scholarly journals Fertilization Modes And The Evolution of Sperm Characteristics In Marine Fishes: Paired Comparisons of The Externally And Internally Fertilizing Species

2021 ◽  
Author(s):  
Takeshi Ito ◽  
Masaya Morita ◽  
Kazuo Inaba ◽  
Kogiku Shiba ◽  
Hiroyuki Munehara ◽  
...  
Keyword(s):  
Sperm Competition ◽  
Sperm Motility ◽  
Sperm Head ◽  
Marine Fishes ◽  
Head Length ◽  
Sperm Length ◽  
Sperm Velocity ◽  
Internal Fertilization ◽  
Sperm Characteristics ◽  
Testis Mass

Abstract Background: Fertilization modes may affect sperm characteristics, such as morphology, velocity, and motility. However, there is surprisingly little information on how fertilization mode affects sperm evolution because several factors (e.g. sperm competition and phylogeny) are intricately intertwined with this factor when phylogenetically distant species are compared. Here, we compared sperm characteristics between six externally and four internally fertilizing marine fishes from three different groups containing close relatives, taking into account the level of sperm competition. We also analysed the relationship between relative testis mass (as an index of sperm competition level) and sperm characteristics.Results: Sperm head morphology was significantly longer in species with internal fertilization than in those with external fertilization, suggesting that a longer head is advantageous for swimming in viscous ovarian fluid or the complex ovarian structure. In addition, sperm motility differed between external fertilizers and internal fertilizers; sperm of externally fertilizing species were only motile in seawater, and sperm of internally fertilizing species were only motile in an isotonic solution. These results suggest that sperm motility has adapted according to the fertilization mode. In contrast, total sperm length and sperm velocity did not correlate with fertilization mode, perhaps because of the different levels of sperm competition. Relative testis mass is positively correlated with sperm velocity and negatively correlated with the ratio of sperm head length/flagellum length. This finding suggests that species with high levels of sperm competition have sperm that are fast and have relatively long flagella compared to head length. These results contradict a previous assumption that the evolution of internal fertilization increases total sperm length. In addition, copulatory behaviour with internal insemination may involve a large intromittent organ, but this is not essential in fish, probably due to the avoidance of water resistance.Conclusions: We propose a new scenario of sperm evolution in which internal fertilization increases sperm head length but not total sperm length and changes sperm motility. In contrast, sperm competition affects sperm length and velocity. Our findings provide a new perspective on the evolutionary biology of sperm in fish.

138 Associations of sperm head morphometrics with quality parameters of frozen-thawed ram semen

2020 ◽  
Vol 32 (2) ◽  
pp. 195
Author(s):  
J. Navaranjan ◽  
J. Szymanowicz ◽  
M. Murawski ◽  
T. Schwarz ◽  
P. M. Bartlewski
Keyword(s):  
Alkaline Phosphatase ◽  
Survival Time ◽  
Aspartate Aminotransferase ◽  
Sperm Quality ◽  
Sperm Head ◽  
Head Length ◽  
Cell Membrane Permeability ◽  
Sperm Length ◽  
Progressive Motility ◽  
Synthetic Line

