scholarly journals Costs and benefits of mating with fertilized females in a species with first male sperm precedence

2018 ◽  
Author(s):  
Leonor R Rodrigues ◽  
Alexandre RT Figueiredo ◽  
Thomas Van Leeuwen ◽  
Isabelle Olivieri ◽  
Sara Magalhães
Keyword(s):  
Sperm Precedence ◽  
Costs And Benefits ◽  
Male Sperm ◽  
Mating Costs ◽  
Mixed Paternity ◽  
Additional Costs ◽  
Males And Females ◽  
Mating Interval ◽  
The Stability ◽  
Open Question

SummaryDifferent patterns of sperm precedence are expected to result in specific mating costs and benefits for each sex, generating different selection pressures on males and females. However, most studies concern species with mixed paternity or last male sperm precedence, neglecting species with first male sperm precedence, in which only the first mating is effective.Here, we measured costs and benefits of multiple mating for both sexes of the spider mite Tetranychus urticae. First, we assessed the stability of the sperm precedence pattern, by mating females to one, two or several males, immediately after the first mating or 24 hours later. We found complete first male precedence, independently of the mating interval and the number of matings. Females paid a cost of polyandry, as multiply-mated females laid fewer eggs than once-mated females. However, while first males had reduced survival when exposed to an intermediate number of virgin females, second males paid no additional costs by matings with several mated females. Moreover, by mating multiply with mated females, males decreased the total number of offspring sired by first males, which suggests that these matings may entail a relative benefit for second males, despite being ineffective.Our results show that complex costs and benefits may arise in males in species with first male precedence. How these costs and benefits affect the maintenance of selection for polyandry remains an open question.

scholarly journals Costs and benefits of multiple mating in a species with first‐male sperm precedence

2020 ◽  
Vol 89 (4) ◽  
pp. 1045-1054 ◽  
Author(s):  
Leonor R. Rodrigues ◽  
Alexandre R. T. Figueiredo ◽  
Thomas Van Leeuwen ◽  
Isabelle Olivieri ◽  
Sara Magalhães
Keyword(s):  
Multiple Mating ◽  
Sperm Precedence ◽  
Costs And Benefits ◽  
Male Sperm

Using FRET to Measure the Time it Takes for a Cell to Destroy a Virus

2019 ◽  
Author(s):  
Candace E. Benjamin ◽  
Zhuo Chen ◽  
Olivia Brohlin ◽  
Hamilton Lee ◽  
Stefanie Boyd ◽  
...  
Keyword(s):  
Cellular Uptake ◽  
Rhodamine B ◽  
Virus Like Particle ◽  
A Cell ◽  
Viral Nanoparticles ◽  
The Stability ◽  
Open Question ◽  
Viral Surface ◽  
Fret Pair

<div><div><div><p>The emergence of viral nanotechnology over the preceding two decades has created a number of intellectually captivating possible translational applications; however, the in vitro fate of the viral nanoparticles in cells remains an open question. Herein, we investigate the stability and lifetime of virus-like particle (VLP) Qβ - a representative and popular VLP for several applications - following cellular uptake. By exploiting the available functional handles on the viral surface, we have orthogonally installed the known FRET pair, FITC and Rhodamine B, to gain insight of the particle’s behavior in vitro. Based on these data, we believe VLPs undergo aggregation in addition to the anticipated proteolysis within a few hours of cellular uptake.</p></div></div></div>

scholarly journals A LIFE-HISTORY PERSPECTIVE ON SEXUAL SELECTION IN A POLYGAMOUS SPECIES

2019 ◽  
Author(s):  
Gao Ke ◽  
Michiel van Wijk ◽  
Zoe Clement ◽  
Martijn Egas ◽  
Astrid Groot
Keyword(s):  
Sexual Selection ◽  
Life History ◽  
Sperm Competition ◽  
Reproductive Output ◽  
Relative Fitness ◽  
Quadratic Model ◽  
Costs And Benefits ◽  
Bateman Gradient ◽  
Multiple Matings ◽  
Males And Females

