scholarly journals Sperm morphology, adenosine triphosphate (ATP) concentration and swimming velocity: unexpected relationships in a passerine bird

2016 ◽  
Vol 283 (1837) ◽  
pp. 20161558 ◽  
Author(s):  
Clair Bennison ◽  
Nicola Hemmings ◽  
Lola Brookes ◽  
Jon Slate ◽  
Tim Birkhead

The relationship between sperm energetics and sperm function is poorly known, but is central to our understanding of the evolution of sperm traits. The aim of this study was to examine how sperm morphology and ATP content affect sperm swimming velocity in the zebra finch Taeniopygia guttata . We exploited the high inter-male variation in this species and created extra experimental power by increasing the number of individuals with very long or short sperm through artificial selection. We found a pronounced quadratic relationship between total sperm length and swimming velocity, with velocity increasing with length up to a point, but declining in the very longest sperm. We also found an unexpected negative association between midpiece length and ATP content: sperm with a short midpiece generally contained the highest concentration of ATP. Low intracellular ATP is therefore unlikely to explain reduced swimming velocity among the very longest sperm (which tend to have a shorter midpiece).

2010 ◽  
Vol 6 (6) ◽  
pp. 797-799 ◽  
Author(s):  
John L. Fitzpatrick ◽  
Francisco Garcia-Gonzalez ◽  
Jonathan P. Evans

Selection imposed through sperm competition is commonly thought to promote the evolution of longer sperm, since sperm length is assumed to be positively associated with sperm swimming velocity. Yet, the basis for this assumption remains controversial, and there is surprisingly little intraspecific evidence demonstrating such a link between sperm form and function. Here, we show that sperm length and velocity are highly correlated in the sea urchin Heliocidaris erythrogramma , but importantly we report that failure to account for within-male variation in these sperm traits can obscure this relationship. These findings, in conjunction with the mounting evidence for extremely high levels of intra-specific variance in sperm traits, suggest that a functional link between sperm morphology and velocity may be more prevalent than what current evidence suggests. Our findings also suggest that selection for faster swimming sperm may promote the evolution of longer sperm, thereby supporting recent findings from macroevolutionary studies.


2010 ◽  
Vol 6 (4) ◽  
pp. 513-516 ◽  
Author(s):  
Renée C. Firman ◽  
Leigh W. Simmons

Evolutionary biologists have argued that there should be a positive relationship between sperm size and sperm velocity, and that these traits influence a male's sperm competitiveness. However, comparative analyses investigating the evolutionary associations between sperm competition risk and sperm morphology have reported inconsistent patterns of association, and in vitro sperm competition experiments have further confused the issue; in some species, males with longer sperm achieve more competitive fertilization, while in other species males with shorter sperm have greater sperm competitiveness. Few investigations have attempted to address this problem. Here, we investigated the relationship between sperm morphology and sperm velocity in house mice ( Mus domesticus ). We conducted in vitro sperm velocity assays on males from established selection lines, and found that sperm midpiece size was the only phenotypic predictor of sperm swimming velocity.


2010 ◽  
Vol 22 (3) ◽  
pp. 516 ◽  
Author(s):  
Martin A. Dziminski ◽  
J. D. Roberts ◽  
Leigh W. Simmons

Sperm traits have been found to vary between individuals within populations in a variety of taxa. Sperm motility, morphometry and viability may be expected to have important effects on male fertility, although previous studies have found varying patterns, especially in external fertilisers. In the present study, we examined the effects of sperm swimming velocity, the proportion of motile spermatozoa, sperm head and tail length and the proportion of live spermatozoa on fertilisation success in the externally fertilising myobatrachid frog Crinia georgiana using IVF techniques and by controlling sperm numbers. We found no effect of any of the sperm traits we measured on IVF success. Neither did we find any relationship between sperm morphology and sperm performance. There was a negative relationship between sperm viability and male body size, which could be a function of age or an alternative tactic of differential investment in spermatozoa by smaller-sized males using sneak tactics in multiple matings. In contrast with most externally fertilising aquatic organisms, high rates of fertilisation appear to be achieved in C. georgiana with relatively low sperm swimming speeds.


2015 ◽  
Vol 282 (1799) ◽  
pp. 20141897 ◽  
Author(s):  
Clair Bennison ◽  
Nicola Hemmings ◽  
Jon Slate ◽  
Tim Birkhead

Sperm competition, in which the ejaculates of multiple males compete to fertilize a female's ova, results in strong selection on sperm traits. Although sperm size and swimming velocity are known to independently affect fertilization success in certain species, exploring the relationship between sperm length, swimming velocity and fertilization success still remains a challenge. Here, we use the zebra finch ( Taeniopygia guttata ), where sperm size influences sperm swimming velocity, to determine the effect of sperm total length on fertilization success. Sperm competition experiments, in which pairs of males whose sperm differed only in length and swimming speed, revealed that males producing long sperm were more successful in terms of (i) the number of sperm reaching the ova and (ii) fertilizing those ova. Our results reveal that although sperm length is the main factor determining the outcome of sperm competition, complex interactions between male and female reproductive traits may also be important. The mechanisms underlying these interactions are poorly understood, but we suggest that differences in sperm storage and utilization by females may contribute to the outcome of sperm competition.


