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Biomedical subjects

B M Burns

Publications and source records attributed to B M Burns.

12 recordsLinked to original sources
PubMed2001

mDYRK3 kinase is expressed selectively in late erythroid progenitor cells and attenuates colony-forming unit-erythroid development.

DYRKs are a new subfamily of dual-specificity kinases that was originally discovered on the basis of homology to Yak1, an inhibitor of cell cycle progression in yeast. At present, mDYRK-3 and mDYRK-2 have been cloned, and mDYRK-3 has been characterized with respect to kinase activity, expression among tissues and hematopoietic cells, and possible function during erythropoiesis. In sequence, mDYRK-3 diverges markedly in noncatalytic domains from mDYRK-2 and mDYRK-1a, but is 91.3% identical overall to hDYRK-3. Catalytically, mDYRK-3 readily phosphorylated myelin basic protein (but not histone 2B) and also appeared to autophosphorylate in vitro. Expression of mDYRK-1a, mDYRK-2, and mDYRK-3 was high in testes, but unlike mDYRK1a and mDYRK 2, mDYRK-3 was not expressed at appreciable levels in other tissues examined. Among hematopoietic cells, however, mDYRK-3 expression was selectively elevated in erythroid cell lines and primary pro-erythroid cells. In developmentally synchronized erythroid progenitor cells, expression peaked sharply following exposure to erythropoietin plus stem cell factor (SCF) (but not SCF alone), and in situ hybridizations of sectioned embryos revealed selective expression of mDYRK-3 in fetal liver. Interestingly, antisense oligonucleotides to mDYRK-3 were shown to significantly and specifically enhance colony-forming unit-erythroid colony formation. Thus, it is proposed that mDYRK-3 kinase functions as a lineage-restricted, stage-specific suppressor of red cell development. (Blood. 2001;97:901-910)

3T3 Cells↗
PubMed2000

REDK, a novel human regulatory erythroid kinase.

We have identified a novel regulatory erythroid kinase (REDK) that is homologous to a family of dual-specificity kinases. The yeast homolog of REDK negatively regulates cell division, suggesting a similar function for REDK, which is primarily localized in the nucleus. REDK is present in hematopoietic tissues, such as bone marrow and fetal liver, but the RNA is expressed at significant levels only in erythroid or erythropoietin (EPO)-responsive cells. Two novel forms of cDNA (long and short) for REDK have been isolated that appear to be alternative splice products and imply the presence of polypeptides with differing amino termini. The ratio of short-to-long forms of REDK increases dramatically in CD34(+) cells cultured with EPO, suggesting differing regulation and function for each form. REDK is predominantly found in nuclear, rather than cytoplasmic, protein extracts, and immunoprecipitated REDK is active in phosphorylating histones H2b, H3, myelin basic protein, and other coimmunoprecipitated proteins. Antisense REDK oligonucleotides promote erythroid colony formation by human bone marrow cells, without affecting colony-forming unit (CFU)-GM, CFU-G, or CFU-GEMM numbers. Maximal numbers of CFU-E and burst-forming unit-erythroid were increased, and CFU-E displayed increased sensitivity to suboptimal EPO concentrations. The data indicate that REDK acts as a brake to retard erythropoiesis. (Blood. 2000;95:2838-2846)

Amino Acid Sequence↗
PubMed1999

Bovine chromosome 4 workshop: consensus and comprehensive linkage maps.

The report of the bovine chromosome 4 (BTA4) workshop is presented. Six laboratories contributed a total of 30,168 informative meioses from 62 loci. Twenty-two loci were typed by at least two independent laboratories and were used to construct a consensus linkage map of BTA4. The remaining 40 loci were subsequently incorporated into a comprehensive map. The sex-averaged consensus map covered 131.4 cM. The female map was 124.3 cM in length, while the male map was 134.3 cM. The comprehensive sex-averaged map spanned 141.6 cM. The length of the female and male comprehensive maps were 123.1 cM and 156.4 cM, respectively. Average genetic distance between loci was 6 and 2.3 cM for the consensus and comprehensive linkage maps, respectively.

Animals↗
PubMed1998

Sequence analysis of the internal transcribed spacer 2 (ITS2) from yeast species within the genus Candida.

