Search Results - (Author, Cooperation:I. P. Tomlinson)

2011-08-19

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; Bilirubin/metabolism ; Cell Line ; Cells, Cultured ; Citric Acid Cycle ; Computer Simulation ; Fumarate Hydratase/deficiency/*genetics/*metabolism ; Fumarates/metabolism ; Genes, Lethal/*genetics ; *Genes, Tumor Suppressor ; Glutamine/metabolism ; Heme/metabolism ; Heme Oxygenase (Decyclizing)/antagonists & inhibitors/*genetics/*metabolism ; Kidney Neoplasms/drug therapy/enzymology/genetics/metabolism ; Leiomyomatosis/congenital/drug therapy/enzymology/genetics/metabolism ; Mice ; Mitochondria/metabolism ; Mutation/*genetics ; NAD/metabolism ; Neoplastic Syndromes, Hereditary ; Skin Neoplasms ; Uterine Neoplasms

2013-03-01

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Aneuploidy ; Cell Line, Tumor ; Chromosomal Instability/drug effects/*genetics ; Chromosome Segregation/drug effects/genetics ; Chromosomes, Human, Pair 18/drug effects/genetics ; Colorectal Neoplasms/*genetics/pathology ; DNA Copy Number Variations/genetics ; DNA Damage/drug effects/genetics ; DNA Replication/drug effects/*genetics ; Gene Deletion ; Gene Silencing ; Genes, Tumor Suppressor ; Humans ; Mitosis/drug effects ; Nucleosides/pharmacology ; Phosphotransferases/genetics ; RNA-Binding Proteins/genetics

2018-07-03

The American Association for Cancer Research (AACR)

1078-0432

1557-3265

Medicine

1572-8889

two-spot ladybird ; Adalia bipunctata ; sexual selection ; female choice ; polymorphism ; melanism

Springer Online Journal Archives 1860-2000

Biology

Abstract In some studies of the two-spot ladybird (Adalia bipunctata), melanic males have been found in excess over the typical morph in matings. Data suggest that a genetic female mating preference is responsible. The mating advantage of melanic males may be important in maintaining a polymorphism between melanic and typical ladybirds in many populations in the United Kingdom (U.K.). It has been reported that preference frequency varies linearly with melanic frequency throughout most of the U.K. One particular population ofAdalia bipunctata near Aberdare, South Wales, is noted for its high frequency of melanic individuals. It has been suggested that local environmental factors account for the high melanic frequency in this population. It is also possible, however, that a female mating preference may be at least partly responsible for the high frequency of melanics (as has been proposed for the rest of the U.K.). In this study, experiments have been performed to determine the level of female mating preference in the Aberdare population. No evidence was found for any mating advantage to melanic males. There was inconsistent and unexpected evidence that melanic females were overrepresented in matings, but the cause for this was unclear. Female mating preference does not appear, therefore, to be responsible for the high melanic frequency in the population ofAdalia bipunctata near Aberdare. There is not a simple association between mating preference and melanic frequency in U. K. populations of the two-spot ladybird.

Electronic Resource

1432-1262

Springer Online Journal Archives 1860-2000

Medicine

Résumé. On relate l'histoire de deux frères ayant développé des thromboses veineuses récidivantes. Chez l'un des frères, les thromboses résultent d'une baisse de l'activité de l'activateur tissulaire du plasmynogène (t-PA). Les deux frères ont également développé de multiples adénomes colo-rectaux synchrones et métachrones. D'autres membres de la famille ont développé des cancers du côlon mais aucun n'a développé de cancers multiples. Nous avons démontré que HNPCC et FAP/AAPC sont des causes peu vraisemblables de ces phénotypes familiaux. Des études préliminaires ont démontré un taux bas de t-PA en cas de tumeurs sporadiques du côlon. Dans sept familles, des mutations de gène t-PA à un locus lié ou contrôlant la production ou l'activité de t-PA peut modifier le phénotype des tumeurs coliques afin d'entraîner la formation de lésions multiples.

Abstract. A family is reported in which a pair of brothers has developed recurrent venous thromboses, which have been shown in one brother (the proband) to result from a reduced level of tissue plasminogen activator (t-PA) activity. Both brothers have also developed multiple synchronous and metachronous colorectal adenomas. Other pedigree members have developed colon cancers, but not multiple colonic tumours. We have shown that HNPCC and FAP/AAPC are unlikely causes of the family's phenotypes. Previous studies have found low levels of t-PA in sporadic colon tumours. In this family, mutations in the t-PA gene, at a linked locus, or at a locus controlling t-PA activity/release may modify the colon tumour phenotype to cause multiple lesions.

Electronic Resource

1432-1203

Springer Online Journal Archives 1860-2000

Biology

Medicine

Abstract Hereditary non-polyposis colorectal cancer (HNPCC) is a clinical syndrome characterised by an inherited predisposition to early onset colorectal and uterine cancers and an increased incidence of other cancers. It is caused by germline defects in the human mismatch repair genes. Defects in two of the known mismatch repair genes (namely hMSH2 and hMLH1) account for over 90% of mutations found in HNPCC families. In this study we have identified 14 families that fulfilled the clinical criteria for HNPCC and screened the hMSH2 and hMLH1 genes for germline mutations using single-strand conformational polymorphism (SSCP) analysis and DNA sequencing. Seven mutations were identified. Of these, there were five frameshifts, one missense mutation and a further novel mutation that involved separate transition and transversion changes in successive amino acid residues. Three of the mutations were in hMSH2 and four in hMLH1. The identification of germ-line mutations in an HNPCC family enables targeted surveillance and the possibility of early curative intervention. SSCP is a simple and effective method for identifying most mutations in the human mismatch repair genes using DNA from fresh, frozen or archival material.

Electronic Resource

1573-3297

Two-spot ladybird ; Adalia bipunctata ; weight ; nonrandom mating ; mating success

Springer Online Journal Archives 1860-2000

Biology

Psychology

Abstract In some populations of the two-spot ladybird,Adalia bipunctata, there is evidence that melanics of both sexes have a general mating advantage over the typical morph. There is also evidence that some female ladybirds possess a simple mating preference for melanic males. We have determined the influence of body weight on mating success in the two-spot ladybird and assessed whether weight differences might influence the mating success of the melanic morph. We found that the “formal mating tests” used in previous studies of the two-spot ladybird did not detect any influence of weight on mating success. Using more sensitive “singleton” tests, however, a significant mating advantage to heavier males was detected, irrespective of morph. There was also evidence in favor of a similar advantage to heavy females, but this was not present in all ladybird groups that were tested. Heavy individuals neither produced more eggs in matings nor showed higher activity rates. We suggest that some form of mate competition favors large individuals: for example, the larger an individual, the greater is the chance of an encounter with a potential mate. There is no evidence in this study that either sex chooses heavier mates. Effects of weight might contribute to the general melanic mating advantage found in some populations but cannot account for all the data in favor of a female mating preference for melanic males.

Electronic Resource