title: Alterations in ambient salinity and pH lead to modulation of developmental gene expression in Microhyla ornata (Duméril and Bibron) and Xenopus laevis (Daudin).
abstract: Naturally fertilized Microhyla ornata and Xenopus laevis embryos at dorsal lip of blastopore stage were exposed to 0.3, and 0.6% sodium chloride for high salinity treatment and dilute hydrochloric acid and sodium hydroxide for treatment with low and high pH, respectively. After treatment for different durations, embryos were studied morphologically and using in situ hybridization with selected genes important for normal development and for coping with environmental stress. Altered salinity and pH caused defects in axis formation and neural tube closure, delay in hatching, abnormal swimming of tadpoles and even developmental arrest. This was accompanied by significant decrease in the expression of selected development-regulating genes like goosecoid (required for gastrulation movements), brachyury (mesodermal marker gene), noggin (involved in neural induction), NCAM (required for neural cell adhesion) and MyoD (essential for muscle development), and considerable increase in the transcription of stress response genes hsp30 and hsp70. Altering the expression of embryonic genes could be one of the mechanisms through which environmental factors influence development of amphibian embryos.
authors.affiliation: Division of Animal Sciences, Agharkar Research Institute, Pune 411 004, India.
authors.forename: Bhagyashri
authors.initials: B
authors.lastname: Chougule
authors.forename: Makoto
authors.initials: M
authors.lastname: Asashima
authors.forename: Vidya
authors.initials: V
authors.lastname: Patwardhan
authors.forename: Surendra
authors.initials: S
authors.lastname: Ghaskadbi
mesh_terms: D000818:Animals; D001001:Anura / Q000196:embryology* / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D006863:Hydrogen-Ion Concentration; D012965:Sodium Chloride / Q000032:analysis*; D014982:Xenopus laevis / Q000196:embryology* / Q000235:genetics
chemical_list: D012965:Sodium Chloride