ABSTRACT: Transcriptome of normal mammary glands of Sprague-Dawley rats at six stages of development: pre-pubertal, peri-pubertal, pubertal, lactation, adult parous and age-matched nulliparous
Project description:There is a lack of systematic investigations of large-scale transcriptome patterns associated with normal breast development. Herein, we profiled whole-transcriptome (by microarrays) of normal mammary glands in female Sprague-Dawley rats, an animal model widely used in breast cancer research, across six distinctive developmental stages – pre-pubertal, peri-pubertal, pubertal, lactation, and adult parous and age-matched nulliparous.
Project description:Cross-species hybridization analysis of mammary glands during pregnancy and lactation. Results provide insight into putative conserved molecular mechanisms regulating mammary gland development. This study was performed to identify orthologous transcripts that are differentially co-expressed in the mammary gland at 2 stages of development (pregnancy and lactation) in wild type Sprague-Dawley rats.
Project description:Cross-species hybridization analysis of mammary glands during pregnancy and lactation. Results provide insight into putative conserved molecular mechanisms regulating mammary gland development. This study was performed to identify orthologous transcripts that are differentially co-expressed in the mammary gland at 2 stages of development (pregnancy and lactation) in wild type Sprague-Dawley rats. Key points are examined in a time series of Sprague Dawley rat mammary gland development, secretory activation and lactation. Triplicate rat (three biological replicates) at each time point were used for statistical power totalling 12 individual arrays in this study. Rats were as staged pregnant day 1 the day that post coital plug was observed, and similarly, lactation day 1 was the first day after birth. Whole mammary glands No. 4 (inguinal) were obtained from female rats at stages of development: virgin (adulthood, 14 wks of age), Pregnant (5 and 14 days of pregnancy) and Lactating (day 1 and 12 postpartum). The two-color (Cy5/Cy3) microarray experiment was designed to hybridize samples from each group against a common reference, a pool of RNA from mammary gland of three parous or virgin female rats.
Project description:Exposure to common environmental chemicals, including those found in personal care products has been linked to mammary cancer at high doses in animal models. Their effects at low doses at levels comparable to human exposure, especially during critical windows of development remain poorly understood. Using a Sprague-Dawley rat model, we investigated the effects of of three environmental chemicals – diethyl phthalate (DEP), methyl paraben (MPB) and triclosan (TCS) – on the transcriptome of normal developing mammary glands at low doses mimicking human exposure. Rats were exposed during three windows of early development – perinatal (gestation day (GD) 1 - 20 or postnatal day (PND) 1 - 20), prepubertal (PND 21 - 41) and pubertal (PND 42 - 62), as well as chronic exposure from birth to end of lactation (PND 1 - 146). Mammary gland whole-transcriptomes were profiled by Affymetrix rat gene 2.0 st arrays.
Project description:We tested the gene expression difference between PDGFRa+ fibroblasts FACS sorted from nulliparous balb/c mouse mammary glands and 6 days post-weaning mammary glands
Project description:RON WT and RON KO at 5, 6, 7 week virgin mammary glands In the study, we demonstrated that RON regulates mammary gland branching morphogenesis in pubertal development associated with changes in gene expression. Keywords: Pubertal mammary glands
Project description:Exposure to common environmental chemicals, including those found in personal care products has been linked to mammary cancer at high doses in animal models. Their effects at low doses at levels comparable to human exposure remain poorly understood. Using a Sprague-Dawley rat model, we investigated the effects of three prevalently used environmental chemicals – diethyl phthalate (DEP), methyl paraben (MPB), triclosan (TCS) – and their mixture (MIX) on the transcriptome of normal developing mammary at levels mimicking human exposure. Rats were exposed from birth to adulthood in parous and nulliparous settings. We used affymetrix arrays to assess the influence of diethyl phthalate (DEP), methyl paraben (MPB), triclosan (TCS) and their mixture (MIX) on global gene expression profiles in rat mammary tissues, using doses comparable to human exposure. Exposure was from birth to adulthood (postnatal day 1 – 180) in parous and nulliparous rats.
Project description:The mammary gland is a unique organ as it undergoes most of its development during puberty and adulthood. Characterising the hierarchy of the various mammary epithelial cells and how they are regulated in response to gestation, lactation and involution is important for understanding how breast cancer develops. Recent studies have used numerous markers to enrich, isolate and characterise the different epithelial cell compartments within the adult mammary gland. However, in all of these studies only a handful of markers were used to define and trace cell populations. Therefore, there is a need for an unbiased and comprehensive description of mammary epithelial cells within the gland at different developmental stages. To this end we used single cell RNA sequencing (scRNAseq) to determine the gene expression profile of individual mammary epithelial cells across four adult developmental stages; nulliparous, mid gestation, lactation and post weaning (full natural involution). Our data from 25,010 individual cells identifies 8 distinct mammary epithelial cell populations and allows their hierarchical structure across development to be charted. Interestingly, the effect of gestation and lactation appeared to be more pronounced for some cell types. For example, our analysis revealed a cluster of luminal progenitor cells in post involution glands, which is distinct from progenitors found in nulliparous glands. The data also showed that few clusters could be fully characterized by a single marker gene. We argue instead that the epithelial cells – especially in the luminal compartment – should rather be conceptualized as being part of a continuous spectrum of differentiation. This view highlights the plasticity of the tissue and might help to explain some of the conflicting results from lineage tracing studies.
Project description:RON WT and RON KO at 5, 6, 7 week virgin mammary glands In the study, we demonstrated that RON regulates mammary gland branching morphogenesis in pubertal development associated with changes in gene expression. Keywords: Pubertal mammary glands In the study, we hybridized RNA from 5, 6, 7 week old virgin female RON WT and KO mammary glands to Affymetrix GeneChip Mouse Genome 430 2.0 Array
Project description:Analysis of protein tyrosine phosphatase 1B (PTP1B) deficient mammary glands from nulliparous mice at estrous and pregnancy day 3, 7, 10 and 15. We used a genetically ablated PTP1B mouse model to gain a deeper knowledge of the role PTP1B plays in mammary gland development and to define the mechanism regulated by this phosphatase. Results provide insight into the role of PTP1B in mammary gland development and differentiation. Mouse mammary glands were isolated from PTP1B -/- and PTP1B +/+ nulliparous mice at estrous and pregnancy day 3, 7, 10 and 15 for RNA extraction and hybridization on Affymetrix microarrays.
