Addition Of SL Research Articles

Interactions with soy lecithin regulate the emulsification capacity of pea protein: Effects of soy lecithin concentration

Interactions between pea protein isolate (PPI, 1%) and soy lecithin (SL, 0.1%–2%) in bulk phase and the impacts on the emulsifying properties of PPI were investigated. Fluorescence spectra, molecular docking, and infrared spectroscopy verified that PPI and SL formed complexes in aqueous phase via hydrophobic interactions, hydrogen bonds, and electrostatic interactions. CMC of SL was increased to 1% in presence of PPI (1%). Increased particle size, surface charge, and surface hydrophobicity of PPI-SL complexes with increasing SL concentrations were observed. Addition of SL transformed the composition of oil/water interface from pure PPI into a mixture of PPI and SL, which decreased the surface tension and resulted in smaller droplet size of emulsions. The inclusion of all PPI-SL complexes enhanced emulsion stability during storage. Incorporating SL below 1% also showed similar protective effects for curcumin against UV irradiation compared to pure PPI. The study may provide a theoretical basis for the rational non-covalent combination of pea protein and lecithin as complex emulsifiers.

Selenium-rich Lactobacillus plantarum alleviates salinity stress in Cyprinus carpio: Growth performance, oxidative stress, and immune and inflammatory responses

Salinity is an important environmental factor that affects the health of aquatic animals, when salinity level above the tolerance threshold can pose a significant threat to the survival of aquatic animals. As a trace element necessary for animal growth, selenium participates in the body’s antioxidant reaction, and protect aquatic animals from oxidative stress damage. Biological methods for synthesizing selenium nanoparticles (bio-Se-NPs) from bacteria are safe, inexpensive, and accessible. Therefore, we synthesized selenium nanoparticles using Lactobacillus plantarum (probiotic) to study the growth, immune, antioxidant, and inflammatory responses of selenium-rich Lactobacillus plantarum (SL, a type of bio-Se-NPs) fed Cyprinus carpio under low-salinity (5 g/L salinity) and high-salinity (10 g/L salinity) stresses. Analyses revealed that the addition of SL at a concentration of 1 mg/kg significantly alleviated the growth inhibition caused by high-salinity stress. SL significantly alleviated salinity-induced liver tissue injury (numerous cytoplasmic vacuolations the accumulation, inflammatory cell infiltration, nuclear lysis, and some blood congestion). SL significantly alleviated the abnormal levels of serum ALT, AST, GGT and LDH caused by salinity stress, and improved lipid metabolism (TG, TC, LDL-C, HDL-C). SL can also regulates cytokines and antioxidant genes (TNF-α, iL-1β, iL-10, TGFβ-1, SOD, CAT, GPx1, and HO-1) through the NF-κB and Nrf-2 signaling pathways and thereby reduce the inflammatory response and increase the antioxidant level, and these effects attenuate salinity-mediated oxidative damage. In conclusion, our findings indicate that SL can significantly promote the growth and development of fish and alleviate the adverse effects of high-salinity stress and thus, SL can be a potential feed additive for alleviating oxidative stress and inflammatory responses.

Supplemental Light-emitting Diode Effects on the Growth, Fruit Quality, and Yield of Two Greenhouse-grown Strawberry (Fragaria ×ananassa) Cultivars

Recent interest in off-season greenhouse-grown food crops, in combination with supplemental (top) lighting (SL), has created opportunities for local production of high-value fruit crops such as strawberries (Fragaria ×ananassa). Light-emitting diodes (LEDs) as SL can be tailored to a specific quality of radiation (i.e., wavelengths) to promote increased production and quality of greenhouse-grown crops. The objectives of this study were to evaluate the effects of three LED light bars on off-season controlled environmental agriculture (CEA) production of 2-day neutral strawberry cultivars: Albion and San Andreas. LED effects on overall vegetative biomass (e.g., stolon production, crown number, and leaf area), marketable fruit yield, and fruit quality [e.g., individual fruit weight and soluble solids content (SSC)] were measured during decreasing daylengths from Oct. to Dec. 2017 (Expt. 1) and increasing daylengths of Jan. to Apr. 2018 (Expt. 2). We hypothesized that the addition of SL via three LED treatments would increase measured parameters. Specifically, it was expected that the LED bars [high blue (HB) and low blue (LB)] with greater intensities of blue and red light would produce greater yields and also increase SSC of the berries. The hypotheses were tested by evaluating three LED light top bars [white far-red (WFR; 440–450 nm), HB, and LB], with wavelength peaks of blue (450 nm) and red (665 nm) light, but differing photosynthetic photon flux densities (PPFDs). Results from these experiments showed that individual strawberry fruit size and SSC were increased with the use of HB and LB LEDs during the shortening days of Expt. 1. Increased leaf area and crown number were also affected positively within all LED treatments (WFR, LB, HB) for ‘San Andreas’. Relative to Expt. 1, the lengthening days of Expt. 2 elicited more limited fruit responses, although increased stolon production within all treatments was reported. In addition, differences between cultivars in leaf area and SSC were observed with ‘San Andreas’ growing larger leaves and ‘Albion’ berries having a greater SSC. Individual fruit weight of both cultivars responded similarly, with increased fruit size in LB and HB, specifically within both Expt. 1 and Expt. 2. Our studies indicate that the addition of SL, in the form of LB and HB improved overall strawberry fruit quality and plant growth during shortening daylengths and under greenhouse CEA conditions.

