scholarly journals The transposable elements of the Drosophila serrata reference panel

2020 ◽  
Author(s):  
Zachary Tiedeman ◽  
Sarah Signor
Keyword(s):  
Transposable Elements ◽  
Transposable Element ◽  
Copy Number ◽  
Genetic Background ◽  
Natural Populations ◽  
Inbred Lines ◽  
Transposable Element Insertion ◽  
Defense Systems ◽  
Drosophila Serrata ◽  
Transposable Element Copy

AbstractTransposable elements are an important element of the complex genomic ecosystem, proving to be both adaptive and deleterious - repressed by the piRNA system and fixed by selection. Transposable element insertion also appears to be bursty – either due to invasion of new transposable elements that are not yet repressed, de-repression due to instability of organismal defense systems, stress, or genetic variation in hosts. Here, we characterize the transposable element landscape in an important model Drosophila, D. serrata, and investigate variation in transposable element copy number between genotypes and in the population at large. We find that a subset of transposable elements are clearly related to elements annotated in D. melanogaster and D. simulans, suggesting they spread between species more recently than other transposable elements. We also find that transposable elements do proliferate in particular genotypes, and that often if an individual is host to a proliferating transposable element, it is host to more than one proliferating transposable element. In addition, if a transposable element is active in a genotype, it is often active in more than one genotype. This suggests that there is an interaction between the host and the transposable element, such as a permissive genetic background and the presence of potentially active transposable element copies. In natural populations an active transposable element and a permissive background would not be held in association as in inbred lines, suggesting the magnitude of the burst would be much lower. Yet many of the inbred lines have actively proliferating transposable elements suggesting this is an important mechanism by which transposable elements maintain themselves in populations.

WORLDWIDE DISTRIBUTION OF TRANSPOSABLE ELEMENT COPY NUMBER IN NATURAL POPULATIONS OF DROSOPHILA SIMULANS

Evolution ◽  
2003 ◽  
Vol 57 (1) ◽  
pp. 159-167 ◽  
Author(s):  
Christian Biémont ◽  
Christiane Nardon ◽  
Grégory Deceliere ◽  
David Lepetit ◽  
Catherine Lœvenbruck ◽  
...  
Keyword(s):  
Transposable Element ◽  
Copy Number ◽  
Natural Populations ◽  
Drosophila Simulans ◽  
Worldwide Distribution ◽  
Transposable Element Copy

scholarly journals On the role of unequal exchange in the containment of transposable element copy number

1988 ◽  
Vol 52 (3) ◽  
pp. 223-235 ◽  
Author(s):  
Charles H. Langley ◽  
Elizabeth Montgomery ◽  
Richard Hudson ◽  
Norman Kaplan ◽  
Brian Charlesworth
Keyword(s):  
Transposable Element ◽  
Copy Number ◽  
Natural Populations ◽  
Crossing Over ◽  
Relevant Parameter ◽  
Normal Crossing ◽  
Unequal Exchange ◽  
Parameter Ranges ◽  
Transposable Element Copy

SummaryA population genetics model of the role of asymmetric pairing and unequal exchange in the stabilization of transposable element copy number in natural populations is proposed and analysed. Monte Carlo simulations indicate that the approximations incorporated into the analysis are robust in the relevant parameter ranges. Given several simple assumptions concerning transposition and excision, equal and unequal exchange, and chromosome structure, predictions of the relative numbers of transposable elements in various regions of the Drosophila melanogaster genome are compared to the observed distribution of roo/B104 elements across chromosomal regions with differing rates of exchange, and between X chromosomes and autosomes. There is no indication of an accumulation of elements in the distal regions of chromosomes, which is expected if unequal exchange is reduced concomitantly with normal crossing over in the distal regions. There is, however, an indication of an excess of elements relative to physical length in the proximal regions of the chromosomes, which also have restricted crossing over. This observation is qualitatively consistent with the model's predictions. The observed distribution of elements between the mid-sections of the X chromosomes and autosomes is consistent with the predictions of one of two models of unequal exchange.

