scholarly journals Asexual freshwater snails make poor mate choice decisions

2021 ◽  
Author(s):  
Sydney Stork ◽  
Joseph Jalinsky ◽  
Maurine Neiman
Keyword(s):  
New Zealand ◽  
Mate Choice ◽  
Sexual Reproduction ◽  
Asexual Reproduction ◽  
Freshwater Snail ◽  
Freshwater Snails ◽  
Choice Assay ◽  
Mating Choice ◽  
Related Trait ◽  
Over Time

Once-useful traits that no longer contribute to fitness tend to decay over time. We address whether the expression of mating-related traits that increase the fitness of sexually reproducing individuals but are likely less useful or even costly to asexual counterparts seems to exhibit decay in the latter. Potamopyrgus antipodarum is a New Zealand freshwater snail characterized by repeated transitions from sexual to asexual reproduction. The frequent coexistence of sexual and asexual lineages makes P. antipodarum an excellent model for the study of mating-related trait loss. We used a mating choice assay including sexual and asexual P. antipodarum females and conspecific (presumed better choice) vs. heterospecific (presumed worse choice) males to evaluate the loss of behavioural traits related to sexual reproduction. We found that sexual females engaged in mating behaviours with conspecific mating partners more frequently and for a greater duration than with heterospecific mating partners, while asexual females seemed to lack the ability to make a choice. These results suggest that selection acting to maintain mate choice in asexual P. antipodarum is weak or ineffective relative to sexual females and that asexual reproduction likely contributes to the evolutionary decay of behavioural traits in this system.

scholarly journals Ant queens adjust egg fertilization to benefit from both sexual and asexual reproduction

2011 ◽  
Vol 7 (4) ◽  
pp. 571-573 ◽  
Author(s):  
S. Aron ◽  
I. Timmermans ◽  
M. Pearcy
Keyword(s):  
Sexual Reproduction ◽  
Asexual Reproduction ◽  
Evolutionary Biology ◽  
Transmission Rate ◽  
Early Spring ◽  
Mating Period ◽  
Cataglyphis Cursor ◽  
Sexual And Asexual Reproduction ◽  
Over Time

An enduring problem in evolutionary biology is the near ubiquity of sexual reproduction despite the inherent cost of transmitting only half the parent's genes to progeny. Queens of some ant species circumvent this cost by using selectively both sexual reproduction and parthenogenesis: workers arise from fertilized eggs, while new queens are produced by parthenogenesis. We show that queens of the ant Cataglyphis cursor maximize the transmission rate of their genes by regulating the proportion of fertilized and parthenogenetic eggs laid over time. Parthenogenetic offspring are produced in early spring, when workers raise the brood into sexuals. After the mating period, queens lay mostly fertilized eggs that will be reared as the non-reproductive caste.

scholarly journals Male evolution under relaxed selection: Evidence for degeneration in sperm produced by male snails from asexual lineages

2019 ◽  
Author(s):  
Joseph Jalinsky ◽  
John M. Logsdon ◽  
Maurine Neiman
Keyword(s):  
New Zealand ◽  
Asexual Reproduction ◽  
Sperm Morphology ◽  
Freshwater Snail ◽  
Snail Species ◽  
Relaxed Selection ◽  
Male Function ◽  
Naturally Occurring ◽  
Male Specific ◽  
Sperm Traits

AbstractHow drastic changes in selective regimes affect trait evolution is an important open biological question. We take advantage of naturally occurring and repeated transitions from sexual to asexual reproduction in a New Zealand freshwater snail species to address how relaxed selection on male-specific traits influences sperm morphology. The occasional production of male offspring by the otherwise all-female asexual lineages allows a unique and powerful opportunity to assess the fate of sperm traits in a context where males are unnecessary. These comparisons revealed that the sperm produced by “asexual” males are markedly distinct from sexual counterparts. In particular, the asexual male sperm harbored markedly higher phenotypic variation and was much more likely to be morphologically abnormal. Together, these data suggest that transitions to asexual reproduction might be irreversible at least in part because male function is likely to be compromised. More broadly, our results are consistent with a scenario where relaxed selection translates into rapid trait degeneration.

scholarly journals Sexual conflict and the alternation of haploid and diploid generations

2006 ◽  
Vol 361 (1466) ◽  
pp. 335-343 ◽  
Author(s):  
David Haig ◽  
Amity Wilczek
Keyword(s):  
Mate Choice ◽  
Sexual Reproduction ◽  
Genomic Imprinting ◽  
Segregation Distortion ◽  
Asexual Reproduction ◽  
Sexual Conflict ◽  
Land Plants ◽  
Maternal Genome ◽  
Selective Forces ◽  
Haploid Complement

