Fertilization modes drive the evolution of sperm traits in Baikal sculpins

2021 ◽  
Author(s):  
T. Ito ◽  
I. Kinoshita ◽  
D. Tahara ◽  
A. Goto ◽  
S. Tojima ◽  
...  
Keyword(s):  
2019 ◽  
Vol 15 (01) ◽  
pp. 71-74
Author(s):  
L M Chaudhary ◽  
C T Khasatiya ◽  
Amarjeet Amarjeet ◽  
A B Yede

The study was carried out on the preservation of epididymal spermatozoa of buck at refrigerated temperature without and with tomato juice as a supplement in Tris egg yolk citrate extender. The eight pairs of testicles including epididymis (total 16) from slaughtered bucks were collected within 2–4 hours of their slaughter. Sperms collected from cauda epididymis were preserved at refrigerated temperature up to 48 hours in tris egg yolk citrate extender at 300 million sperm/mL with different concentration of tomato juice (0%, 4%, 6%, 8%, and 10%) and the physical characteristics of spermatozoa were assessed to know the effect of tomato juice (Tj). The mean dead, abnormal and HOST non-reacted spermatozoa increased significantly (p less than0.05) at every 12-hour intervals of preservation in the dilutor without and with different concentration of tomato juice. Tomato juice exerted an adverse effect on physical characteristics of sperm during refrigeration preservation. All the three sperm traits studied however revealed significant (p less thaN 0.01) positive interrelationships with correlations of 0.31 to 0.72.


2019 ◽  
Vol 2 ◽  
Author(s):  
Antonio Gomez ◽  
David Maddison

Some sperm traits are now recognized as ornaments akin to peacock’s tails evolving under cryptic female choice or weapons in sexual conflicts, but there are still few studies addressing patterns and process in sperm-female evolution. We are studying sperm-female evolution in ground beetles of the genus Dyschirius. Male Dyschirius make groups of sperm, termed conjugates, by pairing sperm to non-cellular rods, or spermatostyles. This pairing creates a conflict for storage space in the female’s reproductive tract between sperm and the spermatostyle, which is incapable of fertilizing eggs. We speculate that the conjugates of some Dyschirius that include large spermatostyles with few sperm are ornaments. We hypothesize that increased spermathecal storage volume is positively correlated with larger spermatostyles and that male genitalic complexity is negatively correlated with elaboration of sperm. We gathered morphological trait data on sperm conjugates and male and female genitalia from several species of Dyschirius. We analyzed these data in a phylogenetic framework using a robust Dyschirius species tree derived from DNA sequence data. We present preliminary results from this ongoing study and solicit feedback from the ECM community.


2020 ◽  
Author(s):  
Noritaka Hirohashi ◽  
Noriyosi Sato ◽  
Yoko Iwata ◽  
Satoshi Tomano ◽  
Md Nur E Alam ◽  
...  

Male animals are not given equal mating opportunities under competitive circumstances. Small males often exhibit alternative mating behaviours and produce spermatozoa of higher quality to compensate for their lower chances of winning physical contests against larger competitors [1]. Because the reproductive benefits of these phenotypes depend on social status/agonistic ranks that can change during growth or aging [2], sperm traits should be developed/switched into fitness optima according to their prospects. However, reproductive success largely relies upon social contexts arising instantaneously from intra- and inter-sexual interactions, which deter males from developing extreme traits and instead favour behavioural plasticity. Nevertheless, the extent to which such plasticity influences developmentally regulated alternative sperm traits remains unexplored. Squids of the family Loliginidae are excellent models to investigate this, because they show sophisticated alternative reproductive tactics (ARTs) by which small males, known as “sneakers”, produce longer spermatozoa and perform extra-pair copulation to attach their sperm packages near the female seminal receptacle (SR). In contrast, large “consort” males have shorter spermatozoa and copulate via pair-bonding to insert their sperm packages near the internal female oviduct [3]. In addition, plasticity in male mating behaviour is common in some species while it is either rare or absent in others. Thus, squid ARTs display a broad spectrum of adaptive traits with a complex repertoire in behaviour, morphology and physiology [3].


2016 ◽  
Vol 11 (6) ◽  
pp. 427-432 ◽  
Author(s):  
Alexandra SCHREMPF ◽  
Astrid MOSER ◽  
Jacques DELABIE ◽  
Jürgen HEINZE
Keyword(s):  

2012 ◽  
Vol 24 (2) ◽  
pp. 497-504 ◽  
Author(s):  
L. Figenschou ◽  
I. Folstad ◽  
G. Rudolfsen ◽  
S.A. Hanssen ◽  
R. Kortet ◽  
...  

