Asymmetric growth-limiting development of the female conceptus.

Introduction: Sex differences in prenatal growth may contribute to sex-dependent programming effects on postnatal phenotype.

Methods: We integrated for the first time phenotypic, histomorphological, clinico-chemical, endocrine and gene expression analyses in a single species, the bovine conceptus at mid-gestation.

Results: We demonstrate that by mid-gestation, before the onset of accelerated growth, the female conceptus displays asymmetric lower growth compared to males.

Correlations between intestinal innate immune genes and cecal microbiota highlight potential for probiotic development for immune modulation in poultry.

Immune function is influenced by the diversity and stability of the intestinal microbiota. A likely trade-off of immune function for growth has been demonstrated in heavier breeds of poultry that have been genetically selected for growth and feed efficiency traits. We investigated the expression of selected innate immune genes and genes encoding products involved in intestinal barrier function to determine whether function changes could be consistently linked to the phenotypic expression of feed conversion ratio (FCR), a common measure of performance within poultry broiler flocks.

Atlas of tissue- and developmental stage specific gene expression for the bovine insulin-like growth factor (IGF) system.

The insulin-like growth factor (IGF) axis is fundamental for mammalian growth and development. However, no comprehensive reference data on gene expression across tissues and pre- and postnatal developmental stages are available for any given species. Here we provide systematic promoter- and splice variant specific information on expression of IGF system components in embryonic (Day 48), fetal (Day 153), term (Day 277, placenta) and juvenile (Day 365-396) tissues of domestic cow, a major agricultural species and biomedical model.

Transcriptional analysis of liver from chickens with fast (meat bird), moderate (F1 layer x meat bird cross) and low (layer bird) growth potential.

Background: Divergent selection for meat and egg production in poultry has resulted in strains of birds differing widely in traits related to these products. Modern strains of meat birds can reach live weights of 2 kg in 35 d, while layer strains are now capable of producing more than 300 eggs per annum but grow slowly. In this study, RNA-Seq was used to investigate hepatic gene expression between three groups of birds with large differences in growth potential; meat bird, layer strain as well as an F1 layer x meat bird.

Evaluation of fatty acid metabolism and innate immunity interactions between commercial broiler, F1 layer × broiler cross and commercial layer strains selected for different growth potentials.

Background: The broiler industry has undergone intense genetic selection over the past 50 yr. resulting in improvements for growth and feed efficiency, however, significant variation remains for performance and growth traits. Production improvements have been coupled with unfavourable metabolic consequences, including immunological trade-offs for growth, and excess fat deposition.

Gene expression studies of developing bovine longissimus muscle from two different beef cattle breeds.

Background: The muscle fiber number and fiber composition of muscle is largely determined during prenatal development. In order to discover genes that are involved in determining adult muscle phenotypes, we studied the gene expression profile of developing fetal bovine longissimus muscle from animals with two different genetic backgrounds using a bovine cDNA microarray. Fetal longissimus muscle was sampled at 4 stages of myogenesis and muscle maturation: primary myogenesis (d 60), secondary myogenesis (d 135), as well as beginning (d 195) and final stages (birth) of functional differentiation of muscle fibers.

Mapping and characterization of the dominant black colour locus in sheep.

Dominant black pigment synthesis in sheep is caused by alterations of the melanocortin-1 receptor (MC1-R) coding sequence. Using five bovine microsatellite markers we have mapped the sheep MC1-R gene to chromosome 14, corresponding to the location in other mammalian species. The existence of two independent mutations, both causing an amino acid substitution, in distantly related breeds of sheep, support the hypothesis that the observed black pigment synthesis is caused by a mutual effect of the two mutations.

Effect of nutrition of oocyte donor on the outcomes of somatic cell nuclear transfer in the sheep.

The purpose of this study was to determine if the nutrition of the oocyte donor ewe influenced the success of somatic cell cloning. Merino ewes were fed at either a high- or a low-nutrition level for 3-5 mo before superovulation treatments. Freshly ovulated oocytes were enucleated and fused with serum-starved adult granulosa cells, and resulting reconstructed embryos were cultured for 6 days in modified synthetic oviduct fluid.