Sperm DNA integrity in Landrace and Duroc boar semen and its relationship to litter size

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RNA sequencing reveals candidate genes and polymorphisms related to sperm DNA integrity in testis tissue from boars

© The Author(s). 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Background: Sperm DNA is protected against fragmentation by a high degree of chromatin packaging. It has been demonstrated that proper chromatin packaging is important for boar fertility outcome. However, little is known about the molecular mechanisms underlying differences in sperm DNA fragmentation. Knowledge of sequence variation influencing this sperm parameter could be beneficial in selecting the best artificial insemination (AI) boars for commercial production. The aim of this study was to identify genes differentially expressed in testis tissue of Norwegian Landrace and Duroc boars, with high and low sperm DNA fragmentation index (DFI), using transcriptome sequencing. Results: Altogether, 308 and 374 genes were found to display significant differences in expression level between high and low DFI in Landrace and Duroc boars, respectively. Of these genes, 71 were differentially expressed in both breeds. Gene ontology analysis revealed that significant terms in common for the two breeds included extracellular matrix, extracellular region and calcium ion binding. Moreover, different metabolic processes were enriched in Landrace and Duroc, whereas immune response terms were common in Landrace only. Variant detection identified putative polymorphisms in some of the differentially expressed genes. Validation showed that predicted high impact variants in RAMP2, GIMAP6 and three uncharacterized genes are particularly interesting for sperm DNA fragmentation in boars. Conclusions: We identified differentially expressed genes between groups of boars with high and low sperm DFI, and functional annotation of these genes point towards important biochemical pathways. Moreover, variant detection identified putative polymorphisms in the differentially expressed genes. Our results provide valuable insights into the molecular network underlying DFI in pigs.publishedVersio

Identifisering av sædparametere og genvarianter som påvirker fertilitet hos råne

Boar fertility has a major impact on overall pig reproductive efficiency, and good semen quality is essential for successful fertilization and proper embryo development. Thus finding semen characteristics that can predict fertility traits like pregnancy rate and total number of piglets born (TNB) is of great importance. However, the results of pregnancy rate and TNB are not available until the boars have been used in production for a period, and determination of phenotypes with effects on fertility at an earlier stage in the boars’ lives would be beneficial for estimating breeding values. To find methods to evaluate the boar’s sperm quality in relation to TNB and thus the boar’s fertility is of great importance also for the semen produced for sale. Identifying gene variants affecting these traits is of equal importance.Det er mange faktorer som påvirker fertilitet, og for hannfertilitet er evnen til å produsere og ejakulere normale fertile sædceller den viktigste faktoren. Fertilitet hos råne har en stor innvirkning på den totale fruktbarheten hos svin, og god sædkvalitet er essensielt for vellykket fertilisering og normal embryoutvikling. Tradisjonelt har utvelgelsen av råner fokusert på økonomisk gunstige egenskaper som for eksempel drektighetsprosent hos purka og totalt antall fødte grisunger (TNB). Resultatene for fertilitetsrate og TNB vil imidlertid ikke være tilgjengelig før rånene har stått i seminproduksjon en periode. Derfor ville det vært svært gunstig i forhold til avlsverdiberegninger å kunne fastslå fenotyper som påvirker fertilitet tidligere i rånens reproduktive liv. For seminproduktet til salg er det også viktig å finne metoder som kan evaluere rånens sædkvalitet i forhold til TNB og dermed rånens fertilitet.Norsvi

Transcriptome profiling of porcine testistissue reveals genes related to spermhyperactive motility

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Relationship between sperm motility characteristics and ATP concentrations, and association with fertility in two different pig breeds

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Association between single-nucleotide polymorphisms within candidate genes and fertility in Landrace and Duroc pigs

Finding effective predictors of traits related to boar fertility is essential for increasing the efficiency of artificial insemi‑nation systems in pig breeding. The objective of this study was to find associations between single‑nucleotide poly‑morphisms (SNPs) within candidate genes and fertility in the breeds Landrace and Duroc. Animals with breeding val‑ues for total number of piglets born, were re‑sequenced for exonic regions of 14 candidate genes related to male and female fertility using samples from 16 Landrace boars and 16 Duroc boars (four with high and four with low breeding value of total number of piglets born for each breed for male fertility, and the same for female fertility) to detect genetic variants. Genotyping for the detected SNPs was done in 619 Landrace boars and 513 Duroc boars. Two SNPs in BMPR1 and one SNP in COX-2 were found significantly associated with the total number of piglets born in Landrace. In Duroc, two SNPs in PLCz, one SNP in VWF and one SNP in ZP3 were found significantly associated with total number of piglets born. These SNPs explained between 0.27% and 1.18% of the genetic variance. These effects are too low for being used directly for selection purposes but can be of interest in SNP‑panels used for genomic selection

Association between single-nucleotide polymorphisms within candidate genes and fertility in Landrace and Duroc pigs

Finding effective predictors of traits related to boar fertility is essential for increasing the efficiency of artificial insemi‑nation systems in pig breeding. The objective of this study was to find associations between single‑nucleotide poly‑morphisms (SNPs) within candidate genes and fertility in the breeds Landrace and Duroc. Animals with breeding val‑ues for total number of piglets born, were re‑sequenced for exonic regions of 14 candidate genes related to male and female fertility using samples from 16 Landrace boars and 16 Duroc boars (four with high and four with low breeding value of total number of piglets born for each breed for male fertility, and the same for female fertility) to detect genetic variants. Genotyping for the detected SNPs was done in 619 Landrace boars and 513 Duroc boars. Two SNPs in BMPR1 and one SNP in COX-2 were found significantly associated with the total number of piglets born in Landrace. In Duroc, two SNPs in PLCz, one SNP in VWF and one SNP in ZP3 were found significantly associated with total number of piglets born. These SNPs explained between 0.27% and 1.18% of the genetic variance. These effects are too low for being used directly for selection purposes but can be of interest in SNP‑panels used for genomic selection

Association between single-nucleotide polymorphisms within candidate genes and fertility in Landrace and Duroc pigs

Finding effective predictors of traits related to boar fertility is essential for increasing the efficiency of artificial insemi‑nation systems in pig breeding. The objective of this study was to find associations between single‑nucleotide poly‑morphisms (SNPs) within candidate genes and fertility in the breeds Landrace and Duroc. Animals with breeding val‑ues for total number of piglets born, were re‑sequenced for exonic regions of 14 candidate genes related to male and female fertility using samples from 16 Landrace boars and 16 Duroc boars (four with high and four with low breeding value of total number of piglets born for each breed for male fertility, and the same for female fertility) to detect genetic variants. Genotyping for the detected SNPs was done in 619 Landrace boars and 513 Duroc boars. Two SNPs in BMPR1 and one SNP in COX-2 were found significantly associated with the total number of piglets born in Landrace. In Duroc, two SNPs in PLCz, one SNP in VWF and one SNP in ZP3 were found significantly associated with total number of piglets born. These SNPs explained between 0.27% and 1.18% of the genetic variance. These effects are too low for being used directly for selection purposes but can be of interest in SNP‑panels used for genomic selection.publishedVersio

Relationship between sperm motility characteristics and ATP concentrations, and association with fertility in two different pig breeds

acceptedVersio