Current methods of mammalian semen evaluation focus on determining spermatozoa motility, concentration, mitochondrial status, and nucleus or chromatin structure integrity, quantifying their ability to bind to ova or measuring seminal plasma content of various biochemical markers. However, there is a paucity of studies that address relationships between sperm head morphometry (the external shape and dimensions of the sperm) and fertilising ability. Sperm head morphometrics are influenced by many molecular and biochemical factors such as genetics, DNA or protein condensation, and cell membrane permeability, all of which can affect semen viability. The objective of this experimental work was to determine quantitative correlations between sperm head dimensions and various indices of sperm quality in frozen-thawed ram semen. Ejaculates were collected from 16 clinically healthy rams (4 Polish Lowland (PON), 4 Olkuska, 5 synthetic line BCP (Berrichon du Cher×Charolais×PON/Polish Merino), and 3 synthetic line SCP (Suffolk×Charolais×PON/Polish Merino) aged 4-12 years) into an artificial vagina in the middle portion of the breeding season. Ejaculates from each ram were divided into two equal portions, diluted with a commercial semen extender prepared in deionised water or nanowater (water declusterised using cold plasma treatment) to a final concentration of 400×106 spermatozoamL−1, and frozen in 0.25-mL plastic straws. After 6 months of being cryogenically preserved, semen samples were thawed and used for the preparation of smears stained with eosin or SpermBlue. Images of the samples containing at least 100 spermatozoa were taken under 200× magnification and used for determination of sperm head morphology with the image analytical software Image Pro Plus (Media Cybernetics Inc.). Sperm progressive motility and survival time, as well as extender concentrations of alkaline phosphatase and aspartate aminotransferase, were measured. Finally, 128 BCP ewes were inseminated laparoscopically with the ram semen and fertility parameters were recorded. The present data were analysed using a multivariate analysis of variance in SAS (SAS Institute Inc.) and Spearman correlation tests. There were no significant effects or interactions of breed, staining method, or extender diluent on sperm head dimensions (head length, width, area, perimeter, and roundness). The mean head length was negatively correlated (P<0.05) with the percentages of spermatozoa with vacuolated, detached, or amorphous heads or small acrosomes; thick and thin midpiece defects, distal droplet, broken tail plus distal droplet, short tail plus distal droplet, and thick midpiece plus proximal droplet; and sperm progressive motility. In addition, sperm head roundness was negatively correlated with the proportion of spermatozoa with coiled tails. There were no correlations of sperm head dimensions with survival time, alkaline phosphatase and aspartate aminotransferase concentrations, or conception and pregnancy rates of artificially inseminated ewes. Sperm length and roundness (but no other measurements) were significantly correlated with segmental sperm defects and motility that may impinge the fertilising ability of frozen-thawed ram semen.

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.

scholarly journals Effects of male telomeres on probability of paternity in sand lizards

2018 ◽  
Vol 14 (8) ◽  
pp. 20180033 ◽  
Author(s):  
Angela Pauliny ◽  
Emily Miller ◽  
Nicky Rollings ◽  
Erik Wapstra ◽  
Donald Blomqvist ◽  
...  
Keyword(s):  
Experimental Data ◽  
Dna Damage ◽  
Sperm Competition ◽  
Telomere Length ◽  
Sperm Motility ◽  
Female Identity ◽  
Laboratory Population ◽  
Lacerta Agilis

Standardized swim-up trials are used in in vitro fertilization clinics to select particularly motile spermatozoa in order to increase the probability of a successful fertilization. Such trials demonstrate that sperm with longer telomeres have higher motility and lower levels of DNA damage. Regardless of whether sperm motility, and successful swim-up to fertilization sites, is a direct or correlational effect of telomere length or DNA damage, covariation between telomere length and sperm performance predicts a relationship between telomere length and probability of paternity in sperm competition, a prediction that for ethical reasons cannot be tested on humans. Here, we test this prediction in sand lizards ( Lacerta agilis ) using experimental data from twice-mated females in a laboratory population, and telomere length in blood from the participating lizards. Female identity influenced paternity (while the mechanism was not identified), while relatively longer male telomeres predicted higher probability of paternity. We discuss potential mechanisms underpinning this result.

scholarly journals Effect of Tramadol on Sperm Profile of Male Albino Rats

2019 ◽  
pp. 1-6
Author(s):  
I. S. Esua ◽  
U. U. Uno ◽  
U. B. Ekaluo
Keyword(s):  
Sperm Motility ◽  
Sperm Count ◽  
Sperm Head ◽  
Male Rats ◽  
Control Group ◽  
Albino Rats ◽  
Dependent Manner ◽  
Sperm Viability ◽  
Albino Rat ◽  
Significant Difference

Background and Aim: Tramadol is a potent analgesic effective in the treatment of mild to severe pains. However, the use of the drug can pose a threat to other organs and systems. Therefore, this study evaluated the effect of graded doses of tramadol on sperm profile of male albino rats. Materials and Methods: Eighteen male rats were divided into three groups (A, B and C) using completely randomized design (CRD) with six rats in each group. Rats in group A served as the control group and were given just food and water while groups B and C were given tramadol at 50 and 100 mg/kg body weight (BW) respectively, daily for the period of 65 days. The treatment was administered via oral gavage and at the end of the treatments, the rats were sacrificed. Immediately after sacrifice, a puncture was made in the epididymis with a sterile pin and examined for semen pH. The epididymes were processed for epididymal sperm motility, viability, count and sperm head abnormality. Results: There was no significant difference in the weight of testes and semen pH. Sperm viability, sperm motility, sperm count and weight of epididymes significantly reduced (p<0.05) in tramadol treated animals when compared with the control. Results also indicated statistically significant (p<0.05) increase in sperm head abnormalities in rats treated with tramadol when compared with the control. Conclusion: The results obtained from this study reveal that tramadol has negative effects on weight of epididymes, sperm count, sperm viability, sperm motility and sperm head abnormalities in male albino rat as mammalian models in a dose dependent manner.

