scholarly journals Larval social cues influence testicular investment in an insect

2021 ◽  
Author(s):  
Junyan Liu ◽  
Xiong Z He ◽  
Xia-Lin Zheng ◽  
Yujing Zhang ◽  
Qiao Wang
Keyword(s):  
Body Weight ◽  
Sperm Competition ◽  
Growth And Development ◽  
Social Cues ◽  
Social Setting ◽  
Testis Size ◽  
Sperm Production ◽  
Competition Level ◽  
Fine Tune ◽  
Paternity Share

Abstract Socio-sexual environment can have critical impacts on reproduction and survival of animals. Consequently, they need to prepare themselves by allocating more resources to competitive traits that give them advantages in the particular social setting they have been perceiving. Evidence shows that a male usually raises his investment in sperm after he detects the current or future increase of sperm competition because relative sperm numbers can determine his paternity share. This leads to the wide use of testis size as an index of the sperm competition level, yet testis size does not always reflect sperm production. To date, it is not clear whether male animals fine-tune their resource allocation to sperm production and other traits as a response to social cues during their growth and development. Using a polygamous insect Ephestia kuehniella, we tested whether and how larval social environment affected sperm production, testis size, and body weight. We exposed the male larvae to different juvenile socio-sexual cues and measured these traits. We demonstrate that regardless of sex ratio, group-reared males produced more eupyrenes (fertile and nucleate sperm) but smaller testes than singly reared ones, and that body weight and apyrene (infertile and anucleate sperm) numbers remained the same across treatments. We conclude that the presence of larval social, but not sexual cues is responsible for the increase of eupyrene production and decrease of testis size. We suggest that male larvae increase investment in fertile sperm cells and reduce investment in other testicular tissues in the presence of conspecific juvenile cues.

scholarly journals Sperm competition and sperm length influence the rate of mammalian spermatogenesis

2009 ◽  
Vol 6 (2) ◽  
pp. 219-221 ◽  
Author(s):  
Steven A. Ramm ◽  
Paula Stockley
Keyword(s):  
Sperm Competition ◽  
Negative Relationship ◽  
Interspecific Variation ◽  
Sperm Length ◽  
Testis Size ◽  
Sperm Production ◽  
Selection For ◽  
High Level ◽  
Sperm Size ◽  
Numerical Advantage

Sperm competition typically favours an increased investment in testes, because larger testes can produce more sperm to provide a numerical advantage in competition with rival ejaculates. However, interspecific variation in testis size cannot be equated directly with variation in sperm production rate—which is the trait ultimately selected under sperm competition—because there are also differences between species in the proportion of spermatogenic tissue contained within the testis and in the time it takes to produce each sperm. Focusing on the latter source of variation, we provide phylogenetically controlled evidence for mammals that species with relatively large testes (and hence a high level of sperm competition) have a shorter duration of the cycle of the seminiferous epithelium and consequently a faster rate of spermatogenesis, enabling males to produce more sperm per unit testis per unit time. Moreover, we identify an independent negative relationship between sperm length and the rate of spermatogenesis, such that spermatogenesis takes longer in species with longer sperm. We conclude that sperm competition selects for both larger testes and a faster rate of spermatogenesis to increase overall sperm production, and that an evolutionary trade-off between sperm size and numbers may be mediated via constraints on the rate of spermatogenesis imposed by selection for longer sperm.

Relationships of basal metabolic rate, relative testis size and cycle length of spermatogenesis in shrews (Mammalia, Soricidae)

2008 ◽  
Vol 20 (3) ◽  
pp. 431 ◽  
Author(s):  
Roumen Parapanov ◽  
Sébastien Nusslé ◽  
Jacques Hausser ◽  
Peter Vogel
Keyword(s):  
Metabolic Rate ◽  
Mating System ◽  
Sperm Competition ◽  
Basal Metabolic Rate ◽  
Cycle Length ◽  
System Level ◽  
Testis Size ◽  
Suncus Murinus ◽  
Sperm Production ◽  
Sorex Minutus

The aim of the present study was to determinate the cycle length of spermatogenesis in three species of shrew, Suncus murinus, Sorex coronatus and Sorex minutus, and to assess the relative influence of variation in basal metabolic rate (BMR) and mating system (level of sperm competition) on the observed rate of spermatogenesis, including data of shrew species studied before (Sorex araneus, Crocidura russula and Neomys fodiens). The dynamics of sperm production were determined by tracing 5-bromodeoxyuridine in the DNA of germ cells. As a continuous scaling of mating systems is not evident, the level of sperm competition was evaluated by the significantly correlated relative testis size (RTS). The cycle durations estimated by linear regression were 14.3 days (RTS 0.3%) in Suncus murinus, 9.0 days (RTS 0.5%) in Sorex coronatus and 8.5 days (RTS 2.8%) in Sorex minutus. In regression and multiple regression analyses including all six studied species of shrew, cycle length was significantly correlated with BMR (r2 = 0.73) and RTS (r2 = 0.77). Sperm competition as an ultimate factor obviously leads to a reduction in the time of spermatogenesis in order to increase sperm production. BMR may act in the same way, independently or as a proximate factor, revealed by the covariation, but other factors (related to testes size and thus to mating system) may also be involved.

