SUMMARYRecombineering, permitting precise modification of genes within bacterial artificial chromosomes (BACs) through homologous recombination mediated by lambda phage-encoded Red proteins, is a widely used powerful tool in mouse, Caenorhabditis and Drosophila genetics. As Agrobacterium-mediated transfer of large DNA inserts from binary BACs and TACs into plants occurs at low frequency, recombineering is so far seldom exploited in the analysis of plant gene functions. We have constructed binary plant transformation vectors, which are suitable for gap-repair cloning of genes from BACs using recombineering methods previously developed for other organisms. Here we show that recombineering facilitates PCR-based generation of precise translational fusions between coding sequences of fluorescent reporter and plant proteins using galK-based exchange recombination. The modified target genes alone or as part of a larger gene cluster can be transferred by high-frequency gap-repair into plant transformation vectors, stably maintained in Agrobacterium and transformed without alteration into plants. Versatile application of plant BAC-recombineering is illustrated by the analysis of developmental regulation and cellular localization of interacting AKIN10 catalytic and SNF4 activating subunits of Arabidopsis Snf1-related (SnRK1) protein kinase using in vivo imaging. To validate full functionality and in vivo interaction of tagged SnRK1 subunits, it is demonstrated that immunoprecipitated SNF4-YFP is bound to a kinase that phosphorylates SnRK1 candidate substrates, and that the GFP-and YFPtagged kinase subunits co-immunoprecipitate with endogenous wild type AKIN10 and SNF4.

Double strand-break (DSB) induction allowed efficient gene targeting in barley (Hordeum vulgare), but little is known about efficiencies in its absence. To obtain such data, an assay system based on the acetolactate synthase (ALS) gene was established, a target gene which had been used previously in rice and Arabidopsis thaliana. Expression of recombinases RAD51 and RAD54 had been shown to improve gene targeting in A. thaliana and positive-negative (P-N) selection allows the routine production of targeted mutants without DSB induction in rice. We implemented these approaches in barley and analysed gene targeting with the ALS gene in wild type and RAD51 and RAD54 transgenic lines. In addition, P-N selection was tested. In contrast to the high gene targeting efficiencies obtained in the absence of DSB induction in A. thaliana or rice, not one single gene targeting event was obtained in barley. These data suggest that gene targeting efficiencies are very low in barley and can substantially differ between different plants, even at the same target locus. They also suggest that the amount of labour and time would become unreasonably high to use these methods as a tool in routine applications. This is particularly true since DSB induction offers efficient alternatives. Barley, unlike rice and A. thaliana has a large, complex genome, suggesting that genome size or complexity could be the reason for the low efficiencies. We discuss to what extent transformation methods, genome size or genome complexity could contribute to the striking differences in the gene targeting efficiencies between barley, rice and A. thaliana.

Pathophysiological alterations in the cochlea and functional tests of the auditory pathway support that in diabetes both vasculopathy and neural changes could be present. The aim of our research was to study the differential effect of type 1 diabetes mellitus (T1DM) on two different age groups. Audiological investigation was carried out in 42 patients and 25 controls at the same age groups. Investigation of the conductive and sensorineural part of the hearing system by pure tone audiometry, distortion product otoacoustic emission measurement and acoustically evoked brainstem response registration were evaluated. Among the 19-39-year-old people the incidence of hearing impairment was not different in the diabetes and control groups. Among the 40-60-year-old people hearing impairment was more common in the diabetes group (75%) than in the control group (15,4%). Among patients with type 1 diabetes, the mean threshold values were higher in both age groups at all frequencies although significant difference was in 19–39 years old group: 500-4000Hz right ear, 4000Hz left ear, in 40–60 years old group: 4000–8000 Hz both ears. In the 19–39 years old diabetes group only at 8000 Hertz on the left side was a significant (p<0,05) difference in otoacoustic emissions. In the 40–60 years old diabetes group significantly less otoacoustic emissions at 8000 Hz on the right side (p<0,01) and at 4000-6000-8000 Hertz on the left side, (p<0,05, p<0,01, p<0,05 respectively) was present compared to the control group. According to ABR (auditory brainstem response) latencies and wave morphologies, a possible retrocochlear lesion arose in 15% of the 19–39 years old and 25% of the 40–60 years old diabetes group. According to our results, T1DM affects negatively the cochlear function and the neural part of the hearing system. The alterations are more and more detectable with aging.

Purpose In 2015 a new regulation and guidelines for the universal newborn hearing screening by AABR measurement have been implemented in Hungary. The aim of our study was to analyse (1) the past 5 years of data from our diagnostic centre about the incidence and types of congenital hearing losses, and (2) the first experiences with the National Newborn Hearing Screening Registry, started in 2019, and (3) the influence of the screening on the pediatric cochlear implant program. Methods 1269 children referred to our diagnostic centre between 2017 and 2021 were investigated. A third AABR measurement and full audiological evaluation were performed. Furthermore, one-year period data of the screening registry, and the number of implanted children at or under the age of 3 were analysed using the national databases. Results Altogether 276 newborns (22% of the referred cases after the two-stage screening) had hearing loss, 134 (49%) out of them was conductive origin, almost twice frequent in male as in female. Permanent sensorineural hearing impairment was found in 142 (51%), 58 (40%) of them had bilateral, severe to profound hearing loss, occurring more frequently in male as in female. The national digital registration of the screening data within 12 months concerned 68%. The number of early cochlear implantation in one year increased from 1 to 23 children in the past 15 years. Conclusion A third AABR after the two-stage screening increased the efficiency and filtered the 78% false-positive cases. The audiological diagnostics verified and typed the hearing losses ensuring the early intervention.

Samples of serum and a series of aqueous standards of SeOp were dried on to the wall of an aluminium cathode cup at a temperature of 293 K, thus ensuring a sample preparation procedure without loss of analyte. Using the Se II 444.62-nm and Se II 444.95-nm spectral lines, the detection limit for the proposed method was established as being 1 ng ml-l. The selenium content of the samples varied between 80 and 120 ng ml-1, which is two orders of magnitude higher than the detection limit of the proposed method. The sodium content of the serum did not interfere in the determination, as the amount of sodium present (140 mmol 1 -1 ) was less than the concentration which can cause a decrease in the spectral line intensity. The relative error of the concentration values is less than 5%. The determination of selenium in serum was performed using direct hollow-cathode discharge atomic emission spectrographic analysis. Optimum conditions for the determination were established. It was found that sputtering of selenium could be achieved, with a satisfactory detection limit and acceptable accuracy, at a power of 240 W. Water cooling was at a flow-rate of 8 I min-1, which provided equal temperatures of the neutral gas and cathode of 430 2 50 K, which is lower than the melting-points of Se and Se02.