-
Proceedings. Biological Sciences Mar 2023Parthenogenesis has been documented in almost every phylum of animals, and yet this phenomenon is largely understudied. It has particular importance in dipterans since... (Review)
Review
Parthenogenesis has been documented in almost every phylum of animals, and yet this phenomenon is largely understudied. It has particular importance in dipterans since some parthenogenetic species are also disease vectors and agricultural pests. Here, we present a catalogue of parthenogenetic dipterans, although it is likely that many more remain to be identified, and we discuss how their developmental biology and interactions with diverse environments may be linked to different types of parthenogenetic reproduction. We discuss how the advances in genetics and genomics have identified chromosomal loci associated with parthenogenesis. In particular, a polygenic cause of facultative parthenogenesis has been uncovered in allowing the corresponding genetic variants to be tested for their ability to promote parthenogenesis in another species, . This study probably identifies just one of many routes that could be followed in the evolution of parthenogenesis. We attempt to account for why the phenomenon has evolved so many times in the dipteran order and why facultative parthenogenesis appears particularly prevalent. We also discuss the significance of coarse genomic changes, including non-disjunction, aneuploidy, and polyploidy and how, together with changes to specific genes, these might relate to both facultative and obligate parthenogenesis in dipterans and other parthenogenetic animals.
Topics: Animals; Drosophila melanogaster; Reproduction; Drosophila; Parthenogenesis; Agriculture
PubMed: 36946111
DOI: 10.1098/rspb.2023.0261 -
Biology Letters May 2021Parthenogenesis is rare in nature. With 39 described true parthenogens, scaled reptiles (Squamata) are the only vertebrates that evolved this reproductive strategy....
Parthenogenesis is rare in nature. With 39 described true parthenogens, scaled reptiles (Squamata) are the only vertebrates that evolved this reproductive strategy. Parthenogenesis is ecologically advantageous in the short term, but the young age and rarity of parthenogenetic species indicate it is less advantageous in the long term. This suggests parthenogenesis is self-destructive: it arises often but is lost due to increased extinction rates, high rates of reversal or both. However, this role of parthenogenesis as a self-destructive trait remains unknown. We used a phylogeny of Squamata (5388 species), tree metrics, null simulations and macroevolutionary scenarios of trait diversification to address the factors that best explain the rarity of parthenogenetic species. We show that parthenogenesis can be considered as self-destructive, with high extinction rates mainly responsible for its rarity in nature. Since these parthenogenetic species occur, this trait should be ecologically relevant in the short term.
Topics: Animals; Lizards; Parthenogenesis; Phenotype; Phylogeny; Reproduction
PubMed: 33975486
DOI: 10.1098/rsbl.2021.0006 -
The Journal of Heredity Dec 2021Parthenogenesis is a relatively rare event in birds, documented in unfertilized eggs from columbid, galliform, and passerine females with no access to males. In the...
Parthenogenesis is a relatively rare event in birds, documented in unfertilized eggs from columbid, galliform, and passerine females with no access to males. In the critically endangered California condor, parentage analysis conducted utilizing polymorphic microsatellite loci has identified two instances of parthenogenetic development from the eggs of two females in the captive breeding program, each continuously housed with a reproductively capable male with whom they had produced offspring. Paternal genetic contribution to the two chicks was excluded. Both parthenotes possessed the expected male ZZ sex chromosomes and were homozygous for all evaluated markers inherited from their dams. These findings represent the first molecular marker-based identification of facultative parthenogenesis in an avian species, notably of females in regular contact with fertile males, and add to the phylogenetic breadth of vertebrate taxa documented to have reproduced via asexual reproduction.
