Biology subjects

Saito, H.

Publications and source records attributed to Saito, H..

3 recordsLinked to original sources

bioRxiv2018

Prediction of environmental response in field-grown rice using expression-dynamics-QTL

How genetic variations affect gene expression dynamics of field-grown plants remains unclear. Using statistical analysis of large-scale time-series RNA-sequencing of field-grown rice from chromosome segment substitution lines (CSSLs), we identified 1675 expression dynamics quantitative trait loci (edQTLs) leading to polymorphisms in expression dynamics under field conditions. Based on the edQTL and environmental information, we successfully predicted gene expression under environments different from training environments, and in rice cultivars with more complex genotypes than the CSSLs. Overall, edQTL identification helped understanding the genetic architecture of expression dynamics under field conditions, which is difficult to assess with laboratory experiments1.The prediction of expression based on edQTL and environmental information will contribute to crop breeding by increasing the accuracy of trait prediction under diverse conditions.

bioinformatics↗

bioRxiv2018

Cerebellar nuclei neurons dictate growth of the cortex through developmental scaling of presynaptic Purkinje cells

Efficient function of neural systems requires the production of specific cell types in the correct proportions. Here we report that reduction of the earliest born neurons of the cerebellum, excitatory cerebellar nuclei neurons (eCN), results in a subsequent reduction in growth of the cerebellar cortex due to an accompanying loss of their presynaptic target Purkinje cells. Conditional knockout of the homeobox genes En1 and En2 (En1/2) in the rhombic lip-derived eCN and granule cell precursors leads to embryonic loss of a subset of medial eCN and cell non-autonomous and location specific loss of Purkinje cells, with subsequent proportional scaling down of cortex growth. We propose that subsets of eCN dictate the survival of their specific Purkinje cell partners, and in turn sonic hedgehog secreted by Purkinje cells scales the expansion of granule cells and interneurons to produce functional local circuits and the proper folded morphology of the cerebellum.

developmental biology↗

bioRxiv2018

Age-dependent dormant resident progenitors are stimulated by injury to regenerate Purkinje neurons

Outside of the neurogenic niches of the brain, postmitotic neurons have not been found to undergo efficient regeneration. Here we demonstrate that Purkinje cells (PCs), which are born at midgestation and are crucial for both development and function of cerebellar circuits, are rapidly and fully regenerated following their ablation at birth. New PCs are produced by a previously unidentified progenitor population and support normal cerebellum development. The number of PC progenitors and their regenerative capacity, however, diminish soon after birth, and consequently PCs are poorly replenished when ablated at postnatal day 5. Nevertheless, the PC-depleted cerebella reach a normal size by increasing cell size, but scaling of neuron types is disrupted and cerebellar function is impaired. Our findings thus provide a new paradigm in the field of neuron regeneration by identifying a unipotent neural progenitor that buffers against perinatal brain injury in a stage-dependent process.\n\nOne sentence summaryInjury induces a dormant progenitor population present at birth to regenerate cerebellar neurons in a time-dependent manner.

developmental biology↗