1
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Gokhman VE, Kuznetsova VG. Structure and Evolution of Ribosomal Genes of Insect Chromosomes. INSECTS 2024; 15:593. [PMID: 39194798 DOI: 10.3390/insects15080593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2024] [Revised: 07/25/2024] [Accepted: 08/02/2024] [Indexed: 08/29/2024]
Abstract
Currently, clusters of 45S and 5S ribosomal DNA (rDNA) have been studied in about 1000 and 100 species of the class Insecta, respectively. Although the number of insect species with known 45S rDNA clusters (also referred to as nucleolus-organizing regions, or NORs) constitutes less than 0.1 percent of the described members of this enormous group, certain conclusions can already be drawn. Since haploid karyotypes with single 45S and 5S rDNA clusters predominate in both basal and derived insect groups, this character state is apparently ancestral for the class Insecta in general. Nevertheless, the number, chromosomal location, and other characteristics of both 45S and 5S rDNA sites substantially vary across different species, and sometimes even within the same species. There are several main factors and molecular mechanisms that either maintain these parameters or alter them on the short-term and/or long-term scale. Chromosome structure (i.e., monocentric vs. holokinetic chromosomes), excessive numbers of rRNA gene copies per cluster, interactions with transposable elements, pseudogenization, and meiotic recombination are perhaps the most important among them.
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Affiliation(s)
| | - Valentina G Kuznetsova
- Department of Karyosystematics, Zoological Institute, Russian Academy of Sciences, St. Petersburg 199034, Russia
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2
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Liang J, Kang L, Michalak P, Sharakhov IV. Hybridization between Aedes aegypti and Aedes mascarensis mosquitoes leads to disruption of male sex determination. Commun Biol 2024; 7:886. [PMID: 39039226 PMCID: PMC11263339 DOI: 10.1038/s42003-024-06560-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Accepted: 07/05/2024] [Indexed: 07/24/2024] Open
Abstract
Understanding the sex determination pathway and its disruptions in mosquitoes is critical for the effective control of disease vectors through genetic manipulations based on sex separation. When male hybrids of Aedes aegypti females and Ae. mascarensis males are backcrossed to Ae. aegypti females, a portion of the backcross progeny manifests as males with abnormal sexual differentiation. We discovered a significant correlation between pupal abnormalities and the feminization of subsequent adults exemplified by the relative abundance of ovarian and testicular tissues. All intersex individuals were genetic males as they expressed a male determining factor, Nix. Further, our analysis of the sex-specific splicing of doublesex and fruitless transcripts demonstrated the presence of both male and female splice variants indicating that sex determination is disrupted. A comparative transcriptomic analysis revealed similar expression levels of most female-associated genes in reproductive organs and carcasses between intersexual males and normal females. Moreover, intersexes had largely normal gene expression in testes but significant gene downregulation in male accessory glands when compared with normal males. We conclude that evolving hybrid incompatibilities between Ae. aegypti and Ae. mascarensis involve disruption of sex determination and are accompanied by changes in gene expression associated with sexual differentiation.
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Affiliation(s)
- Jiangtao Liang
- Department of Entomology, Virginia Polytechnic and State University, Blacksburg, VA, USA
- Fralin Life Science Institute, Virginia Polytechnic and State University, Blacksburg, VA, USA
- Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, Virginia Polytechnic and State University, Blacksburg, VA, USA
| | - Lin Kang
- Department of Biomedical Research, Edward Via College of Osteopathic Medicine, Monroe, LA, USA
- College of Pharmacy, University of Louisiana Monroe, Monroe, LA, USA
- Center for One Health Research, VA-MD College of Veterinary Medicine, Blacksburg, VA, USA
| | - Pawel Michalak
- Department of Biomedical Research, Edward Via College of Osteopathic Medicine, Monroe, LA, USA
- Center for One Health Research, VA-MD College of Veterinary Medicine, Blacksburg, VA, USA
- Institute of Evolution, University of Haifa, Haifa, Israel
| | - Igor V Sharakhov
- Department of Entomology, Virginia Polytechnic and State University, Blacksburg, VA, USA.
