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|Title: ||Hypoxia impairs primordial germ cells (PGCs) development in zebrafish (Danio rerio) embryos|
|Other Titles: ||Di yang sun hai ban ma yu pei tai yuan shi sheng zhi xi bao de fa yu|
|Authors: ||Lo, Kwok Hong Andy (盧國匡)|
|Department: ||Department of Biology and Chemistry|
|Degree: ||Master of Philosophy|
|Issue Date: ||2009|
|Publisher: ||City University of Hong Kong|
|Subjects: ||Zebra danio -- Effect of Anoxemia on.|
Zebra danio -- Embryos.
|Notes: ||CityU Call Number: QL638.C94 L6 2009|
163, 4 leaves : ill. (some col.) 30 cm.
Thesis (M.Phil.)--City University of Hong Kong, 2009.
Includes bibliographical references (leaves 142-157)
|Abstract: ||Primordial Germ Cells (PGCs) are germ cell precursors. They become gametes during
gametogenesis upon sexual maturation in animals. Therefore, alteration of PGC
development could impair reproduction. PGC development has been studied in many
organisms. In zebrafish, vasa and nanos1 are two well known PGC marker genes, and
they are both essential for PGC development. By using whole mount in situ
hybridization with vasa and nos1 riboprobes to label PGCs, two approaches have been
adopted to test the hypothesis that hypoxia causes a reduction of PGCs in terms of
number and volume. Direct cell counting showed fewer numbers of PGCs in hypoxic
stressed embryos (21.8 +/- 5.4) when compared with the control (30.6 +/- 5.2).
Confocal microscopy also revealed a reduction in the volume of PGCs in embryos
exposed to hypoxia (20874 +/- 4603μm3), as compared with the control (31142 +/-
1831 μm3). GFP nos1 3’UTR-injected embryos exposed to hypoxia showed mis-migrated PGCs in cranial regions, dorsal caudal regions and yolk cell extension.
Real-time PCR showed that expression of igfbp1 was up-regulated; suggesting that
igfbp1 induction under hypoxia may be the cause of the observed PGCs migration
defect. Over-expression of HIF-1 α resulted in hypoxia-induced PGC migration defect
and it could be rescued by IGFBP1 morpholino. For the first time, evidence has been
provided that hypoxia induced IGFBP1, which suppresses IGF signalling and results
in PGC migration failure, leading to fewer numbers and lower volumes of PGCs in
the genital ridge.|
|Online Catalog Link: ||http://lib.cityu.edu.hk/record=b2367136|
|Appears in Collections:||BCH - Master of Philosophy |
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