Effect of UV-B irradiated vitamin D enriched yeast supplementation on milk performance and blood chemical profiles in dairy cows

OBJECTIVE

The objective was to evaluate the effects of UV-B irradiated vitamin D-enriched yeast supplementation on milk yield, milk composition, vitamin D in milk, milk fatty acids, blood chemistry, and 25(OH)D status in dairy cows.

METHODS

Six Thai Friesian cows (milk production, 11.2±2.0 kg/d; body weight, 415.0±20.0 kg; and days in milk, 90.0±6.0) were allocated to each treatment in a 3×3 Latin square design, with three treatments and three periods. Each period of the Latin square lasted 49 days consisting of 14 days for diet adaptation and 35 days for sample collection. Dairy cows were randomly assigned to one of three treatments: i) feeding a basal diet without yeast (CON); ii) basal diet + 5 g of live yeast (75 IU/head/d of vitamin D2; LY); and iii) basal diet + 5 g of UV-B irradiated vitamin D enriched yeast (150,000 IU/head/d of vitamin D2; VDY). Feed intake and milk production were recorded daily, milk sample collection occurred on days 14 and 35 of each collection period, and blood plasma was collected on days 0, 7, 14, 21, 28, and 35 of each collection period.

RESULTS

The results show that after a trial period of 14 and 35 days, the VDY group had significantly higher vitamin D content in milk than the LY and CON groups (376.41 vs 305.15, 302.14 ng/L and 413.46 vs 306.76, 301.12 ng/L, respectively). At days 7, 14, 21, 28, and 35 of the experiment, cows fed the VDY group had significantly higher 25(OH)D2 status in blood than the CON and LY groups (51.07 vs 47.16, 48.05 ng/mL; 54.96 vs 45.43, 46.91 ng/mL; 56.16 vs 46.87, 47.16 ng/mL; 60.67 vs 44.39, 46.17 ng/mL and 63.91 vs 45.88, 46.88 ng/mL), respectively.

CONCLUSION

In conclusion, UV-B irradiated vitamin D-enriched yeast supplementation could improve vitamin D content in the milk and 25(OH)D status in dairy cows during the lactation period.

Corrigendum to: Effect of the ratio of maize cob and husk to napier Pakchong 1 silage on nutritive value and in vitro gas production of rumen fluid of Thai native cattle

The present study evaluated the chemical composition and in vitro ruminal digestibility of napier Pakchong 1 silage combined with maize cob and husk in different ratios. The napier Pakchong 1 grass was harvested at 45 days of maturity. The napier Pakchong 1 grass was ensiled with maize cob and husk at ratios of 1:5, 1:10 and 1:15. Three rumen fistulated Thai native cattle (White Lamphun cattle) with an average weight of 154 ± 4.7 kg were used to determine ruminal digestibility by in vitro gas-production technique. Gas production was recorded after incubating for 2, 4, 8, 12, 24, 48, 72 and 96 h. The microbial biomass yield was determined after incubating for 24 h. DM, NDF and ADF of maize cob and husk mixed with napier Pakchong 1 silage declined by increasing the proportion of napier Pakchong 1 grass, while gas production after 4–10 h of incubating maize cob and husk mixed with napier Pakchong 1 grass increased by increasing the proportion of napier Pakchong 1 grass. The metabolisable energy, organic matter digestibility and microbial biomass yield did not differ among the different ratios. The results of the study suggested a recommended ratio of maize cob and husk to napier Pakchong 1 grass of 1:10. The ensiling fermentation increased the proportion of protein in the roughage, which lead to increased in vitro gas production of roughage.

Effect of the ratio of maize cob and husk to napier Pakchong 1 silage on nutritive value and in vitro gas production of rumen fluid of Thai native cattle

The present study evaluated the chemical composition and in vitro ruminal digestibility of napier Pakchong 1 silage combined with maize cob and husk in different ratios. The napier Pakchong 1 grass was harvested at 45 days of maturity. The napier Pakchong 1 grass was ensiled with maize cob and husk at ratios of 1:5, 1:10 and 1:15. Three rumen fistulated Thai native cattle (White Lamphun cattle) with an average weight of 154 ± 4.7 kg were used to determine ruminal digestibility by in vitro gas-production technique. Gas production was recorded after incubating for 2, 4, 8, 12, 24, 48, 72 and 96 h. The microbial biomass yield was determined after incubating for 24 h. DM, NDF and ADF of maize cob and husk mixed with napier Pakchong 1 silage declined by increasing the proportion of napier Pakchong 1 grass, while gas production after 4–10 h of incubating maize cob and husk mixed with napier Pakchong 1 grass increased by increasing the proportion of napier Pakchong 1 grass. The metabolisable energy, organic matter digestibility and microbial biomass yield did not differ among the different ratios. The results of the study suggested a recommended ratio of maize cob and husk to napier Pakchong 1 grass of 1:10. The ensiling fermentation increased the proportion of protein in the roughage, which lead to increased in vitro gas production of roughage.

Investigation on association and expression of ESR2 as a candidate gene for boar sperm quality and fertility

ESR2 is involved in oestrogen-related apoptosis in cell cycle spermatogenesis but their effects have not yet confirmed in pig. Therefore, this study was aimed to investigate the association of ESR2 polymorphism with sperm quality and boar fertility traits and to analyse the ESR2 mRNA and protein expressions in boar reproductive tissues. DNA samples from 203 Pietrain (PI) and 100 Pietrain × Hampshire (PIHA) pigs with records of sperm quality [sperm concentration (SCON), motility (MOT), semen volume (VOL), plasma droplet rate (PDR) and abnormal spermatozoa rate (ASR)] and fertility [non-return rate (NRR) and number of piglet born alive (NBA)] traits were available. A SNP in coding region of ESR2 g.35547A>G in exon 5 was associated with MOT and PDR in the PI and with SCON, VOL, MOT and PDR in PIHA population. For mRNA and protein expression study, a total of six boars were divided into two groups with group I (G-I) and group II (G-II) where G-I characterized for relatively a better sperm quality according to the mean of two groups. mRNA expression was higher in brain and testis than that in all parts of epididymis. Both qRT-PCR and western blot analysis revealed that the ESR2 gene expression and protein expression were significantly higher in testis collected from G-II compared with that of G-I boars. Moreover, ESR2 protein localization in germ cell, Leydig and Sertoli cells, epithelial cells and spermatozoa was remarkable, which indicated the important role of ESR2 in spermatogenesis process. These results might shed new light on the roles of ESR2 in spermatogenesis as candidate for boar fertility, but still the lack of association across populations should be considered.

Association and expression quantitative trait loci (eQTL) analysis of porcine AMBP, GC and PPP1R3B genes with meat quality traits

The aim of this research was to screen polymorphism and to perform association study of porcine AMBP (alpha-1-microglobulin/bikunin precursor), GC (group-specific component protein) and PPP1R3B (protein phosphatase 1, regulatory (inhibitor) subunit 3B) genes with meat quality traits as well as to unravel the transcriptional regulation of these genes by expression QTL (eQTL) study. For this purpose, Duroc × Pietrain F2 resource population (DuPi; n = 313) and a commercial breed Pietrain (Pi; n = 110) were used for association and only DuPi for expression and eQTL study. A SNP was identified in the genes AMBP (g.22229C>T), GC (g.398C>T) and PPP1R3B (c.479A>G), respectively. In DuPi SNP of AMBP was associated (P < 0.05) with meat colour, pH(1L), pH(24L), pH(24H) and conductivity(24L); SNP of GC showed tendency to association (P < 0.10) with pH24H, conductivity(1L) and thawing loss, and SNP of PPP1R3B was associated (P < 0.05) with meat colour, pH(1L), pH(24L), pH(24H) and shear force. In Pi SNPs of AMBP and GC was associated with pH(24H) and PPP1R3B SNP was associated with pH(24L). The mRNA levels in Longissimus dorsi muscle tissue of these three genes were evaluated by using qRT-PCR to identify association between gene expression and meat quality traits as well as to analyse eQTL. The mRNA expression of PPP1R3B associated with pH(24L) (P < 0.05). Expression of these three genes was higher in animals with low pH of muscle. Linkage analysis using QTL Express revealed ten trans-regulated eQTL on seven porcine autosomes. Suggestive eQTL [P < 0.05, CW (chromosome-wide)] were found for PPP1R3B on SSC3 and 13. These results revealed that genetic variation and gene expression of these genes are associated with the meat quality traits. These three genes could influence meat quality and could be potential positional, physiological and functional candidate gene for meat quality traits in pigs. However, the analysis of eQTL also suggested that we need to consider additional genes encoding for transcription factors (TF), via fine-mapping underlying the eQTL peaks, in order to understand interaction among these genes.

Bovine blastocysts with developmental competence to term share similar expression of developmentally important genes although derived from different culture environments

This study was conducted to investigate the gene expression profile of in vivo-derived bovine embryo biopsies based on pregnancy outcomes after transferring to recipients. For this, biopsies of 30-40% embryos were taken from grade I blastocysts (International Embryo Transfer Society Manual) and the remaining 60-70% of the intact embryos were transferred to recipients. Frozen biopsies were pooled into three distinct groups based on the pregnancy outcome after transferring the corresponding parts, namely those resulting in no pregnancy (NP), pregnancy loss (PL), and calf delivery (CD). Array analysis revealed a total of 41 and 43 genes to be differentially expressed between biopsies derived from blastocysts resulting in NP versus CD and PL versus CD respectively. Genes regulating placental development and embryo maternal interaction (PLAC8) were found to be upregulated in embryo biopsies that ended up with CD. Embryo biopsies that failed to induce pregnancy were enriched with mitochondrial transcripts (Fl405) and stress-related genes (HSPD1). Overall, gene expression profiles of blastocysts resulting in NP and CD shared similar expression profiles with respect to genes playing significant roles in preimplantation development of embryo. Finally, comparing the transcript signatures of in vivo- and in vitro-derived embryos with developmental competence to term revealed a similarity in the relative abundance of 18 genes. Therefore, we were able to present a genetic signature associated with term developmental competence independent of the environmental origin of the transferred blastocysts.