PSX-33 Effect of supplementing different proportions of sericea lespedeza with alfalfa silage on intake, digestibility, and nitrogen balance in sheep

Abstract Dietary manipulations to include tannins can change the proportion and amounts of N excreted in the urine and feces as well as improve N-use efficiency in ruminants. This study was conducted to investigate effects on animal digestion parameters of adding different proportions of sericea lespedeza hay (SL) to alfalfa silage. Alfalfa was harvested in June 2018 at 75% bloom, chopped, and then packed at 55% moisture into plastic-lined bins and allowed to ensile for 3 months. Alfalfa silage was either offered alone or mixed with 9, 18, or 27% SL on a DM basis. These diets were offered randomly for ad libitum consumption to 16 ewes (41.8 ± 4.61 kg BW) in a randomized complete block design experiment with 2 periods to provide 4 observations per treatment per experimental period, each consisting of a 14-d dietary adaptation period followed by 5 d of total fecal and urine collection. Data were analyzed using PROC MIXED of SAS and orthogonal linear and quadratic trend analyses were tested. Digestibility (%) of DM and OM and digestible DM and OM intake (g/kg BW) decreased linearly (P < 0.05) with increasing SL addition to the diet. Digestibility of NDF and ADF decreased linearly (P < 0.01) with increasing SL, and apparent absorption (%) of N decreased linearly (P < 0.05) with increasing SL in the diet. Urinary N excretions (g/d) tended (P = 0.10) to decrease linearly while fecal N (g/day) tended to increase (P = 0.10) linearly with increasing SL proportion in the diet. In this study, supplementation with sericea lespedeza as a tannin source to alfalfa silage decreased forage digestibility and digestible organic matter intake and did not positively influence nitrogen use. The study was supported in part by USDA-ARS specific cooperative agreement 58-3655-4-052 and by USDA NIFA grant 2018-67019-27804.

Complete assembly of the Leishmania donovani (HU3 strain) genome and transcriptome annotation

Leishmania donovani is a unicellular parasite that causes visceral leishmaniasis, a fatal disease in humans. In this study, a complete assembly of the genome of L. donovani is provided. Apart from being the first published genome of this strain (HU3), this constitutes the best assembly for an L. donovani genome attained to date. The use of a combination of sequencing platforms enabled to assemble, without any sequence gap, the 36 chromosomes for this species. Additionally, based on this assembly and using RNA-seq reads derived from poly-A + RNA, the transcriptome for this species, not yet available, was delineated. Alternative SL addition sites and heterogeneity in the poly-A addition sites were commonly observed for most of the genes. After a complete annotation of the transcriptome, 2,410 novel transcripts were defined. Additionally, the relative expression for all transcripts present in the promastigote stage was determined. Events of cis-splicing have been documented to occur during the maturation of the transcripts derived from genes LDHU3_07.0430 and LDHU3_29.3990. The complete genome assembly and the availability of the gene models (including annotation of untranslated regions) are important pieces to understand how differential gene expression occurs in this pathogen, and to decipher phenotypic peculiarities like tissue tropism, clinical disease, and drug susceptibility.