2020 ◽  
Vol 18 (3) ◽  
pp. 147470492094255
Author(s):  
Tara DeLecce ◽  
Todd K. Shackelford ◽  
Bernhard Fink ◽  
Mohaned G. Abed

Research in nonhuman animals (including insects, birds, and primates) suggests a trade-off in males between investment in competitive traits and investment in ejaculate quality. Previous research reported a negative association between perceived strength and ejaculate quality, suggesting that this trade-off also applies to human males. We conducted novel analyses of data secured as part of a larger project to assess the relationship between competitive traits (shoulder-to-hip ratio, handgrip strength, and height) and ejaculate quality (indexed by sperm morphology, sperm motility, and sperm concentration) in a sample of 45 men (ages ranging 18–33 years; M = 23.30, SD = 3.60). By self-report, participants had not had a vasectomy and had never sought treatment for infertility. We controlled for several covariates known to affect ejaculate quality (e.g., abstinence duration before providing an ejaculate) and found no statistically significant relationships between competitive traits and ejaculate quality; our findings therefore do not accord with previous research on humans. We highlight the need for additional research to clarify whether there is a trade-off between investment in competitive traits and investment in ejaculate quality in humans.


Author(s):  
Ali Kandeğer ◽  
Memduha Aydın ◽  
Kürşat Altınbaş ◽  
Alparslan Cansız ◽  
Özge Tan ◽  
...  

Objective We aimed to evaluate the relationship between perceived social support, coping strategies, anxiety, and depression symptoms among hospitalized COVID-19 patients by comparing them with a matched control group in terms of age, gender, and education level. Method The patient group (n = 84) and the healthy controls (HCs, n = 92) filled in the questionnaire including the socio-demographic form, Hospital Anxiety Depression Scale, Multidimensional Perceived Social Support Scale, and Brief Coping Orientation to Problems Experienced through the online survey link. Results The COVID-19 patients had higher perceived social support and coping strategies scores than the HCs. However, anxiety and depression scores did not differ significantly between the two groups. In logistic regression analysis performed in COVID-19 patients, the presence of chest CT finding (OR = 4.31; 95% CI = 1.04–17.95) was a risk factor for anxiety and the use of adaptive coping strategies (OR = 0.86; 95% CI = 0.73–0.99) had a negative association with anxiety. In addition, the use of adaptive coping strategies (OR = 0.89; 95% CI = 0.79–0.98) and high perceived social support (OR = 0.97; 95% CI = 0.93– 0,99) had a negative association with depression symptoms. Conclusions Longitudinal studies involving the return to normality phase of the COVID-19 pandemic are needed to investigate the effects of factors such as coping strategies and perceived social support that could increase the psychological adjustment and resilience of individuals on anxiety and depression.


2019 ◽  
Vol 41 (2) ◽  
pp. 212-234
Author(s):  
Joseph J. Merry ◽  
Donna Bobbitt-Zeher ◽  
Douglas B. Downey

In many parts of the world, fertility has declined in important ways in the past century. What are the consequences of this demographic change? Our study expands the empirical basis for understanding the relationship between number of siblings in childhood and social outcomes among adults. An important recent study found that for each additional sibling an individual grows up with, the likelihood of divorce as an adult declines by 3%. We expand this work by (a) determining whether the original pattern replicates in the National Longitudinal Study of Adolescent to Adult Health and (b) extending the analysis beyond divorce to consider whether growing up with siblings is related to prosocial adult behaviors (relationships with parents, friends, and views on conflict management with one’s partner). Our results confirm a negative association between number of siblings and divorce in adulthood. We find mixed results related to other prosocial adult behaviors.


1989 ◽  
Vol 10 (3) ◽  
pp. 214-220 ◽  
Author(s):  
R. JOHN AITKEN ◽  
JANE S. CLARKSON ◽  
TIMOTHY B. HARGREAVE ◽  
D. STEWART IRVINE ◽  
FREDERICK C. W. WU

2014 ◽  
Vol 7 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Jan Boehmer ◽  
Stephen Lacy

This study analyzes how interactivity on Facebook relates to users’ browsing behaviors such as clicking a link, visiting a Web site, clicking articles on a Web site, and spending time on a sports news Web site. Regression analyses of 502 Facebook posts and the corresponding news articles show that the number of individuals who clicked on a link is not related to higher levels of interactivity, but an increase in interactivity did affect the number of overall visits generated. In addition, higher levels of interactivity had a slight negative correlation with the number of pages visited and the time spent on an organization’s Web site. Implications for the training and work routines of sport communication professionals in organizations, journalism, and public relations are discussed.


2021 ◽  
Author(s):  
Jianhong Wu ◽  
Nicola Luigi Bragazzi ◽  
Francesca Scarabel ◽  
Zachary McCarthy ◽  
Jummy David ◽  
...  

The attack ratio in a subpopulation is defined as the total number of infections over the total number of individuals in this subpopulation. Using a methodology based on modified age-stratified transmission dynamics model, we estimated the attack ratio of COVID-19 among children (individuals 0-11 years) in Ontario, Canada when a large proportion of individuals eligible for vaccination (age 12 and above) are vaccinated to achieve herd immunity among this subpopulation, or the effective herd immunity with additional physical distancing measures (hence effective herd immunity). We describe the relationship between this attack ratio among children, the time to remove infected individuals from the transmission chain and the children-to-children daily contact rate, while considering the increased transmissibility of virus variants (using the Delta variant as an example). We further illustrate the generality and applicability of the methodology established by performing an analysis of the attack ratio of COVID-19 among children in the Canadian population. The clinical attack ratio, the number of symptomatic infections over the total population can be informed from the attack ratio, and both can be reduced substantially via a combination of higher vaccine coverage in the vaccine eligible population, reduced social mixing among children, and rapid testing and isolation.


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