Inbreeding depression in sperm quality in a critically endangered amphibian

Zoo Biology ◽  
2020 ◽  
Vol 39 (3) ◽  
pp. 197-204
Author(s):  
Kristin M. Hinkson ◽  
Sinlan Poo
Keyword(s):  
Inbreeding Depression ◽  
Sperm Quality ◽  
Critically Endangered

23 Sperm quality of Pure Spanish stallions is affected by inbreeding coefficient and age

2020 ◽  
Vol 32 (2) ◽  
pp. 137
Author(s):  
Y. Pirosanto ◽  
M. Valera ◽  
A. Molina ◽  
J. Dorado ◽  
S. Demyda-Peyrás
Keyword(s):  
Sperm Motility ◽  
Inbreeding Depression ◽  
Negative Correlation ◽  
Semen Quality ◽  
Sperm Quality ◽  
Sperm Concentration ◽  
Inbreeding Coefficient ◽  
Semen Parameters ◽  
Computer Assisted

Inbreeding depression, a genetic condition produced by the mating of close-related individuals, has been associated with a reduction of fertility in several species. However, a loss in sperm quality was also associated with age. In horses, the few existing reports have described a tendency of both parameters to produce a negative effect on sperm quality. However, those reports were performed using a subjective evaluation of sperm motility. In the present study, a total of 692 ejaculates from 86 Pure Spanish stallions (PRE), aged between 3 and 22 years, were evaluated using a computer-assisted methodology to determine the effect of inbreeding in four semen parameters: free-gel volume (V), sperm concentration (C, by haemocytometer), and total (TM) and progressive (PM) sperm motility (by Spermvision sperm class analyser; Minitube). The inbreeding coefficient (F) was estimated using 300 000 PRE pedigree records approximately (minimum pedigree depth, eight equivalent complete generations; range, between 1 and 30.1%). Stallion, age, ejaculate, and season of semen collection were the variables included in the statistical model (general linear model), with ejaculate and season being the variables with a major effect (by variance components analysis). Our results showed that sperm concentration (r=−0.18; P<0.0001) and volume (to a lesser extent) were reduced with advancing age, both showing a major decline after 15 years of age. To the contrary, sperm motility was not affected by age of the stallion. We also found a negative correlation between the inbreeding coefficient and ejaculate volume (r=−0.14; P<0.001), with a marked decrease seen when F was between 7 and 20%. Also, a negative correlation was observed in PM (r=−0.08; P<0.05), although to a lower extent. Conversely, C and TM were not affected by inbreeding depression (P>0.05). In conclusion, our results demonstrated that high levels of inbreeding can compromise severely the sperm quality of the PRE stallion, which, subsequently, may have a negative influence on fertility. Ongoing studies using genomic data will help to detect genetic variants associated with stallion semen quality and how it is influenced by inbreeding in specific genomic regions.

scholarly journals Effect of inbreeding depression on bull sperm quality and field fertility

2017 ◽  
Vol 29 (4) ◽  
pp. 712 ◽  
Author(s):  
Jesús Dorado ◽  
Rosa Morales Cid ◽  
Antonio Molina ◽  
Manuel Hidalgo ◽  
Julia Ariza ◽  
...  
Keyword(s):  
Inbreeding Depression ◽  
Sperm Morphology ◽  
Semen Quality ◽  
Sperm Quality ◽  
Membrane Integrity ◽  
Calving Interval ◽  
Bull Semen ◽  
Head Displacement ◽  
Highly Active ◽  
And Function

