AAV1 is the optimal viral vector for optogenetic experiments in pigeons (Columba livia)

Although optogenetics has revolutionized rodent neuroscience, it is still rarely used in other model organisms as the efficiencies of viral gene transfer differ between species and comprehensive viral transduction studies are rare. However, for comparative research, birds offer valuable model organisms as they have excellent visual and cognitive capabilities. Therefore, the following study establishes optogenetics in pigeons on histological, physiological, and behavioral levels. We show that AAV1 is the most efficient viral vector in various brain regions and leads to extensive anterograde and retrograde ChR2 expression when combined with the CAG promoter. Furthermore, transient optical stimulation of ChR2 expressing cells in the entopallium decreases pigeons’ contrast sensitivity during a grayscale discrimination task. This finding demonstrates causal evidence for the involvement of the entopallium in contrast perception as well as a proof of principle for optogenetics in pigeons and provides the groundwork for various other methods that rely on viral gene transfer in birds.

Overview of Safety and Efficacy of Non-Viral Gene Transfer in Cartilage Tissue Engineering from the Worldview of Islam

This paper examines the safety and efficacy of non-viral gene transfer in cartilage tissue engineering (TE) from the worldview of Islam. The first clinical trial treating adenosine deaminase deficient patients conducted in 1990 has triggered the development of gene transfer technology. The potential of gene transfer is further explored in TE field with the hope that it could prosper the regenerative medicine application. However, ethical issues become important when it comes to application of new treatment modalities, primarily in gene transfer because of genetic modification influences the basis of life - the DNA. Besides ethical issue, the application of gene transfer in treating diseases also attract views from religious context. The questions on the techniques to administer the gene in human, social acceptance of genetically modified cell and adverse effects from it are still debatable and unresolved. Apart from that dilemma, both safety and efficacy issues are raised due to the scientific uncertainty and social perception of the technology. Despite countless number of encouraging findings and recommendations by the proponents of the technology, gene transfer is currently available only in the research setting. The established guidelines are used to complement and provide the necessary foundations in discussing the aspects involved in the incorporation of gene transfer with cartilage TE. Relevant Islamic input are identified and aligned to those particular guidelines. It is hoped that the integration of Islamic inputs in the existing guidelines could suggest the safest approach in treating cartilage degenerative disease through gene transfer and TE.

Peptides mediating DNA transport on microtubules and their impact on non-viral gene transfer efficiency

Synthetic vectors such as cationic polymers and cationic lipids remain attractive tools for non-viral gene transfer which is a complex process whose effectiveness relies on the ability to deliver a plasmid DNA (pDNA) into the nucleus of non-dividing cells. Once in the cytosol, the transport of pDNAs towards the nuclear envelope is strongly impaired by their very low cytosolic mobility due to their large size. To promote their movement towards the cell nucleus, few strategies have been implemented to exploit dynein, the microtubule’s (MT’s) motor protein, for propagation of cytosolic pDNA along the MTs towards the cell nucleus. In the first part of this review, an overview on MTs, dynein, dynein/virus interaction feature is presented followed by a summary of the results obtained by exploitation of LC8 and TCTEL1 dynein light chain association sequence (DLC-AS) for non-viral transfection. The second part dedicated to the adenoviral protein E3-14.7K, reports the transfection efficiency of polyplexes and lipoplexes containing the E3-14.7K-derived P79-98 peptide linked to pDNA. Here, several lines of evidence are given showing that dynein can be targeted to improve cytosolic pDNA mobility and accumulate pDNA near nuclear envelope in order to facilitate its transport through the nuclear pores. The linkage of various DLC-AS to pDNA carriers led to modest transfection improvements and their direct interaction with MTs was not demonstrated. In contrast, pDNA linked to the P79-98 peptide interacting with TCTEL1 via a cytosolic protein (fourteen seven K-interacting protein-1 (FIP-1)), interaction with MTs is evidenced in cellulo and transfection efficiency is improved.