- Fralin Life Science Institute, Virginia Polytechnic and State University, Blacksburg, VA, USA.
- Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, Virginia Polytechnic and State University, Blacksburg, VA, USA.
- Department of Genetics and Cell Biology, Tomsk State University, Tomsk, Russia.
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3
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Kanippayoor RL, Soeder C, Hsiang T, Jones CD, Moehring AJ. Identification and genetic analysis of a pervasive 'needle-eye' sperm phenotype in Drosophila sterile hybrid males. Proc Biol Sci 2024; 291:20240483. [PMID: 38889778 DOI: 10.1098/rspb.2024.0483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 04/18/2024] [Indexed: 06/20/2024] Open
Abstract
Interspecies hybrid sterility has been extensively studied, especially in the genus Drosophila. Hybrid sterility is more often found in the heterogametic (XY or ZW) sex, a trend called Haldane's rule. Although this phenomenon is pervasive, identification of a common genetic mechanism remains elusive, with modest support found for a range of potential theories. Here, we identify a single precise morphological phenotype, which we call 'needle-eye sperm', that is associated with hybrid sterility in three separate species pairs that span the Drosophila genus. The nature of the phenotype indicates a common point of meiotic failure in sterile hybrid males. We used 10 generations of backcross selection paired with whole-genome pooled sequencing to genetically map the regions underlying the needle-eye (NE) sperm phenotype. Surprisingly, the sterility phenotype was present in ~50% of males even after 10 generations of backcrossing, and only a single region of the X chromosome was associated with sterility in one direction of backcross. Owing to the common phenotype among sterile male hybrids, and the strong effect of individual loci, further exploration of these findings may identify a universal mechanism for the evolution of hybrid sterility.
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Affiliation(s)
| | - Charles Soeder
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Tom Hsiang
- School of Environmental Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Corbin D Jones
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Amanda J Moehring
- Department of Biology, Western University, London, Ontario N6A 5B7, Canada
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4
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Duan T, Sicard A, Glémin S, Lascoux M. Expression pattern of resynthesized allotetraploid Capsella is determined by hybridization, not whole-genome duplication. THE NEW PHYTOLOGIST 2023; 237:339-353. [PMID: 36254103 PMCID: PMC10099941 DOI: 10.1111/nph.18542] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
Polyploidization, the process leading to the increase in chromosome sets, is a major evolutionary transition in plants. Whole-genome duplication (WGD) within the same species gives rise to autopolyploids, whereas allopolyploids result from a compound process with two distinct components: WGD and interspecific hybridization. To dissect the instant effects of WGD and hybridization on gene expression and phenotype, we created a series of synthetic hybrid and polyploid Capsella plants, including diploid hybrids, autotetraploids of both parental species, and two kinds of resynthesized allotetraploids with different orders of WGD and hybridization. Hybridization played a major role in shaping the relative expression pattern of the neo-allopolyploids, whereas WGD had almost no immediate effect on relative gene expression pattern but, nonetheless, still affected phenotypes. No transposable element-mediated genomic shock scenario was observed in either neo-hybrids or neo-polyploids. Finally, WGD and hybridization interacted and the distorting effects of WGD were less strong in hybrids. Whole-genome duplication may even improve hybrid fertility. In summary, while the initial relative gene expression pattern in neo-allotetraploids was almost entirely determined by hybridization, WGD only had trivial effects on relative expression patterns, both processes interacted and had a strong impact on physical attributes and meiotic behaviors.