scholarly journals Semen quality and diversity of morphological sperm abnormalities in bulls: breed and strain effects

2019 ◽  
Vol 22 (8) ◽  
pp. 931-938
Author(s):  
M. A. Kleshchev ◽  
V. L. Petukhov ◽  
L. V. Osadchuk
Keyword(s):  
Sperm Motility ◽  
Environmental Conditions ◽  
Western Siberia ◽  
Semen Quality ◽  
Sperm Count ◽  
Sperm Concentration ◽  
Sperm Head ◽  
Sperm Dna Fragmentation ◽  
Sperm Production ◽  
Sperm Abnormalities

At present great attention is paid to studying genetic regulation of farm animal adaptations to environmental conditions. This problem is very important due to a wide expansion of highly productive cattle breeds created in Europe and North America. However, until the present no investigation of changing semen quality in bulls of imported breeds during their adaptations to environmental conditions of Western Siberia has been conducted. The aim of this study was to investigate semen quality peculiarities and the diversity of morphological sperm abnormalities in bulls of imported and local breeds kept in the environmental conditions of the southern part of Western Siberia. We determined sperm concentration, sperm count, and rate of sperm with progressive motility and percentage of morphologically normal spermatozoa. The rate of sperm abnormalities according to Blome’s classifcation was determined too. It was found that the mean values of sperm concentration, sperm motility and percentage of morphologically normal spermatozoa in the bulls investigated were similar to those in bulls kept in European countries. Inter­breed differences in these parameters were not found. However, bulls of the Red Danish, Angler, and Simmental breeds had a higher percentage of misshapen sperm head and pyriform sperm head than bulls of the Black­White breed. An inter­strain difference in sperm motility in bulls of the Black­White breed was observed. It was found that bulls of Reflection Sovereign 198998 strain had lover sperm motility than bulls of Wis Burke Ideal 1013415 strain. No inter­strain differences in sperm production, percentage of morphologically normal spermatozoa and rate of main sperm abnormalities were found. Thus, it has been found that the environmental conditions of the southern part of Western Siberia do not seriously affect the sperm production, sperm motility or percentage of morphologically normal spermatozoa in bulls. However, the increased rate of misshapen and pyriform sperm heads in the bulls of the foreign breeds points to a need to study sperm DNA fragmentation.

Multiple Matings and Sperm Competition

2020 ◽  
pp. 332-363
Author(s):  
Carola Becker ◽  
Raymond T. Bauer
Keyword(s):  
Genetic Diversity ◽  
Sperm Competition ◽  
Mate Guarding ◽  
Sperm Storage ◽  
Internal Fertilization ◽  
Multiple Matings ◽  
Storage Organs ◽  
Anatomical Adaptations ◽  
Multi Level ◽  
Molecular Aspects

In polyandrous mating systems, females mate multiple times and males have evolved adaptations for sperm competition which increase the number and fitness of their offspring. Mate guarding is a widespread monopolization strategy in groups where female receptivity is temporally restricted and often associated with the molt. Precopulatory guarding occurs in branchipods, copepods, peracarids and decapods. Postcopulatory guarding is notable in numerous brachyurans with males protecting females until her exoskeleton has hardened. During copulation, male success in fertilization depends on an effective sperm transfer mechanism, the precise placement of ejaculates closest to where female gametes are fertilized. Male copulatory systems are highly diverse and strongly adapted to these tasks, especially the structures that interact with the female genital ducts. The elaborate tips of brachyuran gonopods are supposed to act in the displacement, possibly even in the removal of rival sperm masses; however, sperm removal is only evident in crayfish: males eat spermatophores previously deposited by other males. During copulation of several crustacean groups, males transfer secretions that harden and form a sealant. These sperm plugs, plaques and gel layers may protect their own sperm, prevent remating or seal off rival sperm from the site of fertilization. Several groups of isopods and decapods have internal insemination, elaborate sperm storage organs and some exhibit internal fertilization. The intensity of sperm competition increases with the latency between the processes of insemination and fertilization. This chapter gives on overview on mate guarding, male sealants and the anatomical adaptations to sperm competition in crustaceans. We also briefly discuss the consequences of multiple matings for the genetic diversity of broods, i.e., single vs. multiple paternities. There is still a lack of data for many crustacean groups. Moreover, it is often hard to assess how successful a male strategy to ensure paternity actually is as many studies focus on either the behavioral, anatomical, or molecular aspects, while comprehensive multi-level studies on crustacean sperm competition are virtually absent from the literature.

