New Perspectives In The Objective Evaluation Of Animal Welfare, With Focus On The Domestic Pig.

Animal welfare can be viewed as the result of integrating repeated affective evaluations of success in coping with environmental challenges, i.e., subjective challenge adequacy.

Potential Functions of IGFBP-2 for Ovarian Folliculogenesis and Steroidogenesis.

Ovarian follicles, as transient structural and functional complexes with the oocyte and the associated cells, determine the female reproductive cycle and thus fertility. Ovarian function is subject to the strict control of hormones and growth factors and thus regulated by auto-, para-, and endocrine mechanisms but influenced also by endogenous factors. During the waves of follicular growth and development, one follicle (monoovulatory) or a limited number of them (polyovulatory) are selected under hypothalamic-gonadal control for maturation until ovulation, resulting in the fertile oocyte.

Effects of Transport Duration and Environmental Conditions in Winter or Summer on the Concentrations of Insulin-Like Growth Factors and Insulin-Like Growth Factor-Binding Proteins in the Plasma of Market-Weight Pigs.

In previous work using market-weight pigs, we had demonstrated that insulin-like growth factors (IGFs) and insulin-like growth factor binding proteins (IGFBPs) are regulated during shipment characterized by changing conditions of stress due to loading or unloading, transportation, lairage, and slaughter. In addition, we found in a previous study that IGFBP-2 concentrations were lower in pigs transported for longer periods of time. Therefore, we performed a more detailed study on the effects of transport duration and season on the plasma concentrations of IGFs and IGFBPs in adult pigs.

Partial phenotype conversion and differential trait response to conditions of husbandry in mice.

Functional genome analysis usually is performed on the level of genotype-phenotype interaction. However, phenotypes also depend on the relations between genomes and environment. In our experimental system, we observed differential response to environmental factors defined by different conditions of husbandry in a semi-barrier unit or in a SPF (specific pathogen free) barrier unit, which resulted in partial reversal of phenotypes previously observed under semi-barrier conditions.

Interference of stress with the somatotropic axis in pigs - lights on new biomarkers.

The acceptance of animal products is increasingly associated with standardized animal welfare, which relates to appropriate animal husbandry from birth to slaughter. In particular, shipment to the slaughterhouse is considered as a critical process exposing the animals to a number of, in part severe, stressors. New biomarkers may be useful for the assessment of animal welfare.

Exposure of Lactating Dairy Cows to Acute Pre-Ovulatory Heat Stress Affects Granulosa Cell-Specific Gene Expression Profiles in Dominant Follicles.

High environmental temperatures induce detrimental effects on various reproductive processes in cattle. According to the predicted global warming the number of days with unfavorable ambient temperatures will further increase. The objective of this study was to investigate effects of acute heat stress during the late pre-ovulatory phase on morphological, physiological and molecular parameters of dominant follicles in cycling cows during lactation.

Bioanalytical validation for simultaneous quantification of non-aromatic steroids in follicular fluid from cattle via ESI-LC-MS/MS.

The family of steroid hormones is quite attractive for the approach of phenotype monitoring in farm animals. Therefore, we developed a new protocol for the quantitative analysis of natural steroids in follicular fluid from dairy cows. The corresponding steroid profile, which consists of progesterone, corticosterone, hydrocortisone, testosterone, and androstenedione covering three distinct steroid classes, was determined by LC/MS.

Quantitative Western ligand blotting reveals common patterns and differential features of IGFBP-fingerprints in domestic ruminant breeds and species.

The insulin-like growth factor binding proteins (IGFBPs) are determinants of local IGF-effects and thus have an impact on growth and metabolism in vertebrate species. In farm animals, IGFBPs are associated with traits such as growth rate, body composition, milk production, or fertility. It may be assumed, that selective breeding and characteristic phenotypes of breeds are related to differential expression of IGFBPs.

Dissociation of somatic growth, time of sexual maturity, and life expectancy by overexpression of an RGD-deficient IGFBP-2 variant in female transgenic mice.

Impaired growth is often associated with an extension of lifespan. However, the negative correlation between somatic growth and life expectancy is only true within, but not between, species. This can be observed because smaller species have, as a rule, a shorter lifespan than larger species.

