scholarly journals Regulation of Gene Expression by Low Levels of Ultraviolet-B Radiation in Pisum sativum: Isolation of Novel Genes by Suppression Subtractive Hybridisation

2002 ◽  
Vol 43 (4) ◽  
pp. 402-410 ◽  
Author(s):  
Helena Sävenstrand ◽  
Mikael Brosché ◽  
Åke Strid
1992 ◽  
Vol 263 (5) ◽  
pp. C1103-C1110 ◽  
Author(s):  
C. F. Rosen ◽  
D. Gajic ◽  
Q. Jia ◽  
D. J. Drucker

Ultraviolet B radiation (UVB) and phorbol esters are known to promote tumor formation in skin; however, the interaction between UVB and phorbol esters in the regulation of gene expression remains incompletely understood. To define the interaction of UVB and phorbol esters in the control of keratinocyte gene expression, we have studied the effects of the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) and UVB on the regulation of ornithine decarboxylase (ODC) gene expression in a rat keratinocyte cell line. Both UVB and TPA alone increased ODC activity and induced the expression of the ODC gene. The combination of UVB and TPA produced a further increment in ODC gene expression at 12 h, but UVB markedly attenuated the TPA induction of ODC mRNA transcripts at 3 h. Protein synthesis inhibition with cycloheximide also induced ODC mRNA transcripts, but did not eliminate the further induction of ODC gene expression by UVB or TPA. No changes in actin gene expression following exposure to TPA/UVB were detected in the same experiments. UVB and TPA alone or in combination had no effect on the transcriptional activity of an ODC-chloramphenicol acetyltransferase fusion gene in transfected rat keratinocytes. The results of these studies suggest a complex posttranscriptional interaction of phorbol esters and UVB in the control of keratinocyte gene expression.


Genetics ◽  
1984 ◽  
Vol 108 (3) ◽  
pp. 651-667
Author(s):  
Douglas P Dickinson ◽  
Kenneth W Gross ◽  
Nina Piccini ◽  
Carol M Wilson

ABSTRACT Inbred strains of mice carry Ren-1, a gene encoding the thermostable Renin-1 isozyme. Ren-1 is expressed at relatively low levels in mouse submandibular gland and kidney. Some strains also carry Ren-2, a gene encoding the thermolabile Renin-2 isozyme. Ren-2 is expressed at high levels in the mouse submandibular gland and at very low levels, if at all, in the kidney. Ren-1 and Ren-2 are closely linked on mouse chromosome 1, show extensive homology in coding and noncoding regions and provide a model for studying the regulation of gene expression. An investigation of renin genes and enzymatic activity in wild-derived mice identified several restriction site polymorphisms as well as putative variants in renin gene expression and protein structure. The number of renin genes carried by different subpopulations of wild-derived mice is consistent with the occurrence of a gene duplication event prior to the divergence of M. spretus (2.75-5.5 million yr ago). This conclusion is in agreement with a prior estimate based upon comparative sequence analysis of Ren-1 and Ren-2 from inbred laboratory mice.


2014 ◽  
Vol 5 (1) ◽  
pp. 87-98 ◽  
Author(s):  
Luke M. Holmquist ◽  
Andrew M. Ray ◽  
Betsy A. Bancroft ◽  
Nick Pinkham ◽  
Molly A. H. Webb

Abstract Endangered woundfin Plagopterus argentissimus embryos and larvae were exposed to artificial ultraviolet-B (UV-B) radiation to directly examine the effects on mortality. The experiment was part of a project assisting the Virgin River Resource Management and Recovery Program's efforts to increase hatchery production of this endangered fish. The UV-B radiation used in this experiment was administered in treatments of 0.060, 0.030, and 0.015 mW/cm2 to simulate 100, 50, and 25% of the ambient irradiance levels documented in outdoor tanks and living streams at Bubbling Ponds State Fish Hatchery, in Arizona. Embryos and larvae were exposed for 14.5 h followed by 9.5 h of darkness, in correspondence with the daylight hours at Bubbling Ponds. No embryos survived UV-B treatments; mortality among control (UV-B–free) treatments varied (5–100%) among females, indicating that there may be important parental effects that influence embryo mortality. Larval mortality was also 100% for individuals exposed to any of the three UV-B treatments. In contrast to embryo trials, larval mortality in UV-B–free treatments approached 20% for 2-d-old larvae. These experiments provide evidence that woundfin embryos and larvae are sensitive to even low levels of UV-B when exposed for 14.5 h. Susceptibility of larvae to UV-B also appears to be a function of age at exposure, with older larvae exhibiting significantly lower levels of mortality during the initial days of exposure. Experiments with UV-B mitigation strategies indicated that shade cloth, Aquashade®, and elevated dissolved organic carbon can aid in the attenuation of UV-B, and these strategies may assist hatchery managers in implementing UV-B mitigation measures during periods when woundfin are most susceptible.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1736-1736
Author(s):  
Jenna L. Galloway ◽  
Rebecca A. Wingert ◽  
Christine Thisse ◽  
Bernard Thisse ◽  
Leonard I. Zon

Abstract During vertebrate embryonic hematopoiesis, the first blood cells can be identified by expression of the transcription factor genes scl and GATA2, followed by expression of GATA1, a gene required for the erythroid lineage. A high-throughput in situ hybridization screen in zebrafish analyzed the expression pattern of 3700 clones from a hematopoietic cDNA library and discovered 24 genes with expression in the blood. Examination of gene expression in Biklf, GATA1, GATA2, and GATA1/GATA2-deficient animals revealed that most blood genes are dependent upon GATA factors for expression rather than the Krüppel-like transcription factor Biklf. Three novel genes, expressed specifically in erythroid precursors, did not require GATA factors for their expression, demonstrating that some blood genes are regulated in a GATA-independent manner. These three genes were kelch-repeat protein (kelch repeats have been implicated in diverse cellular functions from actin binding to sequestering transcriptions factors), kiaa0650, which contains an SMC-hinge domain, and testhymin, which has no known structural motifs. By using combinations of antisense morpholinos to the known hematopoietic genes biklf , GATA1, GATA2, and scl, we were able to examine the regulation of these novel genes in double and triple knock-down embryos. While expression of kelch-repeat protein was lost in the absence of GATA1 and Biklf, expression of testhymin and kiaa0650 was maintained in GATA1/GATA2/Biklf-deficient embryos, suggesting that these similarly expressed genes are differentially regulated. As with GATA1, kiaa0650 and kelch-repeat protein required Scl for their expression in the early hematopoietic mesoderm while testhymin did not. Furthermore, loss of Scl and GATA2 did not completely ablate testhymin expression, suggesting that this gene is induced by factors upstream or parallel to Scl and GATA2. Taken together, our zebrafish studies establish a regulation of gene expression by a developmental hierarchy of specific transcription factors that act in combination during blood cell maturation.


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