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Current Biology : CB Apr 2023Wang and Underwood introduce apomixis in plants.
Wang and Underwood introduce apomixis in plants.
Topics: Apomixis; Plants; Seeds
PubMed: 37098328
DOI: 10.1016/j.cub.2023.01.051 -
Journal of Experimental Botany Aug 2023The word 'fruit' is derived from the latin 'fructus' which itself is said to be derived from 'frui', which means to enjoy. Along those lines, I hope this year's...
The word 'fruit' is derived from the latin 'fructus' which itself is said to be derived from 'frui', which means to enjoy. Along those lines, I hope this year's Flowering Newsletter brings a lot of joy, because fruits and seeds feature in multiple articles.
Topics: Apomixis; Seeds; Fruit
PubMed: 37419454
DOI: 10.1093/jxb/erad258 -
Ecology and Evolution Jul 2022Sex is evolutionarily more costly than parthenogenesis, evolutionary ecologists therefore wonder why sex is much more frequent than parthenogenesis in the majority of...
Sex is evolutionarily more costly than parthenogenesis, evolutionary ecologists therefore wonder why sex is much more frequent than parthenogenesis in the majority of animal lineages. Intriguingly, parthenogenetic individuals and species are as common as or even more common than sexuals in some major and putative ancient animal lineages such as oribatid mites and rotifers. Here, we analyzed oribatid mites (Acari: Oribatida) as a model group because these mites are ancient (early Paleozoic), widely distributed around the globe, and include a high number of parthenogenetic species, which often co-exist with sexual oribatid mite species. There is evidence that the reproductive mode is phylogenetically conserved in oribatid mites, which makes them an ideal model to test hypotheses on the relationship between reproductive mode and species' ecological strategies. We used oribatid mites to test the frozen niche variation hypothesis; we hypothesized that parthenogenetic oribatid mites occupy narrow specialized ecological niches. We used the geographic range of species as a proxy for specialization as specialized species typically do have narrower geographic ranges than generalistic species. After correcting for phylogenetic signal in reproductive mode and demonstrating that geographic range size has no phylogenetic signal, we found that parthenogenetic lineages have a higher probability to have broader geographic ranges than sexual species arguing against the frozen niche variation hypothesis. Rather, the results suggest that parthenogenetic oribatid mite species are more generalistic than sexual species supporting the general-purpose genotype hypothesis. The reason why parthenogenetic oribatid mite species are generalists with wide geographic range sizes might be that they are of ancient origin reflecting that they adapted to varying environmental conditions during evolutionary history. Overall, our findings indicate that parthenogenetic oribatid mite species possess a widely adapted general-purpose genotype and therefore might be viewed as "Jack-of-all-trades."
PubMed: 35784052
DOI: 10.1002/ece3.9036 -
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 -
Frontiers in Cell and Developmental... 2022Gametogenesis, the production of eggs and sperm, is a fundamental process in sexually reproducing animals. Following gametogenesis commitment and sexual fate decision,...
Gametogenesis, the production of eggs and sperm, is a fundamental process in sexually reproducing animals. Following gametogenesis commitment and sexual fate decision, germ cells undergo several developmental processes to halve their genomic size and acquire sex-specific characteristics of gametes, including cellular size, motility, and cell polarity. However, it remains unclear how different gametogenesis processes are initially integrated. With the advantages of the teleost fish medaka (), in which germline stem cells continuously produce eggs and sperm in mature gonads and a sexual switch gene in germ cells is identified, we found that distinct pathways initiate gametogenesis cooperatively after commitment to gametogenesis. This evokes the concept of functional modules, in which functionally interlocked genes are grouped to yield distinct gamete characteristics. The various combinations of modules may allow us to explain the evolution of diverse reproductive systems, such as parthenogenesis and hermaphroditism.
PubMed: 35693939
DOI: 10.3389/fcell.2022.914570 -
Evolution & Development Jan 2020The absence of a paternal contribution in an unfertilized ovum presents two developmental constraints against the evolution of parthenogenesis. We discuss the constraint...
The absence of a paternal contribution in an unfertilized ovum presents two developmental constraints against the evolution of parthenogenesis. We discuss the constraint caused by the absence of a centrosome and the one caused by the missing set of chromosomes and how they have been broken in specific taxa. They are examples of only a few well-underpinned examples of developmental constraints acting at macro-evolutionary scales in animals. Breaking of the constraint of the missing chromosomes is the best understood and generally involves rare occasions of drastic changes of meiosis. These drastic changes can be best explained by having been induced, or at least facilitated, by sudden cytological events (e.g., repeated rounds of hybridization, endosymbiont infections, and contagious infections). Once the genetic and developmental machinery is in place for regular or obligate parthenogenesis, shifts to other types of parthenogenesis can apparently rather easily evolve, for example, from facultative to obligate parthenogenesis, or from pseudoarrhenotoky to haplodiploidy. We argue that the combination of the two developmental constraints forms a near-absolute barrier against the gradual evolution from sporadic to obligate or regular facultative parthenogenesis, which can probably explain why the occurrence of the highly advantageous mode of regular facultative parthenogenesis is so rare and entirely absent in vertebrates.