Land plants possess a multicellular diploid stage (sporophyte) that begins development while attached to a multicellular haploid progenitor (gametophyte). Although the closest algal relatives of land plants lack a multicellular sporophyte, they do produce a zygote that grows while attached to the maternal gametophyte. The diploid offspring shares one haploid set of genes with the haploid mother that supplies it with resources and a paternal haploid complement that is not shared with the mother. Sexual conflict can arise within the diploid offspring because the offspring's maternal genome will be transmitted in its entirety to all other sexual and asexual offspring that the mother may produce, but the offspring's paternally derived genes may be absent from these other offspring. Thus, the selective forces favouring the evolution of genomic imprinting may have been present from the origin of modern land plants. In bryophytes, where gametophytes are long-lived and capable of multiple bouts of asexual and sexual reproduction, we predict strong sexual conflict over allocation to sporophytes. Female gametophytes of pteridophytes produce a single sporophyte and often lack means of asexual reproduction. Therefore, sexual conflict is predicted to be attenuated. Finally, we explore similarities among models of mate choice, offspring choice and segregation distortion.

scholarly journals Asexual reproduction drives the reduction of transposable element load

2018 ◽  
Author(s):  
Jens Bast ◽  
Kamil S. Jaron ◽  
Donovan Schuseil ◽  
Denis Roze ◽  
Tanja Schwander
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transposable Element ◽  
Sexual Reproduction ◽  
Asexual Reproduction ◽  
Direct Evidence ◽  
Purifying Selection ◽  
Load Reduction ◽  
Over Time

AbstractTheory predicts that sexual reproduction can both facilitate and restrain transposable element (TE) accumulation by providing TEs with a means of spreading to all individuals in a population and facilitating TE load reduction via purifying selection. By quantifying genomic TE loads over time in experimental sexual and asexual Saccharomyces cerevisiae populations, we provide direct evidence that asexual reproduction drives a reduction of TE loads. We show, using simulations, that this reduction occurs via evolution of TE activity, most likely via increased excision rates. Thus, sex is a major driver of genomic TE loads and at the root of the success of TEs.

scholarly journals Asexual reproduction reduces transposable element load in experimental yeast populations

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Jens Bast ◽  
Kamil S Jaron ◽  
Donovan Schuseil ◽  
Denis Roze ◽  
Tanja Schwander
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transposable Element ◽  
Sexual Reproduction ◽  
Asexual Reproduction ◽  
Direct Evidence ◽  
Purifying Selection ◽  
Load Reduction ◽  
Over Time

Theory predicts that sexual reproduction can either facilitate or restrain transposable element (TE) accumulation by providing TEs with a means of spreading to all individuals in a population, versus facilitating TE load reduction via purifying selection. By quantifying genomic TE loads over time in experimental sexual and asexual Saccharomyces cerevisiae populations, we provide direct evidence that TE loads decrease rapidly under asexual reproduction. We show, using simulations, that this reduction may occur via evolution of TE activity, most likely via increased excision rates. Thus, sex is a major driver of genomic TE loads and at the root of the success of TEs.

Molecular basis of adaptive evolution of sperm motility involved in in vivo fertilization of terrestrial animals

Impact ◽  
2020 ◽  
Vol 2020 (6) ◽  
pp. 73-75
Author(s):  
Akihiko Watanabe
Keyword(s):  
Sexual Reproduction ◽  
Sperm Motility ◽  
Asexual Reproduction ◽  
Acrosome Reaction ◽  
Sperm Morphology ◽  
Adaptive Potential ◽  
Selective Pressures ◽  
The Face ◽  
Genetic Profiles

One of the unifying traits of life on this planet is reproduction, or life's ability to make copies of itself. The mode of reproduction has evolved over time, having almost certainly begun with simple asexual reproduction when the ancestral single celled organism divided into two. Since these beginnings' life has tried out numerous strategies, and perhaps one of the most important and successful has been sexual reproduction. This form of reproduction relies on the union of gametes, otherwise known as sperm and egg. Evolutionarily, sexual reproduction allows for greater adaptive potential because the genes of two unique individuals have a chance to recombine and mix in order to produce a new individual. Unlike asexual reproduction which produces genetically-identical clones of the parent individual, sex produces offspring with novel genes and combinations of genes. Therefore, in the face of new selective pressures there is a higher chance that one of these novel genetic profiles will produce an adaptation that is advantageous in the new circumstances. Dr Akihiko Watanabe is a reproductive biologist based in the Department of Biology, Faculty of Science Yamagata University in Japan, he is currently working on three research projects; a comparative study on the signalling pathways for inducing sperm motility and acrosome reaction in amphibians, the mechanism behind the adaptive modification of sperm morphology and motility, and the origin of sperm motility initiating substance (SMIS).

