scholarly journals Interbreed variation in meiotic recombination rate and distribution in the domestic chicken <i>Gallus gallus</i>

2019 ◽  
Vol 62 (2) ◽  
pp. 403-411
Author(s):  
Lyubov P. Malinovskaya ◽  
Katerina V. Tishakova ◽  
Natalia A. Volkova ◽  
Anna A. Torgasheva ◽  
Yakov A. Tsepilov ◽  
...  

Abstract. The efficiency of natural and artificial selection is critically dependent on the recombination rate. However, interbreed and individual variation in recombination rate in poultry remains unknown. Conventional methods of analysis of recombination such as genetic linkage analysis, sperm genotyping and chiasma count at lampbrush chromosomes are expensive and time-consuming. In this study, we analyzed the number and distribution of recombination nodules in spermatocytes of the roosters of six chicken breeds using immunolocalization of key proteins involved in chromosome pairing and recombination. We revealed significant effects of breed (R2=0.17; p<0.001) and individual (R2=0.28; p<0.001) on variation in the number of recombination nodules. Both interbreed and individual variations in recombination rate were almost entirely determined by variation in recombination density on macrochromosomes, because almost all microchromosomes in each breed had one recombination nodule. Despite interbreed differences in the density of recombination nodules, the patterns of their distribution along homologous chromosomes were similar. The breeds examined in this study showed a correspondence between the age of the breed and its recombination rate. Those with high recombination rates (Pervomai, Russian White and Brahma) are relatively young breeds created by crossing several local breeds. The breeds displaying low recombination rate are ancient local breeds: Cochin (Indo-China), Brown Leghorn (Tuscany, Italy) and Russian Crested (the European part of Russia).

2017 ◽  
Vol 151 (1) ◽  
pp. 27-35 ◽  
Author(s):  
Anna A. Torgasheva ◽  
Pavel M. Borodin

Studies on mammals demonstrate wide interspecific variation in the number and distribution of recombination events along chromosomes. Birds represent an interesting model group for comparative analysis of cytological and ecological drivers of recombination rate evolution. Yet, data on variation in recombination rates in birds are limited to a dozen of species. In this study, we used immunolocalization of MLH1, a mismatch repair protein marking mature recombination nodules, to estimate the overall recombination rate and distribution of crossovers along macrochromosomes in female and male meiosis of the gray goose (Anser anser). The average number of MLH1 foci was significantly higher in oocytes than in spermatocytes (73.6 ± 7.8 and 58.9 ± 7.6, respectively). MLH1 foci distribution along individual macrobivalents showed subtelomeric peaks, which were more pronounced in males. Analysis of distances between neighboring MLH1 foci on macrobivalents revealed stronger crossover interference in male meiosis. These data create a framework for future genetic and physical mapping of the gray goose.


2021 ◽  
Vol 25 (6) ◽  
pp. 661-668
Author(s):  
L. P. Malinovskaya ◽  
K. V. Tishakova ◽  
T. I. Bikchurina ◽  
A. Yu. Slobodchikova ◽  
N. Yu. Torgunakov ◽  
...  

Benefits and costs of meiotic recombination are a matter of discussion. Because recombination breaks allele combinations already tested by natural selection and generates new ones of unpredictable fitness, a high recombination rate is generally beneficial for the populations living in a fluctuating or a rapidly changing environment and costly in a stable environment. Besides genetic benefits and costs, there are cytological effects of recombination, both positive and negative. Recombination is necessary for chromosome synapsis and segregation. However, it involves a massive generation of double-strand DNA breaks, erroneous repair of which may lead to germ cell death or various mutations and chromosome rearrangements. Thus, the benefits of recombination (generation of new allele combinations) would prevail over its costs (occurrence of deleterious mutations) as long as the population remains sufficiently heterogeneous. Using immunolocalization of MLH1, a mismatch repair protein, at the synaptonemal complexes, we examined the number and distribution of recombination nodules in spermatocytes of two chicken breeds with high (Pervomai) and low (Russian Crested) recombination rates and their F1 hybrids and backcrosses. We detected negative heterosis for recombination rate in the F1 hybrids. Backcrosses to the Pervomai breed were rather homogenous and showed an intermediate recombination rate. The differences in overall recombination rate between the breeds, hybrids and backcrosses were mainly determined by the differences in the crossing over number in the seven largest macrochromosomes. The decrease in recombination rate in F1 is probably determined by difficulties in homology matching between the DNA sequences of genetically divergent breeds. The suppression of recombination in the hybrids may impede gene flow between parapatric populations and therefore accelerate their genetic divergence. 


