Biomedical subjects

M Ring

Publications and source records attributed to M Ring.

At least 19 recordsLinked to original sources

PubMed2006

Topoisomerase II-alpha expression increases with increasing Gleason score and with hormone insensitivity in prostate carcinoma.

AIM: To investigate and compare topoisomerase II-alpha expression in benign prostatic hyperplasia (BPH), prostate cancer of varying Gleason scores and hormone-insensitive prostate cancer. METHODS: The immunohistochemical expression of topoisomerase II-alpha antibody in the above-mentioned diagnostic categories was investigated and compared. RESULTS: Increased expression of topoisomerase II-alpha was seen in the prostate cancers of Gleason scores 7 and 8-10 (p = 0.000) compared with prostate cancers of Gleason score 6 and BPH (p = 0.245). Statistically significant differences were found in the topoisomerase II-alpha gene expression between prostate cancers categorised by Gleason Score. Also, increased expression of topoisomerase II-alpha was seen in the known hormone-resistant prostate carcinomas compared with prostate cancers with no hormone treatment in the subgroup with Gleason scores 8-10, which approached statistical significance (p = 0.081). No statistically significant difference was observed in topoisomerase II-alpha expression between the groups with BPH and prostate carcinoma of Gleason score 6 (p = 0.245). CONCLUSION: Topoisomerase II-alpha expression was found to increase with the known prognostic marker Gleason score and with hormone insensitivity. Objective evidence is provided for clinical trials with drugs targeting topoisomerase II-alpha to be targeted to patients with prostate cancers of Gleason Score >6 and, in particular, prostate cancers of Gleason Scores 8-10.

Adenocarcinoma↗

PubMed2005

p16INK4A, CDC6, and MCM5: predictive biomarkers in cervical preinvasive neoplasia and cervical cancer.

AIM: To analyse and compare expression patterns of three potential biomarkers-p16(INK4A), CDC6, and MCM5-and evaluate their use as predictive biomarkers in squamous and glandular cervical preinvasive neoplasia. METHODS: Immunocytochemical analysis of p16(INK4A), MCM5, and CDC6 expression was performed on 20 normal, 38 cervical intraepithelial neoplasia 1 (CIN1), 33 CIN2, 46 CIN3, 10 squamous cell carcinoma, 19 cervical glandular intraepithelial neoplasia (cGIN), and 10 adenocarcinoma samples. Staining intensity was assessed using a 0-3 scoring system. p16(INK4A), MCM5, and CDC6 expression was also examined in ThinPrep slides exhibiting mild, moderate, and severe dyskaryosis. Human papillomavirus (HPV) was detected using a modified SYBR green assay. Fluorogenic polymerase chain reaction (PCR) and solution phase PCR were used for specific HPV typing. RESULTS: All three markers showed a linear correlation between expression and grade of dysplasia. p16(INK4A) and MCM5 protein expression was upregulated in all grades of squamous and glandular dysplasia. CDC6 protein was preferentially expressed in high grade lesions and in invasive squamous cell carcinoma. CONCLUSION: p16(INK4A) expression was closely associated with high risk HPV infection-all grades of squamous and glandular cervical lesions were immunohistochemically positive. MCM5 staining intensity was independent of high risk HPV infection, highlighting its potential as a biomarker in both HPV dependent and independent cervical dysplasia. CDC6 may be a biomarker of high grade and invasive lesions of the cervix, with limited use in low grade dysplasia. p16(INK4A) was the most reliable marker of cervical dysplasia. Combinations of dysplastic biomarkers may be useful in difficult diagnostic cases.

Adenocarcinoma↗

PubMed2005

Dynamics of Campylobacter spp. spread investigated in 14 broiler flocks in Switzerland.

Ten conventional and four extensive outdoor broiler flocks, distributed over nine farms, were investigated twice per week during a 35-58-day rearing period to observe the dynamics of Campylobacter spp. spread within these flocks. Strains isolated during this period were genotyped by restriction fragment length polymorphism analysis of the flaA gene and macrorestriction profiling with pulsed field gel electrophoresis. A total of 4112 samples were collected; 157 (3.8%) of these samples were Campylobacter positive, with all C. jejuni. The positive samples were distributed over three conventional and two extensive outdoor flocks on five farms. These five positive flocks were colonized from the fifth to the seventh week of age and remained colonized until slaughter. Each of the flocks showed a flock-specific genotype of Campylobacter that predominated until slaughter. Presuming different ways of entry, a combination of this fact and the observed dynamics of C. jejuni spread within the flocks indicates that a single source from the environment may have been responsible for the colonization of each flock. These conclusions may serve to further develop combat strategies at farm level.

