Efficiency of Two Enucleation Methods Connected to Handmade Cloning to Produce Transgenic Porcine Embryos

The purpose of our work was to establish an efficient-oriented enucleation method to produce transgenic embryos with handmade cloning (HMC). After 41–42 h oocytes maturation, the oocytes were further cultured with or without 0.4 μg/ml demecolcine for 45 min [chemically assisted handmade enucleation (CAHE) group vs polar body (PB) oriented handmade enucleation (OHE) group respectively]. After removal of the cumulus cells and partial digestion of the zona pellucida, oocytes with visible extrusion cones and/or polar bodies attached to the surface were subjected to oriented bisection. Putative cytoplasts without extrusion cones or PB were selected as recipients. Two cytoplasts were electrofused with one transgenic fibroblasts expressing green fluorescent protein (GFP), while non-transgenic fibroblasts were used as controls. Reconstructed embryos were cultured in Well of Wells (WOWs) with porcine zygote medium 3 (PZM-3) after activation. Cleavage and blastocyst rates were registered on day 2 and day 7 of in vitro culture respectively. Meanwhile, the total blastocyst cell number was counted on day 7. We found that the difference was only observed between blastocyst rates (38.6 ± 2% vs 48.1 ± 3%) of cloned embryos with GFP transgenic fibroblast cells after CAHE vs OHE. With adjusted time-lapse for zonae-free cloned embryos cultured in WOWs with PZM-3, it was obvious that in vitro developmental competence after CAHE was compromised when compared with the OHE method. OHE enucleation method seems to be a potential superior alternative method used for somatic cell nuclear transfer (SCNT) with transgenic fibroblast cells.     

High-Power Infrared (8-Micrometer Wavelength) Superlattice Lasers

A quantum-cascade long-wavelength infrared laser based on superlattice active regions has been demonstrated. In this source, electrons injected by tunneling emit photons corresponding to the energy gap (minigap) between two superlattice conduction bands (minibands). A distinctive design feature is the high oscillator strength of the optical transition. Pulsed operation at a wavelength of about 8 micrometers with peak powers ranging from approximately 0.80 watt at 80 kelvin to 0.2 watt at 200 kelvin has been demonstrated in a superlattice with 1-nanometer-thick AlInAs barriers and 4.3-nanometer-thick GaInAs quantum wells grown by molecular beam epitaxy. These results demonstrate the potential of strongly coupled superlattices as infrared laser materials for high-power sources in which the wavelength can be tailored by design.     

Crop–weed hybrids are more frequent for the grain amaranth ‘Plainsman’ than for ‘D136-1’

White-seeded cultivated amaranth [Amaranthus caudatus L., A. cruentus L., and A. hypochondriacus L.] grain is less valuable if contaminated with brown off-type seeds from the hybrid weedy progeny of spontaneous crop–weed crossing. Crop–weed crossing frequency was estimated by using two grain amaranth cultivars. Both cultivars were planted at the same nine locations in the Midwest United States and exposed to pollen from local weedy Amaranthus species. Harvested seeds were grown in a greenhouse, and the frequency of crop–weed hybrids was determined by observing dominant weed traits in the progeny. The cultivar ‘Plainsman’ was approximately tenfold more likely to hybridize with weedy amaranths than was ‘D136-1’. These are the first amaranth cultivars to be evaluated in this way. The reduced hybridization potential of ‘D136-1’ or similar material can be exploited to reduce the occurrence of off-type seed contamination in grain amaranths.     