scholarly journals The Advantages of Segregation and the Evolution of Sex

Genetics ◽  
2003 ◽  
Vol 164 (3) ◽  
pp. 1099-1118 ◽  
Author(s):  
Sarah P Otto
Keyword(s):  
Sexual Reproduction ◽  
Asexual Reproduction ◽  
Deleterious Mutations ◽  
Evolution Of Sex ◽  
Beneficial Mutations ◽  
Selection Regime ◽  
Strong Selection ◽  
Genome Wide ◽  
Low Levels

AbstractIn diploids, sexual reproduction promotes both the segregation of alleles at the same locus and the recombination of alleles at different loci. This article is the first to investigate the possibility that sex might have evolved and been maintained to promote segregation, using a model that incorporates both a general selection regime and modifier alleles that alter an individual’s allocation to sexual vs. asexual reproduction. The fate of different modifier alleles was found to depend strongly on the strength of selection at fitness loci and on the presence of inbreeding among individuals undergoing sexual reproduction. When selection is weak and mating occurs randomly among sexually produced gametes, reductions in the occurrence of sex are favored, but the genome-wide strength of selection is extremely small. In contrast, when selection is weak and some inbreeding occurs among gametes, increased allocation to sexual reproduction is expected as long as deleterious mutations are partially recessive and/or beneficial mutations are partially dominant. Under strong selection, the conditions under which increased allocation to sex evolves are reversed. Because deleterious mutations are typically considered to be partially recessive and weakly selected and because most populations exhibit some degree of inbreeding, this model predicts that higher frequencies of sex would evolve and be maintained as a consequence of the effects of segregation. Even with low levels of inbreeding, selection is stronger on a modifier that promotes segregation than on a modifier that promotes recombination, suggesting that the benefits of segregation are more likely than the benefits of recombination to have driven the evolution of sexual reproduction in diploids.

WIDE VARIATION IN PLOIDY LEVEL AND GENOME SIZE IN A NEW ZEALAND FRESHWATER SNAIL WITH COEXISTING SEXUAL AND ASEXUAL LINEAGES

Evolution ◽  
2011 ◽  
Vol 65 (11) ◽  
pp. 3202-3216 ◽  
Author(s):  
Maurine Neiman ◽  
Dorota Paczesniak ◽  
Deanna M. Soper ◽  
Austin T. Baldwin ◽  
Gery Hehman
Keyword(s):  
New Zealand ◽  
Genome Size ◽  
Ploidy Level ◽  
Freshwater Snail

scholarly journals Influence of breeding strategy on genetic diversity of individuals

2021 ◽  
pp. 1168-1174
Author(s):  
A.A. Poroshina ◽  
◽  
D.Yu. Sherbakov ◽  
Keyword(s):  
Genetic Diversity ◽  
Computer Simulation ◽  
Molecular Evolution ◽  
Microsatellite Markers ◽  
Simulation Model ◽  
Sexual Reproduction ◽  
Asexual Reproduction ◽  
Reproductive Strategy ◽  
Breeding Strategy ◽  
Computer Simulation Model

Abstract. Using a computer simulation model, we tried to investigate how the transition from sexual reproduction to asexual reproduction will affect the population of diploid organisms with a neutral character of molecular evolution. At the same time, special attention was paid to the specificity of microsatellite markers. In this paper, we develop fast and inexpensive methods for assessing the changes in populations that occur with a change in reproductive strategy.

scholarly journals Decline in New Zealand's freshwater fish fauna: Effect of land use

2020 ◽  
Author(s):  
Michael Joy ◽  
KJ Foote ◽  
P McNie ◽  
M Piria
Keyword(s):  
New Zealand ◽  
Land Cover ◽  
Freshwater Fish ◽  
Native Species ◽  
Species Abundance ◽  
Fish Fauna ◽  
Fish Distribution ◽  
Individual Species ◽  
Freshwater Fish Fauna ◽  
Over Time

© 2019 CSIRO. The number of New Zealand's freshwater fish listed as threatened has increased since 1992 when the first New Zealand threat classification system list was compiled. In this study, temporal and land cover-related trends were analysed for data on freshwater fish distribution, comprising more than 20 000 records for the 47 years from January 1970 to January 2017 from the New Zealand Freshwater Fish Database. The analysis included individual species abundance and distribution trends, as well as an index of fish community integrity, namely the Index of Biotic Integrity (IBI). Of the 25 fish species that met the requirements for analysis to determine changes in the proportion of sites they occupied over time, 76% had negative trends (indicating declining occurrence). Of the 20 native species analysed for the proportion of sites occupied over time, 75% had negative trends; 65% of these were significant declines and more species were in decline at pasture sites than natural cover sites. The average IBI score also declined over the time period and, when analysed separately, the major land cover types revealed that the IBI declined at pasture catchment sites but not at sites with natural vegetation catchments.

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