Animals↗

PubMed2004

p16INK4A positivity in benign, premalignant and malignant cervical glandular lesions: a potential diagnostic problem.

A wide array of immunohistochemical markers have been evaluated with respect to their specificity in staining dysplastic cervical cells in cervical biopsies and cervical cytological smears. However, there is still a significant demand for better biomarkers to identify neoplastic cervical glandular and squamous epithelial cells precisely. The CDKN2A gene, located on chromosome 9p21, encodes the tumour suppressor protein, p16INK4A, which decelerates the cell cycle by inactivating CDK4 and CDK6. The aim of this study was to compare and contrast the expression pattern of p16INK4A in benign and neoplastic glandular lesions and tubo-endometrioid metaplasia. All cases in each category displayed some p16INK4A expression. Adenocarcinoma and in situ cases showed a combination of intense nuclear and cytoplasmic staining. It was observed that all cases of tubo-endometrioid metaplasia showed occasional nuclear positivity and definite cytoplasmic staining. These findings may have important implications for the potential utility of p16INK4A as a biomarker for glandular dysplastic lesions. While p16INK4A has been demonstrated to be an excellent marker of cervical dysplasia in squamous neoplastic lesions of the cervix, it has potential pitfalls in cervical glandular lesions that may limit the utility of this biomarker in resolving the nature of suspicious glandular lesions, particularly in cytopathology.

Adenocarcinoma↗

PubMed2003

p16INK4A as a marker for cervical dyskaryosis: CIN and cGIN in cervical biopsies and ThinPrep smears.

AIM: To examine the potential of p16(INK4A) as a biomarker for dysplastic squamous and glandular cells of the cervix in tissue sections and ThinPrep smears. METHODS: Immunocytochemical analysis of p16(INK4A) expression was performed on 22 normal cervical tissue samples, five cervical glandular intraepithelial neoplasia (cGIN), 38 cervical intraepithelial neoplasia 1 (CIN1), 33 CIN2, 46 CIN3, and 10 invasive cancer cases (eight squamous and two adenocarcinomas). All samples were formalin fixed and paraffin wax embedded, and immunohistochemical analysis was carried out using a mouse monoclonal anti-p16(INK4A) antibody after antigen unmasking. The staining intensity was assessed using a 0 to 3 scoring system. In addition, the expression status of p16(INK4A) was examined in 12 normal ThinPrep smears, one smear exhibiting cGIN, and a total of 20 smears exhibiting mild, moderate, and severe dyskaryosis. Human papillomavirus (HPV) detection was carried out using a modified SYBR green assay system. Fluorogenic polymerase chain reaction (PCR) and solution phase PCR were used for specific HPV typing. RESULTS: p16(INK4A) immunoreactivity was absent in all normal cervical tissues examined. Dysplastic squamous and glandular cells were positive for p16(INK4A) expression in all cases included in this study, except for one CIN3 case. p16(INK4A) expression was mainly nuclear in CIN1 cases, and both nuclear and cytoplasmic in CIN2, CIN3, cGIN, and invasive cases. All cases positive for HPV expressed the p16(INK4A) protein, although not all cases found positive for p16(INK4A) were HPV positive. In general, the p16(INK4A) staining intensity was lower in cases negative for HPV or those containing a low risk HPV type. CONCLUSION: This pattern of overexpression demonstrates the potential use of p16(INK4A) as a diagnostic marker for cervical squamous and also glandular neoplastic lesions. In addition, the technique can be used to identify individual dyskaryotic cells in ThinPrep smears. Thus, p16(INK4A) is a useful marker of cervical dyskaryosis.

Biomarkers↗

PubMed2002

Evaluation of liquid-based cytology in cervical screening of high-risk populations: a split study of colposcopy and genito-urinary medicine populations.

A split study evaluated the ThinPrep(R) PapTesttrade mark (TP; Cytyc Corp., Boxborough, MA) compared with current methodologies of cervical cytology in two high-risk cohorts. One thousand, three hundred cases from a colposcopy clinic and a genito-urinary medicine outpatient clinic were examined. The TP reported increased detection of all grades of dyskaryosis (mild, moderate and severe; + 4.5%) and a decrease in borderline and unsuitable cases (- 4.9%). Four cases of high-grade dyskaryosis (moderate or severe) were detected only using the TP, while an additional four cases classified as high-grade dyskaryosis with the TP were reported as borderline by our conventional methods. The split-study finding of increased sensitivity with the TP provides for improved clinical management of patients in our high-risk cohorts.