Control of IGFBP-2 Expression by Steroids and Peptide Hormones in Vertebrates.

IGFBP-2 (1) has been described as a brain tumor oncogene (2) and is widely expressed in cancers from different origins (3-8). IGFBP-2 alone cannot cause malignant transformation, yet progression of brain tumors to higher grade (9) and also has been provided as a protective element in earlier stages of multistage colon carcinogenesis (10). Therefore, it is crucial to understand the factors that determine expression patterns of IGFBP-2 under normal and malignant conditions.

Research resource: preovulatory LH surge effects on follicular theca and granulosa transcriptomes.

The molecular mechanisms that regulate the pivotal transformation processes observed in the follicular wall following the preovulatory LH surge, are still not established, particularly for cells of the thecal layer. To elucidate thecal cell (TC) and granulosa cell (GC) type-specific biologic functions and signaling pathways, large dominant bovine follicles were collected before and 21 hours after an exogenous GnRH-induced LH surge. Antral GCs (aGCs; aspirated by follicular puncture) and membrane-associated GCs (mGCs; scraped from the follicular wall) were compared with TC expression profiles determined by mRNA microarrays.

Bovine large luteal cells show increasing de novo DNA methylation of the main ovarian CYP19A1 promoter P2.

Transformation of the estrogen producing large dominant follicle into a functional progesterone producing corpus luteum involves profound and well-orchestrated changes in cell type-specific gene expression profiles, possibly involving epigenetic mechanisms of gene silencing. As an experimental paradigm to examine the involvement of de novo DNA methylation in the process of luteinization, the transcript abundance and promoter-specific DNA methylation levels of CYP19A1, which encodes the key enzyme for estrogen biosynthesis, were analyzed in enzymatically dispersed and purified large granulosa luteal cells of early- to mid-cycle bovine corpora lutea. To characterize the morphology and physiology of isolated corpora lutea, their weights and the respective plasma progesterone levels were analyzed.

The pre-ovulatory luteinizing hormone surge is followed by down-regulation of CYP19A1, HSD3B1, and CYP17A1 and chromatin condensation of the corresponding promoters in bovine follicles.

The pre-ovulatory luteinizing hormone (LH) surge induces an extensive molecular, physiological, and morphological reorganization of the bovine follicle. This study was designed to elucidate if chromatin modulation is involved in the LH-induced gene regulation. Granulosa and theca of well-characterized large bovine follicles were isolated before and after the LH surge.

DNA methylation is not involved in preovulatory down-regulation of CYP11A1, HSD3B1, and CYP19A1 in bovine follicles but may have a role in permanent silencing of CYP19A1 in large granulosa lutein cells.

The luteinizing hormone-induced morphological and physiological reorganization of the bovine follicle is preceded by a profound and well-orchestrated modulation of gene expression. In the present study, the cell type-specific methylation profiles of CYP11A1, HSD3B1, and CYP19A1, genes that encode key enzymes of steroid hormone biosynthesis, were analyzed to elucidate whether epigenetic parameters such as DNA methylation might be involved in gene regulation during luteinization. Transcript abundance and DNA methylation levels were determined in granulosa and theca of large dominant and late preovulatory follicles and in large granulosa lutein cells isolated from corpora lutea cyclica and graviditatis.

Down-regulation of genes encoding steroidogenic enzymes and hormone receptors in late preovulatory follicles of the cow coincides with an accumulation of intrafollicular steroids.

The transformation of the dominant follicle into a functional corpus luteum is accompanied by a profound molecular and morphological reorganization of somatic cell layers. Several studies have focused on gene expression during early processes of follicular differentiation as it relates to recruitment and selection of dominant follicles. However, little information exists on changes of gene expression profiles in late preovulatory follicles.

Two high-fertility mouse lines show differences in component fertility traits after long-term selection.

Unlabelled: Two selected high-fertility mouse lines, namely FL1 and FL2, and a non-selected control (Fzt:DU), all derived from the same genetic pool, were analysed as an animal model for polytocous species to elucidate the effects of long-term selection and to identify relevant component traits that may be responsible for fertility performance. The index trait used for breeding selection was largely increased by 104% and 142% in the FL1 and FL2 lines, respectively, resulting in an average litter size of 17.3 pups and 18.