Evaluation of Sialyllactose Supplementation of a Prebiotic-Containing Formula on Growth, Intestinal Development, and Bacterial Colonization in the Neonatal Piglet

BackgroundSialyllactose (SL) is a highly abundant oligosaccharide in human milk that has been shown to influence intestinal maturation and cognitive development and exert bifidogenic effects on the gut microbiota. The SL content of infant formula is significantly less than that of human milk, therefore there is interest in determining the effect of supplementing SL to infant formula at the levels in human milk on neonatal outcomes. ObjectiveThe aim of this study was to investigate the effect of varying doses of dietary SL compared with a milk replacer formula on weight gain, gastrointestinal development, and microbiota composition in piglets. MethodsThirty-eight intact male piglets were randomly assigned to 1 of 4 experimental diets from 2 to 32.33 d of age. Diets were formulated to contain SL at 0 mg/L (CON), 130 mg/L (LOW), 380 mg/L (MOD), or 760 mg/L (HIGH). At 32.33 d of age, blood was collected for serum chemistry and blood cellular analyses, and coagulation time. Immediately after humane killing, the small intestine was excised and intestinal segments fixed for quantification of mucin-producing goblet cells and morphologic analysis. In addition, mucosal disaccharide activity was assessed. Colonic luminal contents and feces were collected for measurement of pH, dry matter, volatile fatty acids, and the microbiota. ResultsSL at ≤760 mg/L supported normal growth, intestinal development, and enzyme activity as well as serum chemistries and hematology (P > 0.05). In addition, SL supplementation did not affect overall microbiota structure and diversity in ascending colon contents and feces, but had minor effects on the relative abundances of specific microbes. ConclusionsThe findings in this study demonstrate that SL addition to a prebiotic-containing formula was well-tolerated by neonatal piglets, supported normal growth, and did not result in any adverse effects on serum chemistries or intestinal development. Curr Dev Nutr 2018;0:nzy067.

Interactions between whey protein or polymerized whey protein and soybean lecithin in model system

Soybean lecithin is often used as a surfactant in food formulation. The aim of this study was to investigate the interactions between soybean lecithin (SL, 0-3%, wt/vol) and whey protein (WP, 10%, wt/vol) or polymerized whey protein (PWP, 10%, wt/vol) induced by heating WP solutions at 85°C for 0 to 20 min at pH 7.0. The samples were evaluated for zeta potential, particle size, morphology, rheological properties, thermal properties, secondary structure, and surface hydrophobicity. Zeta potential of WP increased linearly as SL level increased from 0 to 3%, whereas that of PWP changed with plateau at SL level of 1%, which may be due to the aggregation of SL. The addition of SL increased the particle size and apparent viscosity of both WP and PWP. All the samples exhibited different morphology depending on SL level and heating time according to transmission electron microscopy images. Whey protein showed obviously decreased gelation time and increased storage modulus in the presence of SL. Differential scanning calorimetry curves confirmed the effects of SL on the thermal properties of both WP and PWP. Circular dichroism spectra indicated that SL had effects on the secondary structure of both WP and PWP. The changes in surface hydrophobicity indicated the hydrophobic interactions between WP/PWP and SL. Data indicate that the physicochemical and functional properties of WP and PWP can be altered by adding soybean lecithin.

Large strain of temperature insensitive in (1–x)(0.94Bi0.5Na0.5TiO3–0.06BaTiO3) –xSr0.7La0.2TiO3 lead-free ceramics

Novel (1–x)(0.94Bi0.5Na0.5TiO3–0.06BaTiO3)–xSr0.7La0.2TiO3 ternary lead-free ceramics (BNBT–xSL, x = 0.00–0.08) were fabricated by the widely used solid-state sintering technique. The crystal phase, microstructure, dielectric relaxation, piezoelectric, and electromechanical properties of each composition were systematically analyzed. It is found that the addition of SL has little effect on the crystal phase and grain morphology, but it can remarkably improved the relaxation property of the ceramic sample and gave rise to favourable dielectric properties in a wide range of temperatures. In addition, as the SL content increases, the ferroelectric to relaxor temperature (TF-R) is adjusted to below ambient temperature. More importantly, the decay of ferroelectric phase resulted in a significant increase in strain value: the large strain of 0.5% with normalized strain of 625 pm/V was obtained at 80kv/cm and x = 0.04. Finally, the composition exhibited high strain of temperature insensitivity range from room temperature to 100 °C, the strain value remained above 0.4% and kept within 5%. The results are due to the coexistence of rhombohedral polar-nanoregions (PNRs) and tetragonal PNRs during the relaxor region. This result is of great importance to the developments of temperature-insensitive strain sensors and actuators.