Cell Nucleus↗

PubMed2001

Fetal DNA in maternal circulation of first-trimester spontaneous abortions.

OBJECTIVE: To establish whether fetal DNA can be identified in the maternal circulation in first-trimester spontaneous abortions. METHODS: Women with confirmed spontaneous abortions and no histories of previous pregnancy were recruited. Peripheral venous blood samples were obtained and DNA extracted. Real-time quantitative polymerase chain reaction was done using SRY and beta-actin systems for calculating fetal and total DNA, respectively. RESULTS: Of 25 women, SRY-specific signals were detected in 11 indicating that the abortions were male. The remaining 14 were negative for the SRY gene. Women with positive results were of similar gestational age to those who were negative (mean 68.4 and 69.0 days). Fetal:total DNA ratio was calculated for positive samples and ranged from 15.8 to 360.1 x 10(+3). Mean ratio was 99.4 x 10(+3) and median was 67.5 x 10(+3). CONCLUSION: Fetal DNA is present in the maternal circulation of first-trimester spontaneous abortions.

Abortion, Spontaneous↗

PubMed2001

Mechanism of action of the calcium-sensing receptor in human antral gastrin cells.

BACKGROUND AND AIMS: Human G cells express the calcium-sensing receptor and respond to extracellular calcium by releasing gastrin. However, the receptor on G cells is insensitive to serum calcium levels. We investigated whether this is a result of differential regulation of signaling pathways compared with parathyroid or calcitonin cells. METHODS: Gastrin release from primary cultures of human antral epithelial cells enriched for G cells (35%) was measured by radioimmunoassay. G cells were stimulated by increasing extracellular calcium concentration for 1 hour in the presence or absence of antagonists of specific intracellular signaling pathways. Intracellular calcium levels were monitored to evaluate the effect of the antagonists on calcium influx. RESULTS: Inhibition of phospholipase C decreased calcium-stimulated gastrin release, but blockers of adenylate cyclase, phospholipase A(2), or mitogen-activated protein kinase had no effect. Inhibition of protein kinase C, nonselective cation channels, and phosphodiesterase increased basal and calcium-stimulated gastrin release while decreasing calcium influx. These data were consistent with basally active phosphodiesterase. CONCLUSIONS: The calcium-sensing receptor on the G cell activates phospholipase C and opens nonselective cation channels, resulting in an influx of extracellular calcium. Protein kinase C isozymes expressed by the G cells play multiple roles regulating both gastrin secretion and phosphodiesterase activity.

Adenine↗

PubMed2000

Doppler tissue imaging in congestive heart failure patients due to diastolic or systolic dysfunction: a comparison with Doppler echocardiography and the atrio-ventricular plane displacement technique.

BACKGROUND: Doppler tissue imaging (DTI) is an echocardiographic technique by which regional contractility, relaxation properties and time intervals are obtained easily. DTI has been reported to be relatively pre-load independent and could, in comparison with the commonly used mitral pulse wave Doppler (MPWD) method, be of clinical interest for identification of patients with diastolic dysfunction. The atrio-ventricular plane displacement (AVPD) method is an established technique to assess left ventricular systolic function. AIMS: To determine the pulsed Doppler DTI-pattern in patients with heart failure and to examine whether it has a similar capacity as MPWD and AVPD to diagnose diastolic dysfunction. METHODS: We studied 15 controls without congestive heart failure (CHF), 15 patients with diastolic (EF>45%+CHF) and 15 patients with systolic (EF<35%+CHF) left ventricular dysfunction and CHF. RESULTS: The DTI maximal velocities during systole (s), early filling wave (e) and atrial filling wave (a), decrease with reduced left ventricular ejection fraction, r=0.75, r=0.56 and r=0.66 (P<0.001) and regional isovolumetric contraction and intraventricular relaxation time measured by DTI are prolonged, r=0.59 and r=0.73, respectively (P<0.001). The 15 patients with diastolic heart failure were identified by MPWD or DTI but only 11 by AVPD with 8, 10 and 9 false-positive, respectively (P<0.01, P<0.05 and NS). CONCLUSIONS: Regional DTI show a consistent pattern in patients with left ventricular dysfunction and heart failure. Regional DTI has similar accuracy as MPWD in identifying diastolic heart failure patients and is superior to the AVPD technique. DTI may be a useful diagnostic tool in diastolic heart failure patients.

