Wyniki wyszukiwania - Biblioteka Nauki

1

Embryonic muscle stem cells in Drosophila: from dormant state to reactivation

100%

Aradhya R. , Zmojdzian M. , Da Ponte J. P. , Jagla K.

Acta Biologica Cracoviensia. Series Botanica. Supplement

|

2016

|

tom 58

|

nr 1

2

Organization of the Drosophila genome

100%

Jullien N. , Henaut A. , Miassod R.

|

nr 4

EN

The distribution of (A,T)-rich regions has been investigated on a 835kb DNA fragment (D835), from the Drosophila X sex chromosome, unsequenced but provided with detailed physical maps for restriction enzymes-recognizing (A,T)- or (C,G)- or (mixte)-motifs, and on several sequenced DNA fragments, 100-600 kb long, from the autosomal chromosomes. Numerous (A,T)-rich regions are present in all DNA fragments. Their size varies from 0.2 kb to several kb in all cases, except for D835 where some of them extend to 20-30 kb. The relationship between these (A,T)-rich regions and several chromosome landmarks has been examined in the particular case of D835. Topo II in-vitro sites are randomly distributed with regard to (A,T)-richness. However, transcription units and repeated regions are significantly localized outside (A,T)-rich regions. On the opposite, SARs and ARSs are mostly localized within (A,T)-rich regions. Lastly, topo II in-vivo sites are almost exclusively localized in (A,T)-rich regions. Speculations are proposed on why and how (A,T)-rich regions may have appeared during the emergence of Drosophila genome from a primitive genome.

3

Definition of immunogenic carbohydrate epitopes.

88%

Paschinger K. , Fabini G. , Schuster D. , Rendić D. , Iain B.H Wilson

Acta Biochimica Polonica

|

2005

|

tom 52

|

nr 3

629-632

EN

Carbohydrates are known as sources of immunological cross-reactivity of allergenic significance. In celery and in cypress pollen, the major allergens Api g 5 and Cup a 1 are recognised by antisera raised against anti-horseradish peroxidase and by patients' IgE which apparently bind carbohydrate epitopes; mass spectrometric analysis of the tryptic peptides and of their N-glycans showed the presence of oligosaccharides carrying both xylose and core α1,3-fucose residues. Core α1,3-fucose residues are also a feature of invertebrates: genetic and biochemical studies on the fruitfly Drosophila melanogaster, the parasitic trematode Schistosoma mansoni and the nematode worm Caenorhabditis elegans indicate that these organisms possess core α1,3-fucosyltransferases. Various experiments have shown that fucosyltransferases from both fly and worm are responsible in vivo and in vitro for the synthesis of N-glycans which cross-react with anti-horseradish peroxidase; thus, we can consider these enzymes as useful tools in generating standard compounds for testing cross-reactive carbohydrate epitopes of allergenic interest.

4

Functionality versus strength - has functional selection taken place in the case of the ecdysteroid receptor response element?

75%

Grad I. , Kochman M. , Ożyhar A.

Acta Biochimica Polonica

|

2002

|

tom 49

|

nr 3

747-756

EN

Nuclear receptors are ligand-dependent transcription factors responsible for controlling differentiation, growth and development of higher eukaryotes. Three amino acids within the recognition α-helix of the DNA-binding domain of the nuclear receptors constitute the so-called "P-box" which determines response element specificity. In the ultraspiracle (Usp) protein, which together with EcR forms the heterodimeric ecdysone receptor, the P-box residues are E19, G20 and G23. Substitution of E19, the most characteristic amino acid for estrogen receptor-like P-boxes, with alanine showed that the mutation did not appreciably alter the affinity of the wild-type Usp DNA-binding domain (UspDBDWT) for a probe containing natural ecdysone response element (hsp27wt). Since in many cases E19 contacts a G/C base pair in position -4, which is absent in hsp27wt, we analysed the interaction of UspDBDWT, E19A and other P-box region mutants with the hsp27wt derivative which contains a G/C instead of an T/A base pair in position -4. UspDBDWT exhibited higher affinity for this element than for hsp27wt. Moreover, a different interaction pattern of P-box region mutants was also observed. Thus we conclude that the E19 residue of UspDBD is not involved in any hsp27wt sequence-discerning contacts. However, substitution of the hsp27wt T/A base pair in position -4 with G/C generates target sequence with distinct functional characteristics and possibly with a new specificity. These results could serve as a basis for understanding the role of the presence of a T/A or G/C base-pair in the position -4 in the two types of ecdysone response elements found in nature.

