instruction:
Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.
question:
Context: To increase the Zn level in shoots, AtHMA4 was ectopically expressed in tomato under the constitutive CaMV 35S promoter. However, the Zn concentration in the shoots of transgenic plants failed to increase at all tested Zn levels in the medium. Modification of Zn root/shoot distribution in tomato expressing 35S::AtHMA4 depended on the concentration of Zn in the medium, thus indicating involvement of unknown endogenous metal-homeostasis mechanisms. To determine these mechanisms, those metal-homeostasis genes that were expressed differently in transgenic and wild-type plants were identified by microarray and RT-qPCR analysis using laser-assisted microdissected RNA isolated from two root sectors: (epidermis\u2009+\u2009cortex and stele), and leaf sectors (upper epidermis\u2009+\u2009palisade parenchyma and lower epidermis\u2009+\u2009spongy parenchyma).', 'Zn-supply-dependent modification of Zn root/shoot distribution in AtHMA4-tomato (increase at 5\xa0μM Zn, no change at 0.5\xa0μM Zn) involved tissue-specific, distinct from that in the wild type, expression of tomato endogenous genes. First, it is suggested that an ethylene-dependent pathway underlies the detected changes in Zn root/shoot partitioning, as it was induced in transgenic plants in a distinct way depending on Zn exposure. Upon exposure to 5 or 0.5\xa0μM Zn, in the epidermis\u2009+\u2009cortex of the transgenics\' roots the expression of the Strategy I Fe-uptake system (ethylene-dependent LeIRT1 and LeFER) was respectively lower or higher than in the wild type and was accompanied by respectively lower or higher expression of the identified ethylene genes (LeNR, LeACO4, LeACO5) and of LeChln. Second, the contribution of LeNRAMP2 expression in the stele is shown to be distinct for wild-type and transgenic plants at both Zn exposures. Ethylene was also suggested as an important factor in a pathway induced in the leaves of transgenic plants by high Zn in the apoplast, which results in the initiation of loading of the excess Zn into the mesophyll of "Zn accumulating cells".
Answer: In transgenic tomato plants, the export activity of ectopically expressed AtHMA4 changes the cellular Zn status, which induces coordinated tissue-specific responses of endogenous ethylene-related genes and metal transporters. These changes constitute an important mechanism involved in the generation of the metal-related phenotype of transgenic tomato expressing AtHMA4.
answer:
Does engineering high Zn in tomato shoot through expression of AtHMA4 involves tissue-specific modification of endogenous genes?


question:
Context: Cytotechnologists and pathologists often perform onsite evaluations of thyroid fine-needle aspirations (FNAs) to provide immediate feedback regarding whether adequate material has been obtained for cytologic diagnosis. The current study was designed to determine whether onsite adequacy assessment results in a significant decrease in nondiagnostic specimens between ultrasound (US)-guided FNAs of the thyroid and those performed by palpation alone.', 'A search was performed to identify in-house thyroid FNAs performed between January 1, 2000 and December 31, 2003 that were obtained under US guidance or by palpation only. It was then recorded whether an onsite adequacy assessment was performed. The submitting physician and final diagnosis also were recorded for each case. Contingency tables were constructed and evaluated using chi-square analysis.', 'Of 1502 in-house thyroid FNAs included in the current study, 981 (65.3%) were performed under US guidance and 521 (34.7%) were performed with palpation alone. Onsite adequacy assessment of the aspirated material was performed in 323 cases (21.5%), whereas 1179 cases (78.5%) were performed without onsite evaluation. Of the 418 palpation-guided FNAs that were performed without adequacy assessment, 70 (16.7%) were reported to be nondiagnostic, whereas of the 103 palpation-guided FNAs with immediate evaluation, only 7 (6.8%) were determined to be inadequate for diagnosis. This difference was statistically significant (P < 0.025). Of 761 US-guided FNAs without immediate adequacy assessment, 54 (7.1%) were nondiagnostic, which was not statistically different from the nondiagnostic rate of 4.5% (10 of 220 cases) for US-guided FNAs with onsite evaluation. However, when these US-guided FNAs were divided further into 2 groups based on the experience of the radiologist performing the FNA, the nondiagnostic rate in the group of experienced radiologists was only 5.4% (or 32 of 592 US-guided FNAs), even though onsite evaluation was not performed. Among radiologists with less experience, adequacy assessment significantly reduced the nondiagnostic rate from 13.0% (22 of 169 FNAs without adequacy assessment) to 4.5% (10 of 220 FNAs with adequacy assessment) (P < 0.01).
Answer: The results of the current study demonstrate that onsite adequacy assessment of thyroid FNAs significantly reduces the number of nondiagnostic aspirates. However, the benefit of onsite evaluation, at least for US-guided FNAs, depends on the experience of the radiologist. In the current study, experienced radiologists with a relatively low nondiagnostic rate did not benefit from onsite adequacy assessment. This finding confirms the importance of experience in the performance of FNA, but suggests that onsite adequacy assessment may assist the less experienced operator.
answer:
Is the value of onsite adequacy assessment of thyroid fine-needle aspirations a function of operator experience?


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Context: Human de novo single-nucleotide variation (SNV) rate is estimated to range between 0.82-1.70×10(-8) mutations per base per generation. However, contribution of early postzygotic mutations to the overall human de novo SNV rate is unknown.', 'We performed deep whole-genome sequencing (more than 30-fold coverage per individual) of the whole-blood-derived DNA samples of a healthy monozygotic twin pair and their parents. We examined the genotypes of each individual simultaneously for each of the SNVs and discovered de novo SNVs regarding the timing of mutagenesis. Putative de novo SNVs were validated using Sanger-based capillary sequencing.', 'We conservatively characterised 23 de novo SNVs shared by the twin pair, 8 de novo SNVs specific to twin I and 1 de novo SNV specific to twin II. Based on the number of de novo SNVs validated by Sanger sequencing and the number of callable bases of each twin, we calculated the overall de novo SNV rate of 1.31×10(-8) and 1.01×10(-8) for twin I and twin II, respectively. Of these, rates of the early postzygotic de novo SNVs were estimated to be 0.34×10(-8) for twin I and 0.04×10(-8) for twin II.
Answer: Early postzygotic mutations constitute a substantial proportion of de novo mutations in humans. Therefore, genome mosaicism resulting from early mitotic events during embryogenesis is common and could substantially contribute to the development of diseases.
answer:

Do early postzygotic mutations contribute to de novo variation in a healthy monozygotic twin pair?