The present study investigated the effect of inbreeding depression on sperm quality using automated and objective methods and subsequent effects on beef bull field fertility. Individual inbreeding coefficient (F) values and field fertility data were determined using a dataset of AI bulls belonging to the Spanish Retinta Breeders Association (Asociación Nacional de Criadores de Ganado Vacuno Selecto de Raza Retinta (ANCRE)). Animals were clustered in two groups according to the F values as follows: (1) a high inbreeding group (HI; F ≥ 13.5%, mean 16.3); and (2) a non-inbreeding group (NI; F = 0%). In total, 17 different assessments were performed in both experimental groups, including evaluation of sperm morphology, acrosomal and DNA status, sperm plasma membrane integrity and function (hypo-osmotic swelling test), 10 kinetic parameters and the structure of sperm subpopulations. Sperm morphology, acrosomal and DNA status and osmotic tolerance were similar in both groups. Three velocity parameters (curvilinear velocity, straight line velocity and average path velocity) and the amplitude of lateral head displacement were higher in HI (P < 0.05). Cluster analysis of kinematic parameters revealed three different sperm subpopulations (sP1, sP2 and sP3), with the proportion of the sP1 population (highly active but non-progressive spermatozoa) being significantly (P < 0.05) higher in the HI group. Field fertility was assessed using two calving record datasets. In a smaller database including only bulls evaluated in the present study, there was a significant increase in the calving interval of cows sired with HI bulls. Conversely, in an extended genetic analysis of the ANCRE database, inbreeding only explained a small part of the variation in calving interval, and the results of regression analysis were not significant among bulls. The findings of the present study suggest that high inbreeding levels have a moderate effect on bull semen quality, with an increased percentage of highly active but non-progressive spermatozoa, but only when F values reached a certain threshold. This motility pattern could explain, in part, the higher calving interval produced by inbred bulls under field conditions.

150 Runs of Homozygosity Analysis and their Possible Influence on Sperm Motility in Highly Consanguineous Bulls

2018 ◽  
Vol 30 (1) ◽  
pp. 215
Author(s):  
E. Terán ◽  
D. Goszczynski ◽  
A. Molina ◽  
P. Ross ◽  
J. Dorado ◽  
...  
Keyword(s):  
Sperm Motility ◽  
Inbreeding Depression ◽  
Sperm Quality ◽  
Average Length ◽  
Snp Array ◽  
Gene Clusters ◽  
Enrichment Score ◽  
Cattle Population ◽  
Runs Of Homozygosity ◽  
Pedigree Data

Inbreeding depression is associated with emergence of deleterious effects and loss of genetic variability. Widespread use of genotyping technologies and new approaches for identification of runs-of-homozygosity (ROH) provide valuable tools to better understand the effects of inbreeding depression. We have previously demonstrated that inbreeding affects sperm motility patterns in cattle (Dorado et al. 2016 Reprod. Fertil. Dev. 29, 712-720; 10.1071/RD15324), with an increase in individuals presenting a hyperactivated-like motility. In this study, we characterised ROH patterns and performed gene ontology analysis of a large, highly consanguineous cattle population. Thirty-three Retinta bulls [average inbreeding percentage FPED = 16.57% (10.25 to 30.62%)] were genotyped using the Axiom® BOS 1 High-Density SNP Array (Thermo Fisher Scientific, Waltham, MA, USA). The ROH were estimated using CGATOH package and classified upon their length into 5 categories: 1-2, 2-4, 4-8, 8-16, and >16 Mb, which are inversely related to inbreeding events occurring 50 to 3 generations before, respectively. The ROH showed an average length of 3.73 Mb (1.48 to 6.71 Mb). Total FROH was partially explained by the increase in ROH fragments longer than 8 Mb, which is consistent with recent inbreeding events that occurred in this population in the last 6 generations. Additionally, the distribution of ROH varied notably between chromosomes. For instance, >16 Mb runs (very recent inbreeding event) were absent in BTA26 and BTA29, whereas certain loci on BTA7, BTA13, and BTA24 showed >16 Mb runs in 9 animals. To identify candidate biological functions affected by inbreeding, we performed functional analysis of the genome areas covered by ROH >8 Mb (our pedigree data covered 5.87 equivalent complete generations) using the Functional Annotation Clustering tool implemented in DAVID. Candidate regions were defined by occurring in ROH >8 in more than 6 animals and by a distance <1 Mb between adjacent single nucleotide polymorphisms. Eight significant gene clusters (enrichment score >1.30; P < 0.05) were identified, with 2 of these clusters related to sperm motility. One of these clusters (score 1.72) contained 23 genes coding microtubule-related proteins, which are associated with cellular movement structures such as flagella. The other cluster (score 1.42), included 4 genes related to dynein and motile cilium assembly ATPase complexes, associated with movement of eukaryotic flagella. We observed an additional cluster representing an ATP-binding feature, which included 77 genes (score 1.43). These results indicate that inbreeding could affect sperm motility by altering microtubule structure and motility. However, the fact that ROH were unevenly distributed across the genome, even in a highly inbred cattle population, also suggests that different metabolic pathways could be affected in individuals with similar inbreeding values. Therefore, the use of inbreeding coefficients as predictors for sperm quality should be approached carefully.

