title: Marsupial tammar wallaby delivers milk bioactives to altricial pouch young to support lung development.
abstract: Our research is exploiting the marsupial as a model to understand the signals required for lung development. Marsupials have a unique reproductive strategy, the mother gives birth to altricial neonate with an immature lung and the changes in milk composition during lactation in marsupials appears to provide bioactives that can regulate diverse aspects of lung development, including branching morphogenesis, cell proliferation and cell differentiation. These effects are seen with milk collected between 25 and 100days postpartum. To better understand the temporal effects of milk composition on postnatal lung development we used a cross-fostering technique to restrict the tammar pouch young to milk composition not extending beyond day 25 for 45days of its early postnatal life. These particular time points were selected as our previous study showed that milk protein collected prior to ~day 25 had no developmental effect on mouse embryonic lungs in culture. The comparative analysis of the foster group and control young at day 45 postpartum demonstrated that foster pouch young had significantly reduced lung size. The lungs in fostered young were comprised of large intermediate tissue, had a reduced size of airway lumen and a higher percentage of parenchymal tissue. In addition, expression of marker genes for lung development (BMP4, WNT11, AQP-4, HOPX and SPB) were significantly reduced in lungs from fostered young. Further, to identify the potential bioactive expressed by mammary gland that may have developmental effect on pouch young lungs, we performed proteomics analysis on tammar milk through mass-spectrometry and listed the potential bioactives (PDGF, IGFBP5, IGFBPL1 and EGFL6) secreted in milk that may be involved in regulating pouch young lung development. The data suggest that postnatal lung development in the tammar young is most likely regulated by maternal signalling factors supplied through milk.
authors.affiliation: Department of Ecology, Evolution and Behavior, Institute of Life Science, Hebrew University, Edmund J Safra Campus, Jerusalem, Israel. Electronic address: vengamanaidumodepalli@gmail.com.
authors.forename: Vengamanaidu
authors.initials: V
authors.lastname: Modepalli
authors.affiliation: CSIRO Ecosystem Sciences, GPO Box 1700, Canberra, ACT 2601, Australia. Electronic address: Lyn.Hinds@csiro.au.
authors.forename: Lyn A
authors.initials: LA
authors.lastname: Hinds
authors.affiliation: School of Medicine, Deakin University, Pigdons Road, Geelong, VIC, Australia. Electronic address: julie.sharp@deakin.edu.au.
authors.forename: Julie A
authors.initials: JA
authors.lastname: Sharp
authors.affiliation: Walter Eliza Hall Institute, 1G Royal Parade, Parkville, Victoria 3052, Australia. Electronic address: lefevre.c@wehi.edu.au.
authors.forename: Christophe
authors.initials: C
authors.lastname: Lefevre
authors.affiliation: School of Medicine, Deakin University, Pigdons Road, Geelong, VIC, Australia. Electronic address: kevin.nicholas@deakin.edu.au.
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Nicholas
mesh_terms: D000818:Animals; D049109:Cell Proliferation / Q000235:genetics; D005260:Female; D008168:Lung / Q000254:growth & development* / Q000378:metabolism; D007614:Macropodidae / Q000254:growth & development* / Q000378:metabolism; D008892:Milk / Q000378:metabolism*; D008894:Milk Proteins / Q000235:genetics / Q000378:metabolism*; D038081:Organogenesis / Q000235:genetics
chemical_list: D008894:Milk Proteins
keywords: Evolution; Lactation; Lung development; Marsupials; Milk