Mette Handberg-Thorsager

• PhD
• PostDoc Position at Max Planck Institute of Molecular Cell Biology and Genetics

The marine annelid Platynereis dumerilii is a model organism used in many research areas including evolution and development, neurobiology, ecology and regeneration. Here we present the genomes of P. dumerilii and of the closely related P. massiliensis and P. megalops, to facilitate comparative genomic approaches and help explore Platynereis biolog...

Abstract The Nereid Platynereis dumerilii (Audouin and Milne Edwards (Annales des Sciences Naturelles 1:195–269, 1833) is a marine annelid that belongs to the Nereididae, a family of errant polychaete worms. The Nereid shows a pelagobenthic life cycle: as a general characteristic for the superphylum of Lophotrochozoa/Spiralia, it has spirally cleav...

Early development of an animal from an egg involves a rapid increase in cell number and several cell fate specification events accompanied by dynamic morphogenetic changes. In order to correlate the morphological changes with the genetic events, one typically needs to monitor the living system with several imaging modalities offering different spat...

Background: During early development, patterns of cell division-embryonic cleavage-accompany the gradual restriction of blastomeres to specific cell fates. In Spiralia, which include annelids, mollusks, and flatworms, "spiral cleavage" produces a highly stereotypic, spiral-like arrangement of blastomeres and swimming trochophore-type larvae with r...

Autonomous animal locomotion, such as swimming, is modulated by neuronal networks acting on cilia or muscles. Understanding how these networks are formed and coordinated is a complex scientific problem, which requires various technical approaches. Among others, behavioral studies of developing animals treated with exogenous substances have proven t...

The spiral cleavage pattern is characteristic for Spiralia (Lophotrochozoa), a large assembly of marine invertebrates. In most cases, spiral cleavage produces freely swimming, trochophora-type larvae with a simple nervous system that controls ciliary locomotion. These larvae acquire bilateral symmetry, as manifested for example in the larval brain....

Retinoic acid (RA) is an important intercellular signaling molecule in vertebrate development, with a well-established role in the regulation of hox genes during hindbrain patterning and in neurogenesis. However, the evolutionary origin of the RA signaling pathway remains elusive. To elucidate the evolution of the RA signaling system, we characteri...

Cell lineage, cell cycle, and cell fate are tightly associated in developmental processes, but in vivo studies at single-cell resolution showing the intricacies of these associations are rare due to technical limitations. In this study on the marine annelid Platynereis dumerilii, we investigated the lineage of the 4d micromere, using high-resolutio...

Spiral cleavage is the ancestral developmental mode within the Spiralia. It covers a period of the early development characterized by asymmetric divisions with alternating division angles giving the embryo a spiral looking appearance. The position and fate of the cells are determined during the spiral cleavage thus it’s crucial for body plan format...

Cell cycle regulation plays crucial roles in morphogenesis, maintenance of pluripotency, and cell fate decisions during development. In the frog, normal progression of gastrulation requires cell cycle arrest; in tunicates, a long G2 phase in the epidermis is required for neural tube closure; in mouse embryonic stem cells, alteration of G1/S transit...

Background Selective plane illumination microscopy (SPIM a type of light-sheet microscopy) involves focusing a thin sheet of laser light through a specimen at right angles to the objective lens. As only the thin section of the specimen at the focal plane of the lens is illuminated, out of focus light is naturally absent and toxicity due to light (p...

Background: Selective plane illumination microscopy (SPIM a type of light-sheet microscopy) involves focusing a thin sheet of laser light through a specimen at right angles to the objective lens. As only the thin section of the specimen at the focal plane of the lens is illuminated, out of focus light is naturally absent and toxicity due to light (...

BACKGROUND Selective plane illumination microscopy (SPIM a type of light-sheet microscopy) involves focusing a thin sheet of laser light through a specimen at right angles to the objective lens. As only the thin section of the specimen at the focal plane of the lens is illuminated, out of focus light is naturally absent and toxicity due to light (p...

Platynereis is a marine annelid (segmented worm) which develops from an embryo into a 3-segmented larva, and then into a juvenile with many segments before reaching sexual maturity. During its various developmental stages, the worm forms and then continuously adds new segments (or regenerates them upon injury) from its posterior end. A stem cell po...

The origin of chordates has been debated for more than a century, with one key issue being the emergence of the notochord. In vertebrates, the notochord develops by convergence and extension of the chordamesoderm, a population of midline cells of unique molecular identity. We identify a population of mesodermal cells in a developing invertebrate, t...

Few studies have examined the diversity of freshwater planarians in the Iberian Peninsula and Greece. We have searched extensively for specimens, mainly in the Iberian Peninsula, and have gathered information on their taxonomy and biogeography. Two new species of Dendrocoelum and six new species of Phagocata are described. We also review the status...

Planarians can undergo dramatic changes in body size and regenerate their entire body plan from small pieces after cutting. This remarkable morphological plasticity has made them an excellent model in which to analyze phenomena such as morphogenesis, restoration of pattern and polarity, control of tissue proportions and tissue homeostasis. They hav...

Understanding stem cells is a major goal of current research because of its potential medical applications. Although great advances have been made, such as the culturing and differentiation of embryonic stem cells and reprogramming of cell fates, many basic questions remain unanswered. Describing the mechanisms underlying regeneration will help to...

Planarians are highly regenerative organisms with the ability to remake all their cell types, including the germ cells. The germ cells have been suggested to arise from totipotent neoblasts through epigenetic mechanisms. Nanos is a zinc-finger protein with a widely conserved role in the maintenance of germ cell identity. In this work, we describe t...