The Genome Size of Some Species of Hyalomma Ticks from Turkish Thrace 

2018 ◽  
Vol 23 (11) ◽  
pp. 2122 ◽  
Author(s):  
Nadim Yılmazer
Keyword(s):  
Genome Size ◽  
X Chromosome ◽  
Tick Species ◽  
Animal Health ◽  
Chromosome Size ◽  
Diploid Genome ◽  
Flow Cytometric ◽  
Determination System ◽  
Sex Determination System ◽  
First Time

Hyalomma scupense, H. excavatum and H. marginatum are globally important tick species, as well as in Turkey, both in terms of human and animal health. The genome sizes of these tick species were determined in this study for the first time. From flow cytometric measurements, diploid genome sizes of female and male H. scupense were found to be 2.13 pg and 1.75 pg, respectively, while H. excavatum were 2.21 pg and 1.94 pg, and H. marginatum were 2.48 pg and 1.98 pg, respectively. Differences in diploid genome size indicate X chromosome size of females and males in these ticks because they have an XX:XO sex determination system. Thus, it was estimated that the X chromosome of H. scupense, H. excavatum, and H. marginatum may be composed of as much as 0.38 pg, 0.27 pg, and 0.50 pg of DNA, respectively. These findings indicate suitability of these three species for genome sequencing due to the relatively small size of their genomes compared with other tick species.

scholarly journals Restricted X chromosome introgression and support for Haldane's rule in hybridizing damselflies

2021 ◽  
Author(s):  
Janne Swaegers ◽  
Rosa Ana Sanchez-Guillen ◽  
Pallavi Chauhan ◽  
Maren Wellenreuther ◽  
Bengt Hansson
Keyword(s):  
X Chromosome ◽  
Sex Chromosomes ◽  
Hybrid Zones ◽  
Haldane’S Rule ◽  
Haldane's Rule ◽  
Genome Wide ◽  
Determination System ◽  
Heterogametic Sex ◽  
Sex Determination System ◽  
Genomic Introgression

Contemporary hybrid zones act as natural laboratories for the investigation of species boundaries and allow to shed light on the little understood roles of sex chromosomes in species divergence. Sex chromosomes are considered to function as a hotspot of genetic divergence between species; indicated by less genomic introgression compared to autosomes during hybridisation. Moreover, they are thought to contribute to Haldane's rule which states that hybrids of the heterogametic sex are more likely to be inviable or sterile. To test these hypotheses, we used contemporary hybrid zones of Ischnura elegans, a damselfly species that has been expanding its range into the northern and western regions of Spain, leading to chronic hybridization with its sister species Ischnura graellsii. We analysed genome-wide SNPs in the Spanish I. elegans and I. graellsii hybrid zone and found (i) that the X chromosome shows less genomic introgression compared to autosomes and (ii) that males are underrepresented among admixed individuals as predicted by Haldane's rule. This is the first study in Odonata that suggests a role of the X chromosome in reproductive isolation. Moreover, our data adds to the few studies on species with X0 sex determination system and contradicts the hypothesis that the absence of a Y chromosome causes exceptions to Haldane's rule.

WHITE EYE AND CURLED, RECESSIVE MUTANTS ON THE X CHROMOSOME OF ANOPHELES ALBIMANUS

1982 ◽  
Vol 24 (6) ◽  
pp. 661-665 ◽  
Author(s):  
J. A. Seawright ◽  
M. Q. Benedict ◽  
S. Narang ◽  
P. E. Kaiser
Keyword(s):  
Sex Determination ◽  
X Chromosome ◽  
Anopheles Albimanus ◽  
Recessive Lethal ◽  
Y Chromosomes ◽  
Determination System ◽  
Sex Determination System ◽  
Mode Of Inheritance

Two new mutants, white eye (we) and curled (cr), of Anopheles albimanus Wiedemann were isolated and studied. Both mutants are recessive and are approximately 18.9 ± 1.9 units apart on the X chromosome. White eye is fully viable, but cr is a recessive lethal. The mode of inheritance of these two mutants provides further evidence of an X-Y sex determination system in An. albimanus and a lack of homology between the X and Y chromosomes.

scholarly journals Genome size variation and karyotype diversity in eight taxa of Sorbus sensu stricto (Rosaceae) from China

2021 ◽  
Vol 15 (2) ◽  
pp. 137-148
Author(s):  
Jiabao Li ◽  
Kailin Zhu ◽  
Qin Wang ◽  
Xin Chen
Keyword(s):  
Flow Cytometry ◽  
Genome Size ◽  
Size Variation ◽  
Sensu Stricto ◽  
Chromosome Size ◽  
Chromosome Counting ◽  
Genome Size Variation ◽  
Ploidy Levels ◽  
First Time ◽  
Karyotype Symmetry