Diagnosis o Yersinia enterocolitica infections: a review on classical identification techniques and new molecular biological methods

Only three of the eleven species of the genus Yersinia are associated with disease. Y. pestis is the causative agent of plague, Y. pseudotuberculosis and several pathogenic bio/serovars of the species Y. enterocolitica cause yersiniosis. New Y. enterocolitica subspecies with diagnostic relevance have been proposed allowing the differentiation of European and American isolates. The ISO-standard (ISO 102739) summarizes the knowledge gained from enrichment and isolation of Y. enterocolitica from food and feed samples. The final biochemical identification must be carried out by classical tube testing, as commercially available test-systems are not sensitive and specific. For the assessment of the presumptive pathogenicity of a Y. enterocolitica isolate empiric virulence markers can be replaced by PCR assays targeting plasmoidal or chromosomal genes. Their evaluation in terms of routine diagnostic procedures is still missing. The definite identification of Y. enterocolitica isolates can also be achieved by sequencing the 16S rRNA gene. Immunoblot based on plasmoidal encoded Yersinia proteins enables the serological determination of animal and human infections. The development of simple, sensitive and specific rapid identification systems applicable for the direct and indirect diagnosis for veterinary use is a challenge for the future.     

Validation of predictive empirical weed emergence models of Abutilon theophrasti Medik based on intercontinental data

Good weed management relies on the proper timing of weed control practices in relation to weed emergence dynamics. Therefore, the development of models that predict the timing of emergence may help provide growers with tools to make better weed management decisions. The aim of this study was to validate and compare two previously published predictive empirical thermal time models of the emergence of Abutilon theophrasti growing in maize with data sets from the USA and Europe, and test the hypothesis that a robust and general weed emergence model can be developed for this species. Previously developed Weibull and Logistic models were validated against new data sets collected from 11 site-years, using four measures of validation. Our results indicated that predictions made with the Weibull model were more reliable than those made with the Logistic model. However, Weibull model results still contained appreciable biases that prevent its use as a general model of A. theophrasti emergence. Our findings highlight the need to develop more accurate models if the ultimate goal is to make more precise predictions of weed seedling emergence globally to provide growers with universally consistent tools to make better weed management decisions.     

Pathology of Brucella ovis infection in red deer stags (Cervus elaphus)

Abstract

AIM: To describe the pathology of the reproductive tract of red deer stags with active Brucella ovis infection and in stags in which B. ovis infection had resolved.

METHODS: Twenty-three red deer stags of varying history were slaughtered and their epididymides and accessory sex glands examined grossly and by histopathology. At the time of slaughter five of the stags had an active B. ovis infection of 24–55 days duration following exposure to infected rams, 10 stags had been experimentally infected with B. ovis by intravenous inoculation 649 days previously and had developed an active infection but the bacterial infection had resolved at least 308 days prior to slaughter, and eight stags had not been exposed to B. ovis at any time.

RESULTS: Of the five stags with an active infection, one had gross enlargement of the epididymides that could be detected by scrotal palpation. Histological lesions in all five stags included mild to severe, predominantly non-suppurative epididymitis, vesiculitis, prostatitis and ampullitis, with neutrophil exudation in associated glandular ducts. Additional lesions in the epididymides were spermatic granulomas and epithelial hyperplasia with intra-epithelial cyst formation. Of the 10 stags in which the bacterial infection had resolved, two had gross enlargement of the epididymides. The histological lesions were similar to those in stags with active infection but were generally milder, with increased periductal scar tissue in the epididymides. The lesions seen in stags resembled those seen in rams with B. ovis infection but they were usually less florid and had fewer plasma cells. No gross abnormalities or histopathological lesions were detected in the non-infected stags.

CONCLUSIONS: Only a small percentage of red deer stags infected with B. ovis develop lesions of epididymitis that can be detected by scrotal palpation. Gross and histological lesions of the genital tract of stags associated with B. ovis infection are similar to the lesions seen in rams. Lesions in stags persist for >300 days after the bacterial infection has resolved.

CLINICAL RELEVANCE: Brucella ovis infection should be considered when there are gross lesions of epididymitis or histological evidence of inflammation in the epididymides or accessory sex glands of red deer stags. Retrospective diagnosis of B. ovis in stags could be achieved by histological examination of the reproductive organs.