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Affiliation(s)
- Tianlin Duan
- Department of Ecology and Genetics, Evolutionary Biology Centre and Science for Life LaboratoryUppsala University75236UppsalaSweden
| | - Adrien Sicard
- Department of Plant BiologySwedish University of Agricultural Sciences750 07UppsalaSweden
| | - Sylvain Glémin
- Department of Ecology and Genetics, Evolutionary Biology Centre and Science for Life LaboratoryUppsala University75236UppsalaSweden
- UMR CNRS 6553 ECOBIOCampus Beaulieu, bât 14a, p.118, CS 7420535042RennesFrance
| | - Martin Lascoux
- Department of Ecology and Genetics, Evolutionary Biology Centre and Science for Life LaboratoryUppsala University75236UppsalaSweden
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5
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Liang J, Bondarenko SM, Sharakhov IV, Sharakhova MV. Obtaining Polytene, Meiotic, and Mitotic Chromosomes from Mosquitoes for Cytogenetic Analysis. Cold Spring Harb Protoc 2022; 2022:591-598. [PMID: 35960616 DOI: 10.1101/pdb.prot107872] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Chromosome visualization is a key step for developing cytogenetic maps and idiograms, analyzing inversion polymorphisms, and identifying mosquito species. Three types of chromosomes-polytene, mitotic, and meiotic-are used in cytogenetic studies of mosquitoes. Here, we describe a detailed method for obtaining high-quality polytene chromosome preparations from the salivary glands of larvae and the ovaries of females for Anopheles mosquitoes. We also describe how to obtain mitotic chromosomes from imaginal discs of fourth-instar larvae and meiotic chromosomes from the testes of male pupae for all mosquitoes. These chromosomes can be used for fluorescence in situ hybridization (FISH), a fundamental technique in cytogenetic research that is used for physical genome mapping, detecting chromosomal rearrangements, and studying chromosome organization.
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Affiliation(s)
- Jiangtao Liang
- Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24060, USA
| | - Simon M Bondarenko
- Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24060, USA.,Department of Genetics and Cell Biology, Tomsk State University, Tomsk 634050, Russia
| | - Igor V Sharakhov
- Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24060, USA.,Department of Genetics and Cell Biology, Tomsk State University, Tomsk 634050, Russia
| | - Maria V Sharakhova
- Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24060, USA .,Laboratory of Evolutionary Genomics of Insects, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
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6
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Hunnicutt KE, Good JM, Larson EL. Unraveling patterns of disrupted gene expression across a complex tissue. Evolution 2022; 76:275-291. [PMID: 34882778 PMCID: PMC9355168 DOI: 10.1111/evo.14420] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 11/11/2021] [Accepted: 11/26/2021] [Indexed: 02/03/2023]
Abstract
Whole tissue RNASeq is the standard approach for studying gene expression divergence in evolutionary biology and provides a snapshot of the comprehensive transcriptome for a given tissue. However, whole tissues consist of diverse cell types differing in expression profiles, and the cellular composition of these tissues can evolve across species. Here, we investigate the effects of different cellular composition on whole tissue expression profiles. We compared gene expression from whole testes and enriched spermatogenesis populations in two species of house mice, Mus musculus musculus and M. m. domesticus, and their sterile and fertile F1 hybrids, which differ in both cellular composition and regulatory dynamics. We found that cellular composition differences skewed expression profiles and differential gene expression in whole testes samples. Importantly, both approaches were able to detect large-scale patterns such as disrupted X chromosome expression, although whole testes sampling resulted in decreased power to detect differentially expressed genes. We encourage researchers to account for histology in RNASeq and consider methods that reduce sample complexity whenever feasible. Ultimately, we show that differences in cellular composition between tissues can modify expression profiles, potentially altering inferred gene ontological processes, insights into gene network evolution, and processes governing gene expression evolution.
