bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulation of catalase‐specific mRNA and its processing during development in mice
Authors: El‐Hage Samar , Singh Shiva M. 
Published: May 2005

AbstractThis study deals with the pattern of developmental expression of the catalase gene in mice. We have used a mouse catalase 2 kb cDNA (pMCT‐1) and its 1.4 kb 5′ fragment as probes to characterize the transcripts during embryonic development and differentiation. Total RNA was isolated from 8 days postconceptus (p.c.) whole embryos and from livers and carcasses of 13, 15, and 18 day p.c. embryos as well as from the livers of newborn and adult mice of the S.W. strain. The RNA was applied on slot blots, and run on agarose gels to generate northern blots. Blots were hybridized with the 32P‐labeled cDNA probe under different stringency conditions. Autoradiograms were scanned with a densitometer to quantify relative hybridization signals of RNA samples obtained from two or three individual mice representing each stage of development.The catalase transcript is detectable as early as 8 days p.c. with the beginning of somite formation. At this stage, it is primarily in the form of a 12.2 kb transcript. One additional band (2.4 kb) is also apparent at this stage although at a very low intensity. The intensity of the two bands increases with development, particularly during 13‐18 days p.c. in liver and carcass. The 2.4 kb RNA band increases sharply from day 8 through 13, 15, and 18 days p.c. and is confined primarily to the liver. Interestingly, only the 2.4 kb RNA band is seen at and after birth. The 2.4 kb RNA is the known mature message of the catalase gene in mice. The presence of large catalase‐specific RNA species (seen during development in utero only) is interpreted as the primary transcript of this gene. The complete and efficient processing of this primary transcript takes place only after birth and primarily in the liver, which may be related to the physiological role of this enzyme in oxygen metabolism, particularly stressful superoxides, expected with independent respiration. At a lower stringency wash of the northern blots, a 9.5 kb RNA was seen during a narrow window of in utero development. This 9.5 kb band may represent an uncharacterized catalase‐related gene with a possible role in development and differentiation.
Liver‐specific and high‐level expression of human serum amyloid P component gene in transgenic mice
Authors: Iwanaga Tomohisa , Wakasugi Shoji , Inomoto Takeaki , Uehira Masahiro , Ohnishi Shuji , Nishiguchi Seiji , Araki Kimi , Uno Masashi , Miyazaki Jun‐Ichi , Maeda Shuichiro , Shimada Kazunori , Yamamura Ken‐Ichi 
Published: May 2005

AbstractTo analyze the regulation of human serum amyloid P component (SAP) gene expression, we have produced seven transgenic mice. The 3.3 kb human SAP genes containing about 0.8 kb of 5′ and 1.5 kb of 3′ flanking region were injected into fertilized eggs of C57BL/6 mice. In five of the seven transgenic mice, human SAP was detected in the sera and serum concentrations were higher than that of human serum in three lines. The human SAP gene was expressed only in the liver. Amounts of human mRNA in the liver and serum concentrations of human SAP were roughly proportional to the copy number of the integrated gene. Human SAP production lowered the serum levels of mouse endogenous SAP. With the intraperitoneal administration of lipopolysaccharide, the mRNA levels in the liver and serum levels of mouse SAP increased several‐fold in both the control and transgenic mice. On the other hand, neither the mRNA nor the serum levels of human SAP increased significantly.
Temporal and tissue‐specific expression of myosin heavy chain isoforms in developing and adult avian muscle
Authors: Merrifield Peter A. , Sutherland William M. , Litvin Judith , Konigsberg Irwin R. 
Published: May 2005