Investigation into association and expression of PLCz and COX-2 as candidate genes for boar sperm quality and fertility

Phospholipase C zeta (PLCz) and cyclooxygenase isoenzyme type 2 (COX-2) are important in spermatogenesis, but their effect has not yet confirmed in pigs. Therefore, this study was aimed to analyse their association with sperm quality and fertility and to identify the mRNA and protein expression in boars reproductive tissues. DNA samples from 231 Pietrain (PI) and 109 Pietrain × Hampshire (PIHA) pigs with records of sperm quality [sperm concentration (SCON), motility, semen volume, plasma droplet and abnormal spermatozoa rate] and fertility (non-return rate and number of piglet born alive) traits were available. A SNP in non-coding region of PLCz g.158 A > C was associated with SCON (p < 0.05) in PIHA population while the polymorphism of COX-2 g.68 G > A in 3' UTR was not associated with any traits. For mRNA and protein expression study, a total of six boars were divided into two groups with G-I and G-II, where G-I was characterized for relatively better sperm quality. Both genes expressed higher in reproductive tissues compared with non-reproductive tissues. Phospholipase C zeta mRNA expressed higher in testis (p < 0.01), all parts of epididymis and spermatozoa from G-I, while COX-2 expressed higher in testis (p < 0.05), head and body of epididymis (p < 0.01), and spermatozoa from G-II boar. Both proteins were localized in Leydig cells and spermatozoa. These results might shed light on roles of these genes in spermatogenesis as candidate for boar sperm quality and fertility, but still the lack of association across populations should be considered.

Association and expression study of MMP3, TGFβ1 and COL10A1 as candidate genes for leg weakness-related traits in pigs

The present study was aimed to determine the association between metalloproteinase 3 (MMP3), transforming growth factor beta 1 (TGFβ1) and collagen type X alpha I (COL10A1) gene polymorphisms with traits related to leg weakness in pigs. Three hundred Duroc × Pietrain cross breds (DuPi) and 299 pigs of a commercial population (CP) were used for the experiment. DuPi animals were examined for 10 different traits describing leg and feet structure, osteochondrosis (OC) scores and bone density status. Data of OC score at condylus medialis humeri, condylus medialis femoris and distal epiphysis ulna regions of CP were used for association analysis. Significant association (P < 0.05) was found for MMP3 SNP (g.158 C>T) with OC at head of femur and bone mineral density in the DuPi population. Association (P < 0.05) was found between SNP of TGFβ1 (g.180 G>A) with rear leg score and the principle component denoting both OC and feet and leg scores in the DuPi population. No association was found between COL10A1 (g.72 C>T) and leg weakness related traits. The associations of SNPs with OC traits could not be confirmed in the commercial population. Expression analysis of the three candidate genes was performed to compare between healthy and OC. TGFβ1 was found to be highly expressed (P < 0.05) in the OC compared to healthy cartilages, but no significant different expressions were observed for MMP3 and COL10A1 genes. The present finding suggested that TGFβ1 and MMP3 genes variants have an effect on some of the leg weakness related traits.

Molecular mechanism underlying the differential MYF6 expression in postnatal skeletal muscle of Duroc and Pietrain breeds

Among modern western pigs, Duroc (high meat fat ratio) and Pietrain (low meat fat ratio) breeds extensively utilized in commercial pork production differ extremely for their muscle phenotypes. The molecular mechanism, especially the epigenetic mechanism, underlying these breed-specific differences is poorly known. Myogenic factor 6 (MYF6) is the most abundantly expressed myogenic factor in adult muscle. Moreover, MYF6 tends to be expressed more highly in muscle tissue of the lean selection line and is supposed to be one promising candidate gene for growth- and meat quality-related traits in adult pigs. Six months old female Duroc and Pietrain pure breed pigs were used in this study. Protein and mRNA levels of MYF6 in loin eye muscle were determined by Western blotting and quantitative Real-time reverse transcription PCR (qRT-PCR), respectively. The DNA methylation status of the MYF6 5'-regulatory region was determined by bisulfite sequencing PCR (BSP). The global Histone 4 acetylation at lysines 5 (H4K5) and 8 (H4K8) were examined by Western blotting. Pietrain pigs exhibited significant higher expression of MYF6 and hypermethylated E2F1 binding element within MYF6 5'-regulatory region as compared with Duroc pigs. Significant elevation in DNA methyltransferase 1 (DNMT1) expression was observed in Pietrain pigs which are in agreement with hypermethylation of MYF6. Histone acetylation level at neither H4K5 nor H4K8 is significant between two breed pigs. Nevertheless, mRNA and protein expression of E2F1 were significantly elevated in the Pietrain breed. It is thus conceivable that the upregulation of MYF6 transcription in postnatal Pietrain pigs is not associated with cis-activation by epigenetic modification of MYF6 5'-regulatory region, but may be attributed to trans-activation through enriched expression of E2F1.

Polymorphism and expression of the porcine Tenascin C gene associated with meat and carcass quality

The research aimed to screen for polymorphism, expression of Tenascin C (TNC) and association with meat and carcass quality traits. Three single nucleotide polymorphisms were detected. In a Duroc×Pietrain F2 cross (DuPi) population, g.44488C>T was associated with meat color and ham weight; g.68794A>G was associated with pH at 24h post mortem in ham (pH24(H)) and muscle area but g.68841C>T was not statistically associated. Genotyping in a commercial Pietrain (Pi) population showed that g.44488C>T was associated with pH24(H), whereas g.68794A>G was associated with conductivity at 45 min post mortem in loin and backfat thickness. Diplotypes showed significant effects on pH24(H) in both populations. The expression was associated with pH at 45 min post mortem in loin and cooking loss. TNC was significantly higher in animals with higher muscle pH. Linkage analysis revealed four trans-regulated eQTL on four autosomes. These results suggest that TNC could be a potential candidate gene for meat quality traits in pigs.

Quantitative trait loci analysis for leg weakness-related traits in a Duroc × Pietrain crossbred population

Background

Leg weakness issues are a great concern for the pig breeding industry, especially with regard to animal welfare. Traits associated with leg weakness are partly influenced by the genetic background of the animals but the genetic basis of these traits is not yet fully understood. The aim of this study was to identify quantitative trait loci (QTL) affecting leg weakness in pigs.

Methods

Three hundred and ten F₂ pigs from a Duroc × Pietrain resource population were genotyped using 82 genetic markers. Front and rear legs and feet scores were based on the standard scoring system. Osteochondrosis lesions were examined histologically at the head and the condylus medialis of the left femur and humerus. Bone mineral density, bone mineral content and bone mineral area were measured in the whole ulna and radius bones using dual energy X-ray absorptiometry. A line-cross model was applied to determine QTL regions associated with leg weakness using the QTL Express software.

Results

Eleven QTL affecting leg weakness were identified on eight autosomes. All QTL reached the 5% chromosome-wide significance level. Three QTL were associated with osteochondrosis on the humerus end, two with the fore feet score and two with the rear leg score. QTL on SSC2 and SSC3 influencing bone mineral content and bone mineral density, respectively, reached the 5% genome-wide significance level.

Conclusions

Our results confirm previous studies and provide information on new QTL associated with leg weakness in pigs. These results contribute towards a better understanding of the genetic background of leg weakness in pigs.

Investigation on interferon alpha-inducible protein 6 (IFI6) gene as a candidate for meat and carcass quality in pig

The aim of this research was to screen for polymorphism and to perform an association study of IFI6 with meat and carcass quality traits. A SNP (g.370A>G) was detected which was associated (P<0.05) with meat colour, pH 24h post mortem (p.m.) in ham, conductivity 45 min p.m. in loin and conductivity 24 h p.m. in ham, drip loss and carcass length in Duroc x Pietrain and with meat colour, muscle area and ham percentage in the Pietrain population. Highest expression of IFI6 mRNA was detected in skeletal muscle (longissimus dorsi) by qRT-PCR comparing different tissues. Both qRT-PCR and western blot revealed that the IFI6 gene and protein expressions were significantly (P<0.05) higher in skeletal muscle with low drip loss compared to that of high drip loss. IFI6 protein was localized in the myocytes membrane. Results suggested that IFI6 might play roles in meat and carcass quality and is a potential positional, physiological and functional candidate gene for improving meat quality traits in pigs.

Association study and expression analysis of CD9 as candidate gene for boar sperm quality and fertility traits

Cluster-of-differentiation antigen 9 (CD9) gene expressed in the male germ line stem cells is crucial for sperm-egg fusion, and was therefore selected as candidate gene for boar semen quality. The association of CD9 with boar sperm quality and fertility trait was analyzed using a total of 340 boars both from purebred Pietrain and Pietrain×Hampshire crosses. A single nucleotide polymorphism (g.358A>T) in intron 6 was significantly associated with sperm motility (MOT) (P<0.001), plasma droplet rate (PDR) (P<0.001) and abnormal spermatozoa rate (ASR) (P<0.01). Boars were divided into two groups with group 1 (G-I) boars having a higher SCON and SMOT, lower SVOL (sperm volume) and group 2 (G-II) having a lower SCON and SMOT, higher SVOL. The mRNA and protein expression levels were evaluated in reproductive, non-reproductive tissues and spermatozoa from G-I and G-II animals by using quantitative real-time PCR and western blotting. When both reproductive and non-reproductive tissues were examined, highest mRNA was expressed in prostate gland, then in the body of the epididymis, vas deferens and tail of the epididymis. In case of reproductive tissues, CD9 expression was higher in tissues and spermatozoa collected from G-I boars than those collected from G-II boars. The mRNA expression was significantly different (P<0.05) in body of epididymis from G-I and G-II boars. The CD9 protein expression results from western blot were coincided with the results of qRT-PCR. Moreover, CD9 protein localization in Leydig cells, Sertoli cells, epithelial cells and spermatozoa was remarkable which indicated the important role of CD9 in spermatogenesis process. By using mRNA and protein expression profiles, it could be shown that CD9 plays a crucial role during sperm development, especially within the epididymis where the maturation of the sperm, a key process for the sperm quality and motility takes place. These results will improve the understanding of the functions of the CD9 in spermatogenesis within the reproductive tracts and will shed light on CD9 as a candidate gene in the selection of good sperm quality boars.

