scholarly journals Costs and benefits of giant sperm and sperm storage organs in Drosophila melanogaster

2019 ◽  
Author(s):  
Susanne Zajitschek ◽  
Felix Zajitschek ◽  
Sarah Josway ◽  
Reem Al Shabeeb ◽  
Halli Weiner ◽  
...  
Keyword(s):  
Seminal Receptacle ◽  
Fertilization Success ◽  
Inbred Lines ◽  
Sperm Storage ◽  
Sperm Length ◽  
Costs And Benefits ◽  
Female Fitness ◽  
Storage Organ ◽  
Trade Offs ◽  
Storage Organs

ABSTRACTIn the Drosophila lineage, both sperm and the primary female sperm storage organ, the seminal receptacle (SR), may reach extraordinary lengths. In D. melanogaster, long SRs bias fertilization toward long sperm during the displacement stage of sperm competition. This sperm-SR interaction, together with a genetic correlation between the traits, suggests that the coevolution of exaggerated sperm and SR lengths may be driven by Fisherian runaway selection. To further understand the costs and benefits of long sperm and SR genotypes in both sexes, we measured male and female fitness in inbred lines of D. melanogaster derived from four populations previously selected for long sperm, short sperm, long SRs, or short SRs. We specifically asked: do long SRs impose costs or benefits on the females that bear them? Do genotypes that generate long sperm in males impose a fitness cost on females sharing those genotypes? Is long sperm an honest indicator of male viability and associated with increased fitness? And finally, are the benefits of long sperm restricted to competitive fertilization success, or do long-sperm males also have increased mating success and fecundity in single matings? We found that both sexes have increased longevity in long sperm and long SR genotypes, with fewer reproduction-related benefits and evidence for trade-offs in males, compared to females. Our results suggest that sperm length and SR length are both indicators of increased viability.

scholarly journals Quantitative genetic analysis of among-population variation in sperm and female sperm-storage organ length in Drosophila mojavensis

2003 ◽  
Vol 81 (3) ◽  
pp. 213-220 ◽  
Author(s):  
GARY T. MILLER ◽  
WILLIAM T. STARMER ◽  
SCOTT PITNICK
Keyword(s):  
Genetic Analysis ◽  
Seminal Receptacle ◽  
Sperm Storage ◽  
Population Variation ◽  
Sperm Length ◽  
Drosophila Mojavensis ◽  
Storage Organ ◽  
Quantitative Genetic ◽  
Y Chromosomes ◽  
Quantitative Genetic Analysis

In Drosophila, sperm length and the length of the females' primary sperm-storage organ have rapidly coevolved through post-copulatory sexual selection. This pattern is evident even among geographic populations of Drosophila mojavensis. To understand better these traits of potential importance for speciation, we performed quantitative genetic analysis of both seminal receptacle length and sperm length in two divergent populations. Parental strains, F1, F1 reciprocal (F1r), F2, F2r, backcross and backcross reciprocal generations were used in a line-cross (generation means) analysis. Seminal receptacle length is largely an autosomal additive trait, whereas additivity, dominance and epistasis all contributed to the means of sperm length. Either an X-chromosome or a Y-chromosome effect was necessary for models of sperm length to be significant. However, the overall contributions from the X and Y chromosomes to sperm length was small.

scholarly journals Functional morphology of immature mating in a widow spider

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Lenka Sentenská ◽  
Aileen Neumann ◽  
Yael Lubin ◽  
Gabriele Uhl
Keyword(s):  
Sperm Competition ◽  
Storage Conditions ◽  
Sperm Storage ◽  
Sperm Transfer ◽  
Costs And Benefits ◽  
Micro Computed Tomography ◽  
Mating Tactics ◽  
Adult Females ◽  
Storage Organs ◽  
Widow Spider

Abstract Background Mating generally occurs after individuals reach adulthood. In many arthropods including spiders, the adult stage is marked by a final moult after which the genitalia are fully developed and functional. In several widow spider species (genus Latrodectus), however, immature females may mate a few days before they moult to adulthood, i.e. in their late-subadult stage. While the “adult” mating typically results in cannibalism, males survive the “immature” mating. During both “immature” and “adult” matings, males leave parts of their paired copulatory organs within female genitalia, which may act as mating plugs. To study potential costs and benefits of the two mating tactics, we investigated female genital morphology of the brown widow spider, L. geometricus. Light microscopy, histology and micro-computed tomography of early-subadult, late-subadult and adult females were conducted to determine the overall pattern of genital maturation. We compared genitalia of mated late-subadult and adult females to reveal potential differences in the genitalic details that might indicate differential success in sperm transfer and different environments for sperm storage and sperm competition. Results We found that the paired sperm storage organs (spermathecae) and copulatory ducts are developed already in late-subadult females and host sperm after immature mating. However, the thickness of the spermathecal cuticle and the staining of the secretions inside differ significantly between the late-subadult and adult females. In late-subadult females mating plugs were found with higher probability in both spermathecae compared to adult females. Conclusions Sperm transfer in matings with late-subadult females follows the same route as in matings with adult females. The observed differences in the secretions inside the spermathecae of adult and late-subadult females likely reflect different storage conditions for the transferred sperm which may lead to a disadvantage under sperm competition if the subadult female later re-mates with another male. However, since males mating with late-subadult females typically transfer sperm to both spermathecae they might benefit from numerical sperm competition as well as from monopolizing access to the female sperm storage organs. The assessment of re-mating probability and relative paternity will clarify the costs and benefits of the two mating tactics in light of these findings.