AbstractWe have raised monoclonal antibodies (Mabs) to myosin heavy chain isoforms (MHCs) that have specific patterns of temporal expression during the development of quail pectoral muscle and that are expressed in very restricted, tissue‐specific patterns in adult birds. We find that an early embryonic, a perinatal, and an adult‐specific, fast myosin heavy chain a.e co‐expressed at different levels in the pectoral muscle of 8‐12 day quail embryos. The early embryonic MHC disappears from the pectoral muscle at approximately 14 days in ovo, whereas the perinatal MHC persists until 26 days post‐hatching. The adult‐specific MHC accumulates preferentially and eventually completely replaces the other isoforms. These Mabs cross‐react with the homologous isoforms of the chick and detect a similar pattern of MHC expression in the pectoral muscle of developing chicks. Although the early embryonic and perinatal MHC isoforms recognized by our Mabs are expressed in the pectoral muscle only during distinct developmental stages, our Mabs also recognize MHC isoforms present in the heart and extraocular muscle of adult quail. Immunofingerprinting using Staphylococcus aureus protease V8 suggests that the early embryonic and perinatal MHC isoforms that we see are strongly homologous with the adult ventricular and extraocular muscle isoforms, respectively. These observations suggest that at least three distinct MHC isoforms, which are normally expressed in adult muscles, are co‐expressed during the early development of the pectoral muscle in birds. In this respect, the pattern of expression of the MHCs recognized by our Mabs in developing, fast muscle is very similar to the patterns described for other muscle contractile proteins.
Tissue‐ and developmental stage‐specific expression of the rat ornithine carbamoyltransferase gene in transgenic mice
Authors: Murakami Takashi , Takiguchi Masaki , Inomoto Takeaki , Yamamura Ken‐Ichi , Mori Masataka 
Published: May 2005

AbstractRat ornithine carbamoyltransferase (OCT; EC 2.1.3.3) is encoded by a large gene of 75 kilobases. Expression of this gene is restricted to the liver and small intestine, and there is an increase in expression late in gestation. The recombinant gene carrying 1.3 kilobases of the 5′ flanking region of the gene fused to the rat OCT cDNA was microinjected into fertilized eggs, and 17 transgenic mice were produced. Expression in the liver of the transgene was detected in three mice. In these mice, the transgene expression was observed exclusively in the liver and small intestine. Expression of the transgene in the intestine was comparable to that of the endogenous mouse OCT gene, whereas expression in the liver was much lower than that of the endogenous gene. The developmental pattern of expression of the transgene was similar to that of the endogenous gene. Therefore, the 5′ flanking sequence of the rat OCT gene seems to be sufficient for the developmental and tissue‐specific expression of the gene. An explanation for low expression in the liver remains the subject of ongoing study.
Tissue‐Specific effects of maize bronze gene promoter mutations induced by Ds1 insertion and excision
Authors: Sullivan Thomas D. , Schiefelbein John W. , Nelson Oliver E. 
Published: May 2005

AbstractBz‐wm is an allele of the Bz locus of maize isolated by McClintock (1962) as a derivative of bz‐m2 It contains a Ds1 insertion 63 bp upstream of the start of transcription and a 3 bp insertion in the coding region at the site of the Ac element that was present in bz‐m2. Bz‐wm produces, in the aleurone layer of the endosperm, low amounts (∼1% of wild‐type) of a Bz‐gene encoded UDP‐glucose: flavoid 3‐0‐glucosyltransferase (UFGT) polypeptide with altered thermal stability. Three phenotypically wild‐type derivatives, Bz' (wm)‐1, Bz' (wm)‐2 and Bz' (wm)‐3, were isolated in the presence of Ac and shown to have excised the Ds1 element but not fully restored UFGT activity in endosperm assays. In the studies reported here, we have further analyzed these Bz' derivatives of Bz‐wm by determining the DNA sequences left behind on Ds1 excision, and by measuring the amount of UFGT activity and/or Bz mRNA conditioned by Bz‐wm and the Bz' derivatives in different tissues. The data indicate that tissue‐specific differences in expression of the Bz gene have been produced in alleles with mutations caused by transposable elements Ac and Ds. These mutations may affect either the amount of Bz transcription or the stability of the UFGT polypeptide. The sequence or spacing in the ‐63 region of the Bz promoter appears to be critical for maximum expression in aleurone and husk but not in pollen and pigmented seedling tissue.
Genome juggling by transposons: Tam3‐induced rearrangements in Antirrhinum majus
Authors: Martinm Cathie , Lister Clare 
Published: May 2005

