NOPR Collection:

Transgenesis: Embryo modification to sperm mediated gene transfer

2017-03-31T06:41:57Z

Title: Transgenesis: Embryo modification to sperm mediated gene transfer Authors: Vishal, Sonali S; Dalal, Sorab N Abstract: The generation of transgenic animals by conventional transgenic protocols is cumbersome and not very efficient. To improve the efficiency of obtaining transgenic animals, different groups have attempted to genetically modify spermatozoa and these technologies are collectively referred to as sperm mediated gene transfer (SMGT). SMGT technologies involve the modification of either spermatozoa or spermatogonial stem cells that give rise to spermatozoa, followed by either in vitro fertilization or mating with a wild type female to generate transgenic progeny. In addition to the generation of transgenic mice, the use of SMGT technologies has resulted in multiple insights into male reproductive biology. SMGT has bypassed most of the problems associated with the traditional methods of transgenesis and has considerably improved the efficiency of obtaining transgenic animals. Various techniques have been developed by which SMGT can be achieved and this review provides an overview of the evolution of SMGT technology and will indicate how these might be used to further our understanding of mammalian growth and development. Page(s): 459-466

Transcriptional profiling of heat stress responsive genes in different developmental stages of bread wheat (Triticum aestivum L.)

2017-03-31T06:36:25Z

Title: Transcriptional profiling of heat stress responsive genes in different developmental stages of bread wheat (Triticum aestivum L.) Authors: Padaria, Jasdeep Chatrath; Biswas, Koushik; Bhatt, Deepesh; Raipuria, Rajkumar; Prabu, Ramachandira; Vishwakarma, Harinder; Singh, Gyanendra Pratap Abstract: Transcriptional regulation of heat stress response is a complex phenomenon in crop plants, which needs to be evaluated at molecular level for its proper understanding. The present study aimed at identifying differentially expressed heat responsive genes in a thermo-tolerant Indian wheat cultivar Raj3765. Wheat plants of Raj3765 and HD2967 (heat susceptible genotype) were exposed to heat stress at 37°C and 42°C, respectively for different time intervals (30 min to 6 h) at four developmental stages (seedling, tillering, stem elongation & anthesis) and leaf samples collected. Total RNA isolated from leaf samples was used for constructing eight forward subtracted cDNA libraries. A total of 1016 ESTs were generated and assembled into a collection of 377 unigenes, including 114 contigs and 270 singletons. About 23.22 and 20.47% unigenes showed similarities to stress related and abiotic stimulus related genes, respectively; of which 12.59% showed similarities to genes for heat stress responsive functions. Differential expression analysis in response to heat stress of selected six genes by quantitative Real Time-PCR showed up regulation of all the six genes in Raj 3765 as compared to HD2967. The study identified several heat stress responsive genes that can be deployed for development of thermotolerant transgenic wheat. Page(s): 467-476

In silico prediction and characterization of microRNAsfrom pigeon pea [Cajanus cajan (L.) Millsp.]

2017-03-31T06:30:10Z

Title: In silico prediction and characterization of microRNAsfrom pigeon pea [Cajanus cajan (L.) Millsp.] Authors: Bhati, Jyotika; Jethra, Geetika; Sharma, Anu; Rai, Anil Abstract: Pigeon pea [Cajanus cajan (L.) Millsp.] is an important food legume crop cultivated in India. Availability of whole genome sequence of pigeon pea has led to initiation of many studies for annotation of genome sequences. The discoveries of miRNAs in plants and the growing evidence of their involvement in a variety of functional roles have produced a great deal of excitement in plant biology. The present study was undertaken to identify the miRNAs in pigeon pea along with their possible targets using computational methods. Thirteen miRNAs were identified and their targets were identified from mRNA and 3'UTR sequences of pigeon pea using MiRanda, BLAST and psRNA toolkit. This study would help in improved understanding of molecular mechanisms of miRNA and development of novel and more precise techniques for better understanding of post-transcriptional gene silencing in pigeon pea. Page(s): 477-484

Mutation-selection balance acting on the ribosomal genes in Medicago truncatula Gaertn.

2017-03-31T06:27:02Z

Title: Mutation-selection balance acting on the ribosomal genes in Medicago truncatula Gaertn. Authors: Paul, Prosenjit; Malakar, Arup Kumar; Chakraborty, Supriyo Abstract: In recent times, ribosomal protein genes are widely used as reference genes for expressional studies. The present study has analyzed the base compositional variation of Medicago truncatula ribosomal genes for level of expression using bioinformatics. Mononucleotide and dinucleotide usage bias and eventually the codon usage bias were observed in all the genes and thought to result from translational pressure. The ribosomal genes showed positional preference for nucleobases at specific codon positions. To elucidate more precisely the positional preferences, the coding sequences were randomized keeping the actual base composition constant. The randomized sequences showed low stability as compared to their native/natural sequences. Moreover, a significant correlation was observed between the native sequence free energy values and the gene expression level. These results altogether suggest that natural selection and mutational pressure might act coherently on the ribosomal genes to keep the best mono/dinucleotide arrangement within the coding sequence in view of the mRNA stability, fidelity of translation and the level of gene expression. Page(s): 485-490