Population Dynamics of Male-Killing and Non-Male-Killing Spiroplasmas in Drosophila melanogaster

ABSTRACT The endosymbiotic bacteria Spiroplasma spp. are vertically transmitted through female hosts and are known to cause selective death of male offspring in insects. One strain of spiroplasma, NSRO, causes male killing in Drosophila species, and a non-male-killing variant of NSRO, designated NSRO-A, has been isolated. It is not known why NSRO-A does not kill males. In an attempt to understand the mechanism of male killing, we investigated the population dynamics of NSRO and NSRO-A throughout the developmental course of the laboratory host Drosophila melanogaster by using a quantitative PCR technique. In the early development of the host insect, the titers of NSRO were significantly higher than those of NSRO-A at the first- and second-instar stages, whereas at the egg, third-instar, and pupal stages, the titers of the two spiroplasmas were almost the same. Upon adult emergence, the titers of the two spiroplasmas were similar, around 2 × 108 dnaA copy equivalents. However, throughout host aging, the two spiroplasmas showed strikingly different population growth patterns. The titers of NSRO increased exponentially for 3 weeks, attained a peak value of around 4 × 109 dnaA copy equivalents per insect, and then decreased. In contrast, the titers of NSRO-A were almost constant throughout the adult portion of the life cycle. In adult females, consequently, the titer of NSRO was significantly higher than the titer of NSRO-A except for a short period just after emergence. Although infection of adult females with NSRO resulted in almost 100% male killing, production of some male offspring was observed within 4 days after emergence when the titers of NSRO were as low as those of NSRO-A. Based on these results, we proposed a threshold density hypothesis for the expression of male killing caused by the spiroplasma. The extents of the bottleneck in the vertical transmission through host generations were estimated to be 5 × 10−5 for NSRO and 3 × 10−4 for NSRO-A.

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Phenotype and transmission efficiency of artificial and natural male-killing Spiroplasma infections in Drosophila melanogaster

Journal of Invertebrate Pathology ◽

10.1016/j.jip.2011.10.003 ◽

2012 ◽

Vol 109 (2) ◽

pp. 243-247 ◽

Cited By ~ 6

Author(s):

Kate J. Hutchence ◽

Rémi Padé ◽

Heather L. Swift ◽

Daimark Bennett ◽

Gregory D.D. Hurst

Keyword(s):

Drosophila Melanogaster ◽

Transmission Efficiency ◽

Male Killing

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Factors affecting the phenology of the first brood of the sugar-cane froghopper Aeneolamia varia saccharina (Dist.) (Homoptera, Cercopidae) in Trinidad

Bulletin of Entomological Research ◽

10.1017/s0007485300006027 ◽

1975 ◽

Vol 65 (3) ◽

pp. 359-372 ◽

Cited By ~ 1

Author(s):

A. B. S. King

Keyword(s):

Adult Emergence ◽

Dry Season ◽

Soil Conditions ◽

Factors Affecting ◽

Expected Time ◽

Short Period ◽

Incubation Periods ◽

Close Relationship ◽

Dry Soil ◽

Predictive Relationship

AbstractThe size and occurrence of the first brood of adults of Aeneolamia varia saccharina (Dist.) are examined in relation to the pattern of egg eclosion and rainfall. The proportion of eggs hatching within a month of oviposition in the laboratory (short-period eggs) decreased from over 90% in August to less than 20% in January, but the incubation periods of the remaining, long-period eggs were longest in those laid during October and November. The overall hatching distributions tended to be bimodal with most eggs hatching during the early months of the year under moist conditions at 26°C. Dry soil conditions delay eclosion, and eggs obtained from fields during the dry season and then incubated under moist conditions tended to hatch at the normally expected time of the first rains in May. The numbers of eggs expected to produce the first brood, computed from laboratory hatching data and estimates of the numbers and fecundities of froghoppers during the second, third and fourth broods, were less than the actual numbers sampled just before the first rains. There was a close relationship between the first rainfall of over one inch within 48 h and adult emergence 27 and 34 days later, and 85% of field egg populations in May had hatched and/or died by the week after the first rains. However some variation in the date of their occurrence accounted for non-synchrony of first broods over the region. The numbers of diapause eggs in fields sampled during the dry season failed to give a good predictive relationship with first brood adult populations, probably because of density dependent mortality of eggs or hatchling nymphs.

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Dynamics of the abundance of cuckoo wasps (Hymenoptera, Chrysididae) in the conditions of the altitudinal-belt heterogeneity of the North Caucasus

BIO Web of Conferences ◽

10.1051/bioconf/20213500023 ◽

2021 ◽

Vol 35 ◽

pp. 00023

Author(s):

Nikolay Vinokurov

Keyword(s):

