Simple sequence repeats as useful resources to study transcribed genes of cotton

Microsatellites or Simple Sequence Repeats(SSRs) are informative molecular genetic markers in many crop species. SSRs are PCR-based, highly polymorphic, abundant, widely distributed throughout the genome and inherited in a co-dominant manner in most cases. Here we describe the presence of SSRs in cDNAs of cotton. Thirty one SSR primer pairs of 220 (∼14%) tested led to PCR amplification of discrete fragments using cotton leaf cDNA as template. Sequence analysis showed 25% of 24randomly selected cDNA clones amplified with different SSR primer pairs contained repeat motifs. We further showed that sequences from the SSR-containing cDNAs were conserved across G. barbadense and G. hirsutum, revealing the importance of the SSR markers for comparative mapping of transcribed genes. Data mining for plant SSR-ESTs from the publicly available databases identified SSRs motifs in many plant species,including cotton, in a range of 1.1 to4.8% of the submitted ESTs for a given species. This revised version was published online in August 2006 with corrections to the Cover Date.     

Greenhouse evaluation and inheritance analysis of transgenic cotton expressing <Emphasis Type="Italic">PTM3</Emphasis>, a MADS-box gene of Aspen

The PTM3 (MADS-box) gene characterized from flower of Aspen was ectopically expressed in cotton and was found to result in desirable agronomic traits. Among several transgenic lines, the PTM3 cotton event-10 was found to flower significantly earlier than the control and yield better [Ramachandran et al. (2011)]. We report our findings on performance based on greenhouse evaluation and inheritance of PTM3 cotton event-10. The T₁ progeny of event-10 were grown in pots under RBD design. The progeny were confirmed by kanamycin imbibition test, PCR, and GUS assay which showed the segregation of transgene at about 3:1 ratio. GUS assay was performed with pollen from all transgenic plants; plants that expressed gus in all pollen versus those that showed segregation for expression were found to be at a ratio of 1:2. Similar to observations made in the T₀ generation of event-10, the agronomic evaluation of T₁ progeny exhibited, on an average, earliness of 13 days in flowering, 13.5 days in crop maturity, and 22% of yield enhancement. The T₂ progeny of homozygous lines were grown on field soil in the greenhouse under strip trial design to see the effect as observed from potted plants of T₁ progeny. Inheritance of transgene cassette to T₂ progeny was confirmed by the same tests used to analyze T₁ progeny. As exhibited by T₀ and T₁ progenies, the T₂ progeny also showed earliness of 8 days in flowering, 12 days in crop maturity, and 17% of yield enhancement. The data generated from the progeny over two generations confirms that the PTM3 cotton event-10 is superior in agronomic characters as compared to non-transgenic cotton and is of interest for breeding shorter duration varieties with improved yield.     

Environmental and chemical control of growth and flowering of Chamelaucium uncinatum Schauer

The main factor affecting floral initiation of Geraldton Wax-Flower (Chamelaucium uncinatum) is the photoperiod, while temperature is the major factor affecting flower development. Four weeks of short days (SD) are generally required for obtaining full flowering. The number of flowers produced per plant increases with increasing the number of SD. Under mild temperatures of $\text{20}\text{14°}\text{C}$ (day/night), plants initiated flowers even in long days (LD). However, fewer flowers were produced and on higher nodes as compared to SD plants. Chlormequat promoted flowering under prevailing summer conditions of high temperatures and LD. Under prevailing autumn conditions favourable for flower initiation, LD treatment or weekly sprays with gibberellic acid (GA) reduced the number of flowers per plant. Combined treatment of LD and GA reduced both the flowering percentage and the number of flowers per plant. Discontinuing the LD or the GA treatments caused a resumption of full flower initiation.     

