202 research outputs found

    Analysis of the A-U rich hairpin from the intergenic region of tospovirus S RNA as target and inducer of RNA silencing

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    Earlier work indicated that Tomato spotted wilt virus (TSWV) messenger transcripts, and not the (anti)genomic RNAs, are targeted by the RNA silencing machinery. Here, the predicted AU-rich hairpin (HP) structure encoded by the intergenic region (IGR) of the TSWV S RNA, and present at the 3' end of viral mRNAs, was analyzed as a target and inducer for RNA silencing. Virus-derived siRNAs (vsiRNAs) purified from virus infected plants were found to derive from all three genomic RNA segments but predominantly the ambisense M and S RNAs. Further profiling on the S RNA sequence revealed that vsiRNAs were found from almost the entire S RNA sequence, except the IGR from where hardly any vsiRNAs were found. Similar profiles were observed with the distantly related Tomato yellow ring tospovirus (TYRV). Dicer cleavage assays using Drosophila melanogaster (Dm) embryo extracts showed that synthetic transcripts of the IGR-HP region were recognized as substrate for Dicer. Transient agroinfiltration assays of a GFP-sensor construct containing the IGR-HP sequence at its 3' UTR (GFP-HP) did not show more rapid/strong silencing and profiling of the corresponding siRNAs, generated outside the context of a viral infection, still revealed relatively low levels of IGR-HP-derived siRNAs. These data support the idea that the IGR-HP is a weak inducer of RNA silencing and only plays a minor role in the amplification of a strong antiviral RNAi response

    Molecular Diagnosis of Iris Yellow Spot Virus (IYSV) on Onion in Iran

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    Viral symptoms indicative of Iris yellow spot virus (IYSV) were observed on onion in several fields near Chenaran in Khorasan Razavi Province. Mechanical inoculation of herbaceous hosts with onion sap extracts from symptomatic plants showed similar symptoms to those described for IYSV. The mechanically transmitted virus reacted only with antisera specific to IYSV in DAS-ELISA but not with antisera specific to seven other tospoviruses. In RT-PCR, a DNA fragment approximately 822 bp in size was amplified from infected Nicotiana benthamiana by using primers specific to the nucleocapsid (N) gene of IYSV. After cloning and sequencing, the deduced N protein sequence of two isolates (GenBank accession no. HQ148173 and HQ148174) showed 98% amino acid identity with a Sri Lankan isolate, 96% with a Dutch isolate and 92% with a Brazilian isolate. To our knowledge, this is the first molecular characterization of IYSV in Ira

    Strategic crossing of biomass and harvest index—source and sink—achieves genetic gains in wheat

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    To accelerate genetic gains in breeding, physiological trait (PT) characterization of candidate parents can help make more strategic crosses, increasing the probability of accumulating favorable alleles compared to crossing relatively uncharacterized lines. In this study, crosses were designed to complement “source” with “sink” traits, where at least one parent was selected for favorable expression of biomass and/or radiation use efficiency—source—and the other for sink-related traits like harvest-index, kernel weight and grains per spike. Female parents were selected from among genetic resources—including landraces and products of wide-crossing (i.e. synthetic wheat)—that had been evaluated in Mexico at high yield potential or under heat stress, while elite lines were used as males. Progeny of crosses were advanced to the F4 generation within Mexico, and F4-derived F5 and F6 generations were yield tested to populate four international nurseries, targeted to high yield environments (2nd and 3rd WYCYT) for yield potential, and heat stressed environments (2nd and 4th SATYN) for climate resilience, respectively. Each nursery was grown as multi-location yield trials. Genetic gains were achieved in both temperate and hot environments, with most new PT-derived lines expressing superior yield and biomass compared to local checks at almost all international sites. Furthermore, the tendency across all four nurseries indicated either the superiority of the best new PT lines compared with the CIMMYT elite checks, or the superiority of all new PT lines as a group compared with all checks, and in some cases, both. Results support—in a realistic breeding context—the hypothesis that yield and radiation use efficiency can be increased by improving source:sink balance, and validate the feasibility of incorporating exotic germplasm into mainstream breeding efforts to accelerate genetic gains for yield potential and climate resilience

    FEMORAL MONONEUROPATHY: COMPLICATING A DIFFICULT PELVIC URETEROLITHOTOMY

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    Femoral mononeuropathy is a complication of gynecological and urological operations. Tlte objective of this citse report is to bring to the attention of fellow urologists the very existence of this complication and offer measures to prevent it. A 48 year old obese worman with a 2 year history of frequent left renal colics, anil a nonfunction left kidney on IVP underwent a retrograde ureterogram study anil a transvaginal ureterolithotomy, in an exaggerated lithotomy position. Postoperatively, a left leg paralysis required 3 weeks of care and encouragement to heal. To prevent this complication, avoid putting too long and too much pressure by retractors on the psoas muscles. During the abdomino-perineal procedures, frequent change of retractor site and monitoring of distal arterial pulses would he helpful. Also, do not use the exaggerated lithotomy position for an extended period of time

    OUTCOME OF LIVE DONOR RENAL ALLOGRAFT TRANSPLANTATION FROM SINGLE VS MULTIPLE ARTERIES' GRAFTS

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    This study compare:.' [he results 0;,.1 outcome of live-donor transplantation between single-artery "',"' mull/pic-ana)' transplant kidneys. Cadaver kidneys with multiple vessels arc retrieved with a patch of the donor artery. 111is is not possible ill the !iI'C donation seuing. Therefore !i1'C donation of rcnal"nallografts with multiple arteries is lIot a straiglnjorward surgery. We studied 22 muttiplc-anery live donor renal allografts among 223 renal transplantations in a sequential. prospective mOllTlCr [or 3 ynJrs. One-year gra{! survival was l)(j.:V:(, ill single-anery group and 95.5":{, in tlns muliplc . arIer)' group. III the singleartery group the complications wae: dctavcd gm[l [unction ill 3.5'7;, rean astomosis o[ tlu: v-essels in 2,9':k, transient post-transplant dialysis in 1. 5 (X" graft nephrectomy ill 2,5';{, AT"' ill 1":'(" Urine leak in 2.5':{', renal anav stenosis in O.5S'(" and lvmpho cclc ill 1%. NOlie: o] thcsc occurred in the"nmultiptc-oncry group. This difference is statistically significant IX~ = 8.10). Cold ischemia time: l"'(lS significantly lunger in lilt' multiple . anery group (panastomosis was not siglliftcanl~"' dlffaelll among lht' 2,1,'Youps (I = 1.255). Ttu: totat tcngtli of tile operation IVas IOllga ill lhe mutsiptc-oncry group (p < O. 00(5). In conclusion it is appareIH snas t lu: intra-op crativc complications. posi-operati vc complications and one-year grafr survival are ccnnparabtc ill"nsingle - ane'Y' "'."'. mutsiptc - arrcry renal transplantation. tn other words, !i1'C - donor transptannuion with muliip!c . arIa)' reno! units is safe and has a good OI/lCO!1le
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