No fitness consequence of experimentally induced polyandry in a monandrous wasp

Behaviour ◽  
2010 ◽  
Vol 147 (1) ◽  
pp. 85-102 ◽  
Author(s):  
◽  
Keyword(s):  
General Feature ◽  
Multiple Mating ◽  
Parasitic Wasp ◽  
Sperm Storage ◽  
Rapid Decline ◽  
Female Fitness ◽  
Offspring Production ◽  
Spalangia Endius ◽  
Storage Organs ◽  
Fitness Consequence

AbstractTests of the effects of multiple mating by females on female fitness have been primarily with polyandrous species, where a benefit to multiple mating has usually been found. In contrast, no such benefit was found here for the parasitic wasp Spalangia endius, a highly monandrous species. Females that mated only once prior to oviposition exhibited a rapid decline in daughter production long before they died. The production of daughters, but not sons, is sexual in this species, i.e., requires sperm. Nevertheless, females with greatly decreased daughter production did not then remate. When such females were experimentally manipulated into copulating with a second male, additional sperm were stored in the females' sperm storage organs. However, this sperm increase had no significant effect on daughter production, total offspring production or longevity. There was no evidence that either immediate or delayed polyandry currently benefits females. The lack of benefit may be a general feature of highly monandrous species or a common feature of parasitic hymenopterans regardless of mating system.

Brooding and sperm storage by the deep-sea squid Bathyteuthis berryi (Cephalopoda: Decapodiformes)

2012 ◽  
Vol 92 (7) ◽  
pp. 1629-1636 ◽  
Author(s):  
Stephanie L. Bush ◽  
Hendrik J. T. Hoving ◽  
Christine L. Huffard ◽  
Bruce H. Robison ◽  
Louis D. Zeidberg
Keyword(s):  
Deep Sea ◽  
Seminal Receptacle ◽  
Submarine Canyon ◽  
Sperm Storage ◽  
Costs And Benefits ◽  
Remotely Operated Vehicles ◽  
The Family ◽  
Post Spawning ◽  
Egg Care

Squids of the family Bathyteuthidae have generally been infrequently encountered in their deep-sea habitat. Remotely operated vehicles were used to observe seven individuals in situ in the Monterey Submarine Canyon, CA, USA. One of these was a female Bathyteuthis berryi holding a sheet with approximately 360 embedded embryos. Examination of this female after collection revealed the presence of a seminal receptacle on the buccal membrane. We present some potential costs and benefits of post-spawning egg care, a strategy that is now known for two families of deep-dwelling squids, but may turn out to be more common with the increasing exploration of the deep sea.

scholarly journals Multiple sperm storage organs facilitate female control of paternity

2005 ◽  
Vol 272 (1568) ◽  
pp. 1139-1144 ◽  
Author(s):  
Lindsay S.E Snow ◽  
Maydianne C.B Andrade
Keyword(s):  
Sperm Storage ◽  
Conclusive Evidence ◽  
Sperm Precedence ◽  
Storage Organ ◽  
Use Patterns ◽  
Storage Organs ◽  
The Mean ◽  
Female Control ◽  
Latrodectus Hasselti ◽  
Normally Distributed

It has been proposed that multiple sperm storage organs (spermathecae) could allow polyandrous females to control paternity. There is little conclusive evidence for this since insemination of individual spermathecae is generally not experimentally manipulable. Here, we examined sperm use patterns in the Australian redback spider ( Latrodectus hasselti ), which has paired, independent spermathecae. We assessed paternity when two rivals were forced to inseminate a single storage organ or opposite storage organs. When males inseminated a single spermatheca, mean paternity of the female's first mate was 79.8% (median 89.4%), and 38% of first mates achieved 100% paternity. In contrast, when males inseminated opposite organs, the mean paternity of the first mate was 49.3% (median 49.9%), only 10% of males achieved complete precedence, and paternity was normally distributed, suggesting sperm mixing. Males responded to this difference by avoiding previously inseminated female reproductive tracts. Complete sperm precedence can only be achieved if females permit males to copulate with both reproductive tracts. Females often cannibalize smaller males during their first copulation, thus limiting their paternity to 50%. These data show that multiple sperm storage organs can increase female control of paternity.

scholarly journals Molecular evolutionary analysis of seminal receptacle sperm storage organ genes of Drosophila melanogaster

2010 ◽  
Vol 23 (7) ◽  
pp. 1386-1398 ◽  
Author(s):  
A. M. PROKUPEK ◽  
S.-I. EYUN ◽  
L. KO ◽  
E. N. MORIYAMA ◽  
L. G. HARSHMAN
Keyword(s):  
Drosophila Melanogaster ◽  
Seminal Receptacle ◽  
Sperm Storage ◽  
Evolutionary Analysis ◽  
Storage Organ ◽  
Molecular Evolutionary Analysis

scholarly journals Costs and benefits of giant sperm and sperm storage organs in Drosophila melanogaster

