Journal of Cell and Molecular Research

50-55

Authors: Nazila Nouraee, Mohamad Vasei, Shahriar Semnani, Seyed Javad Mowla

MicroRNAs (miRNAs) are a group of short non-coding RNAs implicated in numerous fundamental cellular processes, and their disregulations have been linked to several pathologic conditions, mainly cancers. Determining tissue distribution of miRNAs is a prerequisite for understanding their exact functions during development, tissue homeostasis and abnormality. In situ hybridization is a powerful technique to delineate the sub-cellular localization and tissue distribution patterns of mRNAs as well as miRNAs. Due to the important role of miRNAs in tumorigenesis, we optimized an ISH technique for detection of two well-known miRNAs (miR-302 and miR-21) in formalin-fixed paraffin-embedded (FFPE) tumor samples along with a pluripotent embryonal carcinoma cell line, NTERA-2 (NT2). After fixation of cells on slides/sectioning of FFPE blocks, proteinase K digestion, probe concentration, antibody development and light sensitive color reaction were optimized for both the FFPE samples and cell line. Signals for U6 snRNA, as an internal control, were detected in the nuclei of the cells. MiR-21 and miR-302 expression was detected in the cytoplasm of FFPE samples of seminoma carcinoma and in NT2 cell line, respectively. In this study, we optimized ISH for miRNA detection in FFPE samples and NT2 cell line.

62-67

Authors: Balal Sadeghi, Mohammadreza Nassiri, Ali Masoudi-Nejad, Mojtaba Tahmoorespour, Hesam Dehghani and Hamed Ahmadi

MicroRNAs (miRNA) are a class of noncoding and regulatory RNA molecules about 22 nucleotides in length. MicroRNAs regulate gene expression by an RNA interfering pathway through cleavage or inhibition of the translation of target mRNA. Many miRNAs have been reported for their important roles in developmental processes in various animals, but there is limited information about cattle and sheep miRNAs. The comparative genomics approach due to their conserved nature is a good source for the miRNAs discovery. Cattle and sheep are ideal model organisms for biological and comparative genomics studies. In our study, a computational method based on expressed sequence tag (EST) analysis was used for detection of cattle and sheep miRNAs. In cattle, 25 miRNA candidates found by homology searching frequently clustered at certain chromosomes and 28 miRNAs in sheep had been detected. Our results show that the cattle and sheep miRNA database can be providing useful information for investigating biological functions of miRNAs in cattle and sheep. Furthermore, the bioinformatics approach is a good manner for studying these functions.

76-80

Authors: Eisa Kohan Baghkheirati, Mohammad Bagher Bagherieh-Najjar and Mahnaz Aghdasi

Environmental stresses affect plant growth and cause losses worth hundreds of million dollars to agricultural industry each year. Many genes are induced in response to environmental stresses. The DREB1A gene is a stress-inducible transcription factor which its ectopic over-expression improves plant tolerance to environmental stresses. To produce environmental stress tolerant plants carrying the DREB1A gene, the full length cDNA of the DREB1A gene was amplified from Arabidopsis thaliana Col-0 plants by gene specific primers and cloned into pGEMT-Easy vector, and transformed into E.coli. Presence of the DREB1A gene was confirmed by restriction analysis as well as DNA sequencing. A 668-bp XbaI/BamHI digested fragment of DREB1A gene from the pGEMT::DREB1A construct was sub-cloned into the pBI121 binary vector. The recombinant plasmids were transferred into Agrobacterium tumefaciens cells (strain LBA4404) and screened on LB medium supplied with kanamycin/rifampicin (50 mg/l). Positive bacterial colonies were selected based on colony-PCR analysis and saved for further application in plant materials.

89-96

Authors: Mahnaz Kiani, Homa Zarghami, Farshid Memariani and Ali Tehranifar

Tissue culture methods provide tools to supplement traditional methods for collection, propagation and preservation of endangered plant species. In this study, in vitro propagation of Diaphanoptera khorasanica Rech.f., a rare and threatened plant species with limited distribution range and population was investigated. This species has a potential as an ornamental plant. Single node explants were provided from both adult and seedling sources. Several disinfection treatments were tried to permit selection of a suitable method. Different growth regulators were used for establishment, proliferation and rooting stages. Explants showed the highest establishment percentage after 5 min treatment with 1% sodium hypochlorite (NaOCl), cultured in MS medium containing 2.2 µM 6-benzylaminopurine (BAP) and 2.4 µM indole-3-butyric acid (IBA). The highest proliferation of explants from both adult and seedling source explants was obtained from media supplemented by BA treatment in contrast to TDZ. No significant differences were found between different concentrations of BAP and TDZ. Proliferated shoots in TDZ were longer and had more internode length and less vitrification, in comparison with those in BAP. In vitro rooting of proliferated shoots just induced in liquid half-strength MS medium and rooting was not observed in solid medium. The shoots that originated from adult plants gave rise to the highest rooting rate with 4.8µM α-naphthalene acetic acid (NAA) and 2.4 µM, but NAA rooted plantlets showed higher survival percentage in acclimatization step. This study was aimed towards developing an efficient protocol for in vitro propagation of D. khorasanica and conservation of this vulnerable species.