A new chromosome-assigned Mongolian gerbil genome allows characterization of complete centromeres and a fully heterochromatic chromosome

This is the final version. Available on open access from Oxford University Press via the DOI in this recordData Availability: All sequencing data and the genome are available under SRA BioProject PRJNA397533. Specific accession numbers can be found in supplementary material S1, Supplementary Material online. This Whole Genome Shotgun project has been deposited at DDBJ/ENA/GenBank under the accession JAODIK000000000. The version described in this paper is version JAODIK010000000. The genetic map, a vcf of the genetic markers and their genotypes in the mapping panel, the gff of the gene annotations, the gff of the repetitive element annotations, and “Supplemental_Material 3_codebase.zip”, can be found in the Dryad repository here: Brekke, Thomas D. (2022), Data for “The origin of a new chromosome in gerbils”, Dryad, Dataset, https://doi.org/10.5061/dryad.1vhhmgqws.Chromosome-scale genome assemblies based on ultralong-read sequencing technologies are able to illuminate previously intractable aspects of genome biology such as fine-scale centromere structure and large-scale variation in genome features such as heterochromatin, GC content, recombination rate, and gene content. We present here a new chromosome-scale genome of the Mongolian gerbil (Meriones unguiculatus), which includes the complete sequence of all centromeres. Gerbils are thus the one of the first vertebrates to have their centromeres completely sequenced. Gerbil centromeres are composed of four different repeats of length 6, 37, 127, or 1,747 bp, which occur in simple alternating arrays and span 1-6 Mb. Gerbil genomes have both an extensive set of GC-rich genes and chromosomes strikingly enriched for constitutive heterochromatin. We sought to determine if there was a link between these two phenomena and found that the two heterochromatic chromosomes of the Mongolian gerbil have distinct underpinnings: Chromosome 5 has a large block of intraarm heterochromatin as the result of a massive expansion of centromeric repeats, while chromosome 13 is comprised of extremely large (>150 kb) repeated sequences. In addition to characterizing centromeres, our results demonstrate the importance of including karyotypic features such as chromosome number and the locations of centromeres in the interpretation of genome sequence data and highlight novel patterns involved in the evolution of chromosomes.Leverhulme TrustNatural Environment Research Council (NERC)Ministerio de Economía y Competitivida

Myosin VI small insert isoform maintains exocytosis by tethering secretory granules to the cortical actin.

Before undergoing neuroexocytosis, secretory granules (SGs) are mobilized and tethered to the cortical actin network by an unknown mechanism. Using an SG pull-down assay and mass spectrometry, we found that myosin VI was recruited to SGs in a Ca(2+)-dependent manner. Interfering with myosin VI function in PC12 cells reduced the density of SGs near the plasma membrane without affecting their biogenesis. Myosin VI knockdown selectively impaired a late phase of exocytosis, consistent with a replenishment defect. This exocytic defect was selectively rescued by expression of the myosin VI small insert (SI) isoform, which efficiently tethered SGs to the cortical actin network. These myosin VI SI-specific effects were prevented by deletion of a c-Src kinase phosphorylation DYD motif, identified in silico. Myosin VI SI thus recruits SGs to the cortical actin network, potentially via c-Src phosphorylation, thereby maintaining an active pool of SGs near the plasma membrane

Myosin VI small insert isoform maintains exocytosis by tethering secretory granules to the cortical actin.

Before undergoing neuroexocytosis, secretory granules (SGs) are mobilized and tethered to the cortical actin network by an unknown mechanism. Using an SG pull-down assay and mass spectrometry, we found that myosin VI was recruited to SGs in a Ca(2+)-dependent manner. Interfering with myosin VI function in PC12 cells reduced the density of SGs near the plasma membrane without affecting their biogenesis. Myosin VI knockdown selectively impaired a late phase of exocytosis, consistent with a replenishment defect. This exocytic defect was selectively rescued by expression of the myosin VI small insert (SI) isoform, which efficiently tethered SGs to the cortical actin network. These myosin VI SI-specific effects were prevented by deletion of a c-Src kinase phosphorylation DYD motif, identified in silico. Myosin VI SI thus recruits SGs to the cortical actin network, potentially via c-Src phosphorylation, thereby maintaining an active pool of SGs near the plasma membrane

The Impact of Facial Aesthetic and Reconstructive Surgeries on Patients’ Quality of Life

The aim of the present prospective and descriptive study was to assess the impact of facial aesthetic and reconstructive surgeries on quality of life. Ninety-one patients, of whom 43 had aesthetic surgery and 48 had reconstructive surgery, were analysed. The data were collected using the patient information form, body cathexis scale, and short form (SF)-36 quality of life scale. There were significant differences between before and after the surgery in both groups in terms of body cathexis scale and quality of life (p < 0.05 for both). It was observed that problems regarding the body image perception were encountered more, and the quality of life was poorer in both aesthetic and reconstructive surgery patients before the surgery. However, the problems were decreased, and the quality of life was enhanced after the surgery. Among the parameters of SF-36 quality of life scale, particularly the mean scores of social functioning, physical role functioning, emotional role functioning, mental health, and vitality/fatigue were found low before the surgery, whereas the mean scores were significantly improved after the surgery. The results revealed that facial aesthetic and reconstructive surgical interventions favourably affected the body image perception and self-esteem and that positive reflections in emotional, social, and mental aspects were effective in enhancing self-confidence and quality of life of the individual