Search bioRxiv⌕ Search

Biology subjects

Shiozawa, S.

Publications and source records attributed to Shiozawa, S..

3 recordsLinked to original sources

AI-Driven System for Large-Scale Automated Collection of Mouse Profile Images

As with human communication, recent studies have revealed that animals convey a substantial amount of information through their facial expressions. In these studies, artificial intelligence (AI) technologies have been increasingly employed to analyze animal facial image data. However, collecting large amounts of facial image data for such studies has been labor-intensive. In this study, we developed a system that automatically recognizes and saves the faces of freely moving mice using AI-based object detection and image classification technologies. Through validation experiments, we confirmed that the system can detect, classify, and save a variety of mouse profiles with high accuracy. To further expand the versatility of the system for diverse research applications, the technology has been improved to include a feature for determining mouse sex based on their profiles, leveraging AI algorithms for this purpose. A small dataset was used to evaluate the performance of the sex determination system, yielding 100% accuracy for both male and female classifications. This application enables researchers to efficiently collect facial image data, providing high-quality datasets suitable for AI training. Consequently, the efficiency of facial expression analysis in mice is significantly improved. Importantly, this technology is not limited to mice and has the potential to be applied to other animal species and a wide range of research fields, offering promising potential for diverse applications.

animal behavior and cognition↗

Non-viral derivation of induced pluripotent stem cells from the canine umbilical cord

In our previous study, canine induced pluripotent stem cells (iPSCs) were successfully generated from skin-derived fibroblasts, without the use of viral vectors. However, for clinical application of canine iPSCs in veterinary regenerative medicine, iPSCs generated from less invasive cell sources would be desirable. Therefore, the purpose of this study was to generate iPSCs from canine umbilical cords discarded at fetal birth. Canine umbilical cords were cut into small pieces and cultured in Dulbeccos modified Eagles medium supplemented with 10% fetal bovine serum. Episomal vectors carrying 10 reprogramming gene sets were introduced into fibroblasts obtained from the umbilical cord using electroporation. When putative iPSCs colonies emerged, constitutive cell characterization was performed to evaluate cell morphology, proliferative potential, alkaline phosphatase staining, expression of stem cell markers, and the ability to differentiate into a trilineage following embryoid body and teratoma formation. Multiple putative iPSC colonies formed when reprogramming gene sets were introduced into fibroblasts obtained from the canine umbilical cord. The resulting colony cells stained positive for alkaline phosphatase, and showed expression of OCT4, SOX2, NANOG, SSEA1, and SSEA3 on fluorescent immunostaining for stem cell markers. Furthermore, the mRNA expression of canine endogenous OCT4, SOX2, and NANOG significantly increased, confirming the multi-differentiation potential of cells after embryoid and teratoma formation. In this study, iPSCs were successfully generated from canine umbilical cord without the use of a viral vector. Furthermore, canine umbilical cord-derived iPSCs were successfully cultured in a feeder-free manner. This study contributes to the development of veterinary regenerative medicine by using canine iPSCs.

cell biology↗

Modeling the marmoset brain using embryonic stem cell-derived cerebral assembloids

Studying the non-human primate (NHP) brain is required for the translation of rodent research to humans, but remains a challenge for molecular, cellular, and circuit-level analyses in the NHP brain due to the lack of in vitro NHP brain system. Here, we report an in vitro NHP cerebral model using marmoset (Callithrix jacchus) embryonic stem cell-derived cerebral assembloids (CAs) that recapitulate inhibitory neuron migration and cortical network activity. Cortical organoids (COs) and ganglionic eminence organoids (GEOs) were induced from cjESCs and fused to generate CAs. GEO cells expressing the inhibitory neuron marker LHX6 migrated toward the cortical side of CAs. COs developed their neural activity from a synchronized pattern to an unsynchronized pattern as COs matured. CAs showed mature neural activity with an unsynchronized pattern. The marmoset assembloid system will provide an in vitro platform for the NHP neurobiology and facilitate translation into humans in neuroscience research, regenerative medicine, and drug discovery.

neuroscience↗