WORLDWIDE DISTRIBUTION OF TRANSPOSABLE ELEMENT COPY NUMBER IN NATURAL POPULATIONS OF DROSOPHILA SIMULANS

Evolution ◽  
2003 ◽  
Vol 57 (1) ◽  
pp. 159 ◽  
Author(s):  
Christian Biémont ◽  
Christiane Nardon ◽  
Grégory Deceliere ◽  
David Lepetit ◽  
Catherine Lœvenbruck ◽  
...  
Keyword(s):  
Transposable Element ◽  
Copy Number ◽  
Natural Populations ◽  
Drosophila Simulans ◽  
Worldwide Distribution ◽  
Transposable Element Copy

scholarly journals Transposable elements in individual genotypes of Drosophila simulans

2019 ◽  
Author(s):  
Sarah Signor
Keyword(s):  
Transposable Elements ◽  
Transposable Element ◽  
Dna Sequences ◽  
Copy Number ◽  
Natural Populations ◽  
Population Level ◽  
Drosophila Simulans ◽  
Mobile Dna ◽  
Open Question ◽  
Number Of Individuals

AbstractTransposable elements are mobile DNA sequences that are able to copy themselves within a host’s genome. Within insects they often make up a substantial proportion of the genome. While they are the subject of intense research, often times when copy number is estimated it is estimated only at the population level, or in a limited number of individuals within a population. However, an important aspect of transposable element spread is the variance between individuals in activity. Do transposable elements accumulate at different rates in different genetic backgrounds? Using two populations of Drosophila simulans from California and Africa I estimated transposable element copy number in individual genotypes. Some active transposable elements seem to be a property of the species, while others of the populations. I find that in addition to population level differences in transposable element load certain genotypes accumulate transposable elements at a much higher rate than others. Most likely active transposable elements are fairly rare, and were inherited only by specific genotypes that were used to create the inbred lines. Whether or not this reflects dynamics in natural populations, where transposable elements may accumulate in specific genotypes and maintain themselves in the population rather than being active at low levels population wide, is an open question.

On the evolution and population genetics of hybrid-dysgenesis-causing transposable elements in Drosophila

1986 ◽  
Vol 312 (1154) ◽  
pp. 205-215 ◽  
Keyword(s):  
Population Genetics ◽  
Natural Selection ◽  
Transposable Elements ◽  
Transposable Element ◽  
Natural Populations ◽  
Element Composition ◽  
Hybrid Dysgenesis ◽  
Evolutionary Significance ◽  
Genetic Elements ◽  
Transposable Genetic Elements

Much has been learned about transposable genetic elements in Drosophila , but questions still remain, especially concerning their evolutionary significance. Three such questions are considered here, (i) Has the behaviour of transposable elements been most influenced by natural selection at the level of the organism, the population, or the elements themselves? (ii) How did the elements originate in the genome of the species? (iii) Why are laboratory stocks different from natural populations with respect to their transposable element composition? No final answers to these questions are yet available, but by focusing on the two families of hybrid dysgenesis-causing elements, the P and I factors, we can draw some tentative conclusions.

scholarly journals Colour plasticity in response to social context and parasitic infection in a self-fertilizing fish

2019 ◽  
Vol 6 (7) ◽  
pp. 181418
Author(s):  
Rebecca Jane Pawluk ◽  
Carlos Garcia de Leaniz ◽  
Joanne Cable ◽  
Bernard Tiddeman ◽  
Sofia Consuegra
Keyword(s):  
Social Context ◽  
Individual Variation ◽  
Genetic Background ◽  
Social Dynamics ◽  
Parasitic Infection ◽  
Natural Populations ◽  
Data Interpretation ◽  
Inbred Lines ◽  
Body Coloration ◽  
Pathogen Avoidance

Many animal species rely on changes in body coloration to signal social dominance, mating readiness and health status to conspecifics, which can in turn influence reproductive success, social dynamics and pathogen avoidance in natural populations. Such colour changes are thought to be controlled by genetic and environmental conditions, but their relative importance is difficult to measure in natural populations, where individual genetic variability complicates data interpretation. Here, we studied shifts in melanin-related body coloration in response to social context and parasitic infection in two naturally inbred lines of a self-fertilizing fish to disentangle the relative roles of genetic background and individual variation. We found that social context and parasitic infection had a significant effect on body coloration that varied between genetic lines, suggesting the existence of genotype by environment interactions. In addition, individual variation was also important for some of the colour attributes. We suggest that the genetic background drives colour plasticity and that this can maintain phenotypic variation in inbred lines, an adaptive mechanism that may be particularly important when genetic diversity is low.

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