Biology ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 33
Author(s):  
Christine Green ◽  
Jessica P. Rickard ◽  
Simon P. de Graaf ◽  
Angela J. Crean

Males can adjust sperm motility instantaneously in response to the perceived risk of sperm competition. The speed of this response suggests that sperm motility is regulated by changes in seminal plasma rather than changes in the sperm cells themselves. Hence, here we test whether inter-ejaculate variation in seminal plasma can be used to alter sperm quality prior to use in assisted reproductive technologies. We supplemented fresh ejaculates of Merino rams with seminal plasma collected from previous ‘donor’ ejaculates to test whether changes in sperm kinetics were related to the relative quality of donor to focal ejaculates. We found a positive relationship between the change in sperm traits before and after supplementation, and the difference in sperm traits between the donor and focal ejaculate. Hence, sperm motility can be either increased or decreased through the addition of seminal plasma from a superior or inferior ejaculate, respectively. This positive relationship held true even when seminal plasma was added from a previous ejaculate of the same ram, although the slope of the relationship depended on the identity of both the donor and receiver ram. These findings indicate that seminal plasma plays a key role in the control and regulation of sperm kinetics, and that sperm kinetic traits can be transferred from one ejaculate to another through seminal plasma supplementation.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Silvia Cattelan ◽  
Clelia Gasparini

AbstractVariation in sperm traits is widely documented both at inter- and intraspecific level. However, sperm traits vary also between ejaculates of the same male, due for example, to fluctuations in female availability. Variability in the opportunities to mate can indeed have important consequences for sperm traits, as it determines how often sperm are used, and thus the rate at which they are produced and how long they are stored before the mating. While being stored within males’ bodies, sperm are subjected to ageing due to oxidative stress. Sperm storage may significantly impair sperm quality, but evidence linking male sperm storage and variation in sperm traits is still scarce. Here, we tested the effect of the duration of sperm storage on within-male variation in sperm traits in the zebrafish, Danio rerio. We found that without mating opportunities, sperm number increased as storage duration increased, indicating that sperm continue to be produced and accumulate over time within males without being discharged in another way. Long sperm storage (12 days) was associated with an overall impairment in sperm quality, namely sperm motility, sperm longevity, and sperm DNA fragmentation, indicating that sperm aged, and their quality declined during storage. Our results confirm that male sperm storage may generate substantial variation in sperm phenotype, a source of variation which is usually neglected but that should be accounted for in experimental protocols aiming to assay sperm traits or maximise fertilization success.


Author(s):  
Gurjot Kaur Mavi ◽  
P.P. Dubey ◽  
Ranjna S. Cheema ◽  
S. K. Dash ◽  
B. K. Bansal

The present study was conducted to characterize the semen quality parameters in roosters of three genetic groups viz. Rhode Island Red (RIR), Punjab Red and RIR X local cross. The roosters for each genetic group were also evaluated for fertility rate. There was no significant difference in color, pH and abnormalities among different genetic groups. RIR X local cross had significant higher (p less than 0.01) ejaculate volume (0.51±0.02 ml vs. 0.27±0.01 and 0.30±0.01ml), sperm concentration (2804.70±114.61 vs. 1826.10±77.66 and 2133.50±81.18X106 sperms/ml), sperm motility % (66.60±2.12 vs. 55.38±1.82 and 51.95±1.84), sperm viability % (72.43±2.06 vs. 64.67±1.88 and 51.25±1.89) and HOST % (64.59±2.61 vs. 58.55±1.17 and 47.09±2.11) than RIR and Punjab Red respectively. Interestingly, RIR X local cross had significant lower (p less than 0.01) partially damaged sperm % (36.96±2.81 vs. 41.84±1.78 and 48.98±1.89) and fully damaged sperm % (14.15±3.39 vs. 26.27±1.93 and 31.25±2.46) than RIR and Punjab Red respectively indicating desirable performance. The fertility rate for RIR X local cross was also found to be higher than Punjab Red and RIR respectively. Sperm traits were significantly positively correlated among groups with high correlation between fertility rate and sperm traits. It can be concluded that the selection of roosters on the basis of sperm function tests for artificial insemination may improve fertility rate and thereby may reduce maintenance cost of large number of cocks.


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