Biology subjects

Hosoya, S.

Publications and source records attributed to Hosoya, S..

3 recordsLinked to original sources

bioRxiv2026

Rapid chromosomal rearrangements and sex chromosome turnover underlie the evolution of parapatric Pacific Scomber mackerels

Teleost display remarkable species diversity despite relatively conserved karyotypes, suggesting an important role for chromosomal rearrangements in speciation. Yet this hypothesis remains poorly tested in pelagic marine fishes, as genomic studies have predominantly focused on freshwater and coastal taxa. In this study, we investigated the genomic basis of hybrid incompatibility between two parapatric Pacific mackerels, Scomber japonicus and S. australasicus, hypothesizing chromosomal rearrangements as the major driving forces. We generated haplotype-resolved de novo genome assemblies for both Pacific species and assessed genomic rearrangements along with the genome of the Atlantic species, S. scombrus, reconstructed from publicly available data. Comparative genomic analyses revealed extensive chromosomal rearrangements across the genomes. Notably, the rate of chromosomal inversions was approximately sevenfold higher between the two Pacific species than between allopatric lineages. These rearrangements included complex structural changes involving megabase-scale inversions and associated translocations. Our analyses also showed that the sex chromosomes of the three species evolved independently. In the two Pacific species, large recombination-suppression regions (>10 Mb) arose convergently but through distinct mechanisms: tandem chromosomal inversions in S. japonicus and, most likely, transposable element-mediated sequence divergence in S. australasicus. By contrast, recombination suppression in S. scombrus is restricted to a [~]14 kb hemizygous region containing amhr2Y, generated by duplication and translocation. Population-level analyses further revealed ongoing evolution of recombination-suppressed regions in the Pacific species and uncovered multiple Y chromosome lineages in S. australasicus that differ markedly in the extent of recombination suppression. Together, these results demonstrate rapid structural genome evolution in Scomber and provide a genomic framework for understanding how chromosomal rearrangements contribute to reproductive isolation, sex chromosome turnover, and the diversification of pelagic marine fishes.

evolutionary biology↗

bioRxiv2022

Novel therapeutic strategies for injured endometrium: Autologous intrauterine transplantation of menstrual blood-derived cells from infertile patients

BackgroundMenstrual blood-derived cells show regenerative potential as a mesenchymal stem cell and may therefore be a novel stem cell source of treatment for refractory infertility with injured endometrium. However, there have been few pre-clinical studies using cells from infertile patients, which needs to be addressed before establishing an autologous transplantation. Herein, we aimed to investigate the therapeutic capacity of menstrual blood-derived cells from infertile patients on endometrial infertility. MethodsWe collected menstrual blood-derived cells from volunteers and infertile patients, and confirmed their mesenchymal stem cell phenotype by flowcytometry and induction of tri-lineage differentiation. We compared the proliferative and paracrine capacities of these cells. Furthermore, we also investigated the regenerative potential and safety concerns of the intrauterine transplantation of infertile patient-derived cells using a mouse model with mechanically injured endometrium. ResultsMenstrual blood-derived cells from both infertile patients and volunteers showed phenotypic characteristics of mesenchymal stem cells. In vitro proliferative and paracrine capacities for wound healing and angiogenesis were equal for both samples. Furthermore, the transplantation of infertile patient-derived cells into uterine horns of the mouse model ameliorated endometrial thickness, prevented fibrosis and improved fertility outcomes without any apparent complications. ConclusionsIn our preclinical study, intrauterine transplantation of menstrual blood-derived cells may be a novel and attractive stem cell source for the curative and prophylactic therapy for injured endometrium. Further studies will be warranted for future clinical application.

cell biology↗

bioRxiv2021

Repeated translocation of a supergene underlying rapid sex chromosome turnover in Takifugu fish

Recent studies have revealed a surprising diversity of sex chromosomes in vertebrates. However, the detailed mechanism of their turnover is still elusive. To understand this process, it is necessary to compare closely related species in terms of sex-determining genes and the chromosomes harboring them. Here, we explored the genus Takifugu, in which one strong candidate sex-determining gene, Amhr2, has been identified. To trace the processes involved in transitions in the sex determination system in this genus, we studied 12 species and found that while the Amhr2 locus likely determines sex in the majority of Takifugu species, three species have acquired sex-determining loci at different chromosomal locations. Nevertheless, the generation of genome assemblies for the three species revealed that they share a portion of the male-specific supergene that contains a candidate sex-determining gene, GsdfY, along with genes that potentially play a role in male fitness. The shared supergene span approximately 100 kb and are flanked by two duplicated regions characterized by CACTA transposable elements. These results suggest that the shared supergene has taken over the role of sex-determining locus from Amhr2 in lineages leading to the three species, and repeated translocations of the supergene underlie the turnover of sex chromosomes in these lineages. These findings highlight the underestimated role of a mobile supergene in the turnover of sex chromosomes in vertebrates. SignificanceAlthough turnover of sex chromosomes is very common in many vertebrate lineages, the transition process is still elusive. We studied the sex-determining region (SDR) of 12 congeneric fish species. We found that while nine species retained their ancestral SDR, three species had acquired derived SDRs. Although the derived SDRs resided in three different chromosomes, they harbored a shared supergene flanked by two putative transposable elements. The results highlight the underestimated role of a mobile supergene in turnover of sex chromosomes in vertebrates.

genomics↗