Cryptosporidium oocysts were found in 43 out of 77 calves from two farms in Iwate Prefecture and nine farms on Tanegashima Island, Kagoshima Prefecture, Japan. The DNA fragments of 18S ribosomal RNA (18S rRNA) gene were amplified by a nested PCR from 43 oocyst-positive as well as one oocyst-negative samples. All of them were precisely identified as C. parvum by analyzing the nucleotide sequence...

Four group I introns from the nuclear-encoded (18S) rRNA genes of three chlorophycean green algae are described; two are in Dunaliella parva, and one each is in D. salina and Characium saccatum. The introns within the gene in the latter two organisms are located at the sites equivalent to the 5' and 3' introns of D. parva, respectively. All four introns lack open reading frames and are relative...

Plant mitochondria contain three rRNA genes, rrn26, rrn18 and rrn5, the latter two being co-transcribed. We have recently identified a polynucleotide phosphorylase-like protein (AtmtPNPase) in Arabidopsis mitochondria. Plants downregulated for AtmtPNPase expression (PNP-plants) accumulate 18S rRNA species polyadenylated at internal sites, indicating that AtmtPNPase is involved in 18S rRNA degra...

In a West Nile virus (WNV) -free ecosystem, it is essential to verify the integrity of RNA before concluding that RNA extracted from mosquito specimens is negative for WNV gene sequences. The primary objective of our study was to develop a rapid molecular assay to rapidly screen mosquitoes for the presence of 18S RNA and WNV gene sequences. Mosquitoes, collected from multiple sites on the islan...

The organisation of the mitochondrial ribosomal RNA genes in maize is described. Each of the rRNAs is encoded by a single gene. The 5S and 18S rRNA genes are close together, and separated from the 26S rRNA gene by 16 kb of DNA. There is no evidence of heterogeneity in this gene arrangement.

Phylogenetic analyses of the family Trypanosomatidae have been conducted using both 18S rRNA gene sequences and a variety of protein sequences. Using a variety of phylogenetic methods, 18S rRNA phylogenies indicate that the genus Trypanosoma is not monophyletic. Rather, they suggest that the American and African trypanosomes constitute distinct clades. By contrast, phylogenetic analyses of avai...

In aWestNile virus (WNV)-free ecosystem, it is essential to verify the integrity ofRNA before concluding thatRNAextracted frommosquito specimens is negative forWNVgene sequences. Theprimaryobjectiveofour studywas todevelopa rapidmolecular assay to rapidly screenmosquitoes for the presence of 18S RNA andWNV gene sequences. Mosquitoes, collected frommultiple sites on the island of OÔahu, were poo...

Molecular tools have revolutionized the exploration of biodiversity, especially in organisms for which traditional taxonomy is difficult (Tang et al., 2012). The small subunit (SSU) 18S rRNA gene is one of the most frequently used genes in phylogenetic studies and an important marker for random target PCR in environmental biodiversity screening. 18S rDNA is a nuclear ribosomal gene, commonly re...

background: the aim was to compare three different methods (direct examination, culture and pcr meth­ods) for the diagnosis of acanthamoeba keratitis (ak) in corneal scrapes. methods: twenty eight corneal scrapes and contact lenses were collected from keratitis patients and re­ferred to the de­partment of medical parasitology and mycology, school of public health, tehran univer­sity of medical ...

introduction: at present, most recombinant proteins are produced in prokaryotes especially e coli. yeasts and cho also are used as eukaryotic hosts. leishmania tarentolae, a parasite of lizards, a member of trypanosomatidae family is one of the new systems for expression of heterologous proteins. in this system, some of the parasitic protozoa features are used in expression of mammalian protein...