Aged↗

PubMed2000

Identification and analysis of Lydia, a LTR retrotransposon from Lymantria dispar.

Degenerative PCR primers to conserved amino acid motifs were used to identify an LTR retrotransposon from Lymantria dispar. The isolated retrotransposon, Lydia, is 6655 base pairs (bp) in length and contains perfect 300 bp terminal repeats. The identified gag and pol related ORFs have a high degree of similarity to the corresponding regions of the retrotransposon Ted from Trichoplusia ni, although several reading frameshifts and missense mutations are evident. The high degree of similarity between Lydia and Ted LTRs lends support for a family of lepidopteran retrotransposons. Southern blot analysis of individuals from two geographically distinct gypsy moth populations demonstrates that Lydia is found in both populations and the position of this element within the genome of these isolated populations is variable.

Amino Acid Sequence↗

PubMed2000

Influence of age and cardiovascular factors on regional pulsed wave Doppler myocardial imaging indices.

AIMS: To describe the influence of age and other cardiovascular factors on regional pulsed wave Doppler myocardial imaging (DMI), and to compare DMI with conventional transmitral echocardiography and the atrioventricular plane displacement (AVPD) method. METHODS AND RESULTS: Eighty-eight healthy subjects aged 20-81 years were examined by DMI, performed in the intraventricular septum just below the mitral annulus and in the corresponding lateral region, by transmitral pulsed wave Doppler echocardiography, and by AVPD. The DMI peak velocity during the left ventricular (LV) early filling phase (e), decreased with age from 12.3 +/- 2.3 cm/s in the youngest to 7.0 +/- 1.7 cm/s in the oldest tercentile (r=- 0.76, P<0.001). The DMI peak velocity during atrial contraction (a), increased from 7.5 +/- 2.2 cm/s in the youngest to 9.7 +/- 1.7 cm/s in the oldest tercentile (r=0.41, P<0.001). The DMI systolic peak velocity (s), decreased with age from 8.2 +/- 1.1 (youngest tercentile) to 6.9 +/- 1.1 (oldest tercentile), r=-0.39, P<0.001 cm/s, while the fraction shortening of the LV increased from 33.7 +/- 4.1 to 38.2 +/- 5.9% (r=0.36, P<0.01). The DMI e/a correlated with the transmitral early/atrial (E/A) (r=0.83, P<0.001) and with the AVPD measurement of diastolic function AV-LA/AV-mean (r=0.82, P<0.001). The DMI e velocity correlated with the transmitral E velocity (r=0.38, P<0.001). In the multiple regression analysis of DMI e, age was the strongest factor and LV mass index correlated inversely and independently with e. No DMI variables were influenced by gender, while transmitral E correlated with gender. The LV dimension variables explained 35% (R2 adjusted) of the DMI e velocity changes; only 7% of the transmitral E changes were explained by those variables. CONCLUSION: Regional DMI indices are highly age-dependent. In comparision with conventional echocardiography, regional DMI might be more influenced by LV geometry and by myocardial structural changes. These findings suggest a complementary role for regional DMI to conventional echocardiography for the assessment of myocardial function.

Adult↗

PubMed2000

Localisation of HHV-8 in AIDS related lymphadenopathy.