Diversity of pig production systems at farm level in Europe

The present study was undertaken to perform an inventory of pig production systems, at farm level. The main aim was to document the variety of existing production systems in European countries. Information was collected from available sources, mostly national experts and literature, regarding target markets and information management, apparent degree of intensification, technical and economic performance, environmental impact and animal welfare. Eighty-four production systems were identified in 23 countries, of which 40 were reported as conventional and the remaining 44 were reported as differentiated. The differentiated and conventional production systems differ significantly in many respects; however, high variability was also found within each category as well as a large overlap between the two categories with respect to the distribution of most variables. Most differentiated systems claim to have superior characteristics in at least one dimension of sustainability. The specificities of these claims were analysed and multiple correspondence analysis of the data again showed considerable overlap between conventional and differentiated systems. Hierarchical clustering analysis resulted in three clusters. Systems in Cluster A (mostly conventional) have the characteristics of intensive production oriented towards standard quality. Systems in Cluster C (all differentiated) are just the opposite with numerous characteristics indicative of more extensive and more welfare- and quality-oriented production. Systems in Cluster B (made up of almost equal numbers of conventional and differentiated systems) fall between these two extremes; they are particularly common in Scandinavian countries and the Netherlands.

Epistatic QTL pairs associated with meat quality and carcass composition traits in a porcine Duroc × Pietrain population

Background

Quantitative trait loci (QTL) analyses in pig have revealed numerous individual QTL affecting growth, carcass composition, reproduction and meat quality, indicating a complex genetic architecture. In general, statistical QTL models consider only additive and dominance effects and identification of epistatic effects in livestock is not yet widespread. The aim of this study was to identify and characterize epistatic effects between common and novel QTL regions for carcass composition and meat quality traits in pig.

Methods

Five hundred and eighty five F₂ pigs from a Duroc × Pietrain resource population were genotyped using 131 genetic markers (microsatellites and SNP) spread over the 18 pig autosomes. Phenotypic information for 26 carcass composition and meat quality traits was available for all F₂ animals. Linkage analysis was performed in a two-step procedure using a maximum likelihood approach implemented in the QxPak program.

Results

A number of interacting QTL was observed for different traits, leading to the identification of a variety of networks among chromosomal regions throughout the porcine genome. We distinguished 17 epistatic QTL pairs for carcass composition and 39 for meat quality traits. These interacting QTL pairs explained up to 8% of the phenotypic variance.

Conclusions

Our findings demonstrate the significance of epistasis in pigs. We have revealed evidence for epistatic relationships between different chromosomal regions, confirmed known QTL loci and connected regions reported in other studies. Considering interactions between loci allowed us to identify several novel QTL and trait-specific relationships of loci within and across chromosomes.

Molecular characterization and methylation study of matrix gla protein in articular cartilage from pig with osteochondrosis

Osteochondrosis (OC) or leg weakness is an economically important disease of young fast growing pigs and is a concern of animal welfare. The etiology and pathogenesis of osteochondrosis is not fully understood yet, but any abnormalities in the formation of hypertrophic chondrocytes and disrupted blood supply to the growth cartilage are very important predisposing factors. Matrix gla protein (MGP) as a potential calcification inhibitor of extracellular matrix might contribute to the development of OC. Molecular characterization, polymorphisms analysis, methylation at promoter region and expression of MGP gene and protein were performed in both healthy and OC cartilage collected from a DurocxPietrain resource population. The porcine MGP gene consists of 4 exons and 3 introns. The full-length MGP cDNA isolated from articular cartilage consists of 606 bp with a 69-bp 5' UTR, a 312-bp open reading frame with a start codon, a 225-bp 3' UTR. Three single-nucleotide polymorphisms (SNP) were detected in the intron 1 (A-115G, C-1073T and C-1135A) and one in the 3'UTR (C-3767T). The relative abundance of MGP mRNA was lower (P<0.05) in OC compared with healthy cartilage. Moreover, the intensity of MGP band was lower (P<0.05) in OC group when quantified by western blot. Furthermore, one CpG region was identified in MGP promoter and DNA methylation of three CG sites were higher in OC compared with normal cartilage. This suggested that the high DNA methylation at specific CG sites in the MGP promoter might be involved in the down regulation of MGP in OC. Immunofluorescence of normal cartilage collected from pigs of different ages revealed that MGP signals were higher in younger pigs and decreased in the older pigs. The MGP protein was expressed more near to the cartilage canals. These results suggest that the MGP gene might be a potential candidate gene for the development of OC in pigs.

Suppression of the transcription factor MSX1 gene delays bovine preimplantation embryo development in vitro

This study was conducted to investigate the effect of suppressing transcription factor geneMSX1on the development ofin vitroproduced bovine oocytes and embryos, and identify its potential target genes regulated by this gene. Injection of long double-stranded RNA (LdsRNA) and small interfering RNA (siRNA) at germinal vesicle stage oocyte reducedMSX1mRNA expression by 73 and 37% respectively at metaphase II stage compared with non-injected controls. Similarly, injection of the same anti-sense oligomers at zygote stage reducedMSX1mRNA expression by 52 and 33% at 8-cell stage compared with non-injected controls. Protein expression was also reduced in LdsRNA- and siRNA-injected groups compared with non-injected controls at both stages. Blastocysts rates were 33, 28, 20 and 18% in non-injected control, scrambled RNA (scRNA), LdsRNA- and siRNA-injected groups respectively. Cleavage rates were also significantly reduced in Smartpool siRNA (SpsiRNA)-injected group (53.76%) compared with scRNA-injected group (57.76%) and non-injected control group (61%). Large-scale gene expression analysis showed that 135 genes were differentially regulated in SpsiRNA-injected group compared with non-injected controls, of which 54 and 81 were down- and up-regulated respectively due to suppression ofMSX1. Additionally, sequence homology mapping and gene enrichment analysis with known human pathway information identified several functional modules that were affected due to suppression ofMSX1. In conclusion, suppression ofMSX1affects oocyte maturation, embryo cleavage rate and the expression of several genes, suggesting its potential role in the development of bovine preimplantation embryos.

252 FUNCTIONAL CHARACTERIZATION OF miR-130 FAMILY DURING BOVINE PRE-IMPLANTATION EMBRYO DEVELOPMENT

Small noncoding RNA are known to play a regulatory role in various biological processes including development. Here we aimed to investigate the spatiotemporal expression pattern of the miR-130 microRNA family (miR-130a, miR-130b, and miR-301b) throughout the bovine pre-implantation- stage embryos and to experimentally validate the target of miR-130b. For this, triplicate pools of in vitro-produced immature or mature oocytes (n = 100), zygote (n = 100), 2-cell (n = 50), 4-cell (n = 30), 8-cell (n = 30), morula (n = 20), and blastocyst (n = 20) stage embryos were used to profile the 3 miRNA and one of the predicted target gene MSK1 using SYBR green-based real-time PCR system. Furthermore, based on its expression profile result, miR-130b was selected for localization in all stages of embryos using 3′digoxigenin labeled, LNA-modified oligonucleotide probes. Reporter assay was conducted in cultured bovine cumulus cells to validate the target of miR-130b. The predicted MSK1 gene 3′ untranslated region- containing dual-luciferase miRNA target expression vector (pmirGLO; 600 ng), having renilla luciferase as a control reporter (Promega, Madison, WI, USA), was cotransfected with miR-130b precursor (20 pmol) and/or miR-130b inhibitor (20 pmol) using Lipofectamine 2000 (Invitrogen, Carlsbad, CA, USA) in Opti-MEM1 Medium with 4 independent transfections. Cells were lysed 48 h post-transfection, and luciferase assay was performed in luminometer. Normalization of firefly luciferase activity was based on renilla luciferase activity, and data were presented as mean ± SD. The expression profiling result shows that miR-130b was abundant (>8 to 12-fold) at morula and blastocyst stages. This was further validated by in situ localization, where high fluorescent intensity was seen in the same stages. Greater abundance of miR-301b was evident immediately after fertilization at zygote stage, whereas miR-130a was abundant in equal amount from oocyte until 8-cell stage, after which expression reduced at morula and blastocyst stages. Verification of MSK1 as target of miR-130b using MSK1-pmirGLO-vector showed a significant reduction (>45%) in expression of luciferase when cells were cotransfected with miR-130b precursor compared with cotransfection with miR-130b inhibitor (95%) or only MSK1 construct transfection (100%). MSK1, which was validated as target of miR-130b in the current study for the first time, is known to regulate the phosphorylation of CREB and ATF1 and is required for inhibits of Wnt-fi-catenin pathway and cell proliferation in colon cancer cells (Morán OP et al. 2008 J. Cell Biol. 183(4), 697-710). The results from this study evidenced the spatiotemporal expression of members of the miR130 family during bovine embryo development and their potential regulatory mechanism in the expression of developmentally important gene. The overexpression or inhibition of these miRNA in bovine oocytes and embryos might help in fully understanding their specific role in bovine embryogenesis.

