title: Conservation of Pitx1 expression during amphibian limb morphogenesis.
abstract: In contrast to the pattern of limb emergence in mammals, chicks, and the newt N. viridescens, embryos such as Xenopus laevis and Eleutherodactylus coqui initiate pelvic limb buds before they develop pectoral ones. We studied the expression of Pitx1 in X. laevis and E. coqui to determine if this paired-like homeodomain transcription factor directs differentiation specifically of the hindlimb, or if it directs the second pair of limbs to form, namely the forelimbs. We also undertook to determine if embryonic expression patterns were recapitulated during the regeneration of an amputated limb bud. Pitx1 is expressed in hindlimbs in both X. laevis and E. coqui, and expression is similar in both developing and regenerating limb buds. Expression in hindlimbs is restricted to regions of proliferating mesenchyme.
authors.affiliation: Department of Biological Sciences, University of Windsor, Canada.
authors.forename: W Y
authors.initials: WY
authors.lastname: Chang
authors.forename: F
authors.initials: F
authors.lastname: Khosrowshahian
authors.forename: M
authors.initials: M
authors.lastname: Wolanski
authors.forename: R
authors.initials: R
authors.lastname: Marshall
authors.forename: W
authors.initials: W
authors.lastname: McCormick
authors.forename: S
authors.initials: S
authors.lastname: Perry
authors.forename: M J
authors.initials: MJ
authors.lastname: Crawford
mesh_terms: D000818:Animals; D001001:Anura / Q000196:embryology* / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D005801:Genes, Homeobox; D006614:Hindlimb / Q000196:embryology / Q000254:growth & development / Q000502:physiology; D017403:In Situ Hybridization; D009024:Morphogenesis / Q000235:genetics; D051761:Paired Box Transcription Factors / Q000235:genetics*; D012038:Regeneration; D013045:Species Specificity; D029867:Xenopus Proteins / Q000235:genetics*; D014982:Xenopus laevis / Q000196:embryology* / Q000235:genetics* / Q000254:growth & development / Q000502:physiology
chemical_list: D051761:Paired Box Transcription Factors; D029867:Xenopus Proteins; C101485:homeobox protein PITX1