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Affiliation(s)
- Kelsie E Hunnicutt
- Department of Biological Sciences, University of Denver, Denver, Colorado, 80208
| | - Jeffrey M Good
- Division of Biological Sciences, University of Montana, Missoula, Montana, 59812
| | - Erica L Larson
- Department of Biological Sciences, University of Denver, Denver, Colorado, 80208
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7
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Liang J, Hodge JM, Sharakhov IV. Asymmetric Phenotypes of Sterile Hybrid Males From Reciprocal Crosses Between Species of the Anopheles gambiae Complex. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.660207] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Haldane’s rule of speciation states that sterility or inviability affects the heterogametic sex of inter-species hybrids. Darwin’s corollary to Haldane’s rule implies that there are asymmetric phenotypes in inter-species hybrids from reciprocal crosses. Studying the phenotypes of F1 hybrids among closely related species of malaria mosquitoes can assist researchers in identifying the genetic factors and molecular mechanisms of speciation. To characterize phenotypes of sterile hybrid males in the Anopheles gambiae complex, we performed crosses between laboratory strains of An. merus and either An. gambiae or An. coluzzii. The reproductive tracts had normal external morphology in hybrid males from crosses between female An. merus and male An. gambiae or An. coluzzii. Despite being sterile, these males could copulate with females for a normal period of time and could transfer a mating plug to induce female oviposition and monogamy. In contrast, the entire reproductive tracts in hybrid males from crosses between female An. gambiae or An. coluzzii and male An. merus were severely underdeveloped. These males had atrophic testes and reduced somatic organs of the reproductive system including male accessary glands and ejaculatory duct. In addition, hybrid males with underdeveloped reproductive tracts displayed a shorter copulation time with females and failed to induce female oviposition and monogamy due to their inability to form and transfer a plug to females during mating. The asymmetry of the phenotypes associated with hybrid male sterility suggests that different genetic factors and molecular mechanisms are responsible for reproductive isolation in reciprocal crosses among species of the An. gambiae complex.
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8
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Gamez S, Srivastav S, Akbari OS, Lau NC. Diverse Defenses: A Perspective Comparing Dipteran Piwi-piRNA Pathways. Cells 2020; 9:E2180. [PMID: 32992598 PMCID: PMC7601171 DOI: 10.3390/cells9102180] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 09/22/2020] [Accepted: 09/23/2020] [Indexed: 02/07/2023] Open
Abstract
Animals face the dual threat of virus infections hijacking cellular function and transposons proliferating in germline genomes. For insects, the deeply conserved RNA interference (RNAi) pathways and other chromatin regulators provide an important line of defense against both viruses and transposons. For example, this innate immune system displays adaptiveness to new invasions by generating cognate small RNAs for targeting gene silencing measures against the viral and genomic intruders. However, within the Dipteran clade of insects, Drosophilid fruit flies and Culicids mosquitoes have evolved several unique mechanistic aspects of their RNAi defenses to combat invading transposons and viruses, with the Piwi-piRNA arm of the RNAi pathways showing the greatest degree of novel evolution. Whereas central features of Piwi-piRNA pathways are conserved between Drosophilids and Culicids, multiple lineage-specific innovations have arisen that may reflect distinct genome composition differences and specific ecological and physiological features dividing these two branches of Dipterans. This perspective review focuses on the most recent findings illuminating the Piwi/piRNA pathway distinctions between fruit flies and mosquitoes, and raises open questions that need to be addressed in order to ameliorate human diseases caused by pathogenic viruses that mosquitoes transmit as vectors.
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Affiliation(s)
- Stephanie Gamez
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, CA 92093, USA; (S.G.); (O.S.A.)
| | - Satyam Srivastav
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853-2703, USA;
| | - Omar S. Akbari
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, CA 92093, USA; (S.G.); (O.S.A.)
