Search results for "chromosome"

Eradicating Mosquitoes using Translocations

1969

CHROMOSOMAL translocations have been suggested1,2 as useful mechanisms for genetic control: translocation heterozygotes produce fewer offspring because some of their gametes do not receive a full chromosomal complement. The resultant semisterility has been observed in many plants and animals, chiefly after irradiation or other treatments of laboratory stocks but only rarely in natural populations. Spontaneous translocations originating in a field population are usually eliminated3 quickly because of the lower productivity they confer on the heterozygotes. They can become fixed in all members of a population only if it is small and isolated4.

Eradicating Mosquitoes using Translocations: a First Field Experiment

1972

THEORETICAL considerations have led to the assumption that chromosomal translocations with ensuing semisterility could be used to control pests1–3. Inversions could have the same effect in animals and plants in which crossing over occurs in both sexes4. Many translocations of different type and with various degrees of sterility have been produced in the mosquito Culex pipiens5–8. Preliminary laboratory experiments with these translocations have shown that a cage population can be diminished and finally exterminated after a few generations by the release of translocation heterozygotes into the population9.

Inherited semisterility for control of harmful insects. I. Productions of semisterility due to translocation in the mosquito,Culex pipiens L., by X-r…

1971

In Anbetracht der theoretischen und in einem Freilandexperiment bereits erwiesenen Moglichkeit der Bekampfung von Schadinsekten durch Freilassung semisteriler Tiere wurde die Produktion von Translokationen und damit verbundener Semisterilitat bei der StechmuckeCulex pipiens untersucht. Die Totalrate der erzeugten Translokationen liegt bei Stechmucken im Vergleich zuDrosophila auffallend hoch. Es besteht offenbar eine Korrelation zwischen der Gesamtlange der Chromosomen und der Translokationsrate.

Genetic disorders and periodontal health: A literature review

2009

Periodontal diseases include a group of infl ammatory diseases characterized by progressive destruction of the periodontium. Dental plaque is the initiator of periodontal disease, but disease severity and response to treatment are determined predominantly by host-based risk factors. Genetic disorders can modify the host defense mechanisms or infl uence the homeostasis of the periodontium during childhood, thus increasing patients’ susceptibility to periodontal disease. The periodontal manifestations of these disorders may persist into adulthood. When dealing with periodontal problems, particularly in children and adolescents, it is advisable to establish a differential diagnosis of periodon…

Characteristic Topological Features of Promoter Capture Hi-C Interaction Networks

2020

Current Hi-C technologies for chromosome conformation capture allow to understand a broad spectrum of functional interactions between genome elements. Although significant progress has been made into analysis of Hi-C data to identify the biologically significant features, many questions still remain open. In this paper we describe analysis methods of Hi-C (specifically PCHi-C) interaction networks that are strictly focused on topological properties of these networks. The main questions we are trying to answer are: (1) can topological properties of interaction networks for different cell types alone be sufficient to distinguish between these types, and what the most important of such propert…

Dinamica cromosomica ed evoluzione nei Cercopithecini

2011

Variability of isozyme pattern, chromosome number, and latex colour and components in the closely related Papaver duhium L. and P. lecoqii Lamotte in…

1995

Summary The variability of nine different isozyme systems, chromosome number, colour of fresh and dried latex and presence or absence of meconic acid was investigated in altogether 45 populations of Papaver dubium and P. lecoqii mainly from C Europe. It was found that P. dubium is hexaploid with 2n = 42 chromosomes, has brown dried latex, and contains meconic acid. P. lecoqii is tetraploid with 2n = 28 chromosomes, has red dried latex, and lacks meconic acid. The two taxa can also be distinguished by differences in three of the nine isozymes analysed, and are almost completely monomorphic for their respective isozyme pattern. It is concluded that the two taxa, which cannot be reliably disti…

Is <i>Limonium cavanillesii</i> Erben (Plumbaginaceae) really an extant species?

1999

A new triploid apomictic species (Limonium perplexum) is described from a single coastal locality of E Spain. The new species has been previously confused with L cavanillesii Erben, which is only known from few herbarium specimens and it is believed to be extinct. Overall morphology, chromosome number, and the pollen/stigma combination suggest that L perplexum belongs to the L. duriusculum complex. Based on morphological grounds it is suggested that L. cavanillesii Erben could have been originated through a crossing between L perplexum and L dufourii .

<i>Limonium marisolii</i> L. Llorens (Plumbaginaceae) revisited

1998

A new triploid agamic species, L. leonardi-llorensii , is described from coastal populations of South-West Mallorca. The new species is closely related, on morphological grounds, to the endemic L. marisolii L. Llorens, from which it could be distinguished by several morphological characters (leaves without papillae, longer calyx, more flowers per spikelet) and by a different chromosome number ( 2n = 26, L. leonardi-llorensii ; 2n = 27, L. marisolii ). The relationships between both species are discussed, and it is suggested that both taxa might share some common evolutionary history despite their divergent chromosome number. The origin of L. marisolii from L. leonardi-llorensii through chro…

The taxonomic status of <i>Scilla beirana</i> Samp. (<i>Hyacinthaceae</i>)

1998

ALMEIDA DA SILVA, R.M., F.B. CALDAS & J.A. ROSSELLO (1998). The taxonomic status of Scilla beirana Samp. (Hyacinthaceae). Anales Jard. Bot. Madrid 56(2): 253-260. Populations of Scilla beirana Samp. were sampled in NW Portugal and compared with its relatives S. ramburei Boiss, and S. peruviana L. Leaf and scape anatomy, morphology, chromosome number and idiogram were identical in S. beirana and S. ramburei, but differed from S. peruviana. Diagnostic characters previously used to discriminate S. beirana (width of leaves and flower number) showed continuous, but not clinal, variation, and failed to provide a clear-cut basis for identification and no other morphological attributes were found t…