AbstractTransposable elements are well known for their ability to generate large‐ and small‐scale rearrangements of the sequences flanking their insertion sites. These include deletions, inversions, and duplications.Tam3, a transposon from the Snapdragon (Antirrhinum majus), is highly active in the generation of such rearrangements. We have analysed a number of Tam3‐induced rearrangements at the nivea (niv) locus by Southern blotting, cloning, and sequence determination. The data obtained from these analyses have led to an understanding of the mechanisms by which these complex alleles were formed. We have shown that the primary rearrangements usually occur without excision of the element and therefore result from aberrant transposition attempts. Subsequent rearrangements may occur on excision of the element.Finally, we suggest how the analysis of such rearrangements may not only provide information about Tam3 transposition but also show how transposon‐induced rearrangements may influence the structure and function of the genome as a whole.
Mu1‐Induced mutant alleles of maize exhibit background‐dependent changes in expression and RNA processing
Authors: Strommer Judith , Ortiz Daniel 
Published: May 2005

AbstractWe have examined effects of mutations created by transposition of the Mu1 element of maize into genes coding for Adh1 and Sh1, by means of allozyme measurements, DNA and RNA hybridization, cloning, and sequencing. From our analysis of mutant alleles we conclude that the element acts both to reduce steady‐state levels of RNA and to induce aberrant processing of primary transcripts. We also conclude that genetic background can exert considerable influence in determining the degree to which Mu affects these aspects of gene expression.
Genetic analyses of putative two‐element systems regulating somatic mutability in Mutator‐induced aleurone mutants of maize
Authors: Robertson Donald S. , Stinard Philip S. 
Published: May 2005

AbstractThe Mutator transposable element system (Mu) of maize has been responsible for the induction of numerous mutable aleurone mutants of maize. Unlike similar mutants induced by other transposable element systems, the mutability of Mu‐induced mutants did not seem initially to be regulated by an independent autonomous or regulator element. However, in a continuing study of two Mu‐induced a1 mutable mutants (a1‐Mum2) and a1‐Mum3, lines have been obtained that give evidence of an independently segregating regulator of somatic mutability. Data from several generations of crossing are presented indicating that intense somatic mutability in many of these stocks is under the control of an independent regulator. However, testing of other lines, which initially gave evidence of the presence of an independent regulator, were negative. Some of these latter lines could be expected to have Mutator elements that were modified (methylated) at sites recognized by certain restriction endonucleases. Modification of Mu elements, which is known to affect the expression of somatic mutability, might, at times, be responsible for producing conditions that mimic the segregation of an independent regulator. Lines with stable derivatives of the a1‐Mum2 and a1‐Mum3 can recover intense somatic mutability by crossing with germinally active Mutator stocks. Thus, active Mutator lines contain regulator elements and evidence is presented suggesting that such lines have multiple copies of these elements. Most a1‐ Mum2 and a1‐Mum3 stocks segregating for a regulator do not have germinal Mutator activity. Thus the presence of one or a few putative regulator elements does not necessarily account for the high level of germinal activity in most Mutator stocks.
Genetic and molecular characterization of a‐mrh‐Mrh, a new mutable system of Zea mays
Authors: Shepherd Nancy S. , Rhoades M. M. , Dempsey Ellen 
Published: May 2005

AbstractA new allele of the maize A1 gene, a gene required for anthocyanin pigment biosynthesis, was identified in a genetic stock exhibiting a high frequency of chromosome breakage at the second microspore mitosis. This allele, a‐mrh, is unstable in both somatic and germinal tissue when an independent locus, Mrh, is present in the genome. a‐mrh was molecularly cloned, and a 246 bp DNA insertion with characteristics of a transposable element was identified within the fourth exon of the gene. Southern blot analysis of germinal derivatives of a‐mrh suggests that the DNA insert rMrh is excised from the locus when a wild‐type phenotype is restored. Genetic crosses with components of other two‐element mutable systems of maize failed to induce mutability. We therefore conclude that rMrh is a member of a new, two‐element transposon system of maize. The genetic and molecular characteristics of the elements involved are discussed with respect to stress‐activated transposition, response of an element to developmental signals, and a possible new role of plant transposons in gene evolution.
Unstable genes affecting chloroplast development in soybean
Authors: Chandlee Joel M. , Vodkin Lila O. 
Published: May 2005

