Morphological,genetic and molecular characteristics of barley root hair mutants

Root hairs are tubular outgrowths of specialized epidermal cells called trichoblasts. They affect anchoring plants in soil, the uptake of water and nutrients and are the sites of the interaction between plants and microorganisms. Nineteen root hair mutants of barley representing different stages of root hair development were subjected to detailed morphological and genetic analyses. Each mutant was monogenic and recessive. An allelism test revealed that nine loci were responsible for the mutated root hair phenotypes in the collection and 1–4 mutated allelic forms were identified at each locus. Genetic relationships between the genes responsible for different stages of root hair formation were established. The linkage groups of four loci rhl1, rhp1, rhi1 and rhs1, which had previously been mapped on chromosomes 7H, 1H, 6H and 5H, respectively, were enriched with new markers that flank the genes at a distance of 0.16 cM to 4.6 cM. The chromosomal position of three new genes – two that are responsible for the development of short root hairs (rhs2 and rhs3) and the gene that controls an irregular root hair pattern (rhi2) – were mapped on chromosomes 6H, 2H and 1H, respectively. A comparative analysis of the agrobotanical parameters between some mutants and their respective parental lines showed that mutations in genes responsible for root hair development had no effect on the agrobotanical performance of plants that were grown under controlled conditions. The presented mutant collection is a valuable tool for further identification of genes controlling root hair development in barley.     

DNA methylation of Quercus robur L. plumules following cryo-pretreatment and cryopreservation

Pedunculate oak (Quercus robur) is an ecologically and economically important forest tree species which produces seeds that are classified as recalcitrant. Thus, cryopreservation of seed meristems is a method for long-term preservation of this germplasm in gene banks. During cryopreservation, many factors, such as desiccation, cryoprotection and cooling/rewarming, can induce stress in the frozen meristems. In this study, in vitro survival and the global DNA methylation level of plumules after cryoprotection, desiccation and cryostorage was evaluated. Results indicated that both desiccation and storage in liquid nitrogen have negligible influence on DNA methylation status of Q. robur plumules. These findings support the cryopreservation of plumules as an appropriate method for conservation of Q. robur germplasm.     

"Scleroderma linearis: hemiatrophia faciei progressiva (Parry-Romberg syndrom) without any changes in CNS and linear scleroderma "en coup de sabre" with CNS tumor

Background

Hemifacial atrophy (Parry-Romberg syndrome) is a relatively rare disease. The etiology of the disease is not clear. Some authors postulate its relation with limited scleroderma linearis. Linear scleroderma "en coup de sabre" is characterized by clinical presence of most commonly one-sided linear syndrome. In a number of patients, neurological affection is the medium of the disease. The treatment of both scleroderma varieties is similar to the treatment of limited systemic sclerosis.

Case presentation

We present two cases of a disease: a case of a 49-year-old woman with a typical image of hemifacial atrophy, without any changes of the nervous system and a case of a 33-year-old patient with an "en coup de sabre" scleroderma and with CNS tumor.

Conclusion

We described typical cases of a rare diseases, hemifacial atrophy and "en coup de sabre" scleroderma. In the patient diagnosed with Parry-Romberg syndrome, with Borrelia burgdoferi infection and with minor neurological symptoms, despite a four-year case history, there was a lack of proper diagnosis and treatment. In the second patient only skin changes without any neurological symptoms could be observed and only a precise neurological diagnosis revealed the presence of CNS tumor.     

The SOS Response Master Regulator LexA Is Associated with Sporulation,Motility and Biofilm Formation in Clostridium difficile

The LexA regulated SOS network is a bacterial response to DNA damage of metabolic or environmental origin. In Clostridium difficile, a nosocomial pathogen causing a range of intestinal diseases, the in-silico deduced LexA network included the core SOS genes involved in the DNA repair and genes involved in various other biological functions that vary among different ribotypes. Here we describe the construction and characterization of a lexA ClosTron mutant in C. difficile {"type":"entrez-nucleotide","attrs":{"text":"R20291","term_id":"774925"}}R20291 strain. The mutation of lexA caused inhibition of cell division resulting in a filamentous phenotype. The lexA mutant also showed decreased sporulation, a reduction in swimming motility, greater sensitivity to metronidazole, and increased biofilm formation. Changes in the regulation of toxin A, but not toxin B, were observed in the lexA mutant in the presence of sub-inhibitory concentrations of levofloxacin. C. difficile LexA is, therefore, not only a regulator of DNA damage but also controls many biological functions associated with virulence.     

