scholarly journals Karyotypes and Repetitive DNA Evolution in Six Species of the Genus Mahanarva (Auchenorrhyncha: Cercopidae)

2016 ◽  
Vol 149 (4) ◽  
pp. 321-327 ◽  
Author(s):  
Allison Anjos ◽  
Gabriela C. Rocha ◽  
Andressa Paladini ◽  
Tatiane C. Mariguela ◽  
Diogo C. Cabral-de-Mello

Insects of the Cercopidae family are widely distributed and comprise 59 genera and 431 species in the New World. They are xylemophagous, causing losses in agricultural and pasture grasses, and are considered as emerging pests. Chromosomally, these insects have been studied by standard techniques, revealing variable diploid numbers and primarily X0 sex chromosome systems (males). We performed chromosome studies in 6 Mahanarva (Cercopidae) species using standard and differential chromosome staining as well as mapping of repetitive DNAs. Moreover, the relationship between the repetitive DNAs was analyzed at the interspecific level. A diploid chromosome number of 2n = 19,X0 was documented, with chromosomes gradually decreasing in size. Neutral or GC-rich regions were detected which varied depending on the species. Fluorescence in situ hybridization with a (TTAGG)n telomeric motif probe revealed terminal signals, matching those of the Cot DNAs obtained from each species, that were also restricted to the terminal regions of all chromosomes. Dot blot analysis with the Cot fraction from M. quadripunctata showed that at least part of the repetitive genome is shared among the 6 species. Our data highlight the conservation of chromosomal features and organization of repetitive DNAs in the genus Mahanarva, suggesting a low differentiation for chromosomes and repetitive DNAs in most of the 6 species studied.

Author(s):  
Kun Lee ◽  
Jingyi Si ◽  
Ricai Han ◽  
Wei Zhang ◽  
Bingbing Tan ◽  
...  

There are more supports for the view that human papillomavirus (HPV) infection might be an etiological factor in the development of cervical cancer when the association of persistent condylomata is considered. Biopsies from 318 cases with squamous cell carcinoma of uterine cervix, 48 with cervical and vulvar condylomata, 14 with cervical intraepithelial neoplasia (CIN), 34 with chronic cervicitis and 24 normal cervical epithelium were collected from 5 geographic regions of China with different cervical cancer mortalities. All specimens were prepared for Dot blot, Southern blot and in situ DNA-DNA hybridizations by using HPV-11, 16, 18 DNA labelled with 32P and 3H as probes to detect viral homologous sequences in samples. Among them, 32 cases with cervical cancer, 27 with condyloma and 10 normal cervical epitheliums were randomly chosen for comparative EM observation. The results showed that: 1), 192 out of 318 (60.4%) cases of cervical cancer were positive for HPV-16 DNA probe (Table I)


1994 ◽  
Vol 267 (1) ◽  
pp. C104-C114 ◽  
Author(s):  
J. G. Kiang ◽  
F. E. Carr ◽  
M. R. Burns ◽  
D. E. McClain

The family of 70-kDa heat-shock proteins (HSP-70) is evolutionarily highly conserved and has been shown to enhance cell survival from thermal injury. This study characterized HSP-72 induction in human epidermoid A-431 cells exposed to 45 degrees C for 10 min and determined the relationship between HSP-72, intracellular pH (pHi), adenosine 3',5'-cyclic monophosphate (cAMP), G proteins, and intracellular cytosolic free Ca2+ concentration ([Ca2+]i). Heat shock induced HSP-72 production, which was dependent on both temperature and the duration of heating. This HSP-72 induction was confirmed by Western blot analysis. HSP-72 levels in cells that had been heated then returned to 37 degrees C were elevated at 2 h (1.5 +/- 0.1 x control), reached a maximum at 8 h (2.7 +/- 0.1 x control), and remained above baseline for up to 4 days. Levels of HSP-72 mRNA, determined by dot-blot analysis, reached a maximum at 2 h and returned to baseline within 8 h. Both actinomycin D and cycloheximide blocked HSP-72 induction. Because heating causes intracellular acidification and increases in cAMP and [Ca2+]i, we studied the effect of pHi, cellular cAMP, and [Ca2+]i on HSP-72 induction. The reduction of pHi to 6.9 by acid loading did not affect the basal level of HSP-72 in unheated cells. Treatment with pertussis toxin, cholera toxin, or forskolin, but not 8-bromo-cAMP, 3-isobutyl-1-methylxanthine, or N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide potentiated heat-induced HSP-72 production. Inhibition of the heat-induced increase in [Ca2+]i attenuated, but failed to completely block, heat-induced HSP-72 production, mRNA synthesis, and the heat-shock transcriptional factor-heat-shock element binding complex formation, which suggests there are Ca(2+)-dependent and -independent processes involved in HSP-72 synthesis. Our results show that an increase in [Ca2+]i or activation of G proteins, but not pHi and cAMP, enhances HSP-72 induction.