Effects of mineral admixtures on shear thickening of cement paste

Rheological behaviors are the essential workability characteristics of fresh concrete. Generally speaking, paste volume in self-compacting concrete (SCC) are no less than 340 L/m3. Therefore, rheology of paste could be mainly responsible for rheology of SCC. Mineral admixtures are important for modern concrete, taking great influence on concrete rheology. In this paper, an experiment was designed to investigate the shear thickening behaviors of cement paste replaced by fly ash (FA), slag (SL) and limestone powder (LP), respectively.Results show that plastic viscosity of paste discussed in this paper prominently decrease first and then increase with the shear rate increasing. Therefore, there exist critical shear rate (γcrit), critical shear stress (τcrit) and minimum plastic viscosity (ηmin) in rheological curves at the beginning of shear thickening taking place. The addition of FA, SL and LP into cement paste not only decrease the γcrit, τcrit and ηmin, resulting in cement paste easy to exhibit shear thickening, but also increase the rheological index (n), leading to shear thickening intensity augmenting. γcrit of cement paste with addition 30% SL drops to10s−1, displaying shear thickening response taking place easily compared to cement paste with the same FA and LP contents. Rheological index (n) of cement paste with SL is also larger than cement paste with FA and LP at the same mineral admixtures contents. The shear thickening intensity sequence of cement paste under the effects of mineral admixtures are SL, FA and LP, respectively.

Multi-technique investigation of metakaolin and slag blended portland cement pastes

Increasing incorporation of metakaolin (MK) into field concrete mixtures necessitates careful study of the portland cement/MK hydrating systems. While a number of studies have been conducted on MK blends with cement, the current knowledge on its effect on hydration products and paste microstructure remains incomplete. This study evaluated the effect of MK on the nature of hydration products through X-ray diffraction, while the effect on microstructure was assessed by measuring porosity with nitrogen adsorption and determining nanoindentation modulus as well as volume fractions of CSH with varying packing densities. The 10MK paste hydrated for 7days was compared to the plain ordinary portland cement (OPC) paste as well as to paste containing 52% slag (52SL). No significant effect was observed on the nature of hydration products with MK or SL addition. However, nitrogen-accessible porosity increased with MK and SL addition, the increase being larger with SL. The average indentation modulus for hydration products decreased with addition of MK and SL which corresponded to increasing nitrogen accessible pores.

Microbial properties and attributes of ecological relevance for soil quality monitoring during a chemical stabilization field study

Chemical stabilization is a soil remediation technique based on the incorporation of organic and/or inorganic amendments to metal contaminated soil in order to decrease metal bioavailability and improve soil quality. Consequently, the establishment of follow-up monitoring programmes is essential to ensure the long-term effectiveness of chemical stabilization in terms of both metal bioavailability reduction and soil quality improvement. In this study, three doses (20, 40 and 80tha−1) of a lime-treated sewage sludge, that meets legal standards regarding metal contents, were added to a metalliferous mine soil and a variety of physicochemical and microbial indicators of soil quality were measured over time (immediately before treatment application and one and six months after such application). Soil CaCl2-extractable and plant metal concentrations were also measured. We carried out a complementary interpretation of soil microbial properties through their grouping within a set of ecosystem attributes of ecological relevance: vigour, organization, stability, suppressiveness and redundancy. Sewage sludge addition led to an increase in soil pH, but this beneficial effect was transient. The addition of sewage sludge had a more pronounced effect on parameters used here to estimate soil vigour (dehydrogenase activity, basal and substrate-induced respiration). On the contrary, the addition of sewage sludge did not significantly alter the composition of soil microbial communities, as reflected by PCR-DGGE data. Chemical stabilization was only partly successful: it did improve soil quality but the expected reduction in soil metal bioavailability (as reflected by the values of CaCl2-extractable metal concentration) was clearly observed only for Cd (not for Pb or Zn); however, SL addition led to a significant reduction in shoot metal concentration for the three metals under study. The assessment of soil quality at the attribute level has proven useful for the interpretation of the effect of chemical stabilization on soil functioning.