| | - Nelson C. Lau
- Department of Biochemistry and Genome Science Institute, Boston University School of Medicine, Boston, MA 02118, USA
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9
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Deitz KC, Takken W, Slotman MA. The Genetic Architecture of Post-Zygotic Reproductive Isolation Between Anopheles coluzzii and An. quadriannulatus. Front Genet 2020; 11:925. [PMID: 33005168 PMCID: PMC7480394 DOI: 10.3389/fgene.2020.00925] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 07/24/2020] [Indexed: 11/15/2022] Open
Abstract
The Anopheles gambiae complex is comprised of eight morphologically indistinguishable species and has emerged as a model system for the study of speciation genetics due to the rapid radiation of its member species over the past two million years. Male hybrids between most An. gambiae complex species pairs are sterile, and some genotype combinations in hybrid males cause inviability. We investigated the genetic basis of hybrid male inviability and sterility between An. coluzzii and An. quadriannulatus by measuring segregation distortion and performing a QTL analysis of sterility in a backcross population. Hybrid males were inviable if they inherited the An. coluzzii X chromosome and were homozygous at one or more loci in 18.9 Mb region of chromosome 3. The An. coluzzii X chromosome has a disproportionately large effect on hybrid sterility when introgressed into an An. quadriannulatus genetic background. Additionally, an epistatic interaction between the An. coluzzii X and a 1.12 Mb, pericentric region of the An. quadriannulatus 3L chromosome arm has a statistically significant contribution to the hybrid sterility phenotype. This same epistatic interaction occurs when the An. coluzzii X is introgressed into the genetic background of An. arabiensis, the sister species of An. quadriannulatus, suggesting that this may represent one of the first Dobzhansky-Muller incompatibilities to evolve early in the radiation of the Anopheles gambiae species complex. We describe the additive effects of each sterility QTL, epistatic interactions between them, and genes within QTL with protein functions related to mating behavior, reproduction, spermatogenesis, and microtubule morphogenesis, whose divergence may contribute to post-zygotic reproductive isolation between An. coluzzii and An. quadriannulatus.
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Affiliation(s)
- Kevin C. Deitz
- Department of Entomology, Texas A&M University, College Station, TX, United States
| | - Willem Takken
- Laboratory of Entomology, Wageningen University and Research, Wageningen, Netherlands
| | - Michel A. Slotman
- Department of Entomology, Texas A&M University, College Station, TX, United States
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10
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Davis H, Sosulski N, Civetta A. Reproductive isolation caused by azoospermia in sterile male hybrids of Drosophila. Ecol Evol 2020; 10:5922-5931. [PMID: 32607201 PMCID: PMC7319132 DOI: 10.1002/ece3.6329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 03/16/2020] [Accepted: 04/14/2020] [Indexed: 11/12/2022] Open
Abstract
Recently diverged populations in the early stages of speciation offer an opportunity to understand mechanisms of isolation and their relative contributions. Drosophila willistoni is a tropical species with broad distribution from Argentina to the southern United States, including the Caribbean islands. A postzygotic barrier between northern populations (North America, Central America, and the northern Caribbean islands) and southern populations (South American and the southern Caribbean islands) has been recently documented and used to propose the existence of two different subspecies. Here, we identify premating isolation between populations regardless of their subspecies status. We find no evidence of postmating prezygotic isolation and proceeded to characterize hybrid male sterility between the subspecies. Sterile male hybrids transfer an ejaculate that is devoid of sperm but causes elongation and expansion of the female uterus. In sterile male hybrids, bulging of the seminal vesicle appears to impede the movement of the sperm toward the sperm pump, where sperm normally mixes with accessory gland products. Our results highlight a unique form of hybrid male sterility in Drosophila that is driven by a mechanical impediment to transfer sperm rather than by an abnormality of the sperm itself. Interestingly, this form of sterility is reminiscent of a form of infertility (azoospermia) that is caused by lack of sperm in the semen due to blockages that impede the sperm from reaching the ejaculate.