Topics: Female; Fertility; Homozygote; Humans; Male; Parthenogenesis; Phylogeny
PubMed: 34718632
DOI: 10.1093/jhered/esab052 -
Annual Review of Entomology 2013Female parthenogenesis, or thelytoky, is particularly common in solitary Hymenoptera. Only more recently has it become clear that many eusocial species also regularly... (Review)
Review
Female parthenogenesis, or thelytoky, is particularly common in solitary Hymenoptera. Only more recently has it become clear that many eusocial species also regularly reproduce thelytokously, and here we provide a comprehensive overview. Especially in ants, thelytoky underlies a variety of idiosyncratic life histories with unique evolutionary and ecological consequences. In all eusocial species studied, thelytoky probably has a nuclear genetic basis and the underlying cytological mechanism retains high levels of heterozygosity. This is in striking contrast to many solitary wasps, in which thelytoky is often induced by cytoplasmic bacteria and results in an immediate loss of heterozygosity. These differences are likely related to differences in haplodiploid sex determination mechanisms, which in eusocial species usually require heterozygosity for female development. At the same time, haplodiploidy might account for important preadaptations that can help explain the apparent ease with which Hymenoptera transition between sexual and asexual reproduction.
Topics: Animals; Apomixis; Biological Evolution; Hymenoptera; Parthenogenesis
PubMed: 23072461
DOI: 10.1146/annurev-ento-120811-153710 -
Philosophical Transactions of the Royal... Oct 2016Theory predicts that sexual reproduction is difficult to maintain if asexuality is an option, yet sex is very common. To understand why, it is important to pay attention... (Review)
Review
Theory predicts that sexual reproduction is difficult to maintain if asexuality is an option, yet sex is very common. To understand why, it is important to pay attention to repeatably occurring conditions that favour transitions to, or persistence of, asexuality. Geographic parthenogenesis is a term that has been applied to describe a large variety of patterns where sexual and related asexual forms differ in their geographic distribution. Often asexuality is stated to occur in a habitat that is, in some sense, marginal, but the interpretation differs across studies: parthenogens might not only predominate near the margin of the sexuals' distribution, but might also extend far beyond the sexual range; they may be disproportionately found in newly colonizable areas (e.g. areas previously glaciated), or in habitats where abiotic selection pressures are relatively stronger than biotic ones (e.g. cold, dry). Here, we review the various patterns proposed in the literature, the hypotheses put forward to explain them, and the assumptions they rely on. Surprisingly, few mathematical models consider geographic parthenogenesis as their focal question, but all models for the evolution of sex could be evaluated in this framework if the (often ecological) causal factors vary predictably with geography. We also recommend broadening the taxa studied beyond the traditional favourites.This article is part of the themed issue 'Weird sex: the underappreciated diversity of sexual reproduction'.
Topics: Biological Evolution; Geography; Life History Traits; Parthenogenesis; Reproduction; Sex
PubMed: 27619701
DOI: 10.1098/rstb.2015.0538 -
Heredity Feb 2022Investigating the origin of parthenogenesis through interspecific hybridization can provide insight into how meiosis may be altered by genetic incompatibilities, which...
Investigating the origin of parthenogenesis through interspecific hybridization can provide insight into how meiosis may be altered by genetic incompatibilities, which is fundamental for our understanding of the formation of reproductive barriers. Yet the genetic mechanisms giving rise to obligate parthenogenesis in eukaryotes remain understudied. In the microcrustacean Daphnia pulex species complex, obligately parthenogenetic (OP) isolates emerged as backcrosses of two cyclically parthenogenetic (CP) parental species, D. pulex and D. pulicaria, two closely related but ecologically distinct species. We examine the genome-wide expression in OP females at the early resting egg production stage, a life-history stage distinguishing OP and CP reproductive strategies, in comparison to CP females of the same stage from the two parental species. Our analyses of the expression data reveal that underdominant and overdominant genes are abundant in OP isolates, suggesting widespread regulatory incompatibilities between the parental species. More importantly, underdominant genes (i.e., genes with expression lower than both parentals) in the OP isolates are enriched in meiosis and cell-cycle pathways, indicating an important role of underdominance in the origin of obligate parthenogenesis. Furthermore, metabolic and biosynthesis pathways enriched with overdominant genes (i.e., expression higher than both parentals) are another genomic signature of OP isolates.
