Localized expression of regulatory genes during Ilyanassa development.
Item
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Title
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Localized expression of regulatory genes during Ilyanassa development.
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Identifier
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AAI9510735
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identifier
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9510735
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Creator
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Yan, Kang.
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Contributor
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Adviser: Jack R. Collier
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Date
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1994
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Language
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English
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Publisher
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City University of New York.
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Subject
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Biology, Molecular
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Abstract
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We have searched for the presence and the expression of a proto-oncogene and two homeobox genes in Ilyanassa. Both the H-ras-like and the homeobox genes (Sex comb reduced-like and Antennapedia-like) are present in the Ilyanassa genome and expressed during Ilyanassa embryogenesis. Immunostaining of Ilyanassa embryos with an antibody against the ras protein showed that a ras-like gene was expressed during organogenesis in both normal and lobeless embryos. The ras-like protein was first synthesized in normal 3 day old embryos and in 5 day old lobeless embryos. The ras-like protein was localized in the mesodermal lineages of both normal and lobeless embryos and involved in the differentiation of the mesodermal cells. We suggest that the ras-like gene plays a role in the induction between the mesodermal cells and other cell types or in the proliferation of the mesodermal cells. In situ hybridization provides evidence for localized transcription of the Scr-like and the Antp-like homeobox genes in the ectoderm of Ilyanassa embryos. Their transcripts were first detected in the presumptive head primordium of postgastrula embryos. Expression of both genes is then extended to the ventral region along the anterior-posterior axis of embryos in early and middle stages of organogenesis. This expression is also localized in the foot primordium. Finally, the transcripts of both genes are localized in the larval foot. They may play a role in the formation of the body axis, establishing positional information for the location of the foot primordium along the anterior-posterior axis of the embryo, and the final differentiation of the foot. The most important point is that the transcription of these two homeobox genes is polar lobe-dependent and the influence of the polar lobe on their transcription is different. This is the first evidence that cytoplasmic factors localized in the polar lobe affect the transcription of specific genes.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