254 REGULATORY microRNA IN THE BIDIRECTIONAL COMMUNICATION OF BOVINE OOCYTES AND THE SURROUNDING CUMULUS CELLS

MicroRNA (miRNA) are small molecules (˜22 nucleotide in length) that influence the expression of hundreds of genes for numerous biological processes including development. In this study we aimed to investigate the presence and role of miRNA in the bidirectional communication of oocyte and cumulus cells. For this, triplicate pools each containing 1600 immature and mature oocytes and their corresponding cumulus cells were used for miRNA isolation using miRNeasy® Mini Kit (Qiagen, Hilden, Germany). From each oocyte and cumulus cell group, 50 ng of small RNA was used for reverse transcription using RT2 miRNA First Strand Kit (SABiosciences, Frederick, MD, USA). The resulting small RNA cDNA was used as a template to profile 88 human miRNA related to cell development and differentiation using SYBR green-based real-time PCR system. Data analysis was preformed using the comparative Ct method after normalization using endogenous control RNA (SNORD44, SNORD47, SNORD48, and U6). In addition, miR-205 and miR-210 were used for localization in pre-implantation stages of embryo using 3′digoxigenin labeled, LNA- modified in situ oligonucleotide probes (Exiqon, Vedbaek, Denmark). The result of the PCR array revealed a total of 34 and 49 miRNA to be greatly abundant in immature and mature oocyte, respectively, compared with the corresponding cumulus cells, whereas only 5 and 4 miRNA were enriched in cumulus cells compared with immature and matured oocytes, respectively. Based on expression intensity, 6 oocyte enriched (miR-205, miR-150, miR-96, miR-122, miR-146a, and miR-146b-5p) and 2 cumulus-cell enriched (miR-452 and miR-210) were selected for expression analysis in pre-implantation-stage embryos and in oocyte and cumulus cells matured with or without cumulus and oocyte factors, respectively. All oocyte-specific miRNA were found to be greatly abundant in early stages of embryo development and drop after 4-cells until the blastocyst stage, following a typical maternal transcript profile. Similar results were obtained by localization of miR-205 in pre-implantation-stage embryos, in which signals were greater until the 4-cell stage and reduced thereafter. However, miR-210 and miR-452 showed no defined profile. miR-205, miR-150, miR-122, miR-146a, miR-146b-5p, and miR-452 were found to be abundant at a greater level (P < 0.05) in oocytes matured without cumulus cells compared with those matured in the presence of cumulus cells. The expression of miR-205, miR-150, and miR-122 in cumulus cells was greater in the presence of oocyte cytoplasm during maturation, whereas 16-fold increases in relative abundance of miR-210 were observed in oocyte- optimized cumulus cells. These results evidenced that oocyte and cumulus cells have a distinct set of miRNA, which is dependent on the bidirectional communication of the oocyte and the surrounding cumulus cells. Moreover, maternal miRNA were found to persist until the major genome activation in bovine.

248 DIESTRUS TRANSCRIPTOME DYNAMICS OF BOVINE ENDOMETRIUM IN RELATION TO PREGNANCY SUCCESS AFTER EMBRYO TRANSFER

This experiment aimed to investigate the diestrus transcriptome dynamics of endometrium that resulted in calf delivery or no pregnancy after embryo transfer. Endometrium biopsies were collected from Simmental cyclic heifers at Days 7 and 14 of estrus cycle. On the next cycle, in vivo-produced Day 7 blastocysts were transferred to all animals at Day 7 of estrous cycle. Following pregnancy diagnosis, the endometrial biopsies collected at Day 7 and 14 were categorized based on the pregnancy success. Those endometrial biopsies collected from heifers that subsequently delivered a calf were assigned to the calf-delivery group, and those collected from heifers that did not conceive were assigned to the no-pregnancy group. The endometrial temporal transcriptome profile was compared between Days 7 and 14 in both heifer groups. Total RNA was isolated from each sample in triplicate. Two rounds of RNA amplification were performed using MEGAscript® T7 Kit (Ambion, Inc., Austin, TX, USA) and GeneChip® IVT Labeling Kit (Affymetrix, Inc., Santa Clara, CA, USA), respectively. Following fragmentation, biotin-labeled cRNA samples were hybridized to Affymetrix bovine gene chip array. The microarray data normalization and background correction were performed using GCRMA, and the differentially expressed genes (DEG) (fold change >2,P < 0.05, FDR < 0.3) were identified using LIMMA written on R package integrated with Bioconductor. The result showed that in the calf-delivery group, there were 1867 DEG, among which 1015 and 852 were up- and down-regulated, respectively, in Day 7 compared with Day 14 of the estrous cycle. Some of those genes are believed to be involved in reproductive system development and function (F3, PTGER2, PTGER4, MFGE8, PTGS2, and TDGF1), embryonic development (ALDH1A1,ALDH1A3, FGF2, TGFBR2, PDGFB, and TGFBR2), and nervous system development and function (CYP3A4, CYP3A4, HSD17B4, FOXA2, MET, TDGF, WNT11). The bioinformatic analysis using KEGG revealed that those DEG were classified into several pathways including the MAPK signaling pathway. On the other hand, in the no-pregnancy group, 254 genes were found to be differentially expressed, of which 160 and 94 were up- and down-regulated, respectively, in Day 7 compared with Day 14 of the estrous cycle. Some of these genes were found to be involved in signal transducer activity (AXIN2, AGTR1, MAPK10, NTRK2, TLR2, DMBT1, IL1RN, CDK5, CHRNE), transferase activity (DGKI, TXNDC6, RPS6KA5, RIOK3, MYLK, CDK5, MET, NTRK2), receptor activity (MET,AGTR1, NTRK2, TLR2, DMBT1, CHRNE), regulation of transcription (FOS, ELF1, BHLHB2,ATF3, HOXA11), signal transduction (TLR2, AGTR1, FCNB, DGK, NOTCH2, ADAM9, PLEK), and transcription regulator activity (BHLHB2, FOS, ELF1,ATF3, HOXA11). Those DEG were found to be involved in different pathways including the focal adhesion pathway. In conclusion, the result of the current study revealed a remarkable transcriptome dynamics between Days 7 and 14 of the estrous cycle in cows resulted in calf delivery compared with those that did not support pregnancy.

Depletion of BIRC6 leads to retarded bovine early embryonic development and blastocyst formation in vitro

Baculoviral inhibitors of apoptosis repeat-containing 6 (BIRC6) is believed to inhibit apoptosis by targeting key cell-death proteins. To understand its involvement during bovine preimplantation embryo development, two consecutive experiments were conducted by targeted knockdown of its mRNA and protein using RNA interference. In Experiment 1, the effect of BIRC6 knockdown during the early stages of preimplantation embryo development was assessed by injecting zygotes with long double-stranded RNA (ldsRNA) and short hairpin RNA (shRNA) against BIRC6 mRNA followed by in vitro culturing until 96 h post insemination (hpi). The results showed that in RNA-injected zygote groups, reduced levels of BIRC6 mRNA and protein were accompanied by an increase (P < 0.05) in the proportion of 2- and 4-cell and uncleaved embryos and a corresponding decrease (P < 0.05) in the number of 8-cell embryos. In Experiment 2, the effect of BIRC6 knockdown on blastocyst formation, blastocyst total cell number and the extent of apoptosis was investigated. Consequently, zygotes injected with ldsRNA and shRNA resulted in lower (P < 0.05) blastocyst formation and total blastocyst cell number. Moreover, the apoptotic cell ratio, CASPASE 3 and 7 activity, BAX to BCL-2 ratio and levels of SMAC and CASPASE 9 were higher in blastocysts derived from the ldsRNA and shRNA groups, suggesting increased apoptosis in those blastocysts. The results of this study reveal the importance of BIRC6 expression for embryo survival during bovine preimplantation embryo development. However, whether BIRC6 is essential for implantation and fetal development during bovine pregnancy needs further research.

240 DIFFERENCES IN GLOBAL TRANSCRIPTOME PROFILE OF BOVINE BLASTOCYSTS DERIVED FROM SUPEROVULATED OR SYNCHRONIZED CYCLIC HEIFERS

Estrus synchronization and superovulation are the most widely used procedures in embryo transfer technology. However, changes in the oviduct and uterine environment due to these procedures and the subsequent influence on embryos have not yet been investigated. This study was con- ducted to investigate the effect of oviduct environment of only synchronized or superovulated cyclic heifers on the gene expression profile of blastocysts. Bovine Affymetrix array analysis was performed using 2 groups of blastocysts. The first group was bovine blastocysts produced after superovulation of Simmental heifers (n = 9) using 8 consecutive FSH injections over 4 days in decreasing doses (in total, 300-400 mg of FSH equivalent according to body weight) and flushed at Day 7 by nonsurgical endoscopic method. The second group was bovine blastocysts derived from synchronized Simmental heifers (n = 4) after transfer of 2-cell stage embryos from superovulated donor Simmental heifers (n = 9) by nonsurgical transvaginal endoscopy tubal transfer method. Total RNA was extracted from 3 pools of embryos from each experimental group (6 embryos per pool). A total of 6 biotin-labeled cRNA samples were hybridized on 6 bovine Affymetrix arrays. Data analysis was performed using LIMMA written on R package, which maintained the Bioconductor. Array data analysis revealed a total of 454 transcripts to be differen- tially expressed (P < 0.05, fold change >2) between the 2 groups. Of these, 429 and 25 were up- and down-regulated, respectively, in blastocysts derived from superovulated heifers compared with those derived from synchronized animals. Genes involved in response to stress (HSPA14 and HSPE1), cellular and metabolic processes (CPSF3, ATPIF1, POMP, and MDH2), translation (RPS17, EEF1B2, and EIF4E), and cell commu- nication (FN1, KRT18, and DSG2) were found to be enriched in blastocysts derived from superovulated animals. On the other hand, protein metabolic processes related genes (CLGN) were found to be enriched in blastocysts derived from the synchronized group. The KEGG analysis of the differentially expressed genes showed that the ribosome and oxidative phosphorylation pathways are the dominant pathways and genes involved in these pathways are greatly abundant in the blastocysts derived from superovulated animals. Quantitative real-time PCR has confirmed the transcript abundance of 7 out of 8 genes selected for validation. In conclusion, blastocysts cultured in synchronized animals post 2-cell stage showed significant differences in transcriptome profile compared with their counterparts that remained in superovulated heifers until Day 7. Further functional analysis of some selected candidate genes could give new insights into mechanisms regulating the ability of embryos to survive after transfer.

