Integration of tomato reproductive developmental landmarks and expression profiles, and the effect of SUN on fruit shape

Background  

Universally accepted landmark stages are necessary to highlight key events in plant reproductive development and to facilitate comparisons among species. Domestication and selection of tomato resulted in many varieties that differ in fruit shape and size. This diversity is useful to unravel underlying molecular and developmental mechanisms that control organ morphology and patterning. The tomato fruit shape gene SUN controls fruit elongation. The most dramatic effect of SUN on fruit shape occurs after pollination and fertilization although a detailed investigation into the timing of the fruit shape change as well as gene expression profiles during critical developmental stages has not been conducted.     

Population genetic structure of the round goby in Lake Michigan: implications for dispersal of invasive species

Understanding subsequent dispersal of non-native species following introduction is important for predicting the extent and speed of range expansion and is critical for effective management and risk assessment. Post-introduction dispersal may occur naturally or via human transport, but assessing the relative contribution of each is difficult for many organisms. Here, we use data from seven microsatellite markers to study patterns of dispersal and gene flow among 12 pierhead populations of the round goby (Neogobius melanostomus) in Lake Michigan. We find significant population structure among sampling sites within this single Great Lake: (1) numerous populations exhibited significant pairwise F _ST and (2) a Bayesian assignment analysis revealed three distinct genetic clusters, corresponding to different pierhead locations, and genetic admixture between these clusters in the remaining populations. Genetic differentiation (F _ST) is generally related to geographic distance (i.e., isolation by distance), but is periodically interrupted at the scale of Lake Michigan due to gene flow among geographically distant sites. Moreover, average genetic differentiation among populations exhibit a significant, negative correlation with the amount of shipping cargo at ports. Our results, therefore, provide evidence that genetic structure of the round goby in Lake Michigan results from limited natural dispersal with frequent long-distance dispersal through anthropogenic activities such as commercial shipping. Our study suggests that while round gobies can undoubtedly disperse and found new populations through natural dispersal mechanisms, their spread within and among the Great Lakes is likely aided by transport via ships. We, therefore, recommend that ballast-water treatment and management may limit the spread of non-native species within the Great Lakes after the initial introduction in addition to preventing the introduction of non-native species to the Great Lakes.     

Corneal thickness in congenital glaucoma

Central corneal thickness is very important measurement in glaucoma treatment because it influences the eye pressure measurements. A thinner cornea gives us artifactually lower intraocular pressure and a thicker cornea gives higher intraocular pressure reading, so it has to be corrected in both cases. The aim of this study is to compare central corneal thickness between congenital glaucoma patients and normal subjects. Prospective study included 27 patients with congenital glaucoma and 35 patients in control group. First group was subdivided in two subgroups: A--8 earlier operated patients, B--19 patients treated with topic therapy. Patients had no other corneal disorders, history of trauma, corneal surgery and they were not contact lens wearers. Measurements were performed by specular microscope Tomey EM 3000 on central corneas. This study showed that patients with congenital glaucoma have lower central corneal thickness than normal subjects. Also, the study showed that antiglaucomatous operation doesn't influence central corneal thickness. Central corneal thickness need to be a routine part of examination measurements because of need to correct intraocular pressure according to it, but also the thinner corneas values can suggest congenital glaucoma diagnosis beside the other parameters.     

Phenotypic rescue of a Drosophila model of mitochondrial ANT1 disease

A point mutation in the Drosophila gene that codes for the major adult isoform of adenine nuclear translocase (ANT) represents a model for human diseases that are associated with ANT insufficiency [stress-sensitive B¹ (sesB¹)]. We characterized the organismal, bioenergetic and molecular phenotype of sesB¹ flies then tested strategies to compensate the mutant phenotype. In addition to developmental delay and mechanical-stress-induced seizures, sesB¹ flies have an impaired response to sound, defective male courtship, female sterility and curtailed lifespan. These phenotypes, excluding the latter two, are shared with the mitoribosomal protein S12 mutant, tko^25t. Mitochondria from sesB¹ adults showed a decreased respiratory control ratio and downregulation of cytochrome oxidase. sesB¹ adults exhibited ATP depletion, lactate accumulation and changes in gene expression that were consistent with a metabolic shift towards glycolysis, characterized by activation of lactate dehydrogenase and anaplerotic pathways. Females also showed downregulation of many genes that are required for oogenesis, and their eggs, although fertilized, failed to develop to the larval stages. The sesB¹ phenotypes of developmental delay and mechanical-stress-induced seizures were alleviated by an altered mitochondrial DNA background. Female sterility was substantially rescued by somatic expression of alternative oxidase (AOX) from the sea squirt Ciona intestinalis, whereas AOX did not alleviate developmental delay. Our findings illustrate the potential of different therapeutic strategies for ANT-linked diseases, based on alleviating metabolic stress.KEY WORDS: Adenine nucleotide translocase, Mitochondrial disease, Mitochondrial biogenesis, Alternative oxidase     

