Masahiro Uesaka

Tohoku University | Tohokudai · Graduate School of Life Sciences

In this study, we comprehensively searched for fish‐specific genes in gnathostomes that contribute to development of the fin, a fish‐specific trait. Many previous reports suggested that animal group‐specific genes are often important for group‐specific traits. Clarifying the roles of fish‐specific genes in fin development of gnathostomes, for examp...

Polyploidy or whole-genome duplication (WGD) is a major event that drastically reshapes genome architecture and is often assumed to be causally associated with organismal innovations and radiations. The 2R hypothesis suggests that two WGD events (1R and 2R) occurred during early vertebrate evolution. However, the timing of the 2R event relative to...

Whole genome duplications (WGDs) are major events that drastically reshape genome architecture and are causally associated with organismal innovations and radiations. The 2R Hypothesis suggests that two WGD events (1R and 2R) occurred during early vertebrate evolution. However, the veracity and timing of the 2R event relative to the divergence of g...

Whole genome duplications (WGDs) are major events that drastically reshape genome architecture and are causally associated with organismal innovations and radiations ¹ . The 2R Hypothesis suggests that two WGD events (1R and 2R) occurred during early vertebrate evolution 2,3 . However, the veracity and timing of the 2R event relative to the diverge...

While the concept of “evolutionary conservation” has enabled biologists to explain many ancestral features and traits, it has also frequently been misused to evaluate the degree of changes from a common ancestor, or “derivedness”. We propose that the distinction of these two concepts allows us to properly understand phenotypic and organismal evolut...

Species retaining ancestral features, such as species called living fossils, are often regarded as less derived than their sister groups, but such discussions are usually based on qualitative enumeration of conserved traits. This approach creates a major barrier, especially when quantifying the degree of phenotypic evolution or degree of derivednes...

Rett syndrome (RTT) is a severe neurological disorder, with impaired brain development caused by mutations in MECP2; however, the underlying mechanism remains elusive. We know from previous work that MeCP2 facilitates the processing of a specific microRNA, miR-199a, by associating with the Drosha complex to regulate neuronal functions. Here, we sho...

A Correction to this paper has been published: https://doi.org/10.1038/s42003-021-02005-4

Recapitulation is a hypothetical concept that assumes embryogenesis of an animal parallels its own phylogenetic history, sequentially developing from more ancestral features to more derived ones. This concept predicts that the earliest developmental stage of various animals should represent the most evolutionarily conserved patterns. Recent transcr...

In the mammalian brain, neuronal networks are supported by glial cells. All of the neural cell types, i.e., neurons, astrocytes and oligodendrocytes, are generated from neural stem cells (NSCs). Accumulating evidence suggests that the differentiation capacity of NSCs is conferred by cell-intrinsic epigenetic changes in a spatiotemporal manner. In t...

To understand Haeckel's idea of recapitulation with modern evolutionary biology, one has to realize how evolutionarily conserved embryonic stages appear sequentially in developmental processes as chains of causality. Whether the idea of evolution was accepted or not, Haeckel and von Baer commonly saw an importance of a particularly conserved mid‐em...

Echinoderms are an exceptional group of bilaterians that develop pentameral adult symmetry from a bilaterally symmetric larva. However, the genetic basis in evolution and development of this unique transformation remains to be clarified. Here we report newly sequenced genomes, developmental transcriptomes, and proteomes of diverse echinoderms inclu...

Abstract The relationship between development and evolution has been a central theme in evolutionary developmental biology. Across the vertebrates, the most highly conserved gene expression profiles are found at mid-embryonic, organogenesis stages, whereas those at earlier and later stages are more diverged. This hourglass-like pattern of divergenc...

The relationship between development and evolution is a central topic in evolutionary biology. Recent transcriptome-based studies support the developmental hourglass model, which predicts that the animal embryogenetic program is most strongly conserved at mid-embryonic stages. This model does not necessarily contradict the classical hypothesis that...

Background Understanding the general trends in developmental changes during animal evolution, which are often associated with morphological diversification, has long been a central issue in evolutionary developmental biology. Recent comparative transcriptomic studies revealed that gene expression profiles of mid-embryonic period tend to be more evo...

Despite morphological diversification of chordates over 550 million years of evolution, their shared basic anatomical pattern (or 'bodyplan') remains conserved by unknown mechanisms. The developmental hourglass model attributes this to phylum-wide conserved, constrained organogenesis stages that pattern the bodyplan (the phylotype hypothesis); howe...

Background Recent transcriptome analyses have shown that long non-coding RNAs (ncRNAs) play extensive roles in transcriptional regulation. In particular, we have reported that promoter-associated ncRNAs (pancRNAs) activate the partner gene expression via local epigenetic changes. ResultsHere, we identify thousands of genes under pancRNA-mediated tr...

Rett syndrome (RTT) is a neurodevelopmental disorder caused by MECP2 mutations. Although emerging evidence suggests that MeCP2 deficiency is associated with dysregulation of mechanistic target of rapamycin (mTOR), which functions as a hub for various signaling pathways, the mechanism underlying this association and the molecular pathophysiology of...

In mice, zygotic activation occurs for a wide variety of genes, mainly at the 2-cell stage. Long noncoding RNAs (lncRNAs) are increasingly being recognized as modulators of gene expression. In this study, directional RNA-seq of MII oocytes and 2-cell embryos identified more than 1000 divergently transcribed lncRNA/mRNA gene pairs. Expression of the...

In the mammalian brain, epigenetic mechanisms are clearly involved in the regulation of self-renewal of neural stem cells and the derivation of their descendants, i.e. neurons, astrocytes and oligodendrocytes, according to the developmental timing and the microenvironment, the 'niche'. Interestingly, local epigenetic changes occur, concomitantly wi...

KEY CONCEPTS ● During cortical development, neural stem cells sequentially acquire abilities to differentiate into neurons and glial cells in response to combinations of spatiotemporally regulated extrinsic factors and cell-intrinsic epigenetic changes. ● Combinations of trans-acting epigenetic modifiers can modulate the global and local opening an...

The majority of non-coding RNAs (ncRNAs) involved in mRNA metabolism in mammals have been believed to downregulate the corresponding mRNA expression level in a pre- or post-transcriptional manner by forming short or long ncRNA-mRNA duplex structures. Information on non-duplex-forming long ncRNAs is now also rapidly accumulating. To examine the dire...

A growing number of noncoding RNAs (ncRNAs) are thought to be involved in sequence-specific alterations of epigenetic processes, mostly causing gene repression. In this study, promoter-associated ncRNAs (pancRNAs >200 nucleotides in size) that were endogenously generated from the sense strand at Map2b, antisense strand at Nefl, and both strands at...

An increasing number of noncoding RNAs (ncRNAs) has been identified. Targets of ncRNAs include not only mRNA, but also genomic DNA. It can be hypothesized that ncRNAs derived from gene regulatory regions are involved in sequence-specific alterations of epigenetic processes. We discovered novel endogenous polyA+ ncRNAs (>200 nt in size) derived from...