Abstract Background Ever since Darwin, evolutionary biologists have studied sexual selection driving differences in appearance and behaviour between males and females. An unchallenged paradigm in such studies is that one sex (usually the male) signals its quality as a mate to the other sex (usually the female), who is choosy in accepting a partner. Here, we argue that in polygamous species these roles may change dynamically with the mating status of males and females, depending on direct reproductive costs and benefits of multiple matings, and on sperm competition. We test this hypothesis using a polygamous moth species, as in moths not males but females are the signalers and males are the responders. Results We found that multiple matings are beneficial as well as costly for both sexes. Specifically, the number of matings did not affect the longevity of males or females, but when paired with a new virgin mate every night for five nights, only 67% of the males and 14% of the females mated successfully in all five nights. The female’s reproductive output increased with multiple matings, although when paired with a new virgin male every night, additional matings beyond 3 decreased her reproductive output, so that the Bateman gradient for females fit a quadratic model better than a linear model. The male’s reproductive success was positively affected by the number of matings and a linear regression line best fit the data. Simulations of the effect of sperm competition showed that increasing last-male paternity increases the steepness of the male Bateman gradient and thus the male’s relative fitness gain from additional mating. Irrespective of last-male paternity value, the female Bateman gradient is steeper than the male one for up to three matings. Conclusion Our results suggest that choosiness in moths may well change throughout the mating season, with males being more choosy early in the season and females being more choosy after having mated at least three times. This life-history perspective on the costs and benefits of multiple matings for both sexes sheds new light on sexual selection forces acting on sexual signals and responses.

scholarly journals Serial monogamy benefits both sexes in the biparental convict cichlid

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6535 ◽  
Author(s):  
Jennifer L. Snekser ◽  
Murray Itzkowitz
Keyword(s):  
Reproductive Success ◽  
Brood Size ◽  
Parental Behavior ◽  
Convict Cichlid ◽  
Costs And Benefits ◽  
Serial Monogamy ◽  
Convict Cichlids ◽  
Amatitlania Nigrofasciata ◽  
Males And Females

Monogamy can be either long-term or serial, with new pairs formed with each breeding bout. Costs and benefits are associated with each strategy. Because biparental convict cichlids (Amatitlania nigrofasciata) typically switch mates, exhibiting serial monogamy, we tested for the costs associated with forcing individuals to remain with the same mate. Convict cichlids were observed over two successive breeding bouts, either with the same or a new, equally experienced, mate. Parental behavior did not differ between breeding bouts, nor did brood size. Surprisingly, fish that remained with their original partner for a second bout took significantly longer to produce a brood compared to fish that paired with new partners. New partners were also more likely to successfully produce a second brood than re-mated partners. This is in contrast to the majority of bird studies that show many benefits to staying with the same partner for multiple broods. In convict cichlids, there seems to be no benefit associated with remaining with the same partner and switching mates reduces duration between broods for both males and females, potentially increasing overall reproductive success.

The Influence of the Mineral Composition of Alcoholic Beverages of Grape Origin on their Bottling Resistance

2021 ◽  
pp. 11-13
Author(s):  
Дарья Владиславовна Андриевская ◽  
Екатерина Владимировна Ульянова
Keyword(s):  
Mineral Composition ◽  
Alcoholic Beverages ◽  
Quantitative Composition ◽  
Group 4 ◽  
Physico Chemical ◽  
Wide Range ◽  
Additional Costs ◽  
Group 3 ◽  
Group 2 ◽  
The Stability