The rapid detection of Aujeszky's disease virus in pigs by direct immunoperoxidase labelling

Direct immunoperoxidase labelling on impression smears of brain and pharynx was compared with virus isolation and direct immunofluorescence for the detection of Aujeszky's disease virus in experimentally-infected pigs. Immunoperoxidase labelling was as sensitive as immunofluorescence and more sensitive than virus isolation for tissue that had been stored at room temperature (approximately 20 degrees C) for up to 144 h.     

Evaluation in beef cattle of six deoxyribonucleic acid markers developed for dairy traits reveals an osteopontin polymorphism associated with postweaning growth

The objectives of this study were to 1) estimate the allelic frequencies in US beef cattle of 6 DNA markers reported to be associated with variation in dairy production traits; and 2) evaluate the association of these markers with beef production traits. Several genetic markers have been associated with milk yield or composition, including polymorphisms in secreted phosphoprotein 1 (SPP1; also called osteopontin), growth hormone receptor (GHR), casein S1 (CSN1S1), diacylglycerol O-acyltransferase 1 (DGAT1), peroxisome proliferator-activated receptor gamma co-activator-1alpha (PPARGC1A), and ATP-binding cassette subfamily G (white) member 2 (ABCG2). Allelic frequencies for these 6 markers, and their association with 21 phenotypes, were evaluated in 2 crossbred beef cattle populations that sample influential industry sires. Five of 6 markers were segregating in beef cattle populations; the exception was ABCG2. The SPP1 marker was associated with yearling weight (P = 0.025), live weight at slaughter (P = 0.016), postweaning ADG (P = 0.007), and HCW (P = 0.007) in a large, multisire population representing the 7 most populous beef breeds in the United States. Postweaning growth trait associations were confirmed in an independent population of similar construction, including sires from tropically adapted breeds. The SPP1 marker was associated with yearling weight (P = 0.034), live weight at slaughter (P = 0.011), and postweaning ADG (P = 0.015) and showed a trend toward association with HCW (P = 0.083) in this population. Whereas DGAT1, GHR, and CSN1S1 polymorphisms showed association with some traits in individual populations, the lack of consistent predictive merit between populations indicates they may not be suited for beef cattle selection. No significant associations were observed for the PPARGC1A marker and any of 21 recorded traits, indicating this marker had no apparent value in selection for the beef cattle traits tested in these populations. The SPP1 marker had consistent associations and effect sizes (10.5 to 11.5 kg of live weight at slaughter) in both populations, providing strong evidence for utility of the SPP1 marker for postweaning growth in beef cattle.     

Nitrate removal from ground water — use of a nitrate selective resin and a low concentrated regenerant

A new, strong base, macro-porous anion exchange resin, Amberlite IRA 996, appeared to be more nitrate selective than sulfate selective in treating high nitrate concentrations (18 mg NO _inf3 ^sup? -N L^?1) in potable water. When regeneration is carried out in a closed circuit in which a biological denitrification reactor is incorporated to remove nitrate from the regenerant, regeneration salt requirement and brine production can be minimized. In this combination of ion exchange and biological denitrification, regeneration with 30 g NaHCO₃ L^?1) is possible in 6 hr at a flow rate of 11 BV hr^?1. Accumulation of sulfate in the closed regeneration circuit does not affect the nitrate capacity of the resin.     

A heparin-binding growth factor secreted by macrophage-like cells that is related to EGF.

Macrophage-like U-937 cells secrete a 22-kilodalton heparin-binding growth factor that is mitogenic for BALB-3T3 fibroblasts and smooth muscle cells, but not endothelial cells. The amino acid sequence predicted from complementary DNA clones indicates that the mitogen is a new member of the epidermal growth factor (EGF) family. This heparin-binding EGF-like growth factor (HB-EGF) binds to EGF receptors on A-431 epidermoid carcinoma cells and smooth muscle cells, but is a far more potent mitogen for smooth muscle cells than is EGF. HB-EGF is also expressed in cultured human macrophages and may be involved in macrophage-mediated cellular proliferation.