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Affiliation(s)
- Hunter Davis
- Department of BiologyUniversity of WinnipegWinnipegMBCanada
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11
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Sharma A, Kinney NA, Timoshevskiy VA, Sharakhova MV, Sharakhov IV. Structural Variation of the X Chromosome Heterochromatin in the Anopheles gambiae Complex. Genes (Basel) 2020; 11:E327. [PMID: 32204543 PMCID: PMC7140835 DOI: 10.3390/genes11030327] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/13/2020] [Accepted: 03/16/2020] [Indexed: 12/31/2022] Open
Abstract
Heterochromatin is identified as a potential factor driving diversification of species. To understand the magnitude of heterochromatin variation within the Anopheles gambiae complex of malaria mosquitoes, we analyzed metaphase chromosomes in An. arabiensis, An. coluzzii, An. gambiae, An. merus, and An. quadriannulatus. Using fluorescence in situ hybridization (FISH) with ribosomal DNA (rDNA), a highly repetitive fraction of DNA, and heterochromatic Bacterial Artificial Chromosome (BAC) clones, we established the correspondence of pericentric heterochromatin between the metaphase and polytene X chromosomes of An. gambiae. We then developed chromosome idiograms and demonstrated that the X chromosomes exhibit qualitative differences in their pattern of heterochromatic bands and position of satellite DNA (satDNA) repeats among the sibling species with postzygotic isolation, An. arabiensis, An. merus, An. quadriannulatus, and An. coluzzii or An. gambiae. The identified differences in the size and structure of the X chromosome heterochromatin point to a possible role of repetitive DNA in speciation of mosquitoes. We found that An. coluzzii and An. gambiae, incipient species with prezygotic isolation, share variations in the relative positions of the satDNA repeats and the proximal heterochromatin band on the X chromosomes. This previously unknown genetic polymorphism in malaria mosquitoes may be caused by a differential amplification of DNA repeats or an inversion in the sex chromosome heterochromatin.
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Affiliation(s)
- Atashi Sharma
- Department of Entomology, Virginia Polytechnic and State University, Blacksburg, VA 24061, USA; (A.S.); (V.A.T.); (M.V.S.)
| | - Nicholas A. Kinney
- Genomics Bioinformatics and Computational Biology, Virginia Polytechnic and State University, Blacksburg, VA 24061, USA;
| | - Vladimir A. Timoshevskiy
- Department of Entomology, Virginia Polytechnic and State University, Blacksburg, VA 24061, USA; (A.S.); (V.A.T.); (M.V.S.)
| | - Maria V. Sharakhova
- Department of Entomology, Virginia Polytechnic and State University, Blacksburg, VA 24061, USA; (A.S.); (V.A.T.); (M.V.S.)
- Laboratory of Evolutionary Genomics of Insects, the Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia
- Laboratory of Ecology, Genetics and Environmental Protection, Tomsk State University, 634050 Tomsk, Russia
| | - Igor V. Sharakhov
- Department of Entomology, Virginia Polytechnic and State University, Blacksburg, VA 24061, USA; (A.S.); (V.A.T.); (M.V.S.)
