Mammary Gland Lactation Research Articles

VEDOLIZUMAB DOES NOT ALTER IMMUNOGLOBULIN LEVELS IN BREASTMILK OF MOTHERS WITH IBD

Abstract Diarrheal diseases are a major cause of infant mortality worldwide. Breastfeeding helps prevent such diseases by passive transfer of maternal antibodies against gastrointestinal pathogens previously encountered by the mother. The antibody secreting cells (ASC) that populate the lactating mammary gland (LMG) are educated in gastrointestinal lymphoid tissues, thus they express integrin a4b7. To recruit these ASC, the LMG expresses MAdCAM-1 and CCL28. Vedolizumab (vedo) blocks a combinatorial epitope on integrin a4b7, interfering with lymphocyte recruitment to the gut. Given the shared homing determinants between the gut and LMG, we investigated whether vedo might interfere with ASC trafficking to the LMG, therefore decreasing immunoglobulin (Ig) levels in breast milk. We measured Ig levels by ELISA in cryopreserved breast milk from mothers enrolled in Mommy’s Milk biorepository at the University of California, San Diego without and with Ulcerative Colitis(UC) or Crohn’s Disease(CD) and lactating mothers with UC and CD treated with vedo for more than 18 months. Milk samples were collected between 1 month and 15.45 months after childbirth. The levels of secretory IgA (SIgA) in breast milk of mothers without IBD (n=45) was not different from those of mothers with CD not on vedo (n=15) (301 ± 147 ug/mL vs. 322 ± 207 ug/mL). However, milk SIgA from mothers with UC not on vedo (n=7) were lower than non-IBD controls (213 ± 149 ug/mL vs. 301 ± 147ug/mL, p<0.01). We then compared milk SIgA from patients with CD and UC treated with vedo (CD: n= 9; 256 ± 80ug/mL, UC: n=10; 283 ± 87 ug/mL) with those from non-IBD controls (n=45; 301 ± 147ug/mL) and found no differences. Similarly, SIgA levels were not different between CD with or without vedo (256 ± 80 ug/mL vs. 322 ± 207 ug/mL) and as compared with non-IBD controls SIgA in patients with UC with vedo were unexpectedly higher than UC without vedo (283 ±87 ug/mL vs 213 ± 149 ug/mL, p<0.05). The levels of secretory IgM (SIgM) in milk were not different between mothers with UC or CD treated with vedo compared with non-IBD controls (65 ± 34 ug/mL, 69 ± 32 ug/mL, and 56 ± 37 ug/mL, respectively). Similarly, no significant difference was seen between patients with UC or CD not treated with vedo compared with the non-IBD controls (58±26 ug/mL, and 46 ± 24 ug/mL respectively). We conclude that vedo does not reduce SIgA nor SIgM levels in lactating mothers with IBD. We speculate that the higher SIgA in patients with UC treated with vedo is due to the small sample size. Vedo does not interfere with passive immunity during the lactation period, thus ASC must be able to use another integrin to arrest on microvessels of the LMG during the final stages of pregnancy.

Histochemical and Immunohistochemical Examination of Cranial and Caudal Gland Alveolar Secretion of the Same Lactating Mammary Gland Quarter of One Humped She Camel (Camelus dromedarius)

Histochemical and Immunohistochemical Examination of Cranial and Caudal Gland Alveolar Secretion of the Same Lactating Mammary Gland Quarter of One Humped She Camel (Camelus dromedarius)

Identification and functional analysis of m6A in the mammary gland tissues of dairy goats at the early and peak lactation stages.

N6-methyladenosine (m6A) is the most common reversible epigenetic RNA modification in the mRNA of all higher eukaryotic organisms and plays an important role in the regulation of gene expression and cell function. In this study, m6A-modified methylated RNA immunoprecipitation sequencing (MeRIP-seq) and transcriptome sequencing (RNA-seq) were used to identify the key genes with m6A modification during mammary gland development and lactation in dairy goats. The results showed that m6A methylation occurred at 3,927 loci, which were significantly enriched in the 3' untranslated region (3'UTR) and the termination codon region. In the early stage and peak stage of lactation, m6A methylation occurred extensively in mammary tissues, and a total of 725 differentially expressed m6A-modified genes were obtained, all negatively correlated with mRNA expression. In addition, Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that different methylated genes were mainly involved in the growth and apoptosis of mammary epithelial cells through signaling pathways, such as the mitogen-activated protein kinase (MAPK) and phospholipase D pathways, and then affected the development and lactation of mammary gland. All in all, we identified and analyzed the methylation events related to the development and lactation regulation of mammary gland at the early and peak lactation stages, and provided a theoretical basis to reveal the physiological regulatory system of mammary gland development and lactation in dairy goats.

Genome-wide analysis of the acyl-coenzyme A synthetase family and their association with the formation of goat milk flavour.