Identification and characterization of miRNAs expressed in the bovine ovary

Background

MicroRNAs are the major class of gene-regulating molecules playing diverse roles through sequence complementarity to target mRNAs at post-transcriptional level. Tightly regulated expression and interaction of a multitude of genes for ovarian folliculogenesis could be regulated by these miRNAs. Identification of them is the first step towards understanding miRNA-guided gene regulation in different biological functions. Despite increasing efforts in miRNAs identification across various species and diverse tissue types, little is known about bovine ovarian miRNAs. Here, we report the identification and characterization of miRNAs expressed in the bovine ovary through cloning, expression analysis and target prediction.

Results

The miRNA library (5'-independent ligation cloning method), which was constructed from bovine ovary in this study, revealed cloning of 50 known and 24 novel miRNAs. Among all identified miRNAs, 38 were found to be new for bovine and were derived from 43 distinct loci showing characteristic secondary structure. While 22 miRNAs precursor loci were found to be well conserved in more than one species, 16 were found to be bovine specific. Most of the miRNAs were cloned multiple times, in which let-7a, let-7b, let-7c, miR-21, miR-23b, miR-24, miR-27a, miR-126 and miR-143 were cloned 10, 28, 13, 4, 11, 7, 6, 4 and 11 times, respectively. Expression analysis of all new and some annotated miRNAs in different intra-ovarian structures and in other multiple tissues showed that some were present ubiquitously while others were differentially expressed among different tissue types. Bta-miR-29a was localized in the follicular cells at different developmental stages in the cyclic ovary. Bio-informatics prediction, screening and Gene Ontology analysis of miRNAs targets identified several biological processes and pathways underlying the ovarian function.

Conclusion

Results of this study suggest the presence of miRNAs in the bovine ovary, thereby elucidate their potential role in regulating diverse molecular and physiological pathways underlying the ovarian functionality. This information will give insights into bovine ovarian miRNAs, which can be further characterized for their role in follicular development and female fertility as well.

Association of ZYX polymorphisms with carcass and meat quality traits in commercial pigs

Zyxin (ZYX) is one of the proteins in focal adhesions along the actin fibers playing a role in actin organization and signal transduction. By radiation hybrid and genetic mapping we assigned ZYX to porcine chromosome 18 in the area of quantitative traits loci for carcass and meat quality and muscle fiber traits and hence considered ZYX a functional positional candidate gene. Analysis of a newly detected SNPs (c.+279 C>T, c.+399 A>G, c.+522 A>G) in pigs from different commercial breeds (Pietrain [Pi], German Landrace [LR], German Large White x German Landrace [F1] and PiF1) revealed a significant association with carcass traits (including: side- and backfat thickness, loin weight and carcass lean content) and meat quality traits (including: pH, color and drip loss). However, the lack of consistent association across all pig populations in this study indicates that the association of the SNPs may be depending on causal mutations in linkage disequilibrium and/or interactions with other loci.

Evidence for association of lymphoid enhancer-binding factor-1 (LEF1) with the number of functional and inverted teats in pigs

The lymphoid enhancer-binding factor-1 (LEF1) belongs to a family of regulatory proteins that share homology with the high mobility group protein-1 (HMG1). The LEF1 gene is a mediator in the canonical Wnt-signalling pathway required for morphogenesis of early mammary gland during embryogenesis. Here we describe the molecular characterisation of the porcine LEF1 gene and its association with number of teats and inverted teats in experimental and commercial populations. The 2357-bp cDNA sequence contains an 1197-bp open reading frame encoding a protein of 398 amino acids. The porcine LEF1 protein shares high identity with LEF1 in other mammalian species. The LEF1 gene contains 12 exons and maps to pig chromosome 8 (SSC8). We identified two single nucleotide polymorphisms (SNPs), a T1351C transition and an A1666C transversion, in the 3' end of LEF1. Associations of the SNP A1666C with presence of inverted teats (P<or= 0.01), total number of teats (P <or= 0.01) and total number of inverted teats (P <or= 0.01) were highly significant; SNP T1351C showed near significance with total number of inverted teats (P <or= 0.1) in the experimental DUMI population. SNP T1351C was significantly associated with total number of inverted teats (P= 0.04) and close to significance with affected teats (P = 0.06) in commercial populations. Haplotype analysis confirmed the tendency towards association with affected teats (P = 0.06) in the experimental DUMI population. The function, position, and associations shown here promote LEF1 as a candidate gene for number of teats and in particular for presence and number of inverted teats.

183 EFFECT OF WELL IN WELL CULTURE OF BOVINE EMBRYOS ON GENE EXPRESSION PROFILE

To culture embryos in small groups, the well in well culture system (miniwells harboring 1 single embryo within the well) has been developed previously. In this work, we aimed to examine the effects of the microenvironment provided by well in well culture and embryo density on the relative abundance of transcripts in the resulting embryos. Cumulus–oocyte complexes (COCs) were aspirated from small follicles (2 to 8 mm), and COCs were cultured in 400 μL of modified TCM (TCM-199, Sigma, Taufkirchen, Germany) supplemented with 12% heat-inactivated estrous cow serum and 10 μg mL–1 of FSH (FSH-p, Sheering, Kenilworth, NJ, USA) for 24 h at 39°C in a humidified atmosphere with 5% CO2 in air. Fertilization was performed in Fert-TALP supplemented with 1 μg mL–1 of heparin. Zygotes were allocated randomly in 2 groups, namely: well in well culture (16 miniwells of 0.7 diameter and deepness each containing 1 embryo per well) and group of 16 (group culture of 16 embryos per well). Six pools each containing 20 Day 7 blastocysts derived from the first 2 groups were used to investigate large-scale gene expression analysis using BlueChip cDNA-Array. Three pools each containing 5 blastocysts were used for Array data validation by real-time PCR using primers specific to 5 selected genes (ATP5, PLAC8, KRT8, S100A10, and ZP3). During validation in vivo-derived bovine blastocysts were included to be used as standard. Significance Analysis of Microarray identified 75 transcripts differentially expressed between the 2 groups. Blastocysts derived from well in well culture were found to be enriched with genes regulating different molecular functions including structural constituent of ribosome (RPS29), protein binding (Cul1), calcium ion binding (S100A10, NPTX2), nitric oxide synthase regulator activity (HSPCA), and RNA polymerase II transcription factor activity (UHRF1). However, blastocysts derived from group of 16 culture were found to be enriched with genes involved in oxidoreductase activity (ALOX15, AKR1B), cytochrome-c oxidase activity (COX7A2), hydrogen ion transporting ATP synthase activity (ATP5O), transcription (PTTG1), and cell redox homeostasis (TXN). According to their biological process, genes enriched in blastocysts derived from well in well culture belong to small molecule transport and signal transduction, whereas most downregulated genes have a metabolic function. Comparison of the transcript abundance of the 5 selected genes in the 3 embryo groups showed that the expression of ATP5, PLAC8, and KRT8 in embryos from well in well culture resembles to the relative abundance in blastocyst derived from in vivo culture. However, with respect to the expression of S100A10 and ZP3 genes, blastocysts derived from group culture showed similarity with embryos derived from in vivo. In conclusion, microenvironment affects the gene expression pattern of the resulting embryos.

99 EFFECT OF SUPPRESSION OF BOVINE DNA METHYLTRANSFERASE 1 ON EMBRYONIC DEVELOPMENT AND EXPRESSION OF IMPRINTED GENES

DNA methyltransferase 1 (DNMT1) is believed to be involved in DNA methylation, which is a well-characterized epigenetic modulator shown to have essential functions in germ line and embryonic genome imprinting. This study was conducted to investigate the consequences of suppressing and inhibiting DNMT1 on the development, level of apoptosis, and expression of imprinted genes in pre-implantation bovine embryos. In vitro-produced zygotes were categorized into 4 groups; namely, those injected with Smartpool siRNA (SpsiRNA; Dharmacon Inc., Chicago, IL) (n = 800), 5aza-2′-deoxycytidine (5-AZA; Sigma, St. Louis, MO) (n = 864), nuclease-free water (n = 850), and uninjected control (n = 755). The mRNA expression data were generated using RT-PCR based on the relative standard curve method employing glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as a normalizer. Apoptotic index (API) was calculated by dividing the number of apoptotic cells to total cell number. The proportion of 2-, 4-, 8-cell and 2-, 4-, 8-, and 16-cell embryos was assessed 48 and 72 h, respectively, post-micro injection (pmi), whereas blastocyst rate was assessed at Day 8 pmi. Data on embryonic development and the relative mRNA abundance were analyzed using ANOVA followed by a multiple pair-wise mean comparison using Tukey test. The proportion of 2-, 4-, and 8-cell embryos at 48 h pmi was not significant among treatment groups. However, the proportion of the 8-cell embryos was significantly lower (P < 0.05) in SpsiRNA (16.3 ± 4.5) and 5-AZA injected groups (17.7 ± 4.9) compared with water-injected (26.8 ± 2.9) and uninjected controls (30.7 ± 6.2). The lowest total blastocyst rate (P < 0.05) was observed in the 5-AZA treatment group (16.9 ± 4.9) compared with SpsiRNA (23.4 ± 2.1) and water-injected (24.1 ± 5.3) and uninjected controls (29.4 ± 2.1). Microinjection of SpsiRNA reduced the target mRNA by 80 and 50% in 8-cell and blastocyst stage embryos, respectively, compared with uninjected control, and the protein expression level was also reduced at 8-cell embryos as confirmed by Western blotting. Injection of 5-AZA had no significant effect on mRNA or protein expression. The greatest API (P < 0.05) was found in SpsiRNA (4.2 ± 2.0) and 5-AZA (4.1 ± 1.7) injected groups compared with water-injected (2.8 ± 2.1) and uninjected controls (2.9 ± 2.3). The relative expression study also showed that microinjection of SpsiRNA and 5-AZA increased the expression of IGF2 (by 67 and 55%), IGF2R (29 and 30%), and IGFPB-4 (22 and 24%), respectively, compared with uninjected control, without affecting the expression of both IGF2R and IGFPB-4. In conclusion, suppression of DNMT1 resulted in lower proportion of 8-cell embryos, reduced blastocyst rate, and increased apoptotic index, and affected the expression of some imprinted genes, demonstrating a critical role of this gene in bovine embryonic development.

