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
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
بیولوژی سلول
پیش نمایش صفحه اول مقاله

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 (Gbâ² cad) transcript was formed in the early-stage embryo, and then Gbâ² cad was expressed in the posterior growth zone until the posterior segmentation was completed. Reduction of Gbâ² 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 Gbâ² cad probably through the transcriptional regulation of gap genes including Gbâ² hunchback and Gbâ² Krüppel. Furthermore, Gbâ² 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 Gbâ² 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
Journal: Mechanisms of Development - Volume 122, Issue 2, February 2005, Pages 231-239
نویسندگان
Yohei Shinmyo, Taro Mito, Takashi Matsushita, Isao Sarashina, Katsuyuki Miyawaki, Hideyo Ohuchi, Sumihare Noji,