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:Previoulsly miRNA expression profiling of the whole mammary gland across different stages of pregnancy and lactation has been performed in mice. Since mammary gland has both epithelial and stromal compartments, to specifically identify the miRNAs involved in the transition from pregnancy to lactation a process termed as secretory activation, expression profiling of isolated mammary epithelial cells (MECs) from four CD1 mice each at Pregnancy day 14 (P14) and Lactation day 2 (L2) was performed in the current study. Statistical analysis of the miRNA changes between P14 and L2 identified 32 miRNAs to be differentially expressed with a fold change greater than or equal to 2, of which, the majority of them declinied at the onset of lactation.
Project description:Previoulsly expression profiling of the whole mammary gland across different stages of pregnancy and lactation has been performed on different strains of mice. Since mammary gland has both epithelial and stromal compartments, to specifically identify the genes involved in the transition from pregnancy to lactation a process termed as secretory activation, expression profiling of isolated mammary epithelial cells (MECs) from four CD1 mice each at Pregnancy day 14 (P14) and Lactation day 2 (L2) was performed in the current study. Statistical analysis of the mRNA changes between P14 and L2 identified 5,499 unique genes as being differentially expressed (5% FDR), of which, 2,902 genes and 2,604 genes were higher in P14 or L2 stages, respectively.
Project description:Previously we have shown significant differences in lactation performance, mammary gland histology and expression profiles of mammary transcriptome during peak-lactation (lactation day 9; L9) between the ordinary CBA/CaH (CBA) and the superior QSi5 strains of mice. In the present study, we compared mammary gland histology between CBA and QSi5 at mid-pregnancy (pregnancy day 12; P12). We assessed lactation performance during the first 8 days of lactation of the 13th - 14th generation of the Advanced Intercross Line (AIL) (CBA X QSi5) mice. We utilized an integrative approach to analyzing mammary microarray expression profiles of CBA and QSi5 at P12 and CBA, AIL and QSi5 at L9. The inguinal mammary glands of CBA/CaH and QSi5 during mid-pregnancy (Pregnancy day 12; P12), and the glands of CBA/CaH, AIL and QSi5 during peak lactation (Lactation day 9; L9) were collected and total RNA was extracted for Affymetrix microarray (mouse genome 430 2) assay
Project description:Previously we have shown significant differences in lactation performance, mammary gland histology and expression profiles of mammary transcriptome during peak-lactation (lactation day 9; L9) between the ordinary CBA/CaH (CBA) and the superior QSi5 strains of mice. In the present study, we compared mammary gland histology between CBA and QSi5 at mid-pregnancy (pregnancy day 12; P12). We assessed lactation performance during the first 8 days of lactation of the 13th - 14th generation of the Advanced Intercross Line (AIL) (CBA X QSi5) mice. We utilized an integrative approach to analyzing mammary microarray expression profiles of CBA and QSi5 at P12 and CBA, AIL and QSi5 at L9.
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:Macrophages are involved in immune defense, organogenesis and tissue homeostasis. They also contribute to the different phases of mammary gland remodeling during development, pregnancy and involution post-lactation. Yet, less is known about the dynamics of mammary gland macrophages in the lactation stage. Here, we describe a macrophage population present during lactation in mice. By multi-parameter flow cytometry and single-cell RNA sequencing we reveal this population as distinct from the two resident macrophage subsets present pregestationally. These lactation-induced macrophages (LiMacs) are predominantly monocyte-derived and expand by proliferation in situ concomitant with nursing. LiMacs develop independently of IL-34 but require CSF-1 signaling and are partly microbiota-dependent. Locally, they reside adjacent to the basal cells of the alveoli and extravasate into the milk. Moreover, we also found several macrophage subsets in human milk, resembling LiMacs. Collectively, these findings reveal the emergence of unique macrophages in the mammary gland and milk during lactation.
Project description:The mammary gland of the lactating mouse synthesizes and secretes milk lipid equivalent to its entire body weight in a single 20 day lactation cycle, making it one of the most active lipid synthetic organs known. To test the hypothesis that multiple metabolic control points and potential regulatory mechanisms are involved in activating lipid and lactose synthesis at the onset of lactation we compared the mammary transcriptome of 130 genes involved in glucose metabolism between late pregnancy and early lactation and in response to dietary fat. We utilized data obtained from microarray analysis of mammary glands from quadruplicate FVB mice at pregnancy day 17, and lactation day 2. Diets containing 8% or 40% lipid were fed from lactation days 5 to 10 and mammary glands and livers of triplicate FVB mice prepared for microarray analysis. We also compared the metabolome obtained from magnetic resonance spectroscopy of flash frozen glands of the mammary gland at day 17 of pregnancy with that at day 2 of lactation. The results provide a global picture of the multiple metabolic strategies utilized to turn a quiescent organ into an incredibly efficient machine for massive but balanced lipid and lactose synthesis and implicate the transcription factor SREBP-1c in regulation of part of the pathway. Keywords: Timecourse and dose response to dietary fat
Project description:2-methoxyestradiol (2ME2) induces mammary gland differentiation through amphiregulin-EGFR mediated signaling: molecular distinctions from the mammary gland of pregnant mice.High levels of 2ME2 are observed in the late stages of pregnancy. We investigated the role of 2ME2 on normal mammary gland development. Large scale gene expression assays were performed using Affymetrix GeneChips in pursuit of detailed molecular basis. (1) Mammary glands of wild type FVB mice administered 75 or 150 mg/kg of 2ME2 (2) Mammary glands of normal FVB/Nj mice (i) at day 16 of pregnancy, (ii) day 2 of lactation (iii) day 30 of post-lactation, and (3) mammary epithelial SCp2 cells after 6, 24 and 48 hours of 10 micromol 2ME2 treatment were examined. In vivo studies revealed that 2ME2 treatment up regulates the expression of amphiregulin. The clue to the role of 2ME2 in differentiation comes from studies in vitro which detected down regulation of inhibitor of differentiation (Id-1) gene and consequent up regulation of amphiregulin. The differentiation of E2 negative SCp2 cells by 2ME2 indicate estradiol independent mechanism. For details, please see our paper in Endocrinology 2006. **NOTE: Migrated from caArray 1.x, identifier='gov.nih.nci.ncicb.caarray:Experiment:1015897590892008:1'