Convergence of developmental mutants into a single tomato model system: 'Micro-Tom' as an effective toolkit for plant development research

Background

The tomato (Solanum lycopersicum L.) plant is both an economically important food crop and an ideal dicot model to investigate various physiological phenomena not possible in Arabidopsis thaliana. Due to the great diversity of tomato cultivars used by the research community, it is often difficult to reliably compare phenotypes. The lack of tomato developmental mutants in a single genetic background prevents the stacking of mutations to facilitate analysis of double and multiple mutants, often required for elucidating developmental pathways.

Results

We took advantage of the small size and rapid life cycle of the tomato cultivar Micro-Tom (MT) to create near-isogenic lines (NILs) by introgressing a suite of hormonal and photomorphogenetic mutations (altered sensitivity or endogenous levels of auxin, ethylene, abscisic acid, gibberellin, brassinosteroid, and light response) into this genetic background. To demonstrate the usefulness of this collection, we compared developmental traits between the produced NILs. All expected mutant phenotypes were expressed in the NILs. We also created NILs harboring the wild type alleles for dwarf, self-pruning and uniform fruit, which are mutations characteristic of MT. This amplified both the applications of the mutant collection presented here and of MT as a genetic model system.

Conclusions

The community resource presented here is a useful toolkit for plant research, particularly for future studies in plant development, which will require the simultaneous observation of the effect of various hormones, signaling pathways and crosstalk.     

A comparison of popular approaches to optimize landscape resistance surfaces

Landscape Ecology - Landscape resistance surfaces are often used to address questions related to movement, dispersal, or population connectivity. However, modeling landscape resistance is...     

Update on the role of innate immune receptors during Brucella abortus infection

The innate immune system constitutes an efficient defense mechanism against invading microbial pathogens. Recent studies have revealed the intracellular signaling cascades involved in the TLR-initiated immune response to Brucella spp. infection. However, there is a piece of the puzzle missing that is the role of non-TLR receptors in innate immunity. The involvement of TLR receptors in brucellosis has been investigated by different research groups. It was demonstrated that TLR2 clearly does not play any role in controlling Brucella abortus infection in vivo, whereas TLR9 has been shown to be required for clearance of this bacterium in infected mice. The participation of adaptor molecules, such as MyD88 and TRIF has also been discussed. Recently, we and others have reported the critical role of MyD88- and not TRIF-mediated signaling in dendritic cell maturation and in vivo resistance during B. abortus infection. However, the relationship between specific Brucella molecules and non-TLR receptors and signal transduction pathways needs to be better understood. It is now clear that the interaction between TLRs and recently identified cytosolic innate immune sensors is crucial for mounting effective immune responses. Finally, this review discusses the mechanisms used by Brucella to escape detection by the host innate immune system.     

Plasma biomarkers profile of female dogs with mammary carcinoma and its association with clinical and pathological features

The immunological biomarkers profiles were evaluated using Luminex as putative measures to monitor canine mammary carcinomas (MCs). Forty female dogs were categorized into benign mixed tumour (MC‐BMT = 28) and mammary carcinoma (MC=12). The ascendant biomarker signatures were used to compare the groups. For example, a higher frequency of MC‐BMT animals producing IL‐6, CXCL‐8 and CXCL‐10 was observed, whereas for the MC group IL‐2 and CXCL‐8 were detected. MC‐BMT animals without metastasis had an increase in the levels of IL‐2, CXCL‐8, CXCL‐10, IL‐6, TNF‐α, IL‐15 and a decrease in IL‐10 and CXCL‐8. MC‐BMT animals with metastasis showed only an increase in CXCL‐10 and a decrease in IL‐18. After comparing the ascendant signatures following the presence of metastasis in both groups, a higher frequency of dogs exhibiting IL‐10 production was observed. Pearson correlation (P = 0.0273) and receiver operating characteristic (ROC) curve analysis revealed that this pattern was associated with worse outcome and lower survival rates in MC animals.     

