Development of the insect pathogenic alga Helicosporidium.

This study examined the morphogenesis and replication dynamics of the different life stages (cysts, filamentous cells, vegetative cells) of Helicosporidium sp., a non-photosynthetic, entomopathogenic alga. The isolate (SjHe) used originated from an infected black fly larva.

Differential expression of chitin synthase (CHS) and glucan synthase (FKS) genes correlates with the formation of a modified, thinner cell wall in in vivo-produced Beauveria bassiana cells.

During infection (in vivo), the entomopathogenic fungus Beauveria bassiana produces yeast-like cells that are surrounded by modified cell walls. These modifications have been related to the fungus ability to limit recognition by the host defense system. The composition of the in vivo cell wall was analyzed using a combination of cytochemical and molecular techniques.

Review of microsporidia-mosquito relationships: from the simple to the complex.

Microsporidia in mosquitoes can be divided into two categories based on their life cycles and host-parasite relationships. Some species of microsporidia exhibit simple life cycles with one spore type responsible for oral (horizontal) transmission. They affect only one generation of the mosquito and are not usually host or tissue specific.

A picorna-like virus from the red imported fire ant, Solenopsis invicta: initial discovery, genome sequence, and characterization.

We report the first discovery and genome sequence of a virus infecting the red imported fire ant, Solenopsis invicta. The 8026 nucleotide, polyadenylated, RNA genome encoded two large open reading frames (ORF1 and ORF2), flanked and separated by 27, 223, and 171 nucleotide untranslated regions, respectively. The predicted amino acid sequence of the 5' proximal ORF1 (nucleotides 28 to 4218) exhibited significant identity and possessed consensus sequences characteristic of the helicase, cysteine protease, and RNA-dependent RNA polymerase sequence motifs from picornaviruses, picorna-like viruses, comoviruses, caliciviruses, and sequiviruses.

A nucleopolyhedrovirus from Uranotaenia sapphirina (Diptera: Culicidae).

In this report we present data on biology, gross pathology, ultrastructure, and host range studies of a naturally occurring nucleopolyhedrovirus from the mosquito Uranotaenia sapphirina (UrsaNPV). Development of this virus was restricted to nuclei of epithelial cells in posterior midgut and distal gastric caecum. Occlusion bodies contained numerous singly enveloped rod-shaped virions.