BACKGROUND: Many lymph node abnormalities have been described in AIDS. These include opportunistic infections that sometimes result in spindle cell pseudotumours, Kaposi's sarcoma (KS), malignant lymphoma (Hodgkin's and non-Hodgkin's), and florid reactive hyperplasia. Among these, reactive hyperplasia is the most common manifestation of AIDS related lymphadenopathy. AIM: To examine whether human herpesvirus 8 (HHV-8), the aetiological agent of KS, can be localised in AIDS related lymphadenopathy and whether its appearance in such nodes is predictive of Kaposi's sarcoma development. METHODS: A series of human immunodeficiency virus (HIV) positive men (n = 21) with AIDS related lymphadenopathy who at the time of presentation had KS or subsequently developed KS (n = 5) were examined. The prevalence of HHV-8 was assessed in these patients using solution phase polymerase chain reaction (PCR), real time TaqMan quantitative PCR, and in cell amplification techniques (PCR in situ hybridisation (PCR-ISH) and labelled primer driven in cell amplification). RESULTS: Using standard solution phase PCR in a nested format, only two of the 21 patients with AIDS related lymphadenopathy were positive for HHV-8. The lymph node of one of these patients contained KS lesions. Three HHV-8 positive patients were identified using TaqMan PCR (the original two positive patients and one additional patient). All of the positive patients either subsequently developed KS (n = 2) or had KS at the time of diagnosis (n = 1). Two additional patients subsequently developed KS, but were negative for HHV-8 by solution phase PCR and TaqMan PCR. Using PCR-ISH, HHV-8 amplicons were identified in some lymphoid cells (in one patient) and in spindle cells of the KS lesion in another. The positive lymphoid cells were predominantly concentrated in B cell areas of the affected lymph nodes, confirming the B cell tropism exhibited by HHV-8. CONCLUSIONS: The presence of HHV-8 in AIDS related lymphadenopathy is predictive of KS development and probably represents seeding of HHV-8 infected B cells from the peripheral blood. These findings support a role for HHV-8 in the pathobiology of KS.

AIDS-Related Complex↗

PubMed2000

Improved in situ detection method for telomeric tandem repeats in metaphase spreads and interphase nuclei.

Peptide nucleic acid technology (PNA) has become an extremely useful tool and promises to impact on molecular biology and diagnostics. These synthetic DNA analogues pair with DNA and RNA molecules according to Watson and Crick base pairing rules. This paper describes a sensitive and quick fluorescent in situ hybridisation (ISH) technique to determine DNA telomere repeat sequences (TTA GGG)n using epifluorescence microscopy. Telomeres are special, repeated structures at the end of each eukaryotic chromosome and serve as protective caps to prevent DNA rearrangements and fusion of chromosomes. A model system has been developed, using stimulated peripheral blood lymphocytes, which facilitates simultaneous detection of telomeres in metaphase as well as in interphase nuclei. A fluorescein isothiocyanate labelled PNA probe (18 mer) directed against complementary telomeric sequences at the end of each chromosome is used. In addition, a simple, easy to perform PNA-ISH protocol is described that overcomes common hybridisation problems encountered using DNA and RNA oligoprobes. Furthermore, the usefulness of a chromogenic immunocytochemical detection system is shown for PNA-ISH.

Humans↗

PubMed2000

Cellular localisation of HHV-8 in Castleman's disease: is there a link with lymph node vascularity?

AIMS: Human herpesvirus 8 (HHV-8) has been identified in multicentric Castleman's disease and in angioimmunoblastic lymphadenopathies. However, the presence of the virus does not necessarily indicate an aetiological role in these conditions. This study investigates the cell types infected by HHV-8 in Castleman's disease and examines the correlation between HHV-8 and Castleman's disease lymph node angiogenesis. METHODS: Sixteen formalin fixed, paraffin wax embedded samples from patients with Castleman's disease (six multicentric, 10 solitary) were examined for the presence of HHV-8 using the polymerase chain reaction (PCR), non-isotopic in situ hybridisation, PCR in situ hybridisation (PCR-ISH), and real time quantitative TaqMan PCR to HHV-8 open reading frame 26 (ORF-26), and viral (v)-cyclin encoding regions. Vascularity was assessed using CD34, CD31, and factor VIII immunocytochemistry, and lymph nodes were scored as "low" or "high". RESULTS: Five multicentric Castleman's disease and two solitary Castleman's disease biopsies were positive for HHV-8. HHV-8 was identified in approximately 10% of intranodal B lymphocytes, in endothelial cells, and in subcapsular spindle cell proliferations. The copy number of HHV-8 was low at 10-50 copies/1000 cells. The highest copy number was in subcapsular spindle cells. There was no correlation between vascularity score and HHV-8 status. CONCLUSION: The preferential localisation of HHV-8 in subcapsular spindle cell proliferations (where early intranodal Kaposi's sarcoma initiates) and endothelial cells in Castleman's disease might finally explain the link between intranodal Kaposi's sarcoma and Castleman's disease.

Adult↗

PubMed1999

The role of protein kinase C isozymes in bombesin-stimulated gastrin release from human antral gastrin cells.