Goat milk is rich in fat and protein, thus, has high nutritional values and benefits human health. However, goaty flavour is a major concern that interferes with consumer acceptability of goat milk and the 4-alkyl-branched-chain fatty acids (vBCFAs) are the major substances relevant to the goaty flavour in goat milk. Previous research reported that the acyl-coenzyme A synthetases (ACSs) play a key role in the activation of fatty acids, which is a prerequisite for fatty acids entering anabolic and catabolic processes and highly involved in the regulation of vBCFAs metabolism. Although ACS genes have been identified in humans and mice, they have not been systematically characterized in goats. In this research, we performed genome-wide characterization of the ACS genes in goats, identifying that a total of 25 ACS genes (without ACSM2A) were obtained in the Capra hircus and each ACS protein contained the conserved AMP-binding domain. Phylogenetic analysis showed that out of the 25 genes, 21 belonged to the ACSS, ACSM, ACSL, ACSVL, and ACSBG subfamilies. However, AACS, AASDH, ACSF, and ACSF3 genes were not classified in the common evolutionary branch and belonged to the ACS superfamily. The genes in the same clade had similar conserved structures, motifs and protein domains. The expression analysis showed that the majority of ACS genes were expressed in multi tissues. The comparative analysis of expression patterns in non-lactation and lactation mammary glands of goat, sheep and cow indicated that ACSS2 and ACSF3 genes may participate in the formation mechanisms of goaty flavour in goat milk. In conclusion, current research provides important genomic resources and expression information for ACSs in goats, which will support further research on investigating the formation mechanisms of the goaty flavour in goat milk.

Transcriptome profiling of the nonlactating mammary glands of dairy goats reveals the molecular genetic mechanism of mammary cell remodeling

The mammary gland redevelops to the prepregnancy state during involution, which shows the mammary cells have the characteristics of remodeling. The rapidity and degree of mammary gland involution vary across species (e.g., between model organism mice and dairy livestock). However, the molecular genetic mechanism of involution and remodeling of goat mammary gland has not yet been clarified. This work investigated the structural changes and transcriptome characteristics of the mammary gland tissue of nonlactating dairy goats during the late lactation (LL), the dry period (DP), and late gestation (LG). Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining revealed significant changes in the structure of the nonlactating goat mammary gland, and obvious cell apoptosis occurred at LL and DP. Sequencing identified 1,381 genes that are differentially expressed in mammary gland tissue at the 3 developmental stages. Genes related to cell growth, apoptosis, immunity, nutrient transport, synthesis, and metabolism exhibited adaptive transcriptional changes to meet the needs of a new set of mammary gland lactation functions. The significant enrichment of Gene Ontology terms such as humoral immune response, complement activation, and neutrophil-mediated immunity indicates that the innate immune system plays an important role in maintaining the health of degenerative mammary glands and eliminating apoptotic cells. The peroxisome proliferator-activated receptor signaling pathway plays an important regulatory role in lipid metabolism, especially the adaptive changes in expression of genes encoded lipid transport and enzymes, which promote the formation of milk fat during the lactation. The mammary gland development gene module revealed that pregnancy hormone receptors, cell growth factors and their receptors, and genes encoding insulin-like growth factor binding proteins regulate the physiological process of mammary gland involution through adaptive transcriptional changes. Interestingly, ERBB4 was identified as the hub gene of the network that regulates mammary gland growth and development. Overexpression of ERBB4 in mammary epithelial cells cultured in vitro can reduce cell cycle arrest in G1/S phase and apoptosis by regulating the PI3K/Akt signaling pathway and promote the proliferation of mammary epithelial cells. The gene ERBB4 also affects the expression of genes that initiate mammary gland involution and promote mammary gland remodeling. These findings contribute to an in-depth understanding of the molecular mechanisms involved in mammary gland involution and remodeling.

Mammary epithelial cell transcriptome reveals potential roles of lncRNAs in regulating milk synthesis pathways in Jersey and Kashmiri cattle

BackgroundLong noncoding RNAs (lncRNAs) are now proven as essential regulatory elements, playing diverse roles in many biological processes including mammary gland development. However, little is known about their roles in the bovine lactation process.ResultsTo identify and characterize the roles of lncRNAs in bovine lactation, high throughput RNA sequencing data from Jersey (high milk yield producer), and Kashmiri cattle (low milk yield producer) were utilized. Transcriptome data from three Kashmiri and three Jersey cattle throughout their lactation stages were utilized for differential expression analysis. At each stage (early, mid and late) three samples were taken from each breed. A total of 45 differentially expressed lncRNAs were identified between the three stages of lactation. The differentially expressed lncRNAs were found co-expressed with genes involved in the milk synthesis processes such as GPAM, LPL, and ABCG2 indicating their potential regulatory effects on milk quality genes. KEGG pathways analysis of potential cis and trans target genes of differentially expressed lncRNAs indicated that 27 and 48 pathways were significantly enriched between the three stages of lactation in Kashmiri and Jersey respectively, including mTOR signaling, PI3K-Akt signaling, and RAP1 signaling pathways. These pathways are known to play key roles in lactation biology and mammary gland development.ConclusionsExpression profiles of lncRNAs across different lactation stages in Jersey and Kashmiri cattle provide a valuable resource for the study of the regulatory mechanisms involved in the lactation process as well as facilitate understanding of the role of lncRNAs in bovine lactation biology.

