"DISTANCE EFFECT" IN PIGEON ORIENTATION: AN EVALUATION

Abstract The alcohol dehydrogenase (Adh) region of Drosophila pseudoobscura, which includes the two genes Adh and Adh-Dup, was used to examine the pattern and organization of linkage disequilibrium among pairs of segregating nucleotide sites. A collection of 99 strains from the geographic range of D. pseudoobscura were nucleotide-sequenced with polymerase chain reaction-mediated techniques. All pairs of the 359 polymorphic sites in the 3.5-kb Adh region were tested for significant linkage disequilibrium with Fisher's exact test. Of the 74,278 pairwise comparisons of segregating sites, 127 were in significant linkage disequilibrium at the 5% level. The distribution of five linkage disequilibrium estimators D(ij), D2, r(ij), r2 and D(ij) were compared to theoretical distributions. The observed distributions of D(ij), D2, r(ij) and r2 were consistent with the theoretical distribution given an infinite sites model. The observed distribution of D(ij) differed from the theoretical distribution because of an excess of values at -1 and 1. No spatial pattern was observed in the linkage disequilibrium pattern in the Adh region except for two clusters of sites nonrandomly associated in the adult intron and intron 2 of Adh. The magnitude of linkage disequilibrium decreases significantly as nucleotide distance increases, or a distance effect. Adh-Dup had a larger estimate of the recombination parameter, 4Nc, than Adh, where N is the effective population size and c is the recombination rate. A comparison of the mutation and recombination parameters shows that 7-17 recombination events occur for each mutation event. The heterogeneous estimates of the recombination parameter and the inverse relationship between linkage disequilibrium and nucleotide distance are no longer significant when the two clusters of Adh intron sites are excluded from analyses. The most likely explanation for the two clusters of linkage disequilibria is epistatic selection between sites in the cluster to maintain pre-mRNA secondary structure.

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Membrane potential hyperpolarisation in vesicular arbuscular mycorrhizae ofAllium porrum L.: a non-nutritional long-distance effect of the fungus

PROTOPLASMA ◽

10.1007/bf01666259 ◽

1992 ◽

Vol 168 (3-4) ◽

pp. 136-140 ◽

Cited By ~ 14

Author(s):

M. Fieschi ◽

G. Alloatti ◽

S. Sacco ◽

G. Berta

Keyword(s):

Membrane Potential ◽

Arbuscular Mycorrhizae ◽

Distance Effect ◽

Long Distance ◽

Vesicular Arbuscular Mycorrhizae ◽

Vesicular Arbuscular

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Biological Effect of Muller's Ratchet: Distant Capsid Site Can Affect Picornavirus Protein Processing

Journal of Virology ◽

10.1128/jvi.00538-09 ◽

2009 ◽

Vol 83 (13) ◽

pp. 6748-6756 ◽

Cited By ~ 23

Author(s):

Cristina Escarmís ◽

Celia Perales ◽

Esteban Domingo

Keyword(s):

Three Dimensional ◽

Antigenic Site ◽

Foot And Mouth Disease ◽

Distance Effect ◽

Dimensional Structure ◽

Mouth Disease Virus ◽

Precursor Proteins ◽

Biochemical Level ◽

Capsid Protein Vp1 ◽

Virion Surface

ABSTRACT Repeated bottleneck passages of RNA viruses result in accumulation of mutations and fitness decrease. Here, we show that clones of foot-and-mouth disease virus (FMDV) subjected to bottleneck passages, in the form of plaque-to-plaque transfers in BHK-21 cells, increased the thermosensitivity of the viral clones. By constructing infectious FMDV clones, we have identified the amino acid substitution M54I in capsid protein VP1 as one of the lesions associated with thermosensitivity. M54I affects processing of precursor P1, as evidenced by decreased production of VP1 and accumulation of VP1 precursor proteins. The defect is enhanced at high temperatures. Residue M54 of VP1 is exposed on the virion surface, and it is close to the B-C loop where an antigenic site of FMDV is located. M54 is not in direct contact with the VP1-VP3 cleavage site, according to the three-dimensional structure of FMDV particles. Models to account for the effect of M54 in processing of the FMDV polyprotein are proposed. In addition to revealing a distance effect in polyprotein processing, these results underline the importance of pursuing at the biochemical level the biological defects that arise when viruses are subjected to multiple bottleneck events.

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Mental representation: What can pitch tell us about the distance effect?

Cortex ◽

10.1016/j.cortex.2007.08.002 ◽

2008 ◽

Vol 44 (4) ◽

pp. 470-477 ◽

Cited By ~ 45

Author(s):

R KADOSH ◽

W BRODSKY ◽

M LEVIN ◽

A HENIK

Keyword(s):

Mental Representation ◽

Distance Effect

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Preliminary Attempt to Measure Gravimetrically the Distance-Effect of Chemical Affinity

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.9.11.379 ◽

1923 ◽

Vol 9 (11) ◽

pp. 379-383 ◽

Cited By ~ 2

Author(s):

T. W. Richards ◽

W. T. Richards

Keyword(s):

Distance Effect ◽

Chemical Affinity ◽

Preliminary Attempt

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A SUBJECT-OBJECT ASYMMETRY IN THE ACQUISITION OF RELATIVE CLAUSES IN KOREAN AS A SECOND LANGUAGE

Studies in Second Language Acquisition ◽

10.1017/s0272263103000172 ◽

2003 ◽

Vol 25 (3) ◽

pp. 433-448 ◽

Cited By ~ 50

Author(s):

William O'Grady ◽

Miseon Lee ◽

Miho Choo

Keyword(s):

Second Language ◽

Relative Clauses ◽

Distance Effect ◽

Direct Object ◽

Strong Preference ◽

Structural Factors ◽

Structural Account ◽

Linear Distance ◽

English Speaking ◽

Object Relative

A variety of studies have reported that learners of English as a second language find subject relative clauses easier to produce and comprehend than direct object relatives, but it is unclear whether this preference should be attributed to structural factors or to a linear distance effect. This paper seeks to resolve this issue and to extend our understanding of SLA in general by investigating the interpretation of subject and direct object relative clauses by English-speaking learners of Korean, a left-branching language in which subject gaps in relative clauses are more distant from the head than are object gaps. The results of a comprehension task conducted with 53 beginning and intermediate learners point toward a strong preference for subject relative clauses, favoring the structural account.

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