نتایج جستجو برای: 18S rDNA

تعداد نتایج: 14876  

Journal: :Genetics and molecular research : GMR 2014
L Jiang J Jiang J Liu J Yuan Y Chen Q Zhang X Wang

Half-smooth tongue sole (Cynoglossus semilaevis) is an important aquaculture flatfish in China. Cytogenetic analysis has revealed that its sex determination system is female heterogametic (ZZ/ZW). The W chromosome is morphologically larger and has been considered evolutionarily younger than any other chromosome in the set. However, the genetic origin and evolution process of this neo-chromosome...

Journal: :Clinical cancer research : an official journal of the American Association for Cancer Research 2005
Michael W Y Chan Susan H Wei Ping Wen Zailong Wang Daniela E Matei Joseph C Liu Sandya Liyanarachchi Robert Brown Kenneth P Nephew Pearlly S Yan Tim H-M Huang

PURPOSE Repetitive ribosomal DNA (rDNA) genes are GC-rich clusters in the human genome. The aim of the study was to determine the methylation status of two rDNA subunits, the 18S and 28S genes, in ovarian tumors and to correlate methylation levels with clinicopathologic features in a cohort of ovarian cancer patients. EXPERIMENTAL DESIGN 18S and 28S rDNA methylation was examined by quantitati...

ژورنال: :فصلنامه دامپزشکی و آزمایشگاه 0
ایمانه دلاوری1، حسن شریفی یزدی2، نسرین مقدر3

مقدمه و هدف: نماتودیرلا کملی یکی از انگلهای دستگاه گوارش نشخوارکنندگان است این انگل از نظر شباهتهای مورفولوژیکی بسیار شبیه به جنس نماتودیروس میباشد آنالیز فیلوژنیک نماتودیرلا کملی بر اساس ترادف its1 و its2 حاکی از ارتباط بسیار نزدیک این گونه با بعضی گونه های نماتودیروس است و می توان اظهار داشت که گونه نماتودیرلا کملی به جنس نماتودیروس شباهت زیاد دارد، و تعریف یک جنس جداگانه به نام نماتودیرلا کم...

Journal: :Cellular & molecular biology letters 2002
Barbara Naganowska Anna Zielińska

Double-target fluorescent in situ hybridization (FISH) was used to determine the genomic distribution of ribosomal RNA genes in five Lupinus species: L. cosentinii (2n=32), L. pilosus (2n=42), L. angustifolius (2n=40), L. luteus (2n=52) and L. mutabilis (2n=48). 18S-25S rDNA and 5S rDNA were used as probes. Some interspecific variation was observed in the number and size of the 18S-25S rDNA loc...

Journal: :The Journal of heredity 1998
M L Roose T Schwarzacher J S Heslop-Harrison

In situ hybridization of 18S-5.8S-25S rDNA probes labeled with biotin or rhodamine and 5S rDNA probes labeled with digoxigenin was used to locate rDNA sites on root-tip metaphase chromosomes of Citrus sinensis L. (2n = 2x = 18), Poncirus trifoliata L. Raf. (2n = 2x = 18), and Citrus x Poncirus hybrids (2n = 2x = 18). Counterstaining with the fluorochromes chromomycin A3 and DAPI uniquely identi...

2010
Mohammad A Hejazi Abolfazl Barzegari Nahid Hosseinzadeh Gharajeh Mohammad S Hejazi

Comparison of 18S rDNA gene sequences is a very promising method for identification and classification of living organisms. Molecular identification and discrimination of different Dunaliella species were carried out based on the size of 18S rDNA gene and, number and position of introns in the gene. Three types of 18S rDNA structure have already been reported: the gene with a size of ~1770 bp l...

Journal: :Molecular biology and evolution 1995
D H Fitch B Bugaj-Gaweda S W Emmons

We have investigated the molecular evolution of the nucleotide sequences of 18S ribosomal RNA genes (18S rDNA) from a set of nematodes in the family Rhabditidae (Nematoda: Secernentea). Our aim was to evaluate the usefulness of this gene for molecular systematics of this family, as well as to establish phylogenetic relationships within a group that has potential for comparative studies of the r...

2014
Vanessa Bueno Paulo César Venere Jocicléia Thums Konerat Cláudio Henrique Zawadzki Marcelo Ricardo Vicari Vladimir Pavan Margarido

Hypostomus is a diverse group with unclear aspects regarding its biology, including the mechanisms that led to chromosome diversification within the group. Fluorescence in situ hybridization (FISH) with 5S and 18S rDNA probes was performed on ten Hypostomini species. Hypostomus faveolus, H. cochliodon, H. albopunctatus, H. aff. paulinus, and H. topavae had only one chromosome pair with 18S rDNA...

Journal: :Molecular biology and evolution 1996
S Carranza G Giribet C Ribera Baguñà M Riutort

Sequences of 18S ribosomal DNA (rDNA) are increasingly being used to infer phylogenetic relationships among living taxa. Although the 18S rDNA belongs to a multigene family, all its copies are kept homogeneous by concerted evolution (Dover 1982; Hillis and Dixon 1991). To date, there is only one well-characterized exception to this rule, the protozoan Plasmodium (Gunderson et al. 1987; Waters, ...

Journal: :Hereditas 2000
C Martins A P Wasko C Oliveira J M Wright

In this study, we report the cloning and nucleotide sequence of PCR-generated 5S rDNA from the Tilapiine cichlid fish, Oreochromis niloticus. Two types of 5S rDNA were detected that differed by insertions and/or deletions and base substitutions within the non-transcribed spacer (NTS). Two 5S rDNA loci were observed by fluorescent in situ hybridization (FISH) in metaphase spreads of tilapia chro...

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