Bovine blood components: fractionation, composition, and nutritive value

The objective of this research work was to fractionate bovine blood, collected hygienically in a slaughterhouse, into blood plasma protein concentrate, red blood cell concentrate, globin isolate, and a carboxymethylcellulose-heme iron (CMC-heme) complex. All four fractions were studied for proximate composition and amino acid and mineral contents. The nutritive value of plasma protein concentrate and globin isolate was comparatively studied using rat bioassays. The amino acid content in plasma protein concentrate is well balanced and produced net protein utilization and net protein ratio equivalent to 95% those of casein. Globin isolate ( approximately 91% protein) is deficient in isoleucine and S-containing amino acids and was unable to support rat growth at 10% concentration in the diet. Red blood cell concentrate and the isolated CMC-heme complex were good sources of bioavailable iron. Iron availabilities for CMC-heme and whole blood cell concentrate, related to ferrous sulfate as 100%, were 64 and 70%, respectively.     

Brazilian foot and mouth disease status and meat exportation to the European Union

The aim of this study was to define the differences between the Brazilian states that export and do not export meat to the European Union (EU) and to identify the variables that are important to meet the export requirements. Infrastructure and computerization of the control of animal transit in Brazil that impact on regional health status were evaluated and linked to other variables such as status for foot and mouth disease (FMD) and qualification to export meat to EU. Variables related to transit control of bovines implemented by the state agencies of animal health and inspection in each Brazilian state were evaluated. Using a discriminant analysis, four variables were selected that explained the variation between Brazilian states that were “free” and “not free” of FMD while another four were selected to explain the variation between the zones “approved” and “not approved” to export meat to the EU, including number of official veterinarians, total transit of bovines and buffaloes, total number of animal transit certificates issued for bovine and buffaloes at the state or zone level, and total number of municipalities in the state or zone. It was possible to correctly discriminate between “free” and “not free” FMD states or zones. Variables related to animal transit are important in assessing the state for the classification of animal health situation and for EU approval for the exportation of meat.     

Physiological and biochemical changes of females of Piracanjuba,subjected to induced reproduction

The aim of this experiment was to compare the level of fish female stress during induced reproduction with pituitary extract by two different methods, natural and semiextruded. The reproductive efficiency was 62.5% in the seminatural treatment and 100% in the extruded. Obtained egg volume was 5200 ml and 4000 ml, for seminatural and extruded treatments respectively. The mean number of eggs was 46.7 for the seminatural and 52.0 and for the extruded treatment. The percentage of viable eggs was, respectively, 87.2% and 8.17% for the natural treatment and extruded semimethods. Blood samples were collected to quantify cortisol and glucose levels, as well as red cell series and lymphocyte count. Fishes submitted to induction procedures showed elevated cortisol and glucose levels, compared to the control animals. The results for haematocrit, haemoglobin concentration and red blood cell count showed no significant differences among groups. Significant differences found in the number of lymphocytes and monocytes suggest the general adaptation syndrome. Our results suggest the reproductive induction process with extrusion of gametes as a more stressful method than seminatural reproduction process.     

Chemical Composition and Ruminal Dry Matter and Crude Protein Degradability of Spineless Cactus

The objective of this study was to determine ruminal degradability of the dry matter (DM) and crude protein (CP) of 10 varieties of spineless cactus (Opuntia spp.) grown in north‐eastern Brazil. Two ruminally fistulated steers were used in a randomized complete block design. Ash, CP, acid detergent fiber, and acid detergent lignin levels ranged from 10.4 to 13.3 %, 6.2–7.7 %, 19.8–24.8 % and 3.4–5.4 %, respectively. Relative to the other cactus varieties, Redonda had the highest (P < 0.05) in situ soluble DM fraction and effective DM degradability. No differences in effective DM degradability were observed between the other cactus varieties. In situ soluble CP fraction ranged from 1.7 % of CP for the 69 IPA/UFRPE variety to 11.1 % of CP for the Gigante variety. Slowly degradable CP fraction and its rate of degradation were similar among the cactus varieties (average 90 % of CP and 9 % h^?1, respectively). The cactus variety 69 IP/UFRPE had a lower (P < 0.05) effective ruminal CP degradability (ECPD) than the other varieties, which had a similar ECPD (average 66 % of CP). It was concluded that differences in ruminal degradability exist between cactus varieties, with more variations observed for ruminal DM than for CP degradability.