- Genomics Bioinformatics and Computational Biology, Virginia Polytechnic and State University, Blacksburg, VA 24061, USA;
- Laboratory of Evolutionary Genomics of Insects, the Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia
- Department of Cytology and Genetics, Tomsk State University, 634050 Tomsk, Russia
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12
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George P, Kinney NA, Liang J, Onufriev AV, Sharakhov IV. Three-dimensional Organization of Polytene Chromosomes in Somatic and Germline Tissues of Malaria Mosquitoes. Cells 2020; 9:cells9020339. [PMID: 32024176 PMCID: PMC7072178 DOI: 10.3390/cells9020339] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/22/2020] [Accepted: 01/28/2020] [Indexed: 12/17/2022] Open
Abstract
Spatial organization of chromosome territories and interactions between interphase chromosomes themselves, as well as with the nuclear periphery, play important roles in epigenetic regulation of the genome function. However, the interplay between inter-chromosomal contacts and chromosome-nuclear envelope attachments in an organism’s development is not well-understood. To address this question, we conducted microscopic analyses of the three-dimensional chromosome organization in malaria mosquitoes. We employed multi-colored oligonucleotide painting probes, spaced 1 Mb apart along the euchromatin, to quantitatively study chromosome territories in larval salivary gland cells and adult ovarian nurse cells of Anopheles gambiae, An. coluzzii, and An. merus. We found that the X chromosome territory has a significantly smaller volume and is more compact than the autosomal arm territories. The number of inter-chromosomal, and the percentage of the chromosome–nuclear envelope, contacts were conserved among the species within the same cell type. However, the percentage of chromosome regions located at the nuclear periphery was typically higher, while the number of inter-chromosomal contacts was lower, in salivary gland cells than in ovarian nurse cells. The inverse correlation was considerably stronger for the autosomes. Consistent with previous theoretical arguments, our data indicate that, at the genome-wide level, there is an inverse relationship between chromosome-nuclear envelope attachments and chromosome–chromosome interactions, which is a key feature of the cell type-specific nuclear architecture.
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Affiliation(s)
- Phillip George
- Department of Entomology, Virginia Tech, Blacksburg, VA 24061, USA; (P.G.); (J.L.)
| | - Nicholas A. Kinney
- Genomics, Bioinformatics and Computational Biology, Virginia Tech, Blacksburg, VA 24061, USA; (N.A.K.); (A.V.O.)
| | - Jiangtao Liang
- Department of Entomology, Virginia Tech, Blacksburg, VA 24061, USA; (P.G.); (J.L.)
| | - Alexey V. Onufriev
- Genomics, Bioinformatics and Computational Biology, Virginia Tech, Blacksburg, VA 24061, USA; (N.A.K.); (A.V.O.)
- Department of Computer Science, Virginia Tech, Blacksburg, VA 24061, USA
| | - Igor V. Sharakhov
- Department of Entomology, Virginia Tech, Blacksburg, VA 24061, USA; (P.G.); (J.L.)
- Genomics, Bioinformatics and Computational Biology, Virginia Tech, Blacksburg, VA 24061, USA; (N.A.K.); (A.V.O.)
- Department of Cytology and Genetics, Tomsk State University, 634050 Tomsk, Russian Federation
- Correspondence: ; Tel.: +1-540-231-7316
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13
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Kanippayoor RL, Alpern JHM, Moehring AJ. A common suite of cellular abnormalities and spermatogenetic errors in sterile hybrid males in Drosophila. Proc Biol Sci 2020; 287:20192291. [PMID: 31964309 PMCID: PMC7015338 DOI: 10.1098/rspb.2019.2291] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 12/30/2019] [Indexed: 01/18/2023] Open
Abstract
When two species interbreed, the resulting hybrid offspring are often sterile, with the heterogametic (e.g. XY) hybrid usually being more severely affected. The prevailing theory for this pattern of sterility evokes divergent changes in separate lineages having maladaptive interactions when placed together in a hybrid individual, with recessive factors on the sex chromosome interacting with dominant factors on the autosomes. The effect of these interactions on gametogenesis should not be uniform across species pairs unless genetic divergence follows the same paths in different lineages or if a specific stage of gametogenesis is more susceptible to detrimental genetic interactions. Here, we perform a detailed cellular characterization of hybrid male sterility across three recently diverged species pairs of Drosophila. Across all three pairs, sterile hybrid sperm are alive but exhibit rapid nuclear de-condensation with age, with active, but non-differentiated, mitochondria. Surprisingly, all three sets of interspecies hybrids produce half of the number of sperm per round of spermatogenesis, with each sperm cell containing two tails. We identify non-disjunction failures during meiosis I as the likely cause. Thus, errors during meiosis I may be a general phenomenon underlying Drosophila male sterility, indicating either a heightened sensitivity of this spermatogenic stage to failure, or a basis to sterility other than the prevailing model.
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