172 IDENTIFICATION OF MICRORNAS IN BOVINE OVARY

Tightly regulated expression and interaction of a multitude of genes for ovarian folliculogenesis leading to successful oocyte development could be regulated by recently identified new class of small RNAs of ~22 nt (i.e. microRNAs), which are already proved as one of the vital transcriptional regulators in different biological processes including development. But their presence and expression in bovine ovary has not yet been determined. Here, we have attempted to identify miRNAs in bovine ovary by small RNA-cDNA library construction through 5 ligation independent cloning. For this purpose, total RNA enriched with small RNA was isolated from ovary and size fractionated (18 to 24 nt) by denaturing PAGE. Extracted RNA was first 3′ linkered and after template switching by RT, the second 3′ linkering of the first strand cDNA was performed. These linkered small RNA-cDNAs were then amplified with linker-specific primers consisting of BAN I restriction sites, concatemerized by serial ligation, cloned into TOPO TA vector, and transformed into TOP 10 chemically competent cells. After screening, colonies were picked and sequenced. Bioinformatic analysis was done according to the published criteria for the small RNAs. From 233 clones a total of 479 reads were identified. Frequency of sequence length found in the library was 26.8% for ≤18 nt, 55.1% for 19 to 22 nt, and 18.1% for ≥23 nt. The total 479 sequences identified in the library represent 35% miRNAs, 12% mRNA, 12.1% rRNA, 5.6% tRNA, 4.2% repeat associated siRNA, 3.8% non-repeat-associated siRNA, 4% tiny noncoding RNA, 1% small nuclear RNA, and 16% sequences not matched to bovine genome. All 171 miR sequences comprised 79 distinct miRNAs, of which 45 miRNAs already annotated in miRBase for bovine and the other 34 miRNAs are new discoveries. Of the 34 newly identified miRNAs, 12 are described in other species but not yet in bovine. Most of the miRNAs cloned into multiple times, where let-7a cloned for 10, let-7b for 28, let-7c for 13, miR-21 for 4, miR-23b for 11, miR-24 for 7, miR-27a for 6, miR-126 for 4, and miR-143 for 11 times. Based on best hit score, P-value and free energy by online target prediction, some of the bta-miR identified in the library (let-7b, 15b, 18a, 23b, 101, 125b, 126, 140, 145, 199a) are found to target hundreds of genes related to follicular development, ovulation and hormonal regulation. Further functional characterization of some selected miRNAs including expression profiling and in situ localization in follicles of different size and cycles may supplement the results of this study and will enable us to gain insight into their relation to female fertility.

196 EMBRYO BIOPSY TRANSCRIPTOMICS: A POTENTIAL TOOL TO IDENTIFY TRANSCRIPTS DIRECTLY RELATED TO THE ABILITY OF THE EMBRYO TO INDUCE PREGNANCY AFTER TRANSFER

The incidence of pregnancy loss due to embryonic mortality in cattle is one of the major causes of reproductive failure. The early embryonic loss can be due to problems with the embryo itself, the uterine environment, or interactions between the embryo and the uterus. So, this study was conducted to investigate the gene expression profile of bovine embryo biopsies produced in vivo and in vitro that resulted in different pregnancy outcomes. For this, biopsies representing 30 to 40% of the intact in vitro and in vivo blastocysts were taken, and 60 to 70% part was allowed to re-expand prior to transfer to recipients. Based on the pregnancy outcome after transfer, biopsies (n = 10 per pool) were grouped into 3 distinct phenotypes: those that resulted in no pregnancy, those that resulted in resorption, and those that resulted in successful pregnancy and subsequent calf delivery. A bovine cDNA microarray with 2000 clones was used to analyze the gene expression profiles of 3 replicates from each embryo biopsy group. Array data analysis revealed a total of 50 and 52 genes to be differentially expressed between biopsies derived from in vivo blastocysts that resulted in no pregnancy v. calf delivery and resorption v. calf delivery, respectively. Similarly, a total of 52 and 58 transcripts were differentially expressed between biopsies derived from in vitro-produced blastocysts that resulted in no pregnancy v. calf delivery and resorption v. calf delivery, respectively. Quantitative real-time PCR has confirmed the expression profile of 6 selected candidate genes. A distinct set of genes were found to be commonly expressed between in vitro- and in vivo-derived blastocyst biopsies, which ended up with the same pregnancy outcome. Biopsies, which ended up with calf delivery, were found to be enriched with transcripts involved in nucleosome assembly (KRT8), translation (RPLPO), electron transport (COX-2), and placenta specific (PLAC8). On the other hand, transcripts regulating immune response (TNFa), response to stress (HSPD1), and cell adhesion (CD9) were up-regulated in embryos that resulted in no pregnancy or resorption. Differences in transcript abundance of some genes have been seen between biopsies derived from in vitro and in vivo blastocysts. Biopsies from in vivo-derived blastocysts and that ended up with resorption were found to be enriched with transcripts regulating calcium-binding protein (S100A10, S100A14). Transcription factor-related transcripts (CDX2, HOXB7) were up-regulated in vitro-derived blastocyst biopsies that resulted in no pregnancy. In conclusion, the results evidenced that embryos derived from either in vitro or in vivo have more similarities than differences in their transcript abundance with respect to the ability in initiating pregnancy.

114 DEVELOPMENT OF AN OPTIMIZED WELL IN WELL CULTURE SYSTEM: EFFECT OF MINIWELL CALIBER AND CULTURE DROP VOLUME ON DEVELOPMENTAL COMPETENCE OF BOVINE EMBRYOS

To overcome developmental problems due to the scientific need to track single embryos or due to embryo culture in small groups, the Well in Well culture system has been developed previously. Here we aimed to examine the effects of different MiniWell caliber and different embryo densities on developmental rates. Cumulus oocyte complexes (COC) aspirated from small follicles (2–8 mm) were cultured in modified TCM (TCM199, Sigma, Taufkirchen, Germany) supplemented with 12% heat inactivated oestrus cow serum and 10 μg mL–1 FSH (FSH-p, Sheering, Kenilworth, NJ, USA) for 24 h at 39°C in a humidified atmosphere with 5% CO2 in air. Fertilization was performed in Fert-TALP medium. After 20 h coincubation with sperm cells, presumptive zygotes were allocated into MiniWells of different diameter (0.3, 0.4, 0.5, and 0.7 mm) and depth (0.3, 0.5, and 0.7 mm) to investigate the effect of MiniWell diameter and depth on further development of the embryos. To investigate the effect of embryo density we compared the development of zygotes placed in MiniWells with different total volumes of culture medium per well. For all experiments bovine embryos cultured in groups of 16 and groups of 50 served as controls. Developmental rates of in vitro-produced embryos were analysed by chi-square test. Differences of P < 0.05 were considered to be significant. When embryos were cultured in a 4 × 3 factorial design (n = 240 per treatment group in 16 replicates), MiniWell diameter (0.3 mm v. 0.4 mm v. 0.5 mm v. 0.7 mm) significantly affected developmental rates to the blastocyst stage (21.5% v. 26.9% v. 32.5% v. 31.3%, respectively) and MiniWell depth (0.3 mm v. 0.5 mm v. 0.7 mm) influenced development (24.4% v. 27.4% v. 29.3%, respectively). When embryos (n = 160 per treatment group in 10 replicates) were cultured in different total volumes of culture media per Well (0 μL, v. 150 μL v. 500 μL) development of embryos to the blastocyst stage (3.1% v. 13.1% v. 33.1%, respectively) differed significantly. When a total of 240 embryos cultured in 15 replicates in group of 16 were compared with a total of 750 embryos cultured in 15 replicates in group of 50, embryos cultured in group of 16 reached the blastocyst stage at a significantly lower level than zygotes cultured in the group of 50 (22.2% v. 30.3%), whereas zygotes cultured in MiniWells were able to compensate against low embryo densities reaching a blastocyst rate as high as embryos cultured in group of 50 (31.3 v. 30.3%). The best developmental rate of bovine zygotes to the blastocyst stage was observed in MiniWells with a diameter of 0.7 mm and 0.7 mm depth in 500 μL culture medium per well. In conclusion, we successfully optimized the Well in Well culture system by exploring the most suitable MiniWell properties supporting improved developmental rates to the blastoyst stage by compensating against negative effects of low embryo densities allowing to track each individual embryo over the complete culture period.