В настоящее время известны основные причины формирования различных видов помутнений в спиртных напитках виноградного происхождения. В значительной степени изучены компоненты образующихся при этом осадков. Вместе с тем одна из часто возникающих проблем современного производства заключается в потере стабильности продукции при транспортировании и хранении, что влечет дополнительные расходы предприятий по возврату и технологическим обработкам забракованной продукции. Целью настоящей работы стало сравнительное исследование минерального состава обработанных коньяков и их стабильности к различным видам помутнений. Объекты исследований - образцы обработанных коньяков отечественного производства, которые были разделены в зависимости от возраста на четыре группы: 1 группа - 3-летние, 4-летние и 5-летние; 2 группа - выдержанные «КВ» и выдержанные высшего качества «КВВК»; 3 группа - старые «КС», 4 группа - очень старые «ОС». На 1-м этапе было проведено исследование физико-химических и органолептических показателей продукции. В результате установлено, что все образцы соответствовали требованиям ГОСТ 31732-2014. Тесты на склонность к различным видам помутнений показали стабильность образцов к обратимым коллоидным, белковым и кальциевым помутнениям. Установлено, что качественный состав минеральных веществ обработанных коньяков различного возраста идентичен. При этом массовая концентрация отдельных компонентов варьирует в широком диапазоне. Доля образцов обработанных коньяков, в которых были превышены уровни концентраций отдельных ионов, гарантирующих стабильность продукции, составила в среднем 15%. Сравнительный анализ количественного состава катионов и анионов в обработанных коньяках дает основание предположить, что образцы с высоким содержанием ионов Са2+, Na+ и SO42- имеют высокий риск потери стабильности в дальнейшем. Таким образом, результаты проведенных исследований показали необходимость совершенствования методики определения склонности коньяков к различным видам помутнений в части расширения контролируемых показателей. Currently, the main reasons for the formation of various types of turbidity in alcoholic beverages of grape origin are known. The components of the precipitation formed during this process have been studied to a large extent. At the same time, one of the frequently occurring problems of modern production is the loss of product stability during transportation and storage, which entails additional costs for enterprises to return and process rejected products. The purpose of this work was a comparative study of the mineral composition of processed cognacs and their stability to various types of turbidity. The objects of research were samples of processed cognacs of domestic production, which were divided depending on age into four groups: group 1 - three-year-old, four-year-old and five-year-old; group 2 - aged «KV» and aged of the highest quality «KVVK»; group 3 - old «KS», group 4 - very old «OS». At the first stage, a study of the physico-chemical and organoleptic parameters of the products was carried out. As a result, it was found that all samples met the requirements of GOST 31732-2014. Tests for the propensity to various types of turbidity showed the stability of the samples to reversible colloidal, protein and calcium turbidity. It is established that the qualitative composition of the minerals of processed cognacs of different ages is identical. At the same time, the mass concentration of individual components varies in a wide range. The share of samples of processed cognacs in which the concentration levels of individual ions guaranteeing the stability of products were exceeded averaged 15%. A comparative analysis of the quantitative composition of cations and anions in processed cognacs suggests that samples with a high content of Ca2+, Na+ and SO42- ions have a high risk of loss of stability in the future. Thus, the results of the conducted studies have shown the need to improve the methodology for determining the propensity of cognacs to various types of turbidity in terms of expanding the controlled indicators.

Trends in the population of the Northern Hairy-nosed Wombat Lasiorhinus krefftii in Epping Forest National Park, Central Queensland

1994 ◽  
Vol 1 (2) ◽  
pp. 141 ◽  
Author(s):  
Doug G. Crossman ◽  
Christopher N. Johnsow ◽  
Alan B. Horsup
Keyword(s):  
National Park ◽  
Absolute Size ◽  
Forest Region ◽  
Prolonged Drought ◽  
Males And Females ◽  
The Absolute ◽  
The Stability ◽  
Almost All

The Northern Hairy-nosed Wombat Lasiorhinus krefftii now survives only in Epping Forest National Park, central Queensland. The species was formerly more widespread in the Epping Forest region than at present. Its decline appears to have occurred in three distinct episodes of contraction, two of which were associated with prolonged drought. Indirect monitoring of abundance suggests that the population was stable from 1974 to 1981, when cattle were excluded from the Park, but has increased since 1983. A trapping programme between 1985 and 1989 suggests that the absolute size of the population may be about 70. The population contains approximately equal numbers of males and females; almost all females breed; and a large and apparently increasing proportion of the population consists of young animals. Further increases in density and range within Epping Forest National Park appear possible. Removal of some animals for translocation should be attempted when it is clear that such removals will not jeopardize the stability and vigour of the Epping Forest population.

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