Two of the most effective stimuli of gastrin release from human antral G cells are bombesin and phorbol esters. Both agonists result in activation of the protein kinase C family of isozymes, however, the exact contribution of protein kinase C to the resultant release of gastrin has been difficult to assess, possibly due to the presence of multiple protein kinase C isozymes in the G cells. The results of the present study demonstrated that the human antral G cells expressed 6 protein kinase C isozymes alpha, gamma, theta, epsilon, zeta, and mu. Of these protein kinase C, gamma and theta were translocated by stimulation of the cells by either 10 nM bombesin or 1 nM phorbol ester. Inhibition of protein kinase Cmu (localized to the Golgi complex) did not decrease bombesin-stimulated gastrin release indicating that this isozyme was not involved in the secretory process. The use of selective antagonists of the calcium-sensitive conventional protein kinase C subgroup resulted in an increase in bombesin-stimulated gastrin release and indicated that protein kinase Cgamma was involved in the desensitization of the bombesin response.

Adult↗

PubMed1998

Primary structure of ovine fibroblast growth factor-1 deduced by protein and cDNA analysis.

The amino acid sequence of full-length ovine fibroblast growth factor-1 (FGF-1) was determined by a combination of protein and cDNA sequencing. FGF-1 cDNA analysis indicated that ovine kidney cells express mRNAs encoding both full-length FGF-1 and a truncated FGF-1 variant. An overall comparison of the ovine FGF-1 primary sequence to the eight species studied to date revealed a high degree of conservation, with ovine FGF-1 sharing 90 and 95% sequence identity with human FGF-1 and bovine FGF-1, respectively. Additionally, the FGF-1 proteins from the various species have conserved cysteine residues at positions 30 and 97 and contain acetylated amino-terminal alanine residues. Mass spectrometry analysis confirmed that the blocking group of ovine FGF-1 is also consistent with that of an acetyl-moiety. In contrast to the other FGF-1 proteins, the 154 residue primary sequence of ovine FGF-1 contains three unique amino acid differences: Arg9, Arg44, and Ile123. Ovine FGF-1, unlike human FGF-1, is a potent mitogenic factor for NIH 3T3 fibroblasts in the absence of heparin. In the presence of exogenous heparin, the mitogenic activity of ovine FGF-1 is potentiated slightly.

3T3 Cells↗

PubMed1998

Expression of Schistocerca gregaria ion transport peptide (ITP) and its homologue (ITP-L) in a baculovirus/insect cell system.

We expressed an N-terminally extended Schistocerca gregaria ion transport peptide (ScgITP) and its homologue (ion transport peptide-like; ITP-L) in insect Sf9 cells using baculovirus expression vectors. Antibodies raised against peptide fragments of ITP and ITP-L were used to detect and characterize the baculovirus expressed peptides (bacITP, bacITP-L). Biological activity of the expressed peptides was assayed using the highly specific bioassay for native ITP, namely the increase in ileal short-circuit current which is a measure of active Cl- transport. BacITP and bacITP-L expression was optimal in Sf9 cells infected at a multiplicity of infection of 1, grown in Grace's medium, and harvested 2-3 days after infection. Western blots showed that bacITP was 2 kDa larger than native or synthetic ITP. This difference was not due to glycosylation and could in part be attributed to post-translational cleavage of the ITP propeptide at a site 11 amino acids upstream of the cleavage site used by S. gregaria to produce native ITP. BacITP stimulated ileal short-circuit current but is significantly less active (270-fold) than synthetic ITP (synITP) possibly as a result of the N-terminal extension. Production of bacITP-L permitted us to show that it is not stimulatory in the bioassay but reduces the synITP response in vitro and thus may have some potential for enhancing the effectiveness of biological control agents such as baculoviruses.

Amino Acid Sequence↗

PubMed1996

Identification of a 5' truncated non-LTR-retrotransposon, YAKPs1, from the variegated cutworm, Peridroma saucia, using PCR.

Retrotransposable elements encode for several polypeptides that contain a number of conserved amino acid motifs, especially in the region encoding reverse transcriptase. We have used these motifs to design primers for the PCR amplification of retrotransposon DNA. These primers have allowed us to isolate a retroposon, or LINE (long interspersed nuclear element), from the pest insect, Peridroma saucia. DNA sequence analysis of this element, YAKPs1, demonstrated a high degree of homology to a number of retroposons from Drosophila melanogaster, in particular the Fw and Doc elements with homologies of up to 69%. Determination of the complete sequence of the YAKPs1 element will enable a detailed analysis of its evolutionary relatedness to other elements as well as a greater insight into its mode of action.

Amino Acid Sequence↗