2019 ◽  
Vol 32 (11) ◽  
pp. 1300-1309 ◽  
Author(s):  
Susanne Zajitschek ◽  
Felix Zajitschek ◽  
Sarah Josway ◽  
Reem Al Shabeeb ◽  
Halli Weiner ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Sperm Storage ◽  
Costs And Benefits ◽  
Storage Organs

scholarly journals Reproductive consequences of an extra long-term sperm storage organ

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Akashdeep Dhillon ◽  
Tabashir Chowdhury ◽  
Yolanda E. Morbey ◽  
Amanda J. Moehring
Keyword(s):  
Reproductive Success ◽  
Candidate Gene ◽  
Sperm Competition ◽  
Sperm Storage ◽  
Female Fitness ◽  
Storage Organ ◽  
Empirical Tests ◽  
Reproductive Consequences

Abstract Background Sperm storage plays a key role in the reproductive success of many sexually-reproducing organisms, and the capacity of long-term sperm storage varies across species. While there are theoretical explanations for why such variation exists, to date there are no controlled empirical tests of the reproductive consequences of additional long-term sperm storage. While Dipterans ancestrally have three long-term sperm organs, known as the spermathecae, Drosophila contain only two. Results We identified a candidate gene, which we call spermathreecae (sp3), in which a disruption cause the development of three functional spermathecae rather than the usual two in Drosophila. We used this disruption to test the reproductive consequences of having an additional long-term sperm storage organ. Compared to females with two spermathecae, females with three spermathecae store a greater total number of sperm and can produce offspring a greater length of time. However, they did not produce a greater total number of offspring. Conclusions Thus, additional long-term sperm storage in insects may increase female fitness through extending the range of conditions where she produces offspring, or through increasing the quality of offspring via enhanced local sperm competition at fertilization.

The Effects of the sphragis on male and female genitalia in Acraea (Nymphalidae) butterflies

2020 ◽  
Vol 22 ◽  
Author(s):  
Shannon L Summers ◽  
Akito Y Kawahara ◽  
Ana P. S. Carvalho
Keyword(s):  
Interspecific Variation ◽  
Sperm Storage ◽  
Male Mating ◽  
Museum Collections ◽  
Storage Organ ◽  
Mating Plug ◽  
Males And Females ◽  
Comparison And Analysis ◽  
Imagej Software ◽  
Sexually Antagonistic Coevolution

Male mating plugs have been used in many species to prevent female re-mating and sperm competition. One of the most extreme examples of a mating plug is the sphragis, which is a large, complex and externalized plug found only in butterflies. This structure is found in many species in the genus Acraea (Nymphalidae) and provides an opportunity for investigation of the effects of the sphragis on the morphology of the genitalia, which is poorly understood. This study aims to understand morphological interspecific variation in the genitalia of Acraea butterflies. Using specimens from museum collections, abdomen dissections were conducted on 19 species of Acraea: 9 sphragis bearing and 10 non-sphragis bearing species. Genitalia imaging was performed for easier comparison and analysis and measurements of genitalia structures was done using ImageJ software. Some distinguishing morphological features in the females were found. The most obvious difference is the larger and more externalized copulatory opening in sphragis bearing species, with varying degrees of external projections. Females of the sphragis bearing species also tend to have a shorter ductus (the structure that connects the copulatory opening with the sperm storage organ) than those without the sphragis. These differences may be due to a sexually antagonistic coevolution between the males and females, where the females evolve larger and more difficult to plug copulatory openings and the males attempt to prevent re-mating with the sphragis.

scholarly journals The costs of standardized apprenticeship curricula for training firms

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Jürg Schweri ◽  
Manuel Aepli ◽  
Andreas Kuhn
Keyword(s):  
Regulatory Element ◽  
Recent Survey ◽  
Skills Development ◽  
Costs And Benefits ◽  
Apprenticeship Training ◽  
Training Costs ◽  
Trade Offs ◽  
Training Content ◽  
Productive Process ◽  
Productive Output

AbstractStandardized curricula define the set of skills that must be trained within a training occupation and thus are a key regulatory element of apprenticeship systems. Although clear economic rationales support the usage of such curricula, they necessarily impose costs, especially on firms that train apprentices, but do not use the full set of skills in their productive process and/or train other skills that are not covered by the curriculum. In this paper, we identify the trade-offs involved in setting up training curricula and use data from the most recent survey on the costs and benefits of apprenticeship training among Swiss firms to quantify the associated costs to training firms. On average, training firms state that they do not use 17% of the training content prescribed by the relevant curriculum, and 11% of the companies train additional skills not covered by the curriculum. We show that both kinds of misfit are associated with higher training costs and lower productive output from apprentices. This shows that the regulator imposes costs on firms in order to guarantee broad skills development for apprentices. It also cautions against overly broad curricula that may impose disproportionate costs on firms.

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