Identification of SL addition trans-splicing acceptor sites in the internal transcribed spacer I region of pre-rRNA in Leishmania (Leishmania) amazonensis

Trypanosomatidae is a family of early branching eukaryotes harbouring a distinctive repertoire of gene expression strategies. Functional mature messenger RNA is generated via the trans-splicing and polyadenylation processing of constitutively transcribed polycistronic units. Recently, trans-splicing of pre-small subunit ribosomal RNA in the 5' external transcribed spacer region and of precursor tRNAsec have been described. Here, we used a previously validated semi-nested reverse transcription-polymerase chain reaction strategy to investigate internal transcribed spacer (ITS) I acceptor sites in total RNA from Leishmania (Leishmania) amazonensis. Two distinct spliced leader-containing RNAs were detected indicating that trans-splicing reactions occur at two AG acceptor sites mapped in this ITS region. These data provide further evidence of the wide spectrum of RNA molecules that act as trans-splicing acceptors in trypanosomatids.

Effects and interactions of sodium lactate, sodium diacetate, and pediocin on the thermal inactivation of starved Listeria monocytogenes on bologna

The effects and interactions of temperature (56.3–60 °C), sodium lactate (SL; 0–4.8%), sodium diacetate (SDA; 0–2.5%), and pediocin (0–10,000 AU) on starved Listeria monocytogenes (10 7 CFU/g) on bologna were investigated. Bologna slices containing SL and SDA in the formulation were dipped in pediocin, surface inoculated, and treated at various temperatures using combinations of parameters determined by central composite design. D-values were calculated. The observed D-values ranged from 2.8 min at 60 °C to 24.61 min at 56.3 °C. Injury ranged from 9.1 to 76% under various conditions. The observed D-values were analyzed using second order response surface regression for temperature, SL, SDA, and pediocin, and a predictive model was developed. Predicted D-values were calculated and ranged from 3.7 to 19 min for various combinations of parameters. Temperature alone reduced the predicted D-values from 33.96 min at 56.3 °C to 11.51 min at 60 °C. Addition of SL showed a protective effect. Other combination treatments either reduced or increased D-values depending on temperature. The combination of SL and SDA was effective at lower temperatures, however, higher levels of SDA at higher temperatures made the organism more heat resistant. Pediocin (up to 5000 AU) with increasing temperature and SDA reduced D-values. Depending on temperature and concentration, the interactions between various additives can affect thermal inactivation of L. monocytogenes on bologna. Starvation rendered L. monocytogenes more susceptible to heat and additives.

Effect of feeding sericea lespedeza ( Lespedeza cuneata) on growth performance, blood metabolites, and carcass characteristics of Kiko crossbred male kids

Twenty-four high percentage Kiko crossbred male kids (body weight (BW), 27.8 ± 2.2 kg) were stratified by BW and randomly allocated to one of four experimental treatment groups ( n = 6). Diets contained different levels of the condensed tannin (CT) containing forage sericea lespedeza (SL, Lespedeza cuneata) dried meal replacing alfalfa ( Medicago sativa) pellets (ALF). Experimental treatments included: the control diet – 0% SL and 30% ALF; 10% SL and 20% ALF; 20% SL and 10% ALF; or 30% SL and 0% ALF as fed. Sericea lespedeza whole plant dried meal, incorporated in the grain mix portion of the diet and the mix was fed daily at 70% of total feed offered, with the remaining 30% consisting of bermudagrass ( Cynodon doctylon) hay (BGH). Animals were fed once a day and the intake was adjusted every 3–4 days so that a 4–6% was refused (grain mix/SL and hay). Body weights were taken at the beginning, mid, and end of the study and blood was collected twice, at the beginning and at the end of the study, for complete analysis. The performance period lasted 63 days and at the completion of the study, goats were harvested and carcass characteristics measured. There was no difference in initial or final BW of goats; however, average daily gain (ADG) was higher (quadratic, P = 0.01) in goats consuming either all ALF or SL diets. Average daily dry matter (DM) and CT intake increased (linear, P = 0.04 and P < 0.0001, respectively) as the level of SL increased in the diet; however, body weight gain:feed (G:F, kg/kg dry matter) was lower for 10 or 20% SL diets (quadratic, P = 0.002). Scrotal circumference tended to decrease (quadratic, P = 0.07) in goats fed 10 or 20% SL and height at withers decreased (linear, P = 0.05) with addition of SL. Adjusted body fat thickness decreased (linear, P = 0.02) with added SL. Dressing percentages were low and ranged from 37.6 to 39.1 ± 1.5 for all diets. White blood cells decreased (linear, P = 0.05) and lymphocytes % increased (linear, P = 0.05) with added SL. Serum creatinine kinase and alanine aminotransferase increased (linear, P = 0.01 and P = 0.001, respectively) and serum amylase decreased (linear, P = 0.01) as the level of SL increased. In conclusion, addition of SL up to 30% or CT up to 22.2 mg/kg DM in the diet did not adversely affect growth performance of goats, and it produced lower fat in the carcass.