Human sperm competition: testis size, sperm production and rates of extrapair copulations

2004 ◽  
Vol 68 (2) ◽  
pp. 297-302 ◽  
Author(s):  
Leigh W. Simmons ◽  
Renée C. Firman ◽  
Gillian Rhodes ◽  
Marianne Peters
Keyword(s):  
Sperm Competition ◽  
Human Sperm ◽  
Testis Size ◽  
Sperm Production

scholarly journals Pupal Cues Increase Sperm Production but Not Testis Size in an Insect

2021 ◽  
Author(s):  
Junyan Liu ◽  
Xiong Z He ◽  
Xia-Lin Zheng ◽  
Yujing Zhang ◽  
Qiao Wang
Keyword(s):  
Resource Allocation ◽  
Morphological Traits ◽  
Adult Stage ◽  
Empirical Studies ◽  
Testis Size ◽  
Sperm Production ◽  
Sperm Competition Risk ◽  
Apyrene Sperm ◽  
Eupyrene Sperm ◽  
Fine Tune

Theoretic and empirical studies show that social surroundings experienced by male insects during their larval or adult stage can influence their testicular investment in diverse ways. Although insect pupae do not feed and crawl, they can communicate using sex-specific and/or non-sex specific cues. Yet, it is unknown, in any insect, whether and how male pupae can fine-tune their resource allocation to sperm production and testis size in response to socio-sexual environment. We investigated this question using a moth, Ephestia kuehniella, which produces fertile eupyrene sperm and unfertile apyrene sperm. We held male pupae individually or in groups with different sex ratios, and dissected adults upon eclosion, measured their testis size, and counted both types of sperm. We demonstrated that after exposure to conspecific pupal cues regardless of sex, male pupae increased production of eupyrenes and apyrenes at the same rate but kept testis size unchanged. We suggest that testis size is fixed after pupation because most morphological traits are formed during the larval stage, allowing little room for pupae to adjust testis size. Like adults, male pupae with fully grown testes have sufficient resources to produce more sperm of both types according to the perceived increase of sperm competition risk.

scholarly journals Sperm competition leads to functional adaptations in avian testes to maximize sperm quantity and quality

Reproduction ◽  
2011 ◽  
Vol 141 (5) ◽  
pp. 595-605 ◽  
Author(s):  
Stefan Lüpold ◽  
Joachim Wistuba ◽  
Oliver S Damm ◽  
James W Rivers ◽  
Tim R Birkhead
Keyword(s):  
Sperm Competition ◽  
Relative Number ◽  
Cell Types ◽  
Sperm Length ◽  
Testis Size ◽  
Trade Offs ◽  
Competition Level ◽  
Selection For ◽  
Sperm Output

The outcome of sperm competition (i.e. competition for fertilization between ejaculates from different males) is primarily determined by the relative number and quality of rival sperm. Therefore, the testes are under strong selection to maximize both sperm number and quality, which are likely to result in trade-offs in the process of spermatogenesis (e.g. between the rate of spermatogenesis and sperm length or sperm energetics). Comparative studies have shown positive associations between the level of sperm competition and both relative testis size and the proportion of seminiferous (sperm-producing) tissue within the testes. However, it is unknown how the seminiferous tissue itself or the process of spermatogenesis might evolve in response to sperm competition. Therefore, we quantified the different germ cell types and Sertoli cells (SC) in testes to assess the efficiency of sperm production and its associations with sperm length and mating system across 10 species of New World Blackbirds (Icteridae) that show marked variation in sperm length and sperm competition level. We found that species under strong sperm competition generate more round spermatids (RS)/spermatogonium and have SC that support a greater number of germ cells, both of which are likely to increase the maximum sperm output. However, fewer of the RS appeared to elongate to mature spermatozoa in these species, which might be the result of selection for discarding spermatids with undesirable characteristics as they develop. Our results suggest that, in addition to overall size and gross morphology, testes have also evolved functional adaptations to maximize sperm quantity and quality.

scholarly journals Adaptive plasticity of mammalian sperm production in response to social experience

2008 ◽  
Vol 276 (1657) ◽  
pp. 745-751 ◽  
Author(s):  
Steven A Ramm ◽  
Paula Stockley
Keyword(s):  
Sperm Competition ◽  
Scent Marking ◽  
Social Experience ◽  
Social Cues ◽  
Adaptive Plasticity ◽  
Encounter Rate ◽  
Mus Musculus Domesticus ◽  
Sperm Production ◽  
Sexual Competition ◽  
Female Promiscuity

