Faculty Opinions recommendation of Multilocus patterns of nucleotide variability and the demographic and selection history of Drosophila melanogaster populations.

Author(s):  
Thomas Mitchell-Olds
Genetics ◽  
1996 ◽  
Vol 144 (2) ◽  
pp. 635-645 ◽  
Author(s):  
David A Kirby ◽  
Wolfgang Stephan

Abstract We surveyed sequence variation and divergence for the entire 5972-bp transcriptional unit of the white gene in 15 lines of Drosophila melanogaster and one line of D. simulans. We found a very high degree of haplotypic structuring for the polymorphisms in the 3′ half of the gene, as opposed to the polymorphisms in the 5′ half. To determine the evolutionary mechanisms responsible for this pattern, we sequenced a 1612-bp segment of the white gene from an additional 33 lines of D. melanogaster from a European and a North American population. This 1612-bp segment encompasses an 834bp region of the white gene in which the polymorphisms form high frequency haplotypes that cannot be explained by a neutral equilibrium model of molecular evolution. The small number of recombinants in the 834bp region suggests epistatic selection as the cause of the haplotypic structuring, while an investigation of nucleotide diversity supports a directional selection hypothesis. A multi-locus selection model that combines features from both-hypotheses and takes the recent history of D. melanogaster into account may be the best explanation for these data.


2021 ◽  
Vol 13 (3) ◽  
Author(s):  
J Roman Arguello ◽  
Stefan Laurent ◽  
Andrew G Clark

Heredity ◽  
2006 ◽  
Vol 98 (2) ◽  
pp. 65-68 ◽  
Author(s):  
W Stephan ◽  
H Li

2021 ◽  
Vol 12 ◽  
Author(s):  
Simon Boitard ◽  
Cyriel Paris ◽  
Natalia Sevane ◽  
Bertrand Servin ◽  
Kenza Bazi-Kabbaj ◽  
...  

Gene banks, framed within the efforts for conserving animal genetic resources to ensure the adaptability of livestock production systems to population growth, income, and climate change challenges, have emerged as invaluable resources for biodiversity and scientific research. Allele frequency trajectories over the few last generations contain rich information about the selection history of populations, which cannot be obtained from classical selection scan approaches based on present time data only. Here we apply a new statistical approach taking advantage of genomic time series and a state of the art statistic (nSL) based on present time data to disentangle both old and recent signatures of selection in the Asturiana de los Valles cattle breed. This local Spanish originally multipurpose breed native to Asturias has been selected for beef production over the last few generations. With the use of SNP chip and whole-genome sequencing (WGS) data, we detect candidate regions under selection reflecting the effort of breeders to produce economically valuable beef individuals, e.g., by improving carcass and meat traits with genes such as MSTN, FLRT2, CRABP2, ZNF215, RBPMS2, OAZ2, or ZNF609, while maintaining the ability to thrive under a semi-intensive production system, with the selection of immune (GIMAP7, GIMAP4, GIMAP8, and TICAM1) or olfactory receptor (OR2D2, OR2D3, OR10A4, and 0R6A2) genes. This kind of information will allow us to take advantage of the invaluable resources provided by gene bank collections from local less competitive breeds, enabling the livestock industry to exploit the different mechanisms fine-tuned by natural and human-driven selection on different populations to improve productivity.


2019 ◽  
Vol 37 (3) ◽  
pp. 627-638 ◽  
Author(s):  
Quentin D Sprengelmeyer ◽  
Suzan Mansourian ◽  
Jeremy D Lange ◽  
Daniel R Matute ◽  
Brandon S Cooper ◽  
...  

Abstract A long-standing enigma concerns the geographic and ecological origins of the intensively studied vinegar fly, Drosophila melanogaster. This globally distributed human commensal is thought to originate from sub-Saharan Africa, yet until recently, it had never been reported from undisturbed wilderness environments that could reflect its precommensal niche. Here, we document the collection of 288 D. melanogaster individuals from multiple African wilderness areas in Zambia, Zimbabwe, and Namibia. The presence of D. melanogaster in these remote woodland environments is consistent with an ancestral range in southern-central Africa, as opposed to equatorial regions. After sequencing the genomes of 17 wilderness-collected flies collected from Kafue National Park in Zambia, we found reduced genetic diversity relative to town populations, elevated chromosomal inversion frequencies, and strong differences at specific genes including known insecticide targets. Combining these genomes with existing data, we probed the history of this species’ geographic expansion. Demographic estimates indicated that expansion from southern-central Africa began ∼13,000 years ago, with a Saharan crossing soon after, but expansion from the Middle East into Europe did not begin until roughly 1,800 years ago. This improved model of demographic history will provide an important resource for future evolutionary and genomic studies of this key model organism. Our findings add context to the history of D. melanogaster, while opening the door for future studies on the biological basis of adaptation to human environments.


1989 ◽  
Vol 109 (2) ◽  
pp. 505-516 ◽  
Author(s):  
J S Minden ◽  
D A Agard ◽  
J W Sedat ◽  
B M Alberts

One of the first signs of cell differentiation in the Drosophila melanogaster embryo occurs 3 h after fertilization, when discrete groups of cells enter their fourteenth mitosis in a spatially and temporally patterned manner creating mitotic domains (Foe, V. E. and G. M. Odell, 1989, Am. Zool. 29:617-652). To determine whether cell residency in a mitotic domain is determined solely by cell position in this early embryo, or whether cell lineage also has a role, we have developed a technique for directly analyzing the behavior of nuclei in living embryos. By microinjecting fluorescently labeled histones into the syncytial embryo, the movements and divisions of each nucleus were recorded without perturbing development by using a microscope equipped with a high resolution, charge-coupled device. Two types of developmental maps were generated from three-dimensional time-lapse recordings: one traced the lineage history of each nucleus from nuclear cycle 11 through nuclear cycle 14 in a small region of the embryo; the other recorded nuclear fate according to the timing and pattern of the 14th nuclear division. By comparing these lineage and fate maps for two embryos, we conclude that, at least for the examined area, the pattern of mitotic domain formation in Drosophila is determined by the position of each cell, with no effect of cell lineage.


Author(s):  
Keisuke Touma ◽  
◽  
Satoshi Endo ◽  
Naruaki Toma ◽  
Yuhei Akamine ◽  
...  

The validity of the consultation algorithm is shown in computer shogi. The consultation algorithm determines a move by votes of computer shogi players. In this research, we discuss a method that changes player vote weights during a game. To change player vote weights, we use the selection history of the move and the evaluation function value. Experimental results suggests the validity of our proposed method.


Author(s):  
Lucas P Henry ◽  
Julien F Ayroles

Experimental evolution has a long history of uncovering fundamental insights into evolutionary processes but has largely neglected one underappreciated component--the microbiome. As eukaryotic hosts evolve, the microbiome may also evolve in response. However, the microbial contribution to host evolution remains poorly understood. Here, we analyzed the metagenomes from 10 E&R experiments in Drosophila melanogaster to determine how the microbiome changes in response to host selection. Bacterial diversity was significantly different in 5/10 studies in traits associated with metabolism or immunity. Additionally, we find that excluding reads from a facultative symbiont, Wolbachia, in the analysis of bacterial diversity changes the inference, raising important questions for future E&R experiments in D. melanogaster. Our results suggest the microbiome often responds to host selection but highlights the need for more work to understand how the microbiome changes the host response to selection.


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