AbstractY18 is a nuclear gene of soybean (Glycine max) necessary for normal chloroplast development. An unstable allele (Y18‐m) of the Y18 gene has been previously characterized genetically [Peterson and Weber: Theor Appl Genet 39:156‐162, 1969.] Plants homozygous for the unstable allele produce leaves that exhibit a variegated pattern of green and yellow leaf sectors, indicating somatic mutability events. Germinal instability is detected by the recovery of either pure breeding dominant green (rare) or pure breeding recessive yellow (frequent) plants from the mutable stock. In contrast to most unstable genes identified in other plant systems, the Y18‐m mutation is from the dominant green state to the recessive yellow state, producing a pattern of “reverse variegation.” Current work has focused on further characterization of this mutation at the whole plant level as well as at the biochemical level. These results include observations on the cell‐ and tissue‐type specificity of the mutation, stability of the recessive yellow mutation, and a biochemical analysis of mutant and normal thylakoid membranes to identify the specific polypeptides affected by the y18 mutation. Several polypeptides of the thylakoid membranes are missing, and many, including the major light harvesting complex (LHCP) polypeptides, are reduced. Messenger RNAs for LHCPII were also reduced to a greater extent than other leaf transcripts in the yellow sectors of variegated plants. A comparison of Y18‐m to other soybean mutable genes and transposable element insertions is made.
Alfalfa transposable elements and variegation
Authors: Bingham E. T. , Clement W. M. 
Published: May 2005

AbstractAlfalfa with unstable anthocyanin pigmentation has been independently discovered on six occasions since 1958. Genetic studies showed that each of the six unstable stocks was due to an allele mutable at the basic anthocyanin locus C2 in alfalfa. The alleles are designated c2‐m1 through c2‐m6. Variegated phenotypes of m1, m2, and m3 are similar and express reversion from the recessive to the dominant state. This reversion produces streaks and sectors of pigment in flower petals and seeds that are otherwise white. Reversion occurs at various times in development and may result in periclinal chimeras. The c2‐m4 allele is unique in that it arose during tissue culture, whereas the other mutables were discovered in plant populations. Interestingly, m4 is very stable in planta and only rarely produces a sectored flower, but is very unstable in vitro as measured by about 23% revertant plants regenerated from tissue cultures. Most m4 reversion occurs relatively early in development and results in completely pigmented in vitro revertants, and in large sectors on in planta revertants. Alleles m5 and m6 are phenotypically and genetically similar. Their flowers are basic purple with white streaks thus representing mutation from dominant purple to recessive white. White progeny of m5 and m6 are very stable both in planta and in vitro; reversion of white to purple was never observed. Thus, the loss of function of the dominant allele results in a stable recessive or a deficiency. The absolute stability of m5 white derivatives favors the deficiency model, because transposable element mutations might show reversion. Finally, several mutations are described that reoccur in the mutable populations. It is speculated that they are recent mutations due to transposition of transposable elements.
Transcripts of individual Drosophila actin genes are differentially distributed during embryogenesis
Authors: Tobin Sara L. , Cook Patricia J. , Burn Timothy C. 
Published: May 2005