Genome ◽  
2018 ◽  
Vol 61 (1) ◽  
pp. 59-62 ◽  
Author(s):  
Allison Anjos ◽  
Andressa Paladini ◽  
Tatiane C. Mariguela ◽  
Diogo C. Cabral-de-Mello

Spittlebugs, which belong to the family Cercopidae (Auchenorrhyncha, Hemiptera), form a large group of xylem-feeding insects that are best known for causing damage to plantations and pasture grasses. The holocentric chromosomes of these insects remain poorly studied in regards to the organization of different classes of repetitive DNA. To improve chromosomal maps based on repetitive DNAs and to better understand the chromosomal organization and evolutionary dynamics of multigene families in spittlebugs, we physically mapped the U1 snRNA gene with fluorescence in situ hybridization (FISH) in 10 species of Cercopidae belonging to three different genera. All the U1 snDNA clusters were autosomal and located in interstitial position. In seven species, they were restricted to one autosome per haploid genome, while three species of the genus Mahanarva showed two clusters in two different autosomes. Although it was not possible to precisely define the ancestral location of this gene, it was possible to observe the presence of at least one cluster located in a small bivalent in all karyotypes. The karyotype stability observed in Cercopidae is also observed in respect to the distribution of U1 snDNA. Our data are discussed in light of possible mechanisms for U1 snDNA conservation and compared with the available data from other species.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yongjia Yang ◽  
Fang Chen ◽  
Zhenqing Luo ◽  
Yu Zheng ◽  
Jiayong Zheng ◽  
...  

Y chromosome represents masculinization. The extra Y chromosome of XYY patients usually leads to over-masculinization phenotypes. The occurrence of several DSD cases with XYY in blood is controversial. Is XYY associated with disorder of sex development (DSD)? What is the mechanism behind DSD in males with XYY in blood? To this end, this study retrospectively analyzed blood-karyotype data of 4,437 DSD male children and karyotypes data of 6,259 newborn males as the control. Exome sequencing (ES) was performed to test whether the patients with DSD and with XYY in blood had other variants on known DSD-genes. Testicular biopsy was performed. Fluorescence in situ hybridization (FISH) was used to test whether a sex chromosome mosaicism was present in the oral epithelial cells or gonad tissue of patients with DSD and with XYY in blood. Among 4,437 DSD males who received cytogenetic evaluation, 14 patients with 47,XYY were identified. By contrast, five individuals among the 6,259 controls had 47,XYY. XYY in blood is more frequent among males with DSD than in other males (p = 0.004). The XYY karyotypes were confirmed again by GTG-banding in blood samples and by FISH performed on oral epithelial cells. ES on seven XYY DSD patients was successfully performed, but results did not identify any pathogenic variant on 55 known DSD genes. Gonad biopsy (n = 3) revealed testicular dysplasia and true hermaphroditism. FISH of gonad tissues (n = 3) showed that all of the samples had mosaic for X/XY/XYY. This study is the first to investigate the relationship between XYY in blood and DSD. The knowledge that XYY is in the blood and in oral cells have X/XY/XYY mosaicism in gonadal tissue is new for both researchers and clinicians who seek to understand the genetic basis of DSD males.


1992 ◽  
Vol 40 (11) ◽  
pp. 1761-1767 ◽  
Author(s):  
M Denijn ◽  
R A de Weger ◽  
W den Otter ◽  
J A van Unnik ◽  
C J Lips

Calcitonin (CT) and calcitonin gene-related peptide (CGRP) are encoded by a single gene, the CALC-I gene. They are expressed in the thyroid and in the nervous system by alternative splicing of the pre-messenger RNA derived from the CALC-I gene. In medullary thyroid carcinoma (MTC), a malignancy derived from the calcitonin-producing C-cells in the thyroid, production of calcitonin and CGRP is a common feature. We investigated the CT and CGRP production of four spontaneous MTCs transplanted three to four times and 14 MTC lines transplanted for several years in WAG/Rij rats, a strain with hereditary MTC. The expression of CT and CGRP in the spontaneous and in the transplanted tumors was studied by means of RNA in situ hybridization (RISH), dot-blot analysis, and immunohistochemistry. A down-regulation of CT production in transplanted compared with spontaneous tumors was observed, but an inverse relation between CT and CGRP mRNA content in both spontaneous and transplanted tumors was not observed. In this study, RISH proved to be as sensitive as dot-blot analysis to detect gene expression in tissue samples. The different approaches of analyzing the gene expression in tissue samples (the cellular localization of gene expression by ISH vs the analysis of an extract of a total tissue sample with dot-blot analysis) showed that each technique is equal in value and that they are complementary to each other.


1995 ◽  
Vol 14 (2) ◽  
pp. 199-207 ◽  
Author(s):  
D Gröneveld ◽  
E R M Eckhardt ◽  
A J M Coenen ◽  
G J M Martens ◽  
P H M Balm ◽  
...  

