کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9913697 1550645 2005 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
caudal is required for gnathal and thoracic patterning and for posterior elongation in the intermediate-germband cricket Gryllus bimaculatus
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی بیولوژی سلول
پیش نمایش صفحه اول مقاله
caudal is required for gnathal and thoracic patterning and for posterior elongation in the intermediate-germband cricket Gryllus bimaculatus
چکیده انگلیسی
Although the molecular mechanisms directing anteroposterior patterning of the Drosophila embryo (long-germband mode) are well understood, how these mechanisms were evolved from an ancestral mode of insect embryogenesis remains largely unknown. In order to gain insight into mechanisms of evolution in insect embryogenesis, we have examined the expression and function of the orthologue of Drosophila caudal (cad) in the intermediate-germband cricket Gryllus bimaculatus. We observed that a posterior (high) to anterior (low) gradient in the levels of Gryllus bimaculatus cad (Gb′ cad) transcript was formed in the early-stage embryo, and then Gb′ cad was expressed in the posterior growth zone until the posterior segmentation was completed. Reduction of Gb′ cad expression level by RNA interference resulted in deletion of the gnathum, thorax, and abdomen in embryos, remaining only anterior head. We found that the gnathal and thoracic segments are formed by Gb′ cad probably through the transcriptional regulation of gap genes including Gb′ hunchback and Gb′ Krüppel. Furthermore, Gb′ cad was found to be involved in the posterior elongation, acting as a downstream gene in the Wingless/Armadillo signalling pathways. These findings indicate that Gb′ cad does not function as it does in Drosophila, suggesting that regulatory and functional changes of cad occurred during insect evolution. Since Wnt/Cdx pathways are involved in the posterior patterning of vertebrates, such mechanisms may be conserved in animals that undergo sequential segmentation from the posterior growth zone.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Mechanisms of Development - Volume 122, Issue 2, February 2005, Pages 231-239
نویسندگان
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