Informe Oportunidad acumulado con corte al mes de Noviembre

Banco del conocimiento

Infraestructura tecnológica 2012 - 2013

Banco del conocimiento

An investigation into differences between indoleacetic acid and fusicoccin in their influence on RNA synthesis, protein synthesis and growth in Avena coleoptile tissue

Growth stimulation of Avena coleoptile tissue by indoleacetic acid (IAA) and fusicoccin (FC) was compared by measuring both their influence on RNA and protein synthesis during IAA or FC stimulated growth. FC stimulated growth more than IAA during the initial four hour exposure, after which the growth rate gradually declined to the control rate. FC, but not IAA, increased the uptake of 3H-Ieucine into tissue and the specific radioactivity of extracted protein. Cycloheximide inhibited the incorporation of 3H-Ieucine into protein by approximately 60% to 70% in all cases. In the presence of cycloheximide 3H-radioactivity accumulated in FC-treated tissue, whereas IAA did not seem to influence 3H-accumulation. These results suggest that FC stimulated leucine uptake into the tissue and that increased specific activity of coleoptile protein is due to increased leucine uptake, not an increased rate of protein synthesis. There was no measurable influence of IAA and/or FC on RNA and protein synthesis during the initial hours of a growth stimulation. Inhibitors of RNA and protein synthesis, actinomycin D and cycloheximide, respectively, severely inhibited IAA enhanced growth but only partially inhibited FC stimulated growth. The data are consistent with suggestions that a rapidly turning over protein participates in IAA stimulated growth, and that a continual synthesis of RNA and proteins is an absolute requirement for a long term growth response to IAA. On the contrary, FC-stimulated growth exhibited less dependency on the transcription and translation processes. The data are consistent with proposals suggesting different sites of action for FC and IAA stimulated growth. l?hen compared to CO2-free air, CO2 at 300 ppm had no significant influence on coleoptile growth and protein synthesis in the presence or absence of lAA or FC. Also, I mM malate, pH 6.0 did not influence growth of coleoptiles in the presence or absence of lAA. This result was obtained despite reports indicating that 300 ppm CO2 or I mM malate stimulates growth and protein synthesis. This lack of difference between CO2-treated and untreated tissue could indicate either that the interstitial space CO2 concentration is not actually different in the two treatments due to significant endogenous respiratory CO2 or else the data would suggest a very loose coupling between dark CO2 fixation and growth. IAA stimulated the in vivo fixation of 14c-bicarbonate (NaHI4c03) by about 25% and the addition of cycloheximide caused an inhibition of bicarbonate fixation within 30 min. Cycloheximide has also been reported to inhibit IAA-stimulated H+ excretion. These data are consistent with the acid growth theory and suggest that lAA stimulated growth involves dark CO2 fixation. The roles of dark CO2 fixation in lAA-stimulated growth are discussed.

Cloning of actin genes from a genomic library of the newt, Notophthalmus viridescens

The regenerating urodele limb is a useful model system in which to study, in vivo, the controls of cell proliferation and differentiation. Techniques are available which enable one to experimentally manipulate mitogenic influences upon the blastema, as well the morphogenesis of the regenerating 11mb. Although classical regeneration studies have generated a wealth of knowledge concerning tissue interactions, little 1s known about the process at the level of gene expression. The aim of this project was to clone potentially developmentally regulated genes from a newt genomic library for use in future studies of gene expression during limb regeneration. We decided to clone the cytoskeletal actin gene for the following reasons: 1. its expression reflects the proliferative and differentiatlve states of cells in other systems 2. the high copy number of cytoplasmic actin pseudogenes in other vertebrates and the high degree of evolutionary sequence conservation among actin genes increased the chance of cloning one of the newt cytoplasmic actin genes. 3. Preliminary experiments indicated that a newt actin could probably be identified using an available chick ~-actln gene for a molecular probe. Two independent recombinant phage clones, containing actin homologous inserts, were isolated from a newt genomic library by hybridization with the chick actin probe. Restriction mapping identified actin homologous sequences within the newt DNA inserts which were subcloned into the plasmid pTZ19R. The recombinant plasmids were transformed into the Escherichia coli strain, DHsa. Detailed restriction maps were produced of the 5.7Kb and 3.1Kb newt DNA inserts in the plasmids, designated pTNAl and pTNA2. The short «1.3 Kb) length of the actin homologous sequence in pTNA2 indicated that it was possibly a reverse transcript pseudogene. Problems associated with molecular cloning of DNA sequences from N. viridescens are discussed with respect to the large genome size and abundant highly repetitive DNA sequences.