표고버섯가루, 자몽종자 추출물, 젖산나트륨의 단독 혹은 복합첨가가 저지방 소시지의 품질 및 저장성에 미치는 효과

본 연구는 표고버섯 가루를 이용한 저지방 기능성 소시지를 제조하고 저장성 증진을 위하여 천연의 젖산나트륨과 자몽종자 추출물을 이용하였다. 소시지에 첨가한 표고 버섯은 0.25% 수준 내에서 첨가하였을 때 제품의 품질 변화가 나타나지 않으며 관능성상에도 영향을 주지 않았다. 냉장 저장 중 품질 변화는 먼저, 처리구에 의한 효과에서 젖산나트륨, 표고버섯가루, 자몽종자추출물 단독 또는 복합첨가 할 경우에도 pH, 색도, 유리수분 및 진공감량 모두 처리구간 유의적인 차이를 나타내지 않아 첨가한 물질의 첨가수준이 제품의 품질에 영향을 주지 않는 것으로 평가되었으며, 반면에 젖산나트륨이나 자몽종자 추출물을 단독이나 복합 첨가 시 접종한 Listeria monocytogenes를 줄일 수 있었다. 한편, 저장기간에 의한 효과에서는 pH가 2주까지 낮아지다가 증가하는 경향이었으며, 명도는 다소 감소하다가 증가하였으나, 적색도는 저장 8주에 가장 낮아졌다. 유리 수분의 함량은 저장 기간이 경과할수록 낮아졌고, 반면에 진공 감량은 증가하였다. 이상의 결과에서 표고버섯을 이용한 저지방 기능성 소시지의 제조가 가능하였고, 젖산 나트륨과 자몽종자 추출물을 단독 혹은 복합으로 첨가하여 Listeria monocytogenes의 성장을 저해시킬 수 있었다. 결론적으로, 자몽종자 추출물과 젖산나트륨은 저지방 훈연 소시지의 품질에 영향을 주지 않고 저장성을 증진시키는 천연 보존제로 평가되었다. The study was performed to evaluate the product quality and shelf-life effect of low-fat comminuted sausages (LFS) manufactured with sodium lactate (SL, 2%), grapefruit seed extract (GSE, 0.2%) and Lentinus edodes (LE) powder (0.25%) alone or in combination. Addition of LE powder lower than 0.25% did not affect the product quality and sensory characteristics (p>0.05). However, LFS containing 2% SL in combined with 0.2% GSE inhibited the growth of inoculated Listeria monocytogenes during refrigerated storage for 8 wk. During refrigerated storage, pH decreased until 2 wk of storage and then increased thereafter. In addition, lightness decreased up to the 1st wk and then increased thereafter. However, redness value was the lowest at 8 wk, and expressible moisture (%) was decreased with increased storage time. Purge loss (%) was gradually increased over 8 wk of storage. Microbial counts of Listeria monocytogenes increased as storage time increased. Based on these results, LFS could be manufactured with LE powder (0.25%) and the addition of SL (2%) in combination with GSE (0.2%) inhibited the growth of Listeria monocytogenes during refrigerated storage of LFS.

Sequences involved in mRNA processing in Trypanosoma cruzi

Gene expression in Trypanosomatids requires processing of polycistronic transcripts to generate monocistronic mRNAs by cleavage events that are coupled to the addition of a Spliced Leader sequence (SL) at the 5′-end and a poly(A) tail at the 3′-end of each mRNA. Here we investigate the sequence requirements involved in Trypanosoma cruzi mRNA processing by mapping all available expressed sequence tags and cDNAs containing poly(A) tail and/or SL to genomic intergenic regions. Amongst other parameters, we determined that the median lengths of 5′ untranslated region (UTR) and 3′UTR sequences are 35 and 264 nucleotides, respectively; and that the median distance between SL addition sites and a polypyrimidine motif is 18 nucleotides, whereas the median distance between poly(A) addition sites and the closest polypyrimidine-rich sequence is 40 nucleotides.