195 TRANSCRIPTOME PROFILING OF BOVINE ENDOMETRIUM BASED ON THE PREGNANCY OUTCOME AFTER TRANSFER OF IN VIVO-DERIVED EMBRYOS

Transcriptome profiling of pre-transfer cycle endometrium in relation to its ability to sustain the upcoming pregnancy may pave the way to develop or identify molecular markers that can be utilized to detect and select receptive endometrium before embryo transfer. Here, we aim to show differential expression of genes between endometrium biopsies derived from recipients during pre-transfer cycle based on the pregnancy successes after embryo transfer. For this, endometrium biopsies were taken from 56 Simmental cyclic heifers of the same age at day 7 and 14 of the estrous cycle. On the next cycle, in vivo-produced day 7 blastocysts were transferred to all animals at day 7 of the estrous cycle. Pregnancy diagnosis was done at 28, 42, and 56 days of gestation. Thirty-two cows were returned to heat after 21 days, 7 were pregnant until day 42 but no pregnancy after that, and 15 resulted in calf delivery. Subsequently, the endometrium biopsies sampled during the pre-transfer period were categorized based on the pregnancy outcome. Those endometrial biopsies taken at days 7 and 14 during the pre-transferred period from those that resulted in successful calf delivery were named as d7CD and d14CD, respectively, and those endometrial samples collected at days 7 and 14 during pre-transferred period from those groups that resulted in no pregnancy were named as d7NP and d14NP, respectively. Total RNA was extracted from 3 pools of each experimental group in 3 replicates using RNeasy mini kit (Qiagen, Hilden, Germany). A total of 12 biotin-labeled cRNA samples were hybridized on 12 bovine Affymetrix arrays (Affymetrix, Santa Clara, CA, USA) consisting of 24128 probe sets. The microarray data normalization and background correction was performed using guanine cytosine robust multi-array analysis, and the data analysis was performed using LIMMA written on R package, which maintained the bioconductor. The results showed that 1130 transcripts were differentially expressed between d7CD and d7NP, of which 626 and 504 were up- and down-regulated, respectively, in d7CD. Genes that involve in regulation of transcription (PPARA, NR2F1, MYB, MYB, and CHF2) and the collagen families (COL1A1 and COL1A2) were enriched in d7CD. A total of 234 transcripts were differentially expressed between d14CD and d14NP, of which 94 and 140 were up- and down-regulated, respectively, in d14CD compared to d14NP. Transcripts involved in protein amino acid phosphorylation (MA2K6, GATM, AK3L1, and MAPK10) were found to be enriched in d14CD compared to d14NP. In conclusion, pre-transfer endometrium biopsies showed significant differences in transcriptome profile depending on the pregnancy outcome after transfer of in vivo-derived blastocysts and enable to identify transcripts related to pregnancy establishment.

Effect of the microenvironment and embryo density on developmental characteristics and gene expression profile of bovine preimplantative embryos cultured in vitro

The Well of the Well (WOW) system has been developed to culture embryos in small groups or to track the development of single embryos. In the present study, we aimed to examine the effects of the microenvironment provided by the WOW system and embryo density on developmental rates, embryo quality and preimplantative gene expression profile of the resulting embryos. Embryos cultured in a group of 16 reached the blastocyst stage at a significantly lower level than zygotes cultured in a group of 50 (22.2 vs 30.3%), whereas zygotes cultured in WOW were able to compensate against low embryo densities, reaching a blastocyst rate as high as embryos cultured in a group of 50 (31.3 vs 30.3%). Moreover, embryos derived from WOW culture did not differ in terms of differential cell counts and apoptotic cell index compared with controls. The gene expression analysis revealed 62 transcripts to be upregulated and 33 transcripts to be downregulated by WOW culture. Comparing the in vivo derived blastocysts with the blastocysts derived from WOW culture, and group culture, expression of ATP5A1, PLAC8 and KRT8 was more similar to the embryos derived from WOW culture, whereas expression of S100A10 and ZP3 genes was more similar to blastocysts cultured in a group. In conclusion, microenvironment as well as embryo density significantly affected developmental rates. While subsequent blastocysts did not differ in terms of differential cell counts and apoptotic cell index, significant differences were observed in terms of the relative abundance of transcripts in the resulting embryos.

Expression profiling of muscle reveals transcripts differentially expressed in muscle that affect water-holding capacity of pork

To identify biological processes as well as molecular markers for drip loss, a parameter for water holding capacity of meat, the M. longissimus dorsi transcriptomes of six divergent sib pairs were analyzed using Affymetrix Porcine Genome Array. Functional categories of differentially regulated transcripts were determined by single-gene analysis and gene set analysis. The transcripts being up-regulated at high drip loss belong to groups of genes functionally categorized as genes of membrane proteins, signal transduction, cell communication, response to stimulus, and cytoskeleton. Among genes down-regulated with high drip loss, functional groups of oxidoreductase activity, lipid metabolism, and electron transport were identified. Differential regulation of the abundance of transcripts of these biological networks in live muscle affect mortem biochemical processes of meat maturation. Knowledge of this functional link is indicative for the identification of candidate genes for improvement of meat quality.

SNP analysis, genotyping and mapping of the porcine <i>GPCR142</i> gene (Brief report)

Abstract. The RLN3 gene has been recently reported as a ligand for two related orphan G protein-coupled receptors, GPCR135 and GPCR142 (BATHGATE et al., 2002; LIU et al., 2003a; LIU et al., 2003b; CHEN et al., 2005). Pharmacological studies of the GPCR142 gene indicated that the RLN3 gene is the only member of the RLN family showing the ability to activate this gene (BATHGATE et al., 2002). The GPCR142 gene contains a single exon and is located on chromosome 1 (1q22) in human (FREDRIKSSON et al., 2003). It is expressed abundantly in the hypothalamus with discrete expression in the paraventricular nucleus of the hypothalamus and supraoptic nucleus; as well as in the cortex, septal nucleus and preoptical area (LIU et al., 2003b). The functional roles of the RLN3 gene and its receptors within the mammalian physiology are still unclear. The objectives of this study were to characterize the GPCR142 gene in pigs, to determine the chromosomal location and to analysis the expression profile in pigs.

Molecular and subcellular characterisation of oocytes screened for their developmental competence based on glucose-6-phosphate dehydrogenase activity

Oocyte selection based on glucose-6-phosphate dehydrogenase (G6PDH) activity has been successfully used to differentiate between competent and incompetent bovine oocytes. However, the intrinsic molecular and subcellular characteristics of these oocytes have not yet been investigated. Here, we aim to identify molecular and functional markers associated with oocyte developmental potential when selected based on G6PDH activity. Immature compact cumulus-oocyte complexes were stained with brilliant cresyl blue (BCB) for 90 min. Based on their colouration, oocytes were divided into BCB(-) (colourless cytoplasm, high G6PDH activity) and BCB(+) (coloured cytoplasm, low G6PDH activity). The chromatin configuration of the nucleus and the mitochondrial activity of oocytes were determined by fluorescence labelling and photometric measurement. The abundance and phosphorylation pattern of protein kinases Akt and MAP were estimated by Western blot analysis. A bovine cDNA microarray was used to analyse the gene expression profiles of BCB(+) and BCB(-) oocytes. Consequently, marked differences were found in blastocyst rate at day 8 between BCB(+) (33.1+/-3.1%) and BCB(-) (12.1+/-1.5%) oocytes. Moreover, BCB(+) oocytes were found to show higher phosphorylation levels of Akt and MAP kinases and are enriched with genes regulating transcription (SMARCA5), cell cycle (nuclear autoantigenic sperm protein, NASP) and protein biosynthesis (RPS274A and mRNA for elongation factor 1alpha, EF1A). BCB(-) oocytes, which revealed higher mitochondrial activity and still nucleoli in their germinal vesicles, were enriched with genes involved in ATP synthesis (ATP5A1), mitochondrial electron transport (FL405), calcium ion binding (S100A10) and growth factor activity (bone morphogenetic protein 15, BMP15). This study has evidenced molecular and subcellular organisational differences of oocytes with different G6PDH activity.

Combined line-cross and half-sib QTL analysis in Duroc-Pietrain population

A Duroc-Pietrain resource population was built to detect quantitative trait loci (QTL) that affect growth, carcass composition, and pork quality. The data were analyzed by applying three least-squares Mendelian models: a line-cross (LC) model, a half-sib (HS) model, and a combined LC and HS model (CB), which enabled the detection of QTL that had fixed, equal, and different allele frequencies for alternate breed alleles, respectively. Permutation tests were performed to determine 5% chromosome-wide and 5% genome-wide threshold values. A total of 40 (137) QTL were detected at the 5% genome-wide (chromosome-wide) level for the 35 traits analyzed. Of the 137 QTL detected, 62 were classified as the LC type (LC-QTL), 47 as the HS type (HS-QTL), and 28 as the CB type (CB-QTL). The results indicate that implementation of a series of model-based framework is not only beneficial to detect QTL, but also provides us with a new and more robust interpretation from which further methodology could be developed.

Trait correlated expression combined with expression QTL analysis reveals biological pathways and candidate genes affecting water holding capacity of muscle

Background

Leakage of water and ions and soluble proteins from muscle cells occurs during prolonged exercise due to ischemia causing muscle damage. Also post mortem anoxia during conversion of muscle to meat is marked by loss of water and soluble components from the muscle cell. There is considerable variation in the water holding capacity of meat affecting economy of meat production. Water holding capacity depends on numerous genetic and environmental factors relevant to structural and biochemical muscle fibre properties a well as ante and post slaughter metabolic processes.

Results

Expression microarray analysis of M. longissimus dorsi RNAs of 74 F2 animals of a resource population showed 1,279 transcripts with trait correlated expression to water holding capacity. Negatively correlated transcripts were enriched in functional categories and pathways like extracellular matrix receptor interaction and calcium signalling. Transcripts with positive correlation dominantly represented biochemical processes including oxidative phosphorylation, mitochondrial pathways, as well as transporter activity. A linkage analysis of abundance of trait correlated transcripts revealed 897 expression QTL (eQTL) with 104 eQTL coinciding with QTL regions for water holding capacity; 96 transcripts had trans acting and 8 had cis acting regulation.

Conclusion

The complex relationships between biological processes taking place in live skeletal muscle and meat quality are driven on the one hand by the energy reserves and their utilisation in the muscle and on the other hand by the muscle structure itself and calcium signalling. Holistic expression profiling was integrated with QTL analysis for the trait of interest and for gene expression levels for creation of a priority list of genes out of the orchestra of genes of biological networks relevant to the liability to develop elevated drip loss.

