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Biology subjects

Gall, K.

Publications and source records attributed to Gall, K..

3 recordsLinked to original sources

Hidden rAAV Breakpoints Detected Using Single-Molecule, Modified Base Sequencing

The AAV genome is a single stranded DNA molecule packaged in an icosahedral protein capsid. Vector genomes of plus and minus polarities are packaged and complementary genomic strands hybridize when lysed in vitro. Standard sequencing library methods cause loss of information from individual genomes when mismatches and gaps are repaired. To retain original molecular information, modified bases are used during the repair step which allows pre-existing DNA to be distinguished from DNA added during library preparation. Modified bases introduced during repair are identified using the Sequel II system and used to detect HIDdEN DNA breakpoints (HIDEN-Seq). The most frequent breakpoints in an AAV vector subject to high strand breakage during packaging were linked to adjacent secondary structure, prompting changes in nearby sequences to reduce breakage. This use of modified bases for localizing DNA breaks enables better vector design, resulting in higher quality gene therapy vectors. The same approach can be used in other systems where knowledge of pre-existing sequence and structure is important.

genomics↗

Computational and Image Processing Methods for Analysis and Automation of Anatomical Alignment and Joint Spacing in Reconstructive Surgery

PurposeReconstructive surgeries to treat a number of musculoskeletal conditions, from arthritis to severe trauma, involve implant placement and reconstructive planning components. Anatomically matched 3D printed implants are becoming increasingly patient-specific; however the preoperative planning and design process requires several hours of manual effort from highly trained engineers and clinicians. Our work mitigates this problem by proposing algorithms for the automatic re-alignment of unhealthy anatomies, leading to more efficient, affordable, and scalable treatment solutions. MethodsOur solution combines global alignment techniques such as iterative closest points (ICP) with novel joint space refinement algorithms. The latter is achieved by a low dimensional characterization of the joint space, computed from the distribution of the distance between adjacent points in a joint. ResultsExperimental validation is presented on real clinical data from human subjects. Compared with ground truth healthy anatomies, our algorithms can reduce misalignment errors by 22% in translation and 19% in rotation for the full foot-and-ankle and 37% in translation and 39% in rotation for the hind-foot only, achieving a performance comparable to expert technicians. ConclusionOur methods and histogram-based metric allow for automatic and unsupervised alignment of anatomies, a major step toward a fully automated and data driven re-positioning, designing, and diagnosing tool.

bioengineering↗

FUS/TLS undergoes calcium-mediated nuclear egress during excitotoxic stress and is required for Gria2 mRNA processing

Excitotoxic levels of glutamate represent a physiological stress that is strongly linked to amyotrophic lateral sclerosis (ALS) and other neurological disorders. Emerging evidence indicates a role for neurodegenerative disease linked RNA-binding proteins (RBPs) in the cellular stress response. However, the relationships between excitotoxicity, RBP function and pathology have not been explored. Here, we found that excitotoxicity induced the translocation of select ALS-linked RBPs from the nucleus to the cytoplasm within neurons. RBPs affected by excitotoxicity include TAR DNA-binding protein 43 (TDP-43) and, most robustly, fused in sarcoma/translocated in liposarcoma (FUS/TLS). FUS translocation occurs through a calcium-dependent mechanism and coincides with striking alterations in nucleocytoplasmic transport. Further, glutamate-induced upregulation of Gria2 in neurons was dependent on FUS expression, consistent with a functional role for FUS under excitotoxic stress. These findings reveal a link between prominent factors in neurodegenerative disease, namely excitotoxicity, disease-associated RBPs and nucleocytoplasmic transport.

neuroscience↗