Eight taxa of Sorbus Linnaeus, 1753 sensu stricto (Rosaceae) from China have been studied karyologically through chromosome counting, chromosomal measurement and karyotype symmetry. Genome size was also estimated by flow cytometry. Six taxa, S. amabilis Cheng ex T.T.Yu et K.C.Kuan, 1963, S. hupehensis var. paucijuga (D.K. Zang et P.C. Huang, 1992) L.T. Lu, 2000, S. koehneana C.K. Schneider, 1906, S. pohuashanensis (Hance, 1875) Hedlund, 1901, S. scalaris Koehne, 1913 and S. wilsoniana C.K. Schneider, 1906 are diploids with 2n = 34, whereas two taxa, S. filipes Handel-Mazzetti,1933 and S. ovalis McAllister, 2005 are tetraploid with 2n = 68. In general, the chromosome size is mainly small, and karyotypes are symmetrical with predominance of metacentric chromosomes. Genome size variation of diploids and tetraploids is 1.401 pg –1.676 pg and 2.674 pg –2.684 pg, respectively. Chromosome numbers of S. amabilis and S. hupehensis var. paucijuga, and karyotype and genome size of eight taxa studied are reported for the first time. This study emphasised the reliability of flow cytometry in genome size determination to infer ploidy levels in Chinese native Sorbus species.

Primary sex determination in the nematode C. elegans

Development ◽  
1987 ◽  
Vol 101 (Supplement) ◽  
pp. 5-16 ◽  
Author(s):  
Jonathan Hodgkin
Keyword(s):  
Sex Determination ◽  
X Chromosome ◽  
Germ Line ◽  
X Chromosomes ◽  
C Elegans ◽  
Female Sex ◽  
Determination System ◽  
One Step ◽  
Sex Determination System ◽  
Specific Control

Most nematodes have XO male/XX female sex determination. C. elegans is anomalous, having XX hermaphrodites rather than females. The hermaphrodite condition appears to result from the modification of a basic male/female sex-determination system, which permits both spermatogenesis and oogenesis to occur within a female soma. This modification is achieved by a germ-line-specific control acting at one step in a cascade of autosomal regulatory genes, which respond to X-chromosome dosage and direct male, female, or hermaphrodite development. Mutations of one of these genes can be used to construct artificial strains with ZZ male/WZ female sex determination. Primary sex determination normally depends on the ratio of X chromosomes to autosomes, as in Drosophila, and there appear to be multiple sites on the X chromosome that contribute to this ratio. Also, as in Drosophila, X-chromosome expression is compensated to equalize gene activity in XX and XO animals. Interactions between dosage compensation and sex determination are described and discussed.

Peaceful revolution in genome size: polyploidy in the Nabidae (Heteroptera); autosomes and nuclear DNA content doubling

2020 ◽  
Author(s):  
David Sadílek ◽  
Jitka Vilímová ◽  
Tomáš Urfus
Keyword(s):  
Genome Size ◽  
X Chromosome ◽  
Dna Content ◽  
18S Rdna ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Chromosome Breakage ◽  
Polyploidy Event ◽  
First Time

Abstract Genome size and the position of 18S ribosomal DNA (rDNA) were analysed in two Himacerus, eight Nabis and two Prostemma species from the family Nabidae using flow cytometry and fluorescence in situ hybrization techniques. The karyotypes of Nabis biformis and Nabis maoricus, each with 2n = 16 + XY, and Prostemma aeneicolle, with 2n = 26 + XY, were recorded for the first time. All the species displayed one or two 18S rDNA signals on the X chromosome and up to two signals on the Y chromosome. Several females exhibited two different types of X chromosome breakage, namely within or outside of the 18S rDNA region. Measurements of nuclear DNA content revealed significant differences between all three genera under study. Most notably, the nuclear DNA content of Himacerus species, with 2n = 32/36 + XY (2C = 9–10 pg), was double that of Nabis species, with 2n = 16 + XY (2C = 4–6 pg). Therefore, the previously rejected theory of an autosomal polyploidy event in the evolution of the genus Himacerus is strongly supported by the results of the present study and is now being resurrected.

scholarly journals Low variability of Orchis militaris L. in a local population in the Altay Territory, Russia: evidence from morphometrical and caryological analyses

2021 ◽  
Vol 10 (2) ◽  
Author(s):  
Yulianna G. Zaytseva ◽  
◽  
Alexandra Yu. Nabieva ◽  
Elena V. Zhmud ◽  
◽  
...  
Keyword(s):  
Genome Size ◽  
Rare Species ◽  
Local Population ◽  
Chromosome Counts ◽  
Natural Conditions ◽  
Flow Cytometric Data ◽  
Flow Cytometric ◽  
Its Regions ◽  
Long Time ◽  
First Time

Orchis militaris L. is a rare species at the territory of Russia and in many of its regions. This species has been studied for a long time, but the genome size of its representatives in natural conditions has not been studied yet. This assessment is of great importance for the development of measures for the rare species preservation in natural conditions and in the tissue culture. Chromosome counts were completed by flow cytometric data and morphological observations in order to study the species intrapopulation variability. Here, the flow cytometric data on genome size and DNA content of O. militaris from the Asian part of Russia are presented for the first time.