Topics: Animals; Biological Evolution; Invertebrates; Parthenogenesis; Vertebrates
PubMed: 31622546
DOI: 10.1111/ede.12324 -
Biology of Reproduction Jul 2022Haploid embryonic stem cells are embryonic stem cells of a special type. Their nuclei contain one complete set of genetic material, and they are capable of self-renewal... (Review)
Review
Haploid embryonic stem cells are embryonic stem cells of a special type. Their nuclei contain one complete set of genetic material, and they are capable of self-renewal and differentiation. The emergence of haploid embryonic stem cells has aided research in functional genomics, genetic imprinting, parthenogenesis, genetic screening, and somatic cell nuclear transfer. This article reviews current issues in haploid stem cell research based on reports published in recent years and assesses the potential applications of these cells in somatic cell nuclear transfer, genome imprinting, and parthenogenesis.
Topics: Cell Differentiation; Embryonic Stem Cells; Haploidy; Parthenogenesis; Stem Cell Research
PubMed: 35639627
DOI: 10.1093/biolre/ioac110 -
Genes Apr 2021Sexual reproduction in plants is a complex, stringently regulated process that leads to the creation of diaspores for a new generation: sexual seeds [...].
Sexual reproduction in plants is a complex, stringently regulated process that leads to the creation of diaspores for a new generation: sexual seeds [...].
Topics: Apomixis; Gene Expression Regulation, Plant; Plant Physiological Phenomena; Plant Proteins; Plants
PubMed: 33923377
DOI: 10.3390/genes12040576 -
Cells Sep 2021Recently, it was pointed out that classic models for the evolution of anisogamy do not take into account the possibility of parthenogenetic reproduction, even though sex...
Recently, it was pointed out that classic models for the evolution of anisogamy do not take into account the possibility of parthenogenetic reproduction, even though sex is facultative in many relevant taxa (e.g., algae) that harbour both anisogamous and isogamous species. Here, we complement this recent analysis with an approach where we assume that the relationship between progeny size and its survival may differ between parthenogenetically and sexually produced progeny, favouring either the former or the latter. We show that previous findings that parthenogenesis can stabilise isogamy relative to the obligate sex case, extend to our scenarios. We additionally investigate two different ways for one mating type to take over the entire population. First, parthenogenesis can lead to biased sex ratios that are sufficiently extreme that one type can displace the other, leading to de facto asexuality for the remaining type that now lacks partners to fuse with. This process involves positive feedback: microgametes, being numerous, lack opportunities for syngamy, and should they proliferate parthenogenetically, the next generation makes this asexual route even more prominent for microgametes. Second, we consider mutations to strict asexuality in producers of micro- or macrogametes, and show that the prospects of asexual invasion depend strongly on the mating type in which the mutation arises. Perhaps most interestingly, we also find scenarios in which parthenogens have an intrinsic survival advantage yet facultatively sexual isogamous populations are robust to the invasion of asexuals, despite us assuming no genetic benefits of recombination. Here, equal contribution from both mating types to zygotes that are sufficiently well provisioned can outweigh the additional costs associated with syngamy.
Topics: Biological Evolution; Gametogenesis; Germ Cells; Models, Biological; Mutation; Parthenogenesis; Phaeophyceae; Zygote
PubMed: 34572116
DOI: 10.3390/cells10092467 -
Insects Oct 2023Insects are renowned for their remarkable diversity of reproductive modes. Among these, the largest non-holometabolous order, Hemiptera, stands out with one of the most... (Review)
Review
Insects are renowned for their remarkable diversity of reproductive modes. Among these, the largest non-holometabolous order, Hemiptera, stands out with one of the most diversified arrays of parthenogenesis modes observed among insects. Although there are extensive reviews on reproduction without fertilization in some hemipteran higher taxa, no such analysis has been conducted for the large suborders Fulgoromorpha (planthoppers) and Cicadomorpha (leafhoppers). In both groups, there are species that reproduce by true parthenogenesis, specifically thelytoky, and in Fulgoromorpha, there are species that reproduce by pseudogamy or, more specifically, sperm-dependent parthenogenesis. In this review paper, we give and discuss the only currently known examples of true parthenogenesis in Fulgoromorpha and Cicadomorpha, mainly from the planthopper family Delphacidae and the leafhopper family Cicadellidae. We analyze patterns of distribution, ecology, mating behavior, acoustic communication, and cytogenetic and genetic diversity of parthenoforms and discuss hypotheses about the origin of parthenogenesis in each case. We also highlight examples in which natural populations show a shift in sex ratio toward females and discuss possible causes of this phenomenon, primarily the influence of endosymbiotic bacteria capable of altering the reproductive strategies of the hosts. Our review is mainly based on studies in which the authors have participated.
PubMed: 37887832
DOI: 10.3390/insects14100820