Paratylenchus shenzhenensis n. sp. was collected from the rhizosphere soil of Anthurium andraeanum in Shenzhen, Guangdong Province, China. The new species is characterized by having a female with a small body (249-302 μm), well developed stylet (17-21 μm), rounded head with four submedian lobes and lip-region with a slight depression at the oral area, small post-vulval uterine sac with a few ve...

The saturation values for ribosomal RNA hybridization have been determined for DNA from diploid and polytene tissues of Drosophila melanogaster. These values have been measured in XO and XX larvae which have, respectively, one and two nucleolus organizers in the diploid chromosome set. The results show that (1) in diploid cells the ribosomal (r)DNA is present in amounts proportional to the numb...

The nucleolus is the subnuclear membrane-less organelle where rRNA is transcribed and processed and ribosomal assembly occurs. During the last 20 years, however, the nucleolus has emerged as a multifunctional organelle, regulating processes that go well beyond its traditional role. Moreover, the unique organization of rDNA in tandem arrays and its unusually high transcription rates make it pron...

Abstract We establish a new genus of planocerid polyclad, Heteroplanocera gen. nov., based on species, H. katoi sp. collected at depth 245 m off the coast Izu Peninsula, West Pacific, Japan. nov. is distinguished from other genera by following characteristics: (i) pair nuchal tentacles, (ii) muscular bulb, (iii) spermiducal bulbs (instead seminal vesicle), (iv) free prostatic vesicle, (v) acces...

background: cystic hydatid disease is an important zoonosis, affecting humans and animals and is a significant public health and economic problem throughout the world and iran. since extraction of dna from the parasite is a primary and crucial step which has a principal effect on pcr results, in the current study five simple methods for dna extraction from protoscoleces of echinococcus granulos...

A newly described Asian taeniid which is morphologically indistinguishable from adult Taenia saginata has been identified in the aboriginal population of Taiwan. Hybridization patterns of restriction enzyme digested genomic DNA isolated from "Taiwan" Taenia and Taenia saginata revealed distinct variations between these cestodes. We have demonstrated by Southern blot analysis of ribosomal DNA fr...

SEQUENCE AND ITS ORIGIN: Fragments of Pseudomonas aeruginosa (strain K, ATCC 25102) DNA encoding two tRNA genes have been seguenced as part of a project directed towards sequencing a complete ribosomal RNA operon from this organism. Clones from a BamHl library of P. aeruginosa DNA ligated into plasmid pOC9 were isolated by hybridisation with P. aeruginosa 16S and 23S ribosomal RNA molecules tha...

During the development of Xenopus oocytes there is a special DNA synthesis that leads to a thousandfold amplification of the genes that code for ribosomal RNA. We have used the electron microscope to study this process. Our primary observation is the presence of ribosomal DNA in rolling-circle intermediates at the time of amplification. We believe that these intermediates are involved in the am...

In DNA of the dinoflagellate Crypthecodinium cohnii, 38% of the thymine is replaced by the modified base 5-hydroxymethyluracil, and approximately 3% of the cytosine is replaced by 5-methylcytosine. Both of the modified bases are non-randomly distributed in the DNA. Determinations of 3' nearest neighbors show that HOMeU is preferentially located in the dinucleotides HOMeUpA and HOMeUpC. Pyrimidi...