scholarly journals Genome size variation and karyotype diversity in eight taxa of Sorbus sensu stricto (Rosaceae) from China

2021 ◽  
Vol 15 (2) ◽  
pp. 137-148
Author(s):  
Jiabao Li ◽  
Kailin Zhu ◽  
Qin Wang ◽  
Xin Chen
Keyword(s):  
Flow Cytometry ◽  
Genome Size ◽  
Size Variation ◽  
Sensu Stricto ◽  
Chromosome Size ◽  
Chromosome Counting ◽  
Genome Size Variation ◽  
Ploidy Levels ◽  
First Time ◽  
Karyotype Symmetry

Eight taxa of Sorbus Linnaeus, 1753 sensu stricto (Rosaceae) from China have been studied karyologically through chromosome counting, chromosomal measurement and karyotype symmetry. Genome size was also estimated by flow cytometry. Six taxa, S. amabilis Cheng ex T.T.Yu et K.C.Kuan, 1963, S. hupehensis var. paucijuga (D.K. Zang et P.C. Huang, 1992) L.T. Lu, 2000, S. koehneana C.K. Schneider, 1906, S. pohuashanensis (Hance, 1875) Hedlund, 1901, S. scalaris Koehne, 1913 and S. wilsoniana C.K. Schneider, 1906 are diploids with 2n = 34, whereas two taxa, S. filipes Handel-Mazzetti,1933 and S. ovalis McAllister, 2005 are tetraploid with 2n = 68. In general, the chromosome size is mainly small, and karyotypes are symmetrical with predominance of metacentric chromosomes. Genome size variation of diploids and tetraploids is 1.401 pg –1.676 pg and 2.674 pg –2.684 pg, respectively. Chromosome numbers of S. amabilis and S. hupehensis var. paucijuga, and karyotype and genome size of eight taxa studied are reported for the first time. This study emphasised the reliability of flow cytometry in genome size determination to infer ploidy levels in Chinese native Sorbus species.

Karyotype of the South African katydid Hetrodes pupus (Linnaeus, 1758) (Orthoptera, Tettigoniidae) with special reference to relationships within the Hetrodinae subfamily

Zootaxa ◽  
2009 ◽  
Vol 2137 (1) ◽  
pp. 43-50 ◽  
Author(s):  
ELŻBIETA WARCHAŁOWSKA-ŚLIWA ◽  
ALEXANDER G. BUGROV
Keyword(s):  
Comparative Analysis ◽  
Sex Determination ◽  
Special Reference ◽  
South African ◽  
X Chromosome ◽  
Chromosome Evolution ◽  
Cytogenetic Study ◽  
Meiotic Chromosomes ◽  
Determination System ◽  
Sex Determination System

The taxonomic position of Hetrodes pupus (Tettigoniidae, Hetrodinae) was clarified by a cytogenetic study of mitotic and meiotic chromosomes, including the localization of heterochromatin by C-banding. The karyotype of this species consists of 26 acrocentric autosomes and an acrocentric X chromosome, the largest element of the karyotype (2n male=27, FN=27; sex determination system is X0 male/XX female). A cytogenetic comparative analysis of the Hetrodinae and other katydids revealed (1) the similarity of the karyotypic features of Hetrodinae and Microtettigoninae, indicating monophyly; (2) that the morphology of the Hetrodinae karyotype is the result of parallel chromosome evolution via a decrease in the number of chromosome arms (FN).

scholarly journals Leaves and Seeds as Materials for Flow Cytometric Estimation of the Genome Size of 11 Rosaceae Woody Species Containing DNA-Staining Inhibitors

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Iwona Jedrzejczyk ◽  
Elwira Sliwinska
Keyword(s):  
Genome Size ◽  
Dna Content ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Woody Species ◽  
Size Estimation ◽  
Flow Cytometric ◽  
Cell Cytosol ◽  
High Concentrations ◽  
First Time

The presence of some secondary metabolites in the cell cytosol can cause a stoichiometric error in the flow cytometric estimation of nuclear DNA content. There is no fully reliable method to completely eliminate the effect of these compounds on nuclei fluorescence, and therefore using plant organs/parts free of staining inhibitors is recommended. Eleven species of Rosaceae with high concentrations of propidium-iodide-staining inhibitors were studied to check the possibility of using seeds instead of leaves for genome size estimation. Despite optimizing the concentration and composition of antioxidants in nuclei-isolation buffer for each species, the effect of cytosolic compounds present in the leaves could not be avoided entirely. None of the seeds of the studied species contained inhibitors, and they produced histograms of good quality. The genome size of the studied species ranged from 1.15 to 3.17 pg/2C; for 10 species the DNA content was estimated for the first time.

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