thelohania solenopsae another microsporidium that infects Wre ants, which has four reported spore types that are present in various ant developmental stages. SpeciWcally, uninucleate octospores, or meiospores, contained in sporophorous vesicles are present in adults and pupae (Knell et al, 1977); binucleate, Nosema-like spores, or free spores, present primarily in adults but also reported in pupae and larvae (Knell et al, 1977;Sokolova et al, 2004); binucleate spores from pupae (Shapiro et al, 2003); and binucleate megaspores observed in adults and brood (Sokolova et al, 2004). A reported Wfth spore, the macrospore, was recently considered to be abnormal octospores, or teratospores (Sokolova et al, 2004).…”

The nature of Thelohania solenopsae (Microsporidia) cysts in abdomens of red imported fire ants, Solenopsis invicta

“…Thelohania solenopsae, a microsporidium parasitizing Wre ants, Solenopsis invicta, produces at least four types of spores in Wre ants, S. invicta: Thelohania-like octospores, Nosema-like spores (Knell et al, 1977), megaspores (Sokolova and Fuxa, 2001;Sokolova et al, 2004b), and diplokaryotic spores with large posterior vacuoles developing exclusively in brood (Shapiro et al, 2003). Milky white oval bodies often are found in ant abdomens during dissections.…”