Population Dynamics ◽

New Species ◽

Weather Conditions ◽

Nature Management ◽

North Caucasus ◽

Protection Measures ◽

Altitudinal Belt ◽

The North ◽

Short Period ◽

First Time

The work provides data on the dynamics of the abundance of 205 taxa from 19 genera: Cleptes, Colpopyga, Elampus, Omalus, Philoctetes, Pseudomalus, Hedychridium, Hedychrum, Holopyga, Chrysidea, Chrysis, Euchroeus, Chrysura, Pseudochrysis, Spinolia, Spinolia, including species rare and new for the fauna of the North Caucasus and Russia. By the nature of the population dynamics, five groups of cuckoo wasps were identified: spring – represented by 7 species from 4 genera; spring-summer – 76 species from 10 genera; summer – 113 species from 16 genera; summer-autumn – 4 species from 2 genera and spring-summer-autumn – 5 species from 3 genus. According to the duration of flight, eurychronous species of cuckoo wasps were identified, which are found throughout the season from spring to autumn; mesochronous – the years of which affect the end of May and summer months and stenochronous – confined to a short period of time. Eurychronic accounted for 2.4%, mesochronous 24.9%, stenochronic 72.7%. The number of generations of cuckoo wasps is related to the dynamics of the number of the host. In the mountains, the peaks of activity shift towards the middle of summer, most species have one peak of activity; due to the frequent changes in weather conditions in the mountains, the phenological characteristics of the cuckoo wasps and their hosts do not coincide in terms with the lowland populations and the periods of activity can be extended in time. Phenological characteristics of rare and new species for the fauna of the North Caucasus and Russia are presented for the first time. The data obtained expand the understanding of the biodiversity and dynamics of the abundance of cuckoo wasps in the North Caucasus and can be used for environmental protection measures and rational nature management in the south of Russia.

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Prenatal Exposure to Dexamethasone in the Mouse Alters Cardiac Growth Patterns and Increases Pulse Pressure in Aged Male Offspring

PLoS ONE ◽

10.1371/journal.pone.0069149 ◽

2013 ◽

Vol 8 (7) ◽

pp. e69149 ◽

Cited By ~ 27

Author(s):

Lee O'Sullivan ◽

James S. M. Cuffe ◽

Tamara M. Paravicini ◽

Sally Campbell ◽

Hayley Dickinson ◽

...

Keyword(s):

Prenatal Exposure ◽

Pulse Pressure ◽

Growth Patterns ◽

Male Offspring ◽

Cardiac Growth

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The Transplantation of Ovaries between Genetically Sterile and Wild Type Drosophila melanogaste

Zeitschrift für Naturforschung B ◽

10.1515/znb-1965-0404 ◽

1965 ◽

Vol 20 (4) ◽

pp. 292-297 ◽

Cited By ~ 38

Author(s):

Robert C. King ◽

Dietrich Bodenstein

Keyword(s):

Drosophila Melanogaster ◽

Body Cavity ◽

Ovarian Tumors ◽

Wild Type ◽

Adult Females ◽

Recessive Genes ◽

Initiating Factors ◽

Adult Drosophila ◽

Do So ◽

Drosophila Melanogaste

Ovarian tumors are characteristically found in adult Drosophila melanogaster females homozygous for certain recessive genes (fes, nw and fu). Ovaries genetically destined to become tumorous do so even when they are transplanted to a normal abdomen. Normal ovaries transplanted to the abdomen of females homozygous for such tumor genes do not become tumorous. Therefore there is no evidence for diffusible tumorigenic agents as initiating factors in the development of the ovarian tumors characteristic of females homozygous for fes, nw or fu. Vitellogenesis is retarded in adult females homozygous for certain recessive genes (fs 2.1, ty and ap4). Transplantation of ovaries from homozygous females to the abdominal body cavity of females carrying the + alleles of the gene in question fails to cure the implant in the case of fs 2.1 and ty. Ovaries of ap4/ap4 genotype produce abundant yolk when implanted into wild type abdomens. Thus it is the abdominal environment of ap4 which is at fault, rather than a malfunctioning of the ovary.

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QUANTITATIVE ASSESSMENT OF ANISOCOTYLY IN HABERLEA RHODOPENSIS AND RAMONDA MYCONI

Edinburgh Journal of Botany ◽

10.1017/s0960428619000179 ◽

2019 ◽

Vol 76 (3) ◽

pp. 377-391

Author(s):

B.-H. Huang ◽

K. Nishii ◽

C.-N. Wang ◽

M. Möller

Keyword(s):

Quantitative Assessment ◽

New World ◽

Growth Patterns ◽

World Species ◽

Old World ◽

Haberlea Rhodopensis ◽

Short Period ◽

Irregular Growth ◽

Basal Meristem ◽

Ramonda Myconi

Anisocotyly, the unequal development of cotyledons post germination, is a unique trait observed only in Old World Gesneriaceae (Lamiales). New World Gesneriaceae have isocotylous seedlings. In both Old and New World Gesneriaceae, cotyledons initially grow equally for a short period just after germination. In the New World species, both cotyledons cease their growth at the same time early on, whereas in Old World species one cotyledon continues to expand to become a macrocotyledon while the other withers away. In this study, cotyledon growth was observed in two European Old World Gesneriaceae: Haberlea rhodopensis and Ramonda myconi. The results were compared with those for the typical anisocotylous species Streptocarpus rexii and the typical isocotylous species Corytoplectus speciosus. We found that the cotyledon growth patterns in Haberlea rhodopensis and Ramonda myconi were intermediate between the typical anisocotylous or isocotylous species. Haberlea rhodopensis and Ramonda myconi showed irregular growth patterns, with some plants being slightly anisocotylous but most being isocotylous. The developmental basis for the residual anisocotyly, the extended basal meristem activity in the macrocotyledon, appeared to be identical in the European species to that in the typical Old World Streptocarpus rexii but weakly expressed, rare and terminated early. In conclusion, European Gesneriaceae retain a reduced anisocotylous growth that may be linked to their early plumule development.