2021 ◽  
Vol 55 (1) ◽  
Author(s):  
Ian R. Henderson ◽  
Kirsten Bomblies

Sex, as well as meiotic recombination between homologous chromosomes, is nearly ubiquitous among eukaryotes. In those species that use it, recombination is important for chromosome segregation during gamete production, and thus for fertility. Strikingly, although in most species only one crossover event per chromosome is required to ensure proper segregation, recombination rates vary considerably above this minimum and show variation within and among species. However, whether this variation in recombination is adaptive or neutral and what might shape it remain unclear. Empirical studies and theory support the idea that recombination is generally beneficial but can also have costs. Here, we review variation in genome-wide recombination rates, explore what might cause this, and discuss what is known about its mechanistic basis. We end by discussing the environmental sensitivity of meiosis and recombination rates, how these features may relate to adaptation, and their implications for a broader understanding of recombination rate evolution. Expected final online publication date for the Annual Review of Genetics, Volume 55 is November 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2020 ◽  
Vol 8 ◽  
Author(s):  
Manuel De Rojas ◽  
Jorge Doña ◽  
Ivan Dimov

Rhinonyssid mites are permanent parasites of birds that inhabit their respiratory tract. There are around 600 species described worldwide and almost all species of birds are found to have embedded rhinonyssid mites. Despite their presumed relevance, these mites are largely unstudied due to the difficulty in sampling them and, therefore, the majority of mite-host associations and species-prevalence data are unknown. In this study, 179 mite specimens belonging to 27 species and eight genera were identified. Notably, 18 new mite-bird associations were documented for the first time, thus increasing the known host range for these mite species. In addition, mite-host associations found in this study were compared with known associations from these species of birds in the European part of Russia and in Europe. Overall, this study represents the largest survey to date carried out on rhinonyssid mites in Russia and one of the most comprehensive datasets on rhinonyssid host-range.


2020 ◽  
Vol 21 (6) ◽  
pp. 2222
Author(s):  
Wei Ren ◽  
Xiaoping Gong ◽  
Kun Li ◽  
Hongwei Zhang ◽  
Fanjun Chen ◽  
...  

Efficient recombination is critical to both plant breeding and gene cloning. However, almost all traditional recombination studies and genetic improvements require the slow and labor-intensive population construction process, and little is known about the recombination characteristics of populations of different types, generations, and origins. Here, we provide a simple and efficient simulation method for population construction based on doubled haploid (DH) and intermated B73 × Mo17 maize (IBM) populations to predict the recombination pattern. We found that the chromosomes had 0, 1, 2, and 3 recombination events that occurred at rates of 0.16, 0.30, 0.23, and 0.15, respectively, in the DH and the recombination rate of each chromosome in the IBM population ranged from 0 to 12.1 cM per 125 kb. Based on the observed recombination parameters, we estimated the number of recombination events and constructed the linkage maps of the simulated DH and recombination inbred line (RIL) populations. These simulated populations exhibited similar recombination patterns compared with the real populations, suggesting the feasibility of this simulation approach. We then compared the recombination rates of the simulated populations of different types (DH induced or self-crossed), generations, and origins (using the 8, 16, and 32 multiparent advanced generation intercross (MAGIC) populations), and suggested a rapid and cost-effective population construction procedure for breeders and geneticists, while maintaining an optimal recombination rate. This study offers a convenient method for optimizing the population construction process and has broader implications for other crop species, thereby facilitating future population studies and genetic improvement strategies.


Author(s):  
Lev V. Razumovsky

On the basis of author's graphical analysis method, the typification of lake ecosystems transformation scenarios depending on the size of lakes was carried out. It was confirmed that the type of transformation depends not only on size of the lake, but also on the landscape and climatic region in which it is located. The distinctive features of lake ecosystems transformation types in the European part of Russia and in Western Siberia were analyzed and compared.


2011 ◽  
pp. 101-116 ◽  
Author(s):  
B. Yu. Teteryuk

The results of a sintaxonomical study of plant communities of the Yamozero lake (the North-East of the European part of Russia) are presented. The diversity of the aquatic and helophytic vegetation of the Yamozero lake consists of 16 associations and 2 communities of 6 unions, 4 orders and 2 classes of the floristic classification: Potamogetonetea (7 associations, 2 communities), Phragmito-Magnocaricetea (9 associations). Many of described associations are widely distributed in the Central and the Eastern Europe. Some associations have the boundaries of their ranges. Some communities include 2 rare species of regional level: Isoetes setacea and Sagittaria natans.


2018 ◽  
Vol 52 (1) ◽  
pp. 91-100
Author(s):  
E. Yu. Blagoveshchenskaya

The paper provides the results of seven-year study of downy mildew on Skadovsky Zvenigorod Biological Station of Moscow State University (ZBS MSU, Moscow Region). A total of 29 species of Peronosporales (Oomycota) were revealed during the study. An annotated list of species is presented, among them Peronospora anemones is recorded for the first time for Russia, P. chelidonii and P. stachydis are new for the European part of Russia, 8 species are new for the Moscow Region.


2008 ◽  
pp. 76-85 ◽  
Author(s):  
B. Yu. Teteryuk

The results of a syntaxonomical study of plant communities of the large lake Donty (North-East of the European part of Russia) are presented. The diversity of hydrophytic vegetation has been classified into 3 classes (Lemnetea, Potametea and Phragmito-Magnocaricetea), 5 orders, 8 alliances, 20 associations and 1 community. Subasso­ciation Scolochloetum festucaceae caricetosum aquatilis is new. Communities of associations Caricetum aquatilis, Equisetetum fluviatilis, Potamo—Nupharetum luteae, Potametum perfo­liati are mostly wide distributed, while these of Phragmitetum communis, Scolochloetum festucaceae ones are relatively rare as well as Lemno—Spirodeletum polyrchizae, Elodeo—Potametum alpini, Potamo—Nupharetum pumilae, Potametum praelongi and Scirpetum lacustris are very rare. Some communities contain 2 regional rare species: Scolochloa festucacea and Ranunculus lingua.


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