254 MOLECULAR AND SUBCELLULAR CHARACTERIZATION OF OOCYTES SCREENED FOR THEIR DEVELOPMENTAL COMPETENCE BASED ON G6PDH ACTIVITY

Oocyte selection based on glucose-6-phosphate dehydrogenase (G6PDH) activity has been successfully used to differentiate between competent and incompetent bovine oocytes (Alm 2005 Theriogenology 63, 2194–2205). However, the intrinsic molecular and subcellular characteristics of these oocytes have not yet been investigated. Here we aim to compare the developmental, molecular, and subcellular characteristics of oocytes selected using brilliant cresyl blue (BCB) staining based on G6PDH activity. Immature compact cumulus–oocyte complexes (COCs) were stained with 26 µm BCB (B-5388, Sigma-Alderich, Taufenkirchen, Germany) for 90 min. Based on their coloration, oocytes were divided into BCB– (colorless cytoplasm, high G6PDH activity) and BCB+ (colored cytoplasm, low G6PDH activity). The chromatin configuration and the mitochondrial activity of oocytes were determined by fluorescence labelling and photometric measurement (n = 337). The abundance and phosphorylation pattern of protein kinases Akt and MAP kinase were estimated by western blot analysis (n = 500). A bovine cDNA microarray with 2000 clones was used to analyze the gene expression profiles of BCB+ and BCB– oocytes (n = 580). BCB+ oocytes were found to result in a higher blastocyst rate (33.1 � 3.1%) until Day 8 of in vitro culture compared to BCB– ones (12.1 � 1.5%). Moreover, BCB+ oocytes showed higher phosphorylation levels of Akt and MAP kinase compared to the BCB– oocytes. After array data analysis, BCB+ oocytes were found to be enriched with genes regulating transcription (SMARCA5), cell cycle (NASP), and protein biosynthesis (RPS274A and EEF1A1), while the BCB– oocytes had a higher level of genes involved in ATP synthesis (ATP5A1), mitochondrial electron transport (FL405), calcium ion binding (S100A10), and growth factor activity (BMP-15). Independent real-time quantitative PCR validated 90% (9/10) of the genes investigated to be in agreement with the array expression profile. The study has shown evidence of differences in molecular and subcellular organization of oocytes with different G6PDH activity.

190 SUPPRESSION OF A TRANSCRIPTION FACTOR MSX1 GENE IN BOVINE PREIMPLANTATION EMBRYOS AND ITS EFFECT ON mRNA, PROTEIN, AND EXPRESSION OF DOWNSTREAM GENES

MSX1 is a transcription factor gene that orchestrates gene expression and regulates cell growth, proliferation, differentiation, cell-to-cell communication, and the apoptotic pathway during pattern formation in vertebrate embryogenesis. However, its role in bovine preimplantation embryo is not known. Here we aim to investigate the effects of suppressing MSX1 transcript on the development of in vitro-produced bovine embryos, study the expression of mRNA and protein products of the gene, and identify downstream genes using microarray analysis. In the first experiment, IVP zygotes were injected with 341 bp-long dsRNA (LdsRNA) (n = 384), 19 bp small interfering RNA (siRNA) (n = 374), and scrambled sequence RNA (scRNA) (n = 388). Uninjected zygotes (n = 313) were used as control. Developmental phenotype data were collected during culture until Day 8. The mRNA and protein expression levels of the different treatment groups were validated at the 8-cell and blastocyst stages using quantitative real-time PCR and immunohistochemistry, respectively. Developmental phenotype and mRNA data were analyzed using ANOVA under statistical package SPSS (SPSS, Inc., Chicago, IL, USA). In the second experiment, custom SMARTpool siRNA (Dharmacon Inc., Chicago, IL, USA) targeting bovine MSX1 (NM_174798) was used for microinjection together with siRNA and uninjected control. Following treatment at zygote stage, 8-cell embryos were used for mRNA isolation and subsequent array hybridization using bovine cDNA array containing 2000 clones. Array data analysis was performed using statistical analysis of microarray (SAM) procedure. While 33% and 29% of the zygotes from the control and scRNA treatment groups, respectively, reached blastocyst stage, only 20% and 19% of the zygotes from the LdsRNA and siRNA treatment groups, respectively, reached the same stage. Injection of LdsRNA and siRNA at the zygote stage reduced the mRNA expression level by 52% and 33% at the 8-cell stage and by 77% and 87%, respectively, at the blastocyst stage as compared to the control. Similarly, cellular protein expression levels in LdsRNA- and siRNA-injected treatment groups were found to be lower than the control groups at each stage. In all cases, injection of scRNA had no effect on mRNA and protein levels. SAM analysis revealed that, of the total 2000 clones, 3.5% and 5.4% were found to be differentially expressed in embryos injected with SMARTpool and siRNA, respectively, compared to the control. Genes involved in various activities including transcription factors (ALF), cell growth (BMP-15), metabolism (RIOK3), and cytokinasis (AURKA) were found to be down-regulated in 8-cell embryos treated with SMARTpool siRNA compared to the controls. On the other hand, genes involved in protein synthesis (RPL23), energy metabolism (COQ1), cell growth (MNS1) and skeletal development (LGALS3) were found to be upregulated in the same samples. In conclusion, suppression of MSX1 at the mRNA and protein level significantly affected the development of bovine embryos, and our study revealed list of downstream genes regulated by the activity of MSX1.

112 Birc6/Apollon INVOLVED IN BOVINE PREIMPLANTATION EMBRYO DEVELOPMENT

Baculoviral inhibitor of apoptosis repeat-containing (Birc)6 gene is known by different names as Birc6, Apollon, Bruce, or KIAA1289. The bovine Birc6 contains the ubiquitin conjugating enzyme. A deletion of the C-terminal half and the ubiquitin conjugating enzyme domain of the mouse apollon is known to activate apoptosis and resulted in embryonic lethality. Moreover, its overexpression in drug-resistance cancer cells suggested its antiapoptotic role. However, its involvement in bovine preimplantation embryo development is not yet known. Therefore, this experiment was conducted to investigate the role of Birc6 in bovine preimplantitive embryos by targeted suppression of the Birc6 mRNA using RNA interference (RNAi). For this, gene-specific long double-stranded RNA (dsRNAi) and short hairpin RNA (shRNAi) targeting Birc6 were in vitro synthesized. In vitro-fertilized zygotes were injected with dsRNAi (n = 347) and shRNAi (n = 374), and uninjected zygotes (n = 366) were used as a control. Sham injection was not used as an additional control in this experiment, because water-injected and uninjected control embryos (Nganvongpanit et al. 2006 Mol. Reprod. Dev. 53, 153–163) have shown similar embryonic development. Following microinjection, the proportion of uncleaved zygotes, 2-, 4- and 8-cell embryos, and the Birc6 mRNA knockdown were determined at 96 h post-insemination (hpi). The effect of Birc6 knockdown on genes involved in apoptotic pathway was evaluated by determining the pro-apoptotic Bax mRNA. The specificity of RNAi was investigated by quantifying glyceraldehyde 3-phosphate dehydrogenase in each treatment group. SPSS version 12.0 (SPSS Inc., Chicago, IL, USA) was used for statistical analysis. The least significant difference t-test pairwise comparison was done between the treatment groups to test varation in uncleaved zygotes, 2-, 4-, and 8-cell embryos. The results showed that the proportion of 8-cell embryos (mean � SEM) was significantly (P < 0.05) higher in control (49.1 � 3.3) compared to dsRNAi (34 � 4.4) and shRNAi (33.5 � 5.2) groups, but the proportion of the 2-cell embryos was significantly higher in dsRNAi (15.1 � 2.3) and shRNAi (14.9 � 3.5) compared to control (8.9 � 1.7), indicating developmental arrest of 2-cell embryos in RNAi groups before reaching the 8-cell stage. Furthermore, the proportion of uncleaved embryos tended to be higher in dsRNAi (34.6 � 3.2) and shRNAi (35.2 � 4.4) compared to control (28.2 � 3.02). The data on the level of suppression on these embryos showed that the Birc6 mRNA in 2-cell embryos was reduced by 85% in dsRNAi and by 50% in shRNAi treatment groups. In 8-cell embryos, 40 and 50% knockdown was achieved in shRNAi and dsRNAi groups, respectively, compared to the control. Similarly, in 8-cell embryos, there was a 23 and 70% increase in mRNA level of Bax in dsRNAi and shRNAi groups, respectively, compared to control, indicating the incidence of apoptosis in the RNAi groups. In conclusion, significantly lower proportions of 8-cell embryos and higher proportion of 2-cell and uncleaved embryos in Birc6 RNAi treatment groups compared to the control groups may reveal the involvement of Birc6 in bovine preimplantation embryo development.

Molecular genetic analysis of porcine mannose-binding lectin genes, MBL1 and MBL2, and their association with complement activity

Mannose-binding lectin (MBL) mediates activation of the complement system via the lectin pathway. Two forms of MBL, MBL-A and MBL-C, were characterized in rodents, rabbits, bovine and rhesus monkeys, whereas only one form was identified in humans, chimpanzees and chickens. The two forms are encoded by two distinct genes named MBL1 and MBL2, which have been identified in many species including the pig. In this report, we studied the two porcine genes MBL1 and MBL2. The porcine MBL genes had higher identities to bovine rather than primate and rodent sequences. Both genes were assigned to chromosome 14 by radiation hybrid panel and linkage mapping. Both MBL genes were highly expressed in liver. MBL1 was also found to be expressed in the lung, testis and brain, whereas low expression of MBL2 was detected in the testis and kidney. New single nucleotide polymorphisms of porcine MBL2 gene were found and genotyped in an experimental F2 pig population, together with a previously reported SNP of MBL1. MBL1 genotypes differed in C3c serum concentration, i.e. in vivo complement activity, at P < 0.1. Correspondingly, linkage analysis revealed a quantitative trait locus for C3c serum level close to the position of the MBL genes. The study thus promotes the porcine MBL genes as functional and positional candidate gene for complement activity.