5

Diptera follicular cells differentiation in a comparative lens. Professor Kubrakiewicz's interest in flies oogenesis

75%

Mazurkiewicz-Kania M.

Acta Biologica Cracoviensia. Series Botanica. Supplement

|

2016

|

tom 58

|

nr 1

6

The spotted wing drosophila Drosophila suzukii (Matsumura, 1931) – monitoring and first records in Poland

75%

Labanowska B. H. , Piotrowski W.

|

2015

|

tom 23

|

nr 2

7

High mobility group proteins: components that modulate insect chromatin

75%

Wisniewski J. R.

Zoologica Poloniae

|

1998

|

tom 43

|

nr 1-4

8

The value of interdisciplinary research: lessons from the 2017 Nobel Prize in chronobiology

63%

Giebultowicz J. M.

|

nr 1

EN

Since 1901, the Nobel Prize has been awarded to scientists who have made the most important discoveries for the benefit of humanity. The 2017 Nobel Prize in Physiology or Medicine was awarded jointly to Jeffrey C. Hall, Michael Rosbash and Michael W. Young “for their discoveries of molecular mechanisms controlling the circadian rhythm.” It may be surprising to learn that those three scientists dedicated their entire careers to research on the fruit fly, Drosophila melanogaster. However, as their studies progressed, it became increasingly clear that the mechanism of the biological clock that they discovered in Drosophila is very similar to a timekeeping mechanism present in mammals, including humans. Through interdisciplinary work between scientists performing basic research on model organisms and doctors working in medical schools, we have learned over time that daily rhythms support human health while disruption of these rhythms is associated with a range of pathological disorders such as cardiovascular problems, metabolic, neurological, and many other diseases. This short review will highlight critical milestones on the way to understanding biological clocks, focusing on the roles played by the three Nobel Prize winners.

9

The toxic effect of aluminium and its supposable mechanism in Drosophila

63%

Kiss A. S. , Kiss I. , Csikkel-Szolnoki A.

|

tom 12

|

nr 4

281-285

EN

During the early epoch of biological evolution, aluminium was not available for the primitive organisms because of the low solubility of aluminium compounds. This can explain why aluminium is toxic for the present-day living organisms. We studied the toxic effect of aluminium by feeding Drosophila melanogaster adults for 24 hrs. with a 1% sugar solution containing different concentrations of aluminium sulphate. The effect of magnesium chloride was also tested in combination with aluminium. After 24 hrs. we calculated the survival rate, and solubilised the flies in concentrated nitric acid in a microwave oven. The Al, Na, Mg and Zn content of the solubilised flies was measured with the ICP-AES method. We found no change in the Zn content while the Al and Mg content changed according to the treatment, and the Na content decreased significantly (20-30%) in all the cases. We suppose that the flies were mainly killed by the elevated sodium efflux resulting in a decreased intracellular pH. The cause of the elevated Na efflux could be the increased rigidity of the cell membrane caused by the aluminium. We discuss the experimental results and the supposable mechanism of toxicity.

10

Invertebrate systems for hypothesis-driven microbiome research

63%

Newton I. L. G. , Sheehan K. B. , Lee F. J. , Horton M. A. , Hicks R. D.

Microbiome Science and Medicine

|

2013

|

tom 1

|

nr 1

EN

A number of novel, invertebrate systems have emerged as excellent models for the study of microbiomes. Due to their small size, evolutionary diversity, ease of culture, and – in many cases – relatively simple gut communities, invertebrates of many different orders can be tools to drive hypothesis-driven microbiome research. In this review we highlight several host systems amenable to microbiota analyses and specific questions that can be easily addressed in those systems. These questions address functional equivalence across similar habitats, host-specificity and coevolution of host-microbe interactions, and acquisition and transmission dynamics of host-associated communities. We propose that host systems be chosen based on the question of interest, and that insect systems are excellent tools for the vast behavioral, ecological, and genetic diversity that allows them to address a variety of these questions.

