Latest Research on Molecular Identification

Molecular identification of prey in predator diets

In many situations prey choice by predators in the field cannot be established or quantified using direct observation. The remains of some prey may be visually identified in the guts and faeces of predators but not all predators ingest such hard remains and even those that do consume them may also ingest soft‐bodies prey that leave no recognizable remnants. The result is, at best, a biased picture of prey choice. A range of molecular techniques and applications are reviewed that allow prey remains to be identified, often to the species and even stage level. [1]

Molecular identification and isolation of the Waxy locus in maize

The Waxy (Wx) locus in maize determines the amylose content of pollen and endosperm tissue. There are several mutant alleles of the locus caused by insertion of transposable controlling elements. In the present study, we have used the properties of controlling element alleles to identify the Wx locus and its gene product, with the subsequent objective of isolating the elements causing the mutations. We present evidence that the Wx locus encodes a starch granule-bound 58 kd polypeptide that is synthesized in vitro as a 65 kd precursor. We describe the isolation of recombinant plasmids containing cDNA inserts homologous to Wx mRNA and a recombinant λ phage containing a genomic Eco RI fragment encompassing most or all of the Wx transcription unit. We show that a mutation caused by the controlling element Dissociation (Ds) is attributable to an insertion of approximately 2.4 kb at the Wx locus. [2]

Molecular identification of a volume-regulated chloride channel

A volume-regulated chloride current ( I Cl.vol) is ubiquitously present in mammalian cells, and is required for the regulation of electrical activity, cell volume, intracellular pH, immunological responses, cell proliferation and differentiation. However, the molecule responsible for I Cl.vol has yet to be determined1,2,3. Although three putative chloride channel proteins expressed from cloned genes (P-glycoprotein4, p I Cln (ref. 5) and ClC-2 (ref. 6)) have been proposed to be the molecular equivalent of I Cl.vol, neither P-glycoprotein nor p I Cln is thought to be a chloride channel or part thereof7,8, and the properties of expressed ClC-2 channels differ from native I Cl.vol (refs. 3, 6). [3]

Molecular Identification of Aspergillus Strains and Quick Detection of Aflatoxin from Selected Common Spices in Tanzania
Twenty three Aspergillus species isolated from nine commonly used spices in Tanzania were characterized to determine presence of potential aflatoxin producers. PCR of one regulatory (aflR) and three structural (aflD, aflM and aflO) aflatoxin biosynthetic pathway genes followed by nucleotide sequence analysis of 5.8S ITS rDNA region identified the potential aflatoxin producing strains.  Four Aspergillus strains had all four genes which were missing in two strains while the other strains had 1 to 3 genes. Among the four strains having all four genes, three were identified as A. flavus and one A. parasiticus.  Red chill was contaminated with three potential aflatoxin producer strains: A. flavus, A. parasiticus and A. tamarii. A. flavus was identified from red chill, black pepper and ginger. Using lateral flow immune-chromatographic assay, red chill tested positive with detectable ≥ 4 ppb of total aflatoxins. These results demonstrated that A. flavus is the most contaminant strain in the spices tested and thus may have risk implications based on their potential to produce aflatoxin. Further, both PCR of genes involved in aflatoxin production pathway and quick detection of total aflatoxin can be used to assess the quality of spices and predict its safety to consumers. [4]

Molecular Identification of Candida dubliniensis among Candida albicans Isolated from Oral Cavity of Cancer Patients using PCR-RFLP, in a Tertiary Care Hospital in Kashmir, India

Aims: To retrospectively evaluate 186 stock strains of C. albicans strains isolated from oral cavity of HIV negative patients with various malignancies for the presence of C. dubliniensis isolates among them by PCR-RFLP.

Place and Duration of Study: Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, between October 2013 and October 2014.

Methodology: This study included 186 stock strains of C. albicans tentatively identified by phenotypic methods like germ tube formation in human serum, colony color on chromogenic candida differential agar, characteristic morphology on corn meal agar and assimilation of sugars isolated from HIV negative patients with various malignancies. DNA extraction was performed by chemical method. PCR amplification of ITS1-5.8S-ITS2 rDNA region was achieved using the ITS1 and ITS4 primer pairs which amplify the ITS region of both species, providing a single PCR product of expected size (540 bp). There is no visible difference between these two species with regard to their ITS PCR products. Digestion of amplified products was performed by using restriction enzyme BlnI (AvrII) which cleaves DNA where there is a CCTAGG sequence. The products of digestion generate one band of 540 bp for C. albicans, and two bands of 200 bp and 340 bp for C. dubliniensis because BlnI has one recognition site within the ITS region of C. dubliniensis, whereas none within that of C. albicans. [5]

Reference

[1]  Symondson, W.O.C., 2002. Molecular identification of prey in predator diets. Molecular ecology, 11(4), pp.627-641.

[2]  Shure, M., Wessler, S. and Fedoroff, N., 1983. Molecular identification and isolation of the Waxy locus in maize. Cell, 35(1), pp.225-233.

[3]  Duan, D., Winter, C., Cowley, S., Hume, J.R. and Horowitz, B., 1997. Molecular identification of a volume-regulated chloride channel. Nature, 390(6658), pp.417-421.

Temu, G. E. (2016) “Molecular Identification of Aspergillus Strains and Quick Detection of Aflatoxin from [4] Selected Common Spices in Tanzania”, Journal of Scientific Research and Reports, 10(7), pp. 1-8. doi: 10.9734/JSRR/2016/26102.

[5] Jan, A., Bashir, G., Fomda, B. A., Fatima, A., Lone, M. and Roohi, S. (2016) “Molecular Identification of Candida dubliniensis among Candida albicans Isolated from Oral Cavity of Cancer Patients using PCR-RFLP, in a Tertiary Care Hospital in Kashmir, India”, Microbiology Research Journal International, 14(2),

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