ABSTRACT Melanin-concentrating hormone (MCH) is a neuropeptide involved in background adaptation in teleost fish, and in multiple regulatory functions in mammals and fish. To study the expression of the MCH preprohormone (ppMCH) in teleosts, we first cloned a hypothalamic cDNA encoding the complete ppMCH of tilapia (Oreochromis mossambicus), and a cRNA probe derived from a 270 bp ppMCH cDNA fragment was used for the expression studies. The level of ppMCH mRNA expression in tilapia hypothalamus, measured by dot blot analysis, was significantly higher in fish adapted to a white background than in black-adapted animals, which is in accordance with the reported MCH plasma and tissue concentrations in fish. Northern blot analysis not only revealed a strong ppMCH mRNA signal in the hypothalamus, but also the presence of ppMCH mRNA in the neurointermediate lobe (NIL) of the pituitary. In situ hybridization and immunocytochemistry showed that ppMCH mRNA as well as MCH immunoreactivity are located in perikarya of two hypothalamic regions, namely in the nucleus lateralis tuberis (NLT) and the nucleus recessus lateralis (NRL). Quantitative analysis by dot blot hybridization revealed about eight times more ppMCH mRNA in the NLT than in the NRL and NIL of mature tilapias. ppMCH mRNA in the NIL could be localized to cell bodies of the neurohypophysis, which were also MCH immunoreactive.


Author(s):  
O.L. Krivanek ◽  
G.J. Wood

Electron microscopy at 0.2nm point-to-point resolution, 10-10 torr specimei region vacuum and facilities for in-situ specimen cleaning presents intere; ing possibilities for surface structure determination. Three methods for examining the surfaces are available: reflection (REM), transmission (TEM) and profile imaging. Profile imaging is particularly useful because it giv good resolution perpendicular as well as parallel to the surface, and can therefore be used to determine the relationship between the surface and the bulk structure.


Genetics ◽  
1998 ◽  
Vol 149 (1) ◽  
pp. 143-155 ◽  
Author(s):  
Bruce D McKee ◽  
Kathy Wilhelm ◽  
Cynthia Merrill ◽  
Xiao-jia Ren

Abstract In Drosophila melanogaster, deletions of the pericentromeric X heterochromatin cause X-Y nondisjunction, reduced male fertility and distorted sperm recovery ratios (meiotic drive) in combination with a normal Y chromosome and interact with Y-autosome translocations (T(Y;A)) to cause complete male sterility. The pericentromeric heterochromatin has been shown to contain the male-specific X-Y meiotic pairing sites, which consist mostly of a 240-bp repeated sequence in the intergenic spacers (IGS) of the rDNA repeats. The experiments in this paper address the relationship between X-Y pairing failure and the meiotic drive and sterility effects of Xh deletions. X-linked insertions either of complete rDNA repeats or of rDNA fragments that contain the IGS were found to suppress X-Y nondisjunction and meiotic drive in Xh−/Y males, and to restore fertility to Xh−/T(Y;A) males for eight of nine tested Y-autosome translocations. rDNA fragments devoid of IGS repeats proved incapable of suppressing either meiotic drive or chromosomal sterility. These results indicate that the various spermatogenic disruptions associated with X heterochromatic deletions are all consequences of X-Y pairing failure. We interpret these findings in terms of a novel model in which misalignment of chromosomes triggers a checkpoint that acts by disabling the spermatids that derive from affected spermatocytes.


Author(s):  
Shotaro Tada ◽  
Norifumi Asakuma ◽  
Shiori Ando ◽  
Toru Asaka ◽  
Yusuke Daiko ◽  
...  

This paper reports on the relationship between the H2 chemisorption properties and reversible structural reorientation of the possible active site around Al formed in-situ within polymer-derived ceramics (PDCs) based on...


Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 938
Author(s):  
Ladislav Menšík ◽  
Lukáš Hlisnikovský ◽  
Pavel Nerušil ◽  
Eva Kunzová

The aim of the study was to compare the concentrations of risk elements (As, Cu, Mn, Ni, Pb, Zn) in alluvial soil, which were measured by a portable X-ray fluorescence analyser (pXRF) in situ (FIELD) and in the laboratory (LABORATORY). Subsequently, regression equations were developed for individual elements through the method of construction of the regression model, which compare the results of pXRF with classical laboratory analysis (ICP-OES). The accuracy of the measurement, expressed by the coefficient of determination (R2), was as follows in the case of FIELD–ICP-OES: Pb (0.96), Zn (0.92), As (0.72), Mn (0.63), Cu (0.31) and Ni (0.01). In the case of LABORATORY–ICP-OES, the coefficients had values: Pb (0.99), Zn (0.98), Cu and Mn (0.89), As (0.88), Ni (0.81). A higher dependence of the relationship was recorded between LABORATORY–ICP-OES than between FIELD–ICP-OES. An excellent relationship was recorded for the elements Pb and Zn, both for FIELD and LABORATORY (R2 higher than 0.90). The elements Cu, Mn and As have a worse tightness in the relationship; however, the results of the model have shown its applicability for common use, e.g., in agricultural practice or in monitoring the quality of the environment. Based on our results, we can say that pXRF instruments can provide highly accurate results for the concentration of risk elements in the soil in real time for some elements and meet the principle of precision agriculture: an efficient, accurate and fast method of analysis.


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