Lt. Col. John Clark Papers, 1838-1851 [photocopy]

Lt. Col. John Clark (1787-1862) was born in Kingston, Upper Canada. In 1801 Clark became a private in the 1st regiment of the Lincoln Militia, serving under Ralfe Clench. By June 1812 he was promoted to lieutenant by Maj. Gen. Sir Isaac Brock. During the War of 1812 he served as lieutenant and adjutant for the Lincoln Militia flank company on the Niagara frontier under Col. William Claus, and was present at the surrender of the enemy at the battle of Queenston Heights. By 1838 the Lincoln Militia was being re-organized and Lt. Col John Clark was requested to lead the 5th Regiment, made up of men from both Grantham and Louth townships in Lincoln County. He served in this capacity until his retirement in 1851?. Around this same time Clark bought from William May Jr. a house in Grantham Township. He was to call his home Walnut Dale Farm. John Clark also served as the customs collector for Port Dalhousie, and as a secretary in the Welland Canal Company. One hundred years later efforts by a local heritage group to save John Clark’s home failed, when the house was hit by arsonists. By this time the house had become known as the May-Clark-Seiler House. See RG 195 Anne Taylor Fonds for more information regarding the efforts of the heritage group to save this home. Clark died in 1862 at the age of 79 years and is buried in Victoria Lawn Cemetery. John Clark’s daughter Catherine (mentioned in the diary portion of the papers) was married to William Morgan Eccles.

Independent Chronicle Vol. XLVI No. 2476- August 4, 1814

A semi-weekly paper that was published from 1801 to 1817. It was previously called the Independent chronicle and the universal advertiser, and was later the Independent chronicle and Boston patriot (Semiweekly). Publishers were Abijah Adams and Ebenezer Rhoades. Topics of interest in this issue include: Page 1: Proclamation from James Madison pardoning military deserters if they return to military service; announcement to officers and soldiers in the military offering reward for the return of military deserters; U.S. General W. Scott's account of the battle of Chippewa; U.S. General P. B. Porter's account of the battle of Chippewa; Major J. Hindman's account of the battle of Chippewa; news of British war ships attacking and capturing U.S. cargo ships; Page 2: news of a soldier shot for desertion; military news from Erie, Pennsylvania; New York appropriates money to pay troops and build two encampments; James Madison issues orders for state of Rhode Island to raise a militia of 500 troops; U.S. military news from Bermuda; report of the death of Capt. Parker of the U.S. ship Syren; account of the battle of Chippewa and a list of important officers wounded; report of a raft captured that was taking supplies to the British; report of U.S. General Brown being wounded in battle; list of further details of the battle of Chippewa; report of Indian attack near Champlain; news of prisoner exchange and announcement that exchanged prisoners should return to their regiments; listing of the total number of British forces in the U.S.; report of British shipwrecks; Naval news for the Port of Boston; news of various U.S. war ships; Page 4: Marshal's notice announcing a trial for members of a private American ship accused of supplying the British with provisions;

Independent Chronicle Vol. XLVI No. 3477- August 8, 1814

A semi-weekly paper that was published from 1801 to 1817. It was previously called the Independent chronicle and the universal advertiser, and was later the Independent chronicle and Boston patriot (Semiweekly). Publishers were Abijah Adams and Ebenezer Rhoades. Topics of interest in this issue include: Page 1: notice from the U.S. War Department seeking proposals for the supply of rations to troops; account of the battle of Bridgewater; list of important military figures wounded in the battle; news of prisoner exchange; Americans and the British negotiate and new prisoner exchange convention; Page 2: report of more British troops sailing to North America; report of some Indian tribes signing a treaty to fight against the British; report of battle near Detroit; report of militia moving from Fredricksburg, Virginia to Baltimore, Maryland; report of troop numbers and casualties in the battle of Bridgewater; report that Commodore Chauncey has recovered from his illness; news of American Naval forces sailing from Sackett's Harbor; Indian tribes sign peace treaty with U.S.; news of U.S. relations with Indians in the southern U.S.; account of battle of Bridgewater and list of casualties; report of the number of men killed and wounded on both sides in the battle of Chippewa; Page 3: report of surprise attack on the British; news of warship movements in and out of Halifax; frigate Java launched in Baltimore; news of British ship movements; 3 companies of Massachusetts militia arrive at Fort Warren; news of ship movements in and out of the Port of Boston; various Marshal's notices alleging U.S. ships supplying goods to the British;