Inbreeding depression in a critically endangered carnivore

2016 ◽  
Vol 25 (14) ◽  
pp. 3309-3318 ◽  
Author(s):  
Karin Norén ◽  
Erika Godoy ◽  
Love Dalén ◽  
Tomas Meijer ◽  
Anders Angerbjörn
Keyword(s):  
Inbreeding Depression ◽  
Critically Endangered

Heterozygosity-Fitness Correlations and Inbreeding Depression in Two Critically Endangered Mammals

2012 ◽  
Vol 26 (6) ◽  
pp. 1121-1129 ◽  
Author(s):  
MarÍA JOSÉ Ruiz-López ◽  
Natalia Gañan ◽  
José Antonio Godoy ◽  
Ana Del Olmo ◽  
Julian Garde ◽  
...  
Keyword(s):  
Inbreeding Depression ◽  
Critically Endangered

Evidence of inbreeding depression in the critically endangered parrot, the kakapo

2014 ◽  
Vol 18 (4) ◽  
pp. 341-347 ◽  
Author(s):  
K. L. White ◽  
D. K. Eason ◽  
I. G. Jamieson ◽  
B. C. Robertson
Keyword(s):  
Inbreeding Depression ◽  
Critically Endangered

scholarly journals Heterozygosity–Fitness Correlations Reveal Inbreeding Depression in Neonatal Body Size in a Critically Endangered Rock Iguana

2019 ◽  
Author(s):  
Jeanette B Moss ◽  
Glenn P Gerber ◽  
Mark E Welch
Keyword(s):  
Body Size ◽  
Inbreeding Depression ◽  
Genetic Load ◽  
Critically Endangered ◽  
First Year ◽  
Isolated Populations ◽  
Conditional Expression ◽  
Age Dependent ◽  
Endangered Population ◽  
Related Trait

Abstract Inbreeding depression, though challenging to identify in nature, may play an important role in regulating the dynamics of small and isolated populations. Conversely, greater expression of genetic load can enhance opportunities for natural selection. Conditional expression concentrates these opportunities for selection and may lead to failure of detection. This study investigates the possibility for age-dependent expression of inbreeding depression in a critically endangered population of rock iguanas, Cyclura nubila caymanensis. We employ heterozygote-fitness correlations to examine the contributions of individual genetic factors to body size, a fitness-related trait. Nonsignificant reductions in homozygosity (up to 7%) were detected between neonates and individuals surviving past their first year, which may reflect natural absorption of inbreeding effects by this small, fecund population. The majority of variation in neonate body size was attributed to maternal or environmental effects (i.e., clutch identity and incubation length); however, heterozygosity across 22 microsatellite loci also contributed significantly and positively to model predictions. Conversely, effects of heterozygosity on fitness were not detectable when adults were examined, suggesting that inbreeding depression in body size may be age dependent in this taxon. Overall, these findings emphasize the importance of taking holistic, cross-generational approaches to genetic monitoring of endangered populations.

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