Sperm competition theory predicts that males should invest prudently in ejaculates according to levels of female promiscuity. Males may therefore be sensitive to cues in their social environment associated with sexual competition, and tailor investment in sperm production accordingly. We tested this idea experimentally for the first time, to our knowledge, in a mammal by comparing reproductive traits of male house mice ( Mus musculus domesticus ) that had experienced contrasting encounter regimes with potential sexual competitors. We found that daily sperm production and numbers of sperm in the caput epididymis were significantly higher in subjects that had experienced a high encounter rate of social cues from three other males compared to those that had experienced a low encounter rate of social cues from just one other male. Epididymal sperm counts were negatively correlated with the frequency of scent-marking behaviour across all males in our study, suggesting that investment in ejaculate production may be traded off against traits that function in gaining copulations, although there was no difference in overall levels of scent marking between treatment groups. We conclude that social experience-mediated phenotypic plasticity in mammalian spermatogenesis is likely to be adaptive under sperm competition, enabling males to balance the energetic costs and paternity-enhancing benefits of ejaculate production, and is a potentially widespread explanation for intraspecific variation in ejaculate expenditure.

scholarly journals Pupal Cues Increase Sperm Production but Not Testis Size in an Insect

Insects ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 679
Author(s):  
Junyan Liu ◽  
Xiong Z. He ◽  
Xia-Lin Zheng ◽  
Yujing Zhang ◽  
Qiao Wang
Keyword(s):  
Resource Allocation ◽  
Morphological Traits ◽  
Adult Stage ◽  
Empirical Studies ◽  
Testis Size ◽  
Sperm Production ◽  
Sperm Competition Risk ◽  
Apyrene Sperm ◽  
Eupyrene Sperm ◽  
Fine Tune

Theoretic and empirical studies show that social surroundings experienced by male insects during their larval or adult stage can influence their testicular investment in diverse ways. Although insect pupae do not feed and crawl, they can communicate using sex-specific and/or non-sex specific cues. Yet, it is unknown, in any insect, whether and how male pupae can fine-tune their resource allocation to sperm production and testis size in response to socio-sexual environments. We investigated this question using a moth, Ephestia kuehniella, which produces fertile eupyrene sperm and unfertile apyrene sperm. We held male pupae individually or in groups with different sex ratios, and dissected adults upon eclosion, measured their testis size, and counted both types of sperm. We demonstrated that after exposure to conspecific pupal cues regardless of sex, male pupae increased production of eupyrenes and apyrenes at the same rate but kept testis size unchanged. We suggest that testis size is fixed after pupation because most morphological traits are formed during the larval stage, allowing little room for pupae to adjust testis size. Like adults, male pupae with fully grown testes have sufficient resources to produce more sperm of both types according to the perceived increase in sperm competition risk.

scholarly journals Growth and development of children under 5 years of age with tetralogy of Fallot in a Chinese population

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xin Li ◽  
Jin Zhu ◽  
Jun An ◽  
Yuqing Wang ◽  
Yili Wu ◽  
...  
Keyword(s):  
Body Weight ◽  
Tetralogy Of Fallot ◽  
Growth Retardation ◽  
Growth And Development ◽  
Heart Defects ◽  
Body Height ◽  
Child Growth ◽  
The Body ◽  
Early Age ◽  
Local Conditions

AbstractCongenital Heart Defects (CHDs) are associated with different patterns of malnutrition and growth retardation, which may vary worldwide and need to be evaluated according to local conditions. Although tetralogy of Fallot (TOF) is one of the first described CHDs, the etiology outcomes in growth and development of TOF in early age child is still unclear in most cases. This study was designed to investigate the growth retardation status of Chinese pediatric TOF patients under 5 years old. The body height, body weight and body mass index (BMI) of 262 pediatric patients (138 boys and 124 girls) who underwent corrective surgery for TOF between 2014 and 2018 were measured using conventional methods. The average body height, body weight and BMI of the patients were significantly lower than WHO Child Growth Standards, while the most affected was body height. Meanwhile, higher stunting frequency and greater deterioration of both the body height and weight happened in elder age (aged 13–60 months) rather than in infant stage (aged 0–12 months) among these patients. Our results confirmed that intervention should be given at early age to prevent the growth retardation of TOF patients getting severer.

Relative testis size and mating systems in anurans: large testis in multiple-male mating in foam-nesting frogs

2011 ◽  
Vol 61 (2) ◽  
pp. 225-238 ◽  
Author(s):  
Wen Bo Liao ◽  
Zhi Ping Mi ◽  
Cai Quan Zhou ◽  
Ling Jin ◽  
Xian Han ◽  
...  
Keyword(s):  
Sperm Competition ◽  
Published Data ◽  
Male Mating ◽  
Data Sets ◽  
Testis Size ◽  
Data Set ◽  
Monogamous Species ◽  
Large Testis ◽  
Testes Size ◽  
Testis Mass

AbstractComparative studies of the relative testes size in animals show that promiscuous species have relatively larger testes than monogamous species. Sperm competition favours the evolution of larger ejaculates in many animals – they give bigger testes. In the view, we presented data on relative testis mass for 17 Chinese species including 3 polyandrous species. We analyzed relative testis mass within the Chinese data set and combining those data with published data sets on Japanese and African frogs. We found that polyandrous foam nesting species have relatively large testes, suggesting that sperm competition was an important factor affecting the evolution of relative testes size. For 4 polyandrous species testes mass is positively correlated with intensity (males/mating) but not with risk (frequency of polyandrous matings) of sperm competition.

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