scholarly journals The Effect of Genetically Modified Food on Infertility Indices: A Systematic Review Study

2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Parisa Keshani ◽  
Mohammad Hossein Sharifi ◽  
Mohammad Reza Heydari ◽  
Hassan Joulaei
Keyword(s):  
Systematic Review ◽  
Adverse Effects ◽  
Sperm Motility ◽  
Genetically Modified ◽  
Sperm Head ◽  
Gm Crops ◽  
Control Group ◽  
Gm Crop ◽  
Gm Plants ◽  
Sperm Abnormality

Background and Objectives. With the increase in the growth of genetically modified (GM) crops, concerns as to the adverse effects of GM crops have risen in the community. The present systematic review seeks to assess the GM plants’ potential impacts on the sperm parameters, including sperm head, sperm motility, sperm abnormality, and fertility index. Materials and Methods. A structured literature search was independently performed by three authors on Scopus, Web of Science, PubMed, and Embase in January 2019. A total of 1467 publications were obtained by the search strategy after eliminating the duplicates. Moreover, the review only included articles written in English language. Other pertinent peer-reviewed publications were chosen (“snowballing”) from the reference lists in the selected publications. To assess the GM crop effects on infertility, experimental studies designed with the control group were selected. On the basis of abstract screening and full-text reviewing, 39 relevant publications were selected, seven of which were used in our review. To access the quality of articles, we used the Cochrane checklist. The collected articles were scored independently by three authors, and the publications with the eligibility criteria were included in our review. No article was excluded due to quality assessment. Results and Conclusion. Our findings indicated that GM products had no adverse effects on infertility indices such as the sperm head, sperm motility, sperm abnormality, and fertility indices. Long-term research still seems to be strongly necessary to ensure that the use of GM plants does not cause any harm to consumers, especially in infertility area.

scholarly journals Seminal fluid and accessory male investment in sperm competition

2020 ◽  
Vol 375 (1813) ◽  
pp. 20200068
Author(s):  
Steven A. Ramm
Keyword(s):  
Sperm Competition ◽  
Seminal Fluid ◽  
Complex Mixture ◽  
Internal Fertilization ◽  
Animal Evolution ◽  
Male Investment ◽  
Trade Offs ◽  
Fluid Production ◽  
Alternative Routes ◽  
Paternity Success

Sperm production and allocation strategies have been a central concern of sperm competition research for the past 50 years. But during the ‘sexual cascade’ there may be strong selection for alternative routes to maximizing male fitness. Especially with the evolution of internal fertilization, a common and by now well-studied example is the accessory ejaculate investment represented by seminal fluid, the complex mixture of proteins, peptides and other components transferred to females together with sperm. How seminal fluid investment should covary with sperm investment probably depends on the mechanism of seminal fluid action. If seminal fluid components boost male paternity success by directly enhancing sperm function or use, we might often expect a positive correlation between the two forms of male investment, whereas trade-offs seem more likely if seminal fluid acts independently of sperm. This is largely borne out by a broad taxonomic survey to establish the prevailing patterns of seminal fluid production and allocation during animal evolution, in light of which I discuss the gaps that remain in our understanding of this key ejaculate component and its relationship to sperm investment, before outlining promising approaches for examining seminal fluid-mediated sperm competitiveness in the post-genomic era. This article is part of the theme issue ‘Fifty years of sperm competition’.

Sign in / Sign up

Export Citation Format

Share Document