Nucleotide sequences of the internal transcribed spacer 2 (ITS2) regions were determined for 13 species within the genus Candida, representing a collection of those species pathogenic for humans. No two species had identical sequences and the sizes of ITS2 varied fourfold, representing an apparent continuous gradient of nucleotides. When present, sequence homologies were observed in the 5' end of ITS2, and many species exhibited more limited homologies within three known conserved domains found in other yeasts. Cluster analysis of primary sequence revealed a concordance with a known taxonomic subfamily and suggests that certain species within the genus form a similar grouping. A majority of species exhibited similar presumptive RNA secondary structures, consistent with the hypothesis that these spacer regions are essential for correct processing of the 5.8S and 28S subunits.

Base Sequence↗
PubMed1998

Report of the first workshop on the genetic map of bovine chromosome 1.

A report of the first workshop on the genetic map of bovine chromosome 1 (BTA1) is presented. Five laboratories contributed 31,962 informative meioses from 70 loci. Thirty-two loci which had been typed by at least two laboratories were used to construct a framework genetic map with a likelihood ratio support of at least 1000:1 for locus order. The resulting sex-averaged framework map contained 26 loci and spanned 163.6 CM. The lengths of the female and male maps were 159.5 CM and 165.3 CM, respectively, and there was evidence for an expansion in the telomeric one-third of the male map. Of the four cases where order for closely linked loci differed among the maps produced for each of the contributing laboratories, a consensus order was obtained for three in the framework map. The average genetic distance between framework loci on the sex-averaged map was 6.3 CM.

Animals↗
PubMed1996

Report of the first workshop on the genetic map of bovine chromosome 23.

A report of the first workshop on the genetic map of bovine chromosome 23 (BTA23) is given. Five laboratories contributed data from 29 loci, including a total 11586 informative genotypes. The combined pedigrees represented 1930 potentially informative meioses. Eighteen of the 29 loci were common to two or more data sets and were used to construct a framework linkage map of BTA23. Twelve of the 18 could be ordered on the linkage map with a likelihood ratio of greater than 1000:1. Thus, a low resolution consensus map was constructed with a high level of support for order. The sex-averaged, female and male maps span 54.5, 52.7 and 55.8 cM, respectively. Sex-specific differences in recombination frequency were identified for eight pairs of framework loci. Average genetic distance between framework loci on the sex-averaged map is 5.0 cM.

Animals↗
PubMed1991

Fetal development and gestational changes in Bos taurus and Bos indicus genotypes in the tropics.

Weights of the gravid uterus and fetus as well as the fetal measurements were determined at slaughter for 107 Bos taurus cows grazed on improved pastures and for 70 Bos indicus cows grazed on native pastures in northern Australia. The stage of gestation was assessed from palpation per rectum in early-to-mid gestation and at slaughter and from fetal development characteristics at slaughter. The age and breed of the cow and the sex of the fetus did not significantly affect any of the uterine components or fetal measurements. Growth curves had dominant, positive linear components but negative quadratic ones, which improved the fit, particularly for the later stages of gestation. Uterine components and fetal measurements were highly correlated (0.94 to 0.99). For Bos taurus cows, there were higher estimates at birth for weights of the gravid uterus and the fetus, but estimates for other fetal measurements were similar to those for Bos indicus cows. Major fetal growth occurred during the third trimester, with the length of the foreleg tending to change relatively slowly and the head width quite fast during the first trimester. Correction factors for cow liveweight to adjust to commonality for non-pregnancy were 5, 7, 10, 14, 20, 29, 43 and 65 kg for Bos taurus and 2, 4, 6, 10, 15, 23, 35 and 51 kg for Bos indicus at 2 to 9 months of gestation.

Journal Article↗
PubMedDate not supplied

The polled locus maps to BTA1 in a Bos indicus x Bos taurus cross.

Two hundred and nine reciprocal backcross and F2 progeny produced by embryo transfer from Angus (Bos taurus) and Brahman (Bos indicus) parents and their 60 parents and grandparents were utilized to localize the locus (POLL) responsible for the polled phenotype in a genetic map of bovine chromosome 1. Progeny were scored for polled, scurred, and horned phenotypes at 1 year of age and again following skull disection at slaughter at 20 months of age. Phenotype frequencies were independent of gender. One hundred and forty-two informative meioses for POLL and 13 microsatellite loci with an average of 267 informative meioses per locus contributed to a genetic map spanning 124.6 cM with an average interval of 9.6 cM. POLL mapped proximal to the centromere and 4.9 cM from TGLA49 supporting a previous study that employed two anonymous microsatellites. Difficulties in discriminating between scurred and horned phenotypes indicate that bracketing markers will be essential for refining the model for inheritance of the horned, scurred, and polled phenotypes and for effective marker assisted selection (MAS) for polled.

Animals↗