Expression of human aldo-keto reductase 1C2 in cell lines of peritoneal endometriosis: potential implications in metabolism of progesterone and dydrogesterone and inhibition by progestins

The human aldo-keto reductase AKR1C2 converts 5α-dihydrotestosterone to the less active 3α-androstanediol and has a minor 20-ketosteroid reductase activity that metabolises progesterone to 20α-hydroxyprogesterone. AKR1C2 is expressed in different peripheral tissues, but its role in uterine diseases like endometriosis has not been studied in detail. Some progestins used for treatment of endometriosis inhibit AKR1C1 and AKR1C3, with unknown effects on AKR1C2. In this study we investigated expression of AKR1C2 in the model cell lines of peritoneal endometriosis, and examined the ability of recombinant AKR1C2 to metabolise progesterone and progestin dydrogesterone, as well as its potential inhibition by progestins. AKR1C2 is expressed in epithelial and stromal endometriotic cell lines at the mRNA level. The recombinant enzyme catalyses reduction of progesterone to 20α-hydroxyprogesterone with a 10-fold lower catalytic efficiency than the major 20-ketosteroid reductase, AKR1C1. AKR1C2 also metabolises progestin dydrogesterone to its 20α-dihydrodydrogesterone, with 8.6-fold higher catalytic efficiency than 5α-dihydrotestosterone. Among the progestins that are currently used for treatment of endometriosis, dydrogesterone, medroxyprogesterone acetate and 20α-dihydrodydrogesterone act as AKR1C2 inhibitors with low μM K(i) values in vitro. Their potential in vivo effects should be further studied.     

Engineering of Candida antarctica lipase B for hydrolysis of bulky carboxylic acid esters

Candida antarctica lipase B (CALB) is a widely used biocatalyst with high activity and specificity for a wide range of primary and secondary alcohols. However, the range of converted carboxylic acids is more narrow and mainly limited to unbranched fatty acids. To further broaden the biotechnological applications of CALB it is of interest to expand the range of converted carboxylic acid and extend it to carboxylic acids that are branched or substituted in close proximity of the carboxyl group. An in silico library of 2400 CALB variants was built and screened in silico by substrate-imprinted docking, a four step docking procedure. First, reaction intermediates of putative substrates are covalently docked into enzyme active sites. Second, the geometry of the resulting enzyme-substrate complex is optimized. Third, the substrate is removed from the complex and then docked again into the optimized structure. Fourth, the resulting substrate poses are rated by geometric filter criteria as productive or non-productive poses. Eleven enzyme variants resulting from the in silico screening were expressed in Escherichia coli BL21 and measured in the hydrolysis of two branched fatty acid esters, isononanoic acid ethyl ester and 2-ethyl hexanoic acid ethyl esters. Five variants showed an initial increase in activity. The variant with the highest wet mass activity (T138S) was purified and further characterized. It showed a 5-fold increase in hydrolysis of isononanoic acid ethyl ester, but not toward sterically more demanding 2-ethyl hexanoic acid ethyl ester.     

Adsorption of chitosan on PET films monitored by quartz crystal microbalance

The adsorption behavior of chitosan on poly(ethylene terephthalate) (PET) model film surface was studied using the quartz crystal microbalance (QCM) technique. QCM with a dissipation unit (QCM-D) represents a very sensitive technique for adsorption studies at the solid/liquid interface in situ, with capability of detecting a submonolayer of adsorbate on the quartz crystal surface. Chitosan as well as PET were chosen for this study due to their promising biocompatible properties and numerous possibilities to be used in biomedical applications. As a first step, PET foils were activated by alkaline hydrolysis in order to increase their hydrophilicity. Model thin films were prepared from PET foils by the spin coating technique. The chemical composition of the obtained model PET films was analyzed using X-ray photoelectron spectroscopy (XPS) and their morphology was characterized by atomic force microscopy (AFM). Furthermore, the adsorption behavior of chitosan on these activated PET films and the influence of adsorption parameters (pH, ionic strength and chitosan solution concentration) were investigated in detail. Additionally, the surface chemistry and morphology of the PET films and the chitosan coated PET films were analyzed with XPS and AFM.