e., small nuclear ribonucleoproteins (snRNPs) and SC35 protein, in growing pollen tubes of Hyacinthus
orientalis L. were analyzed in vitro and in vivo. The results indicated that the restart of RNA synthesis occurred first in the vegetative and then in the generative nucleus of both in vitro and in vivo growing pollen tubes. Changes in RNA synthesis were accompanied by the redistribution of splicing machinery elements in both vegetative and generative nuclei of the growing pollen tube. At stages of pollen tube growth when the vegetative and generative nuclei were transcriptionally active, clear differences in the distribution TPX-0005 in vitro pattern of the splicing system components were observed in both pollen nuclei. While both small nuclear RNA with a trimethylguanosine cap on
the 5 ‘ end and SC35 protein were diffusely distributed in the nucleoplasm in the vegetative nucleus, the studied antigens were only present in the areas between condensed chromatin in the generative nucleus. When the transcriptional activity of both pollen nuclei could no longer be observed at later stages of pollen tube growth, snRNPs and SC35 protein were still present in the vegetative nuclei but not in the generative nuclei. We, therefore, investigated potential differences in the spatial organization of splicing system elements during pollen tube growth. They clearly reflect differences Selleckchem INK1197 in gene expression patterns in the vegetative and the generative cells, which may be determined by the different biological roles of angiosperm male gametophyte cells.”
“Fenestrations of cerebral arteries are most common in the vertebrobasilar (VB) system, and magnetic resonance (MR) angiographic studies of these variations are sparse.
We retrospectively reviewed MR angiographic images of 3,327 patients; images were obtained using two 1.5-T imagers and picked up fenestrations of the intracranial vertebral artery (VA), VB junction, and basilar artery
(BA) for evaluation.
In 92 patients, we found 93 fenestrations (2.80%), which included 18 of the intracranial VA (0.54% prevalence), 6 of the VB junction (0.18%), and 69 of the BA (2.07%). Most VA fenestrations were large, and the posterior inferior cerebellar artery arose from Sirolimus supplier the fenestrated segment in 10 patients (56%). Fenestrations of the VB junction were small and triangular. Sixty-five (94%) of the 69 BA fenestrations were located at the proximal segment and had small slit-like configurations. The anterior inferior cerebellar artery arose from the fenestrated segment in 27 patients (37%). We found 18 cerebral aneurysms in 16 (17%) of the 92 patients with fenestration but detected only one aneurysm at the fenestration.
The overall prevalence of fenestrations of the intracranial VB system was 2.77%. We found associated cerebral aneurysms relatively frequently but rarely at the fenestration.