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Transgenic Testing Does Not Support a Role for Additional Candidate Genes in Wolbachia Male Killing or Cytoplasmic Incompatibility

mSystems ◽

10.1128/msystems.00658-19 ◽

2020 ◽

Vol 5 (1) ◽

Author(s):

Jessamyn I. Perlmutter ◽

Jane E. Meyers ◽

Seth R. Bordenstein

Keyword(s):

Drosophila Melanogaster ◽

Copy Number ◽

Cytoplasmic Incompatibility ◽

Functional Study ◽

Content Type ◽

Transgenic Expression ◽

Additional Gene ◽

Reproductive Parasitism ◽

Transcript Length ◽

Male Killing

ABSTRACT Endosymbiotic bacteria in the genus Wolbachia remarkably infect nearly half of all arthropod species. They spread in part because of manipulations of host sexual reproduction that enhance the maternal transmission of the bacteria, including male killing (death of infected males) and unidirectional cytoplasmic incompatibility (CI; death of offspring from infected fathers and uninfected mothers). Recent discoveries identified several genes in prophage WO of Wolbachia (wmk, cifA, and cifB) that fully or partially recapitulate male killing or CI when transgenically expressed in Drosophila melanogaster. However, it is not yet fully resolved if other gene candidates contribute to these phenotypes. Here, we transgenically tested 10 additional gene candidates for their involvement in male killing and/or CI. The results show that despite sequence and protein architecture similarities or comparative associations with reproductive parasitism, transgenic expression of the candidates does not recapitulate male killing or CI. Sequence analysis across Wmk and its closest relatives reveals amino acids that may be important to its function. In addition, evidence is presented to propose new hypotheses regarding the relationship between wmk transcript length and its ability to kill a given host, as well as copy number of wmk homologs within a bacterial strain, which may be predictive of host resistance. Together, these analyses continue to build the evidence for identification of wmk, cifA, and cifB as the major genes that have thus far been shown to cause reproductive parasitism in Wolbachia, and the transgenic resources provide a basis for further functional study of phage WO genes. IMPORTANCE Wolbachia are widespread bacterial endosymbionts that manipulate the reproduction of diverse arthropods to spread through a population and can substantially shape host evolution. Recently, reports identified three prophage WO genes (wmk, cifA, and cifB) that transgenically recapitulate many aspects of reproductive manipulation in Drosophila melanogaster. Here, we transgenically tested 10 additional gene candidates for CI and/or male killing in flies. The results yield no evidence for the involvement of these gene candidates in reproductive parasitism, bolstering the evidence for identification of the cif and wmk genes as the major factors involved in their phenotypes. In addition, evidence supports new hypotheses for prediction of male-killing phenotypes or lack thereof based on wmk transcript length and copy number. These experiments inform efforts to understand the full basis of reproductive parasitism for basic and applied purposes and lay the foundation for future work on the function of an interesting group of Wolbachia and phage WO genes.

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The distribution of transposable elements within and between chromosomes in a population of Drosophila melanogaster. I. Element frequencies and distribution

Genetics Research ◽

10.1017/s0016672300030792 ◽

1992 ◽

Vol 60 (2) ◽

pp. 103-114 ◽

Cited By ~ 65

Author(s):

Brian Charlesworth ◽

Angela Lapid ◽

Darlene Canada

Keyword(s):

Population Dynamics ◽

Drosophila Melanogaster ◽

Linkage Disequilibrium ◽

Transposable Elements ◽

Copy Number ◽

Polytene Chromosomes ◽

Chromosome Band ◽

High Frequencies ◽

Copy Numbers

SummaryData were collected on the distribution of nine families of transposable elements among second and third chromosomes isolated from a natural population of Drosophila melanogaster, by means of in situ hybridization of element probes to polytene chromosomes. It was found that the copy numbers per chromosome in the distal sections of the chromosome arms followed a Poisson distribution. Elements appeared to be distributed randomly along the distal sections of the chromosome arms. There was no evidence for linkage disequilibrium in the distal sections of the chromosomes, but some significant disequilibrium was detected in proximal regions. There were many significant correlations between different element families with respect to the identity of the sites that were occupied in the sample. There were also significant correlations between families with respect to sites at which elements achieved relatively high frequencies. Element frequencies per chromosome band were generally low in the distal sections, but were higher proximally. These results are discussed in the light of models of the population dynamics of transposable elements. It is concluded that they provide strong evidence for the operation of a force or forces opposing transpositional increase in copy number. The data suggest that the rate of transposition perelement per generation is of the order of 10−4, for the elements included in this study.

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