VISUALIZING HOMOLOGOUS RECOMBINATION WITH INTERACTIVE COMPUTER PROGRAM

2011 ◽  
Vol 08 (04) ◽  
pp. 263-272 ◽  
Author(s):  
XIAOLI YANG ◽  
RONG GE ◽  
CHARLES TSENG
Keyword(s):  
Genetic Variation ◽  
Homologous Recombination ◽  
Computer Program ◽  
Molecular Mechanisms ◽  
Genetic Recombination ◽  
Genetic Material ◽  
Interactive Computer Program ◽  
Learning Programs ◽  
Computer Based ◽  
Mitosis And Meiosis

Homologous recombination is important for DNA repair and for increasing genetic variation, whereby it enriches the gene pool and keeps populations viable. In eukaryotes, genetic recombination takes place during meiosis. For genes on different chromosomes, mixing of paternal and maternal genes is achieved through the random formation of different chromosome configurations at metaphase I of meiosis. This process accounts for the genetic principle of the independent assortment of unlinked genes. Recombination of paternal and maternal genes on different members of the homologous chromosome pair, on the other hand, can only be achieved through the exchange of genetic material between nonsister chromatids, resulting in increased genetic variation. The molecular mechanisms of homologous recombination are complicated and often difficult for students to understand. The objective of this research is to develop an interactive computer program for teaching this important biological process. The software program, along with related computer-based genetics learning programs — for mitosis and meiosis, as well as for a cytogenetics laboratory — will be useful for genetics education at the high school and university levels.

Digital Filtering — An Interactive Computer Program for the Design and Simulation of a Finite Impulse Response (F.I.R.) Digital Filter

1986 ◽  
Vol 23 (4) ◽  
pp. 339-348 ◽  
Author(s):  
I. M. Longair
Keyword(s):  
Computer Program ◽  
Impulse Response ◽  
Digital Filter ◽  
Finite Impulse Response ◽  
Digital Filtering ◽  
Interactive Computer Program ◽  
Electronic Engineering ◽  
Low Pass ◽  
Computer Based ◽  
Fir Digital Filter

Digital filtering techniques have become an important part of the curriculum of electronic engineering courses. This paper details a computer-based teaching aid, for the popular BBC model B microcomputer, which may be used to design and display the characteristics of a low-pass finite impulse response (FIR) digital filter.

Tejo 1– An Interactive Program for the Division of Estuaries into Homogeneous Areas

1987 ◽  
Vol 19 (9) ◽  
pp. 43-51 ◽  
Author(s):  
A. S. Câmara ◽  
M. Cardoso da Silva ◽  
L. Ramos ◽  
J. Gomes Ferreira
Keyword(s):  
Water Quality ◽  
Computer Program ◽  
Heuristic Algorithm ◽  
Management Model ◽  
Interactive Program ◽  
Basin Management ◽  
Interactive Computer Program ◽  
Lake Basins

The division of an estuary into homogeneous areas from both hydrodynamic and ecological standpoints is essential to any estuarine basin management model. This paper presents an approach based on a heuristic algorithm to achieve such a division. The methodology implemented through an interactive computer program named Tejo 1 applies morphological, water quality and management criteria in order to achieve the disaggregation. The approach is equally applicable to river or lake basins, with only minor adaptations. An application of Tejo 1 to the Tejo estuary is included for illustrative purposes, which resulted in the final division of the estuary into 11 homogeneous areas.

scholarly journals Ability of a bacterial chromosome segment to invert is dictated by included material rather than flanking sequence.

Genetics ◽  
1991 ◽  
Vol 129 (4) ◽  
pp. 1021-1032 ◽  
Author(s):  
M J Mahan ◽  
J R Roth
Keyword(s):  
Homologous Recombination ◽  
Parent Strain ◽  
Genetic Material ◽  
Chromosomal Inversion ◽  
Chromosome Segment ◽  
Bacterial Chromosome ◽  
Flanking Sequence ◽  
Flanking Sequences ◽  
Almost All

Abstract Homologous recombination between sequences present in inverse order within the same chromosome can result in inversion formation. We have previously shown that inverse order sequences at some sites (permissive) recombine to generate the expected inversion; no inversions are found when the same inverse order sequences flank other (nonpermissive) regions of the chromosome. In hopes of defining how permissive and nonpermissive intervals are determined, we have constructed a strain that carries a large chromosomal inversion. Using this inversion mutant as the parent strain, we have determined the "permissivity" of a series of chromosomal sites for secondary inversions. For the set of intervals tested, permissivity seems to be dictated by the nature of the genetic material present within the chromosomal interval being tested rather than the flanking sequences or orientation of this material in the chromosome. Almost all permissive intervals include the origin or terminus of replication. We suggest that the rules for recovery of inversions reflect mechanistic restrictions on the occurrence of inversions rather than lethal consequences of the completed rearrangement.

scholarly journals Genetic variation in recombination rate in the pig

2021 ◽  
Vol 53 (1) ◽  
Author(s):  
Martin Johnsson ◽  
Andrew Whalen ◽  
Roger Ros-Freixedes ◽  
Gregor Gorjanc ◽  
Ching-Yi Chen ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Recombination Rate ◽  
Large Scale ◽  
Genome Wide Association Study ◽  
Genetic Material ◽  
A Genome ◽  
Pig Genome ◽  
Genetic Length ◽  
Trait Locus ◽  
Genomic Regions

Abstract Background Meiotic recombination results in the exchange of genetic material between homologous chromosomes. Recombination rate varies between different parts of the genome, between individuals, and is influenced by genetics. In this paper, we assessed the genetic variation in recombination rate along the genome and between individuals in the pig using multilocus iterative peeling on 150,000 individuals across nine genotyped pedigrees. We used these data to estimate the heritability of recombination and perform a genome-wide association study of recombination in the pig. Results Our results confirmed known features of the recombination landscape of the pig genome, including differences in genetic length of chromosomes and marked sex differences. The recombination landscape was repeatable between lines, but at the same time, there were differences in average autosome-wide recombination rate between lines. The heritability of autosome-wide recombination rate was low but not zero (on average 0.07 for females and 0.05 for males). We found six genomic regions that are associated with recombination rate, among which five harbour known candidate genes involved in recombination: RNF212, SHOC1, SYCP2, MSH4 and HFM1. Conclusions Our results on the variation in recombination rate in the pig genome agree with those reported for other vertebrates, with a low but nonzero heritability, and the identification of a major quantitative trait locus for recombination rate that is homologous to that detected in several other species. This work also highlights the utility of using large-scale livestock data to understand biological processes.

Formation, translocation and resolution of Holliday junctions during homologous genetic recombination

1995 ◽  
Vol 347 (1319) ◽  
pp. 21-25 ◽  
Keyword(s):  
Molecular Mechanisms ◽  
Genetic Recombination ◽  
Holliday Junctions ◽  
The Novel ◽  
E Coli ◽  
The Past ◽  
Endonucleolytic Cleavage ◽  
Insight Into ◽  
Made In

Over the past three or four years, great strides have been made in our understanding of the proteins involved in recombination and the mechanisms by which recombinant molecules are formed. This review summarizes our current understanding of the process by focusing on recent studies of proteins involved in the later steps of recombination in bacteria. In particular, biochemical investigation of the in vitro properties of the E. coli RuvA, RuvB and RuvC proteins have provided our first insight into the novel molecular mechanisms by which Holliday junctions are moved along DNA and then resolved by endonucleolytic cleavage.

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