Topics: Animals; Daphnia; Female; Hybridization, Genetic; Meiosis; Parthenogenesis; Transcriptome
PubMed: 35039663
DOI: 10.1038/s41437-022-00498-1 -
Science (New York, N.Y.) Jun 2022The rarity of parthenogenetic species is typically attributed to the reduced genetic variability that accompanies the absence of sex, yet natural parthenogens can be...
The rarity of parthenogenetic species is typically attributed to the reduced genetic variability that accompanies the absence of sex, yet natural parthenogens can be surprisingly successful. Ecological success is often proposed to derive from hybridization through enhanced genetic diversity from repetitive origins or enhanced phenotypic breadth from heterosis. Here, we tested and rejected both hypotheses in a classic parthenogen, the diploid grasshopper . Genetic data revealed a single hybrid mating origin at least 0.25 million years ago, and comparative analyses of 14 physiological and life history traits showed no evidence for altered fitness relative to its sexual progenitors. Our findings imply that the rarity of parthenogenesis is due to constraints on origin rather than to rapid extinction.
Topics: Animals; Biological Evolution; Chimera; Diploidy; Grasshoppers; Hybridization, Genetic; Parthenogenesis
PubMed: 35653484
DOI: 10.1126/science.abm1072 -
Sexual Development : Genetics,... 2008Parthenogenesis, the development of an embryo from a female gamete without any contribution of a male gamete, is very rare in vertebrates. Parthenogenetically... (Review)
Review
Parthenogenesis, the development of an embryo from a female gamete without any contribution of a male gamete, is very rare in vertebrates. Parthenogenetically reproducing species have, so far, only been found in the Squamate reptiles (lizards and snakes). Facultative parthenogenesis, switching between sexual and clonal reproduction, although quite common in invertebrates, e.g. Daphnia and aphids, seems to be even rarer in vertebrates. However, isolated cases of parthenogenetic development have been reported in all vertebrate groups. Facultative parthenogenesis in vertebrates has only been found in captive animals but might simply have been overlooked in natural populations. Even though its evolutionary impact is hard to determine and very likely varies depending on the ploidy restoration mechanisms and sex-determining mechanisms involved, facultative parthenogenesis is already discussed in conservation biology and medical research. To raise interest for facultative parthenogenesis especially in evolutionary biology, I summarize the current knowledge about facultative parthenogenesis in the different vertebrate groups, introduce mechanisms of diploid oocyte formation and discuss the genetic consequences and potential evolutionary impact of facultative parthenogenesis in vertebrates.
Topics: Animals; Biological Evolution; Female; Male; Parthenogenesis; Reproduction; Vertebrates
PubMed: 19276631
DOI: 10.1159/000195678 -
The Journal of Heredity May 2022
Topics: Animals; Endangered Species; Genetic Variation; Parthenogenesis
PubMed: 35575075
DOI: 10.1093/jhered/esac003 -
Current Opinion in Insect Science Apr 2023Endosymbionts are maternally transmitted, and therefore benefit from maximizing female offspring numbers. Parthenogenesis-induction (PI) is the most effective type of... (Review)
Review
Endosymbionts are maternally transmitted, and therefore benefit from maximizing female offspring numbers. Parthenogenesis-induction (PI) is the most effective type of manipulation for transmission, but has solely been detected in haplodiploid species, whereas cytoplasmic incompatibility (CI) is detected frequently across the arthropod phylum, including haplodiploids. This puzzling observation led us to hypothesize that the molecular sex-determination mechanism of the haplodiploid host may be a constraining factor in the ability of endosymbionts to induce parthenogenesis. Recent insights indicate that PI-endosymbionts may be able to directly manipulate sex-determination genes to induce the necessary steps required for PI in haplodiploids. However, sex-determination cascades vary extensively, so PI-induction would require a specialized and host-dependent tool set. Contrastingly, CI-related genes target conserved cell-cycle mechanisms, are located on mobile elements, and spread easily. Finally, endosymbiont-manipulations may have a strong impact on the effectiveness of haplodiploid biocontrol agents, but can also be used to enhance their efficacy.
Topics: Animals; Female; Parthenogenesis; Wolbachia; Arthropods; Sex Determination Processes
PubMed: 36958587
DOI: 10.1016/j.cois.2023.101023