11

Definition of immunogenic carbohydrate epitopes

63%

Paschinger K. , Fabini G. , Schuster D. , Rendic D. , Wilson I. B. H.

|

nr 3

EN

Carbohydrates are known as sources of immunological cross-reactivity of allergenic significance. In celery and in cypress pollen, the major allergens Api g 5 and Cup a 1 are recognised by antisera raised against anti-horseradish peroxidase and by patients' IgE which apparently bind carbohydrate epitopes; mass spectrometric analysis of the tryptic peptides and of their N-glycans showed the presence of oligosaccharides carrying both xylose and core α1,3-fucose residues. Core α1,3-fucose residues are also a feature of invertebrates: genetic and biochemical studies on the fruitfly Drosophila melanogaster, the parasitic trematode Schistosoma mansoni and the nematode worm Caenorhabditis elegans indicate that these organisms possess core α1,3-fucosyltransferases. Various experiments have shown that fucosyltransferases from both fly and worm are responsible in vivo and in vitro for the synthesis of N-glycans which cross-react with anti-horseradish peroxidase; thus, we can consider these enzymes as useful tools in generating standard compounds for testing cross-reactive carbohydrate epitopes of allergenic interest.

12

SARs on an 835 kb DNA fragment from the Drosophila genome

63%

Miassod R. , Jullien N.

Acta Biochimica Polonica

|

1995

|

tom 42

|

nr 2

EN

We have investigated the loop organization of a 835 kilobases DNA fragment from the Drosophila genome. This analysis has focused on the perodicity of the distribution of anchoring sequences (SARs) and its relationship to the distribution of A,T-rich regions, transcription units, repeated elements, putative replication origins and topoisomerase II cleavege sites. Altogether, the data support the idea of an active participation of SARs to the structural organization and functioning of this eukaryotic genome.

13

The two major protein isoforms of ankyrin 2 are differentially localized in Drosophila neurons

63%

Hortsch M. , Paisley K. L. , Tian M. Z. , Qian M. , Bouley M. , Chandler R.

Cellular and Molecular Biology Letters

|

2001

|

tom 06

|

nr 2

14

Cystocyte and lymphocyte derived fusomes-spectrosomes: analogies and differences: a mini-review

63%

Dubielecka P. M. , Stebelska K. , Jazwiec B. , Sikorski A. F.

Cellular and Molecular Biology Letters

|

2003

|

tom 08

|

nr 1

EN

Structures analogous to Drosophila spectrosomes were found in mammalian lymphocytes. Repasky and colleagues discovered an intracellular spectrin-rich structure in lymphoid cells, which had far-reaching parallels with the fusome/spectrosome of D. melanogaster germ cells. This fact implies that spectrosomes may be characteristic not only of insect germ cells, but also that an analogous structure may play an important role in other cell types. The term “spectrosome” was first used by Lin and Spradling in 1995 to describe a large sphere of fusomal material in D. melanogaster germline stem cells and their differentiated daughter cells - cytoblasts. In the D. melanogaster ovary, membrane skeletal proteins such as ankyrin, α/β spectrin as well as adducin-like Hts protein(s) were found in this specific organelle - spectrosome/fusome. These organelles are involved in the creation of mitotic spindles and D. melanogaster cyst formation and oocyte differentiation, but the role of analogous spectrin based aggregates found in nucleated cells still remains unclear.

15

The interaction between L1-type proteins and ankyrins - a master switch for L1-type CAM functions

51%

Hortsch M. , Nagaraj K. , Godenschwege T. A.

|

2009

|

tom 14

|

nr 1

57-69

EN

L1-type cell adhesion molecules (CAMs) are important mediators of neural differentiation, including axonal outgrowth and pathfinding and also of synapse formation and maintenance. In addition, their interactions with cytoskeletal components are highly conserved and regulated. How these different aspects of CAM functionality relate to each other is not well understood. Based on results from our and other laboratories we propose that ankyrin-binding to L1-type CAMs provides a master switch. The interaction with ankyrins directs L1-type adhesive proteins into different functional contexts, either ankyrin-independent functions, such as neurite outgrowth and axonal pathfinding or into ankyrin-dependent functions, such as L1’s role at axon initial segments (AIS), paranodal regions, synapses and in dendrites.

