Project description:Hypothalami from Fat (FL) and Lean lines (LL) of juvenile broiler chickens were obtained by divergent selection for high or low levels of abdominal fat at SRA-INRA, France. Gene expression patterns were measured during the development of adiposity at 1 to 7 weeks of age. Differentially expressed genes associated with line, age, or line-by-age were identified. Various phenotypic and metabolic alterations are present between the lines (i.e., abdominal fat, T3 levels and glycemia), however there are no alterations in ad libitum food intake between the lines. A balanced block hybrdization design and the Del-Mar 14K chicken integrated systems microarrays were used to measure gene expression during development. 561 genes were differentially expressed between line, and 442 genes were significant for line-by-age interactions. The greatest number of genes were differentially expressed at week 1 of age, prior to any divergence in adiposity between the two lines. Keywords: Chickens divergently selected for fatness or leanness, transcriptional profiling, differentially expressed genes Four biological replicates were used for each genotype (FL and LL) at four different ages (weeks 1, 3, 5 and 7). 20 micrograms of total RNA from each sample were analyzed using DEL-MAR 14K integrated systems microarrays in a reference design. Each experimental sample was labeled with Cy3 and then hybridized with an aliquot of the reference pool (Cy5). The reference pool of hypothalamic total RNA was generated from an equal aliquot of all the RNA samples (fat and lean lines, week 1, 3, 5, and 7).
Project description:The Del-Mar 14K chip was used to interrogate differential expression of transcripts in the white isthmus (WI) compared with the adjacent magnum (Mg) and uterine (Ut) segments of the hen oviduct. Differential expression of genes common to both comparisons (WI/Mg and WI/Ut) was detected for 204 annotated proteins. Of these, 58 genes were overexpressed in both WI/Mg and WI/Ut, and are therefore considered to be the most interesting candidates for WI - specific functions. Additionally, general analysis revealed 135 clones hybridizing to overexpressed transcripts (WI/Mg + WI/Ut), and corresponding to 102 NCBI annotatated non-redundant Gallus gallus gene ID~s. This combined analysis revealed that structural proteins highly over-expressed in white isthmus were collagen X (COL10A1), Fibrillin (FBN1) and Cysteine Rich Eggshell Membrane Protein (CREMP). In addition, genes encoding collagen-processing enzymes were over-expressed, as were proteins known to regulate disulfide cross-linking, suggesting that coordinated upregulation of gene networks in the white isthmus is associated with eggshell membrane fibre formation. IPA interactome analysis reinforces the key role of the estrogen receptor and SMAD3 in mediating gene regulation during eggshell membrane synthesis. These results will assist with development of selection strategies to improve eggshell quality and food safety of the table egg. Keywords: Laying hen, eggshell, oviduct, Isthmus expression, cDNA microarray, indirect cDNA labelling, Alexa Fluor dyes Keywords: Expression profiling by array
Project description:The inner ear utilizes sensory hair cells as mechano-electric transducers for sensing sound and balance. In mammals, these hair cells lack the capacity for regeneration. Unlike mammals, hair cells from non-mammalian vertebrates, such as birds, can be regenerated throughout the life of the organism making them a useful model for studying inner ear genetics pathways. The zinc finger transcription factor GATA3 is required for inner ear development and mutations cause sensory neural deafness in humans. In the avian cochlea GATA3 is expressed throughout the sensory epithelia; however, expression is limited to the striola of the utricle. The striola corresponds to an abrupt change in morphologically distinct hair cell types and a 180° shift in hair cell orientation. We used 3 complimentary approaches to identify potential downstream targets of GATA3 in the avian utricle. Specifically we used microarray expression profiling of GATA3 knockdown by siRNA and GATA3 over-expression treatments as well as direct comparisons of GATA3 expressing cells from the striola and non GATA3 expressing cells from the extra-striola.
Project description:The Del-Mar 14K chip was used to interrogate differential expression of transcripts in the white isthmus (WI) compared with the adjacent magnum (Mg) and uterine (Ut) segments of the hen oviduct. Differential expression of genes common to both comparisons (WI/Mg and WI/Ut) was detected for 204 annotated proteins. Of these, 58 genes were overexpressed in both WI/Mg and WI/Ut, and are therefore considered to be the most interesting candidates for WI - specific functions. Additionally, general analysis revealed 135 clones hybridizing to overexpressed transcripts (WI/Mg + WI/Ut), and corresponding to 102 NCBI annotatated non-redundant Gallus gallus gene ID~s. This combined analysis revealed that structural proteins highly over-expressed in white isthmus were collagen X (COL10A1), Fibrillin (FBN1) and Cysteine Rich Eggshell Membrane Protein (CREMP). In addition, genes encoding collagen-processing enzymes were over-expressed, as were proteins known to regulate disulfide cross-linking, suggesting that coordinated upregulation of gene networks in the white isthmus is associated with eggshell membrane fibre formation. IPA interactome analysis reinforces the key role of the estrogen receptor and SMAD3 in mediating gene regulation during eggshell membrane synthesis. These results will assist with development of selection strategies to improve eggshell quality and food safety of the table egg. Keywords: Laying hen, eggshell, oviduct, Isthmus expression, cDNA microarray, indirect cDNA labelling, Alexa Fluor dyes Keywords: Expression profiling by array A balanced block hybridization design (Dye switch) was used where half of the samples were labelled with AlexaM-BM-. 555 fluorescent dye and the other half with AlexaM-BM-. 647. A total of 16 microarray slides were used for hybridization to 32 samples that correspond to four tissue contrast (White isthmus versus magnum and uterus versus white isthmus).