AbstractThe temporal and spatial patterns of accumulation of transcripts from individual actin genes during Drosophila embryogenesis have been determined by in situ hybridization. We describe the subcloning into transcription vectors of unique DNA fragments derived from the 3′ transcribed, but nontranslated region of each actin gene. These fragments then served as templates for the synthesis in vitro of single‐stranded, radioactive gene‐specific RNA probes. Probe characterization and hybridization to developmental RNA blots are presented, demonstrated the independent developmental accumulation of actin transcripts from each gene. Each gene‐specific probe has been hybridized in situ to the transcripts present in embryonic frozen sections. The results of these experiments have demonstrated that transcripts from each actin gene accumulate differentially in developing Drosophila tissues. The 5C and 42A actin genes are cytoplasmic actin genes, with transcripts distributed in all cells and tissues of the developing embryo. Therefore these genes presumably encode the cytoplasmic actins used for functions common to all cells. Transcripts from both cytoplasmic actin genes are evenly distributed in preblastoderm embryos, becoming localized to the periphery at blastoderm formation [5C: Burn et al.: Dev Biol 131:345‐355, 1989]. Later in development, levels of these cytoplasmic transcripts vary in specific tissues. While the patterns of localization of 5C actin transcripts have been published [Burn et al.: Dev Biol 131:345‐355, 1989], differential neurological localization is presented here; 42A transcripts are localized at higher concentrations in the midgut, the brain, nerve cord, and gonad. Both 87E and 57B transcripts accumulated in the developing larval body wall musculature, but at differing levels and in differing patterns. Transcripts of the 79B and the 88F actin genes were undetectable in embryos. The results of these experiments suggest dedicated contributions of individual actin genes to complex developmental processes.
Expression of NA, K‐ATpase α and β subunit genes during preimplantation development of the mouse
Authors: Watson Andrew J. , Pape Cynthia , Emanuel Janet Rettig , Levenson Robert , Kidder Gerald M. 
Published: May 2005

AbstractNaK‐ATPase is a plasma membrane enzyme that plays a critical role in eutherian blastocoel formation (cavitation) by pumping Na+ into the extracellular space enclosed by the trophectoderm. Previous experiments with the mouse had shown that the α (catalytic) subunit of the enzyme becomes detectable by immunocyto‐chemistry in the late morula, just prior to the onset of cavitation. In the present study we have used cDNAs corresponding to three mRNA isoforms of the α subunit and a β subunit to determine which genes are expressed during preimplantation development and to explore the timing of their expression. Of the three α subunit cDNAs tested by Northern blot hybridization with blastocyst RNA, only α1 produced a hybridization signal, recognizing a single mRNA about 4 kb in length. This mRNA is relatively abundant in zygotes but barely detectable by the 2‐cell stage and then accumulates steadily thereafter to reach its preimplantation maximum in blastocysts. The β1 cDNA detected mRNA of about 2.6‐2.8 kb. This mRNA is present in zygotes but could not be detected in 2‐, 4‐, or 8‐ cell stages; it is present at a low level in late morulae and is abundant in blastocysts. The temporal profile of accumulation of β1 mRNA thus matches more closely than does α1 the timing of appearance of the catalytic subunit. This suggests that the β subunit may regulate production of the holoenzyme and hence the timing of cavitation.
Mutations affecting embryonic cell migrations in Caenorhabditis elegans
Authors: Manser James , Wood William B. 
Published: May 2005

AbstractFour recessive mutations that affect long‐range embryonic migration of the two canal‐associated neurons (CANs) in C. elegans were isolated and characterized with the goal of identifying genes involved in control of directed cell movement. Mutant animals were identified initially by their “withered” tails, a phenotype associated with abnormal CAN migration; the mutants were then analyzed for abnormal cell migrations by Nomarski microscopy. Based on genetic complementation tests, the mutations were assigned to four different loci, two new (mig‐10 III, mig‐11 III) and two previously identified (unc‐39 V, vab‐8 V). Mutations at all four loci affect CAN migration with high to moderate penetrance (the percentage of mutant animals that exhibit the phenotype). In addition, two other bilaterally symmetric pairs of neurons (ALM and HSN), the mesoblast M, and a pair of coelomocyte mother cells are affected by one or more of the mutations, generally with lower penetrance. With the exceptions of HSN and the right coelomocyte mother cell, which occasionally migrate beyond their normal destinations, the cells affected appear to migrate either incompletely or not at all. All the migration phenotypes show incomplete penetrance and variable expressivity, although genetic tests suggest that mutations at mig‐10 and vab‐8 result in complete or nearly complete loss of gene function. The variability in mutant phenotypes allowed tests for interdependence of several of the affected migrations; all those analyzed appeared independent of one another. The possible nature of the mutant defects and possible roles of these four loci in cell migration are discussed.