16

Diversification of follicular cells in the ovaries of the horse fly Haematopota italica [Diptera: Tabanidae]. Similarities and differences with the Drosophila model system

51%

Jaglarz M. K. , Jablonska A. , Kisiel E. , Bilinski S. M.

Folia Biologica

|

2009

|

tom 57

|

nr 1-2

1-12

17

Germ cell mutagenesis in Drosophila: Multiple endpoint analysis

51%

Nivard M. J. M. , Wijen J. , Vogel E. W.

Acta Biochimica Polonica

|

1998

|

tom 45

|

nr 2

EN

Genotoxic carcinogens, able to damage DNA by alkylation reactions, represent a very diverse class of agents which are capable of producing a wide range of DNA modifications. The mechanisms leading to genetic changes as a result of exposure to alkylating agents (AAs) have been studied in male germ cells of Drosophila using a structure-activity relationship approach (SAR). The analytical tools available concern both genetic and molecular assays. The genetic tests enable to quantify excision repair and clastogenic potency of the AA after treatment of post-meiotic male germ cells and to determine the degree of germ-cell specificity, i.e., the mutagenic effectiveness in post-versus premeiotic cell stages. For a selected group of alkylating agents the molecular spectra have been studied in post-meiotic cell stages. On the basis of these descriptors clear SAR's between genotoxic activity in germ cells and physico-chemical parameters (s-values and O6/N7-alkylguanine adducts) and carcinogenic potency in rodents became apparent, resulting in five distinct classes of alkylating agents so far. These classes are: 1) SN2-type monofunctional AAs, 2) SN1-type monofunctional AAs, 3) polyfunctional AAs, 4) agents able to form etheno-DNA adducts, and 5) aflatoxin B1 (AFB1) a bulky-adduct forming agent. The recent finding that the molecular data obtained with Drosophila and data of the specific locus tests in male mice show remarkable similarities for most genotoxic agents supports the view that Drosophila is a useful model system for the study of transgenerational damage.

18

Human genome sequenced: achievements and shortcomings in big science

51%

Blin N.

|

tom 42

|

nr 4

19

The pharmacologic versatility of a neurotoxic polypeptide

51%

Elazar M. , Shichor I. , Zlotkin E.

|

nr 3

20

Myosins and pathology: genetics and biology

51%

Redowicz M. J.

Acta Biochimica Polonica

|

2002

|

tom 49

|

nr 4

EN

This article summarizes current knowledge on the genetics and possible molecular mechanisms of human pathologies resulted from mutations within the genes encoding several myosin isoforms. Mutations within the genes encoding some myosin isoforms have been found to be responsible for blindness (myosins III and VIIA), deafness (myosins I, IIA, IIIA, VI, VIIA and XV) and familial hypertrophic cardiomyopathy (β cardiac myosin heavy chain and both the regulatory and essential light chains). Myosin III localizes predominantly to photoreceptor cells and is proved to be engaged in the vision process in Drosophila. In the inner ear, myosin I is postulated to play a role as an adaptive motor in the tip links of stereocilia of hair cells, myosin IIA seems to be responsible for stabilizing the contacts between adjacent inner ear hair cells, myosin VI plays a role as an intracellular motor transporting membrane structures within the hair cells while myo- sin VIIA most probably participates in forming links between neighbouring stereocilia and myosin XV probably stabilizes the stereocilia structure. About 30% of patients with familial hypertrophic cardiomyopathy have mutations within the genes encoding the β cardiac myosin heavy chain and both light chains that are grouped within the regions of myosin head crucial for its functions. The alterations lead to the destabilization of sarcomeres and to a decrease of the myosin ATPase activity and its ability to move actin filaments.