Development of body, head and brain features in the Australian fat-tailed dunnart (Sminthopsis crassicaudata; Marsupialia: Dasyuridae); A postnatal model of forebrain formation

PLoS One. 2017 Sep 7;12(9):e0184450. doi: 10.1371/journal.pone.0184450. eCollection 2017.

Abstract

Most of our understanding of forebrain development comes from research of eutherian mammals, such as rodents, primates, and carnivores. However, as the cerebral cortex forms largely prenatally, observation and manipulation of its development has required invasive and/or ex vivo procedures. Marsupials, on the other hand, are born at comparatively earlier stages of development and most events of forebrain formation occur once attached to the teat, thereby permitting continuous and non-invasive experimental access. Here, we take advantage of this aspect of marsupial biology to establish and characterise a resourceful laboratory model of forebrain development: the fat-tailed dunnart (Sminthopsis crassicaudata), a mouse-sized carnivorous Australian marsupial. We present an anatomical description of the postnatal development of the body, head and brain in dunnarts, and provide a staging system compatible with human and mouse developmental stages. As compared to eutherians, the orofacial region develops earlier in dunnarts, while forebrain development is largely protracted, extending for more than 40 days versus ca. 15 days in mice. We discuss the benefits of fat-tailed dunnarts as laboratory animals in studies of developmental biology, with an emphasis on how their accessibility in the pouch can help address new experimental questions, especially regarding mechanisms of brain development and evolution.

MeSH terms

  • Animals
  • Basal Forebrain / embryology*
  • Basal Forebrain / growth & development
  • Basal Forebrain / metabolism
  • Brain / embryology
  • Brain / growth & development
  • Brain / metabolism
  • Developmental Biology
  • Humans
  • Marsupialia / embryology*
  • Marsupialia / growth & development
  • Marsupialia / metabolism
  • Mice

Grants and funding

This work was funded by the National Health and Medical Research Council (NHMRC) Principal Research Fellowship 1005751 (LJR); Australian Research Council (ARC) Discovery Project 160103958 (LJR, RS); ARC Discovery Early Career Researcher Award Fellowship 160101394 (RS); NHMRC CJ Martin Early Career Fellowship (PK); Australian Postgraduate Award (LRF, LRM); UQ-QBI Doctoral scholarship (AP). The contents of this article are solely the responsibility of the authors and do not necessarily represent the official views of any of the funding bodies. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.