Sexual dimorphism in lizard body shape: the roles of sexual selection and fecundity selection

Sexual dimorphism is widespread in lizards, with the most consistently dimorphic traits being head size (males have larger heads) and trunk length (the distance between the front and hind legs is greater in females). These dimorphisms have generally been interpreted as follows: (1) large heads in males evolve through male-male rivalry (sexual selection); and (2) larger interlimb lengths in females provide space for more eggs (fecundity selection). In an Australian lizard (the snow skink, Niveoscincus microlepidotus), we found no evidence for ongoing selection on head size. Trunk length, however, was under positive fecundity selection in females and under negative sexual selection in males. Thus, fecundity selection and sexual selection work in concert to drive the evolution of sexual dimorphism in trunk length in snow skinks.     

Peritoneal cavity is dominated by IFNγ-secreting CXCR3+ Th1 cells

The chemokine receptor CXCR3, which was shown to take part in many inflammatory processes, is considered as a Th1 specific marker. Here, we show in a mouse model that CXCR3 expressing CD4(+) cells preferentially migrate to the peritoneal cavity under steady-state conditions. The peritoneal cavity milieu leads to an up-regulated expression of CXCR3. However, blocking of known ligands of this chemokine receptor did not alter the preferential migration. The peritoneal cavity environment also results in an increased percentage of memory cells producing cytokines. Up-regulation of IFNγ production occurs mostly in CXCR3(+) cells considered as Th1, whereas the up-regulation of IL-4 affects mostly in CXCR3(-) cells which are considered as Th2. We conclude that the peritoneal cavity does not change the Th-lineage of the cells, but that domination of this anatomic niche by Th1 cells rather results from preferential migration to this compartment.     

Three-way interaction among plants,bacteria, and coleopteran insects

Main conclusion

Coleoptera, the largest and the most diverse Insecta order, is characterized by multiple adaptations to plant feeding. Insect-associated microorganisms can be important mediators and modulators of interactions between insects and plants. Interactions between plants and insects are highly complex and involve multiple factors. There are various defense mechanisms initiated by plants upon attack by herbivorous insects, including the development of morphological structures and the synthesis of toxic secondary metabolites and volatiles. In turn, herbivores have adapted to feeding on plants and further sophisticated adaptations to overcome plant responses may continue to evolve. Herbivorous insects may detoxify toxic phytocompounds, sequester poisonous plant factors, and alter their own overall gene expression pattern. Moreover, insects are associated with microbes, which not only considerably affect insects, but can also modify plant defense responses to the benefit of their host. Plants are also frequently associated with endophytes, which may act as bioinsecticides. Therefore, it is very important to consider the factors influencing the interaction between plants and insects. Herbivorous insects cause considerable damage to global crop production. Coleoptera is the largest and the most diverse order in the class Insecta. In this review, various aspects of the interactions among insects, microbes, and plants are described with a focus on coleopteran species, their bacterial symbionts, and their plant hosts to demonstrate that many factors contribute to the success of coleopteran herbivory.

     

Proteomic analysis of changes in protein expression in liver mitochondria in apoE knockout mice

The involvement of both apolipoprotein E (apoE) and mitochondria in lipid metabolism is widely recognized, however there is surprisingly scarce data about the putative mitochondrial action(s) of this protein. The aim of the study was to screen the alterations in liver mitochondrial proteome caused by apoE deficiency. We applied 2DE-LC-MS/MS methodology to investigate the changes in liver mitochondrial protein expression in 6-months old apoE(-/-) mice as compared to C57BL/6J controls. ApoE(-/-), but not C57BL/6J mice developed visible atherosclerotic changes in aorta and mild, diffuse steatosis of the liver. Collectively, 18 differentially expressed proteins were identified in mitochondria, related to apoptosis, antioxidant and detoxifying mechanisms of mitochondria, as well as lipid metabolism and transport. In conclusion, differential proteomic approach revealed several lines of proteomic evidence that mitochondrial function in the liver of apoE(-/-) mice could be altered as a result of overlapping of pathological and compensatory changes in expression of proteins.