Biology subjects

Nakaya, M.

Publications and source records attributed to Nakaya, M..

4 recordsLinked to original sources

bioRxiv2026

Adolescent prodromal phenotypes of psychiatric disorders: insights from a novel DISC1-perturbed monkey model

Neurodevelopmental deficits frequently lead to mild but significant adolescent social and cognitive changes, representing prodromal manifestations of adult-onset psychiatric disorders in a cross-disease manner. Although experimental medicine utilizes animal models to address the mechanisms, rodent brains lack critical structures for human higher brain functions such as the dorsolateral prefrontal cortex. To fill this translational gap, we generated monkeys with an impaired DISC1 gene locus, targeting the multifunctional protein essential for neurodevelopment and involved in transdiagnostic mental health risks. Here we analyze the F0 animals by minimizing mosaicism. At ages equivalent to human adolescence, these monkeys exhibited blunted responsiveness to social stimuli and increased internal drives, mirroring altered social behaviors in the prodromal stage in humans. Resting-state functional MRI data indicated disrupted global functional connectivity and reorganization of network topology, marked by a shift in the dominance of brain hubs from prefrontal regions to sensory areas. This primate model provides a unique platform for studying psychiatric disorders, such as schizophrenia, across the developmental trajectory.

neuroscience↗

bioRxiv2026

A novel recombinant BCG vaccine using a mycobacteriophage promoter shows improved protection against tuberculosis

The limited efficacy of conventional bacillus Calmette-Guerin (BCG) vaccination against adult pulmonary tuberculosis highlights the need for improved vaccine strategies. Genome integration can overcome the plasmid instability of recombinant BCG, but we hypothesized that this approach would be constrained by reduced transcriptional activity of conventional promoters when present as a single genomic copy. Here we identified P79, a mycobacteriophage-derived promoter that sustains high-level expression from a single genomic locus and used it to construct a genome-integrated recombinant BCG, termed LRC-BCG. LRC-BCG secretes the HSP70-MMPII fusion antigen flanked by the PEST sequences, maintained stable antigen expression over serial passages, and induced strong activation of macrophages and dendritic cells in vitro. In vivo, LRC-BCG inhibited Mycobacterium tuberculosis multiplication more effectively than conventional BCG, even at low doses. These findings demonstrate the feasibility of using P79 for stable genome-integrated recombinant BCG and support LRC-BCG as a promising tuberculosis vaccine candidate.

microbiology↗

bioRxiv2024

Atlas of Cynomolgus Macaque Hematopoiesis

Self-renewal and differentiation are inherent properties of hematopoietic stem cells (HSCs) that are necessary to support hematopoiesis; however, the underlying mechanisms, especially in human, remain unclear. Here, using the cynomolgus macaque as a surrogate model, we develop a new gating strategy to isolate with high purity transplantable cynomolgus HSCs and generated a single-cell transcriptomic map of cynomolgus HSCs and progenitor cells -- that covering gestational periods previously not analyzed in human. We show that hematopoietic cells from the late-1st to early-3rd trimester fetal liver and late-2nd trimester and thereafter bone marrow have repopulating potential, closely mimicking humans. Unexpectedly however, we found unlike in human, cynomolgus HSCs express CD38 but not CD33, indicating that these cellular counterparts are molecularly distinct. Our transcriptomic analysis reveals the presence of a direct differentiation pathway from HSCs to megakaryocyte lineages, lineage-primed multipotent progenitors and also identified putative HSC surface markers. Taken together, our comprehensive dataset highlights not only the utility of cynomolgus monkeys as model systems to study hematopoiesis but also their potential for translational applications.

cell biology↗

bioRxiv2020

Chromosomal-scale De novo Genome Assemblies of Cynomolgus Macaque and Common Marmoset

Cynomolgus macaque (Macaca fascicularis) and common marmoset (Callithrix jacchus) have been widely used in human biomedical research. Their genomes were sequenced and assembled initially using short-read sequences, with the advent of massively parallel sequencing. However, the resulting contig sequences tended to remain fragmentary, and long-standing primate genome assemblies used the human genome as a reference for ordering and orienting the assembled fragments into chromosomes. Here we performed de novo genome assembly of these two species without any human genome-based bias observed in the genome assemblies released earlier. Firstly we assembled PacBio long reads, and the resultant contigs were scaffolded with Hi-C data. The scaffolded sequences obtained were further refined based on assembly results of alternate de novo assemblies and Hi-C contact maps by resolving identified inconsistencies. The final assemblies achieved N50 lengths of 149 Mb and 137 Mb for cynomolgus macaque and common marmoset, respectively, and the numbers of scaffolds longer than 10Mb are equal to their chromosome numbers. The high fidelity of our assembly is ascertained by concordance to the BAC-end read pairs observed for common marmoset, as well as a high resemblance of their karyotypic organization. Our assembly of cynomolgus macaque outperformed all the available assemblies of this species in terms of contiguity. The chromosome-scale genome assemblies produced in this study are valuable resources for non-human primate models and provide an important baseline in human biomedical research.

genomics↗