Effects of a High-Grain Diet With a Buffering Agent on Milk Protein Synthesis in Lactating Goats.

Chinese dairy industries have developed rapidly, providing consumers with high-quality sources of nutrition. However, many problems have also appeared during the development process, especially the low quality of milk. To improve milk quality, a large amount of concentrated feed is usually added to the diet within a certain period of time, which increases the milk production to a certain extent. However, long-term feeding with high-concentration feed can lead to subacute rumen acidosis. Therefore, the present study aimed to determine the effect of adding a buffer on subacute rumen acidosis, and the improvement of milk production and milk quality. We also aimed to study the mechanism of promoting mammary gland lactation. A total of 12 healthy mid-lactating goats were randomly divided into two groups, they were high-grain diet group (Control) and buffering agent group. To understand the effects of high-grain diets with buffers on amino acids in jugular blood and the effects of amino acids on milk protein synthesis, Milk-Testing™ Milkoscan 4000, commercial kits, and high-performance liquid chromatography (HPLC) measurements were integrated with the milk protein rate, the amino acid concentration in jugular venous blood samples, quantitative real-time PCR, comparative proteomics, and western blotting to study differentially expressed proteins and amino acids in mammary gland tissues of goats fed high-grain diets. Feeding lactating goats with buffering agent increased the percentage of milk protein in milk, significantly increased the amino acid content of jugular blood (p < 0.05), and increase the amino acid transporter levels in the mammary gland. Compared with the high-grain group, 2-dimensional electrophoresis technology, matrix-assisted laser desorption/ionization-time of flight/time of flight proteomics analyzer, and western blot analysis further verified that the expression levels of beta casein (CSN2) and lactoferrin (LF) proteins in the mammary glands of lactating goats were higher when fed a high-grain diets and buffers. The mechanism of increased milk protein synthesis was demonstrated to be related to the activation of mammalian target of rapamycin (mTOR) pathway signals.

A Robust Mammary Organoid System to Model Lactation and Involution-like Processes.

The mammary gland is a highly dynamic tissue that changes throughout reproductive life, including growth during puberty and repetitive cycles of pregnancy and involution. Mammary gland tumors represent the most common cancer diagnosed in women worldwide. Studying the regulatory mechanisms of mammary gland development is essential for understanding how dysregulation can lead to breast cancer initiation and progression. Three-dimensional (3D) mammary organoids offer many exciting possibilities for the study of tissue development and breast cancer. In the present protocol derived from Sumbal et al., we describe a straightforward 3D organoid system for the study of lactation and involution ex vivo. We use primary and passaged mouse mammary organoids stimulated with fibroblast growth factor 2 (FGF2) and prolactin to model the three cycles of mouse mammary gland lactation and involution processes. This 3D organoid model represents a valuable tool to study late postnatal mammary gland development and breast cancer, in particular postpartum-associated breast cancer. Graphic abstract: Mammary gland organoid isolation and culture procedures.

Deep small RNA-Seq reveals microRNAs expression profiles in lactating mammary gland of 2 sheep breeds with different milk performance

Micro ribonucleic acid (miRNA) is a type of noncoding RNA, and it has been revealed to play important roles in the activity of the mammary gland (MG) in some species. However, the function of miRNAs in MG of sheep is poorly understood. In the study, Gansu Alpine Merino (GAM; n = 9) and Small-tailed Han sheep (STH; n = 9) with different milk production traits were investigated. Microstructures and the expression profile of miRNAs of MG tissues at peak lactation were studied. Mature alveolar lumens of MG in appearance were larger in STH than GAM. The expression levels of CSN2 and the content of rough endoplasmic reticulum were also higher in STH ewes than GAM ewes. A total of 124 mature miRNAs were expressed, and 18 of these were differentially expressed between the 2 breeds. The KEGG analysis results showed that the targeted genes of differentially expressed miRNAs were mainly involved in some metabolic pathways and signaling pathways related to MG development, milk protein, and fat synthesis. The findings in the study can improve our understanding of the roles of miRNAs in the development and lactation of MG in sheep.

Proteomic Analysis Reveals Proteins and Pathways Associated with Lactation in Bovine Mammary Epithelial Cell-Derived Exosomes.

Milk-derived exosomes have been reported, which are involved in many biological processes. The exosomes derived from mammary glands are not known yet, and their relationship with mammary gland lactation and the origin of milk-derived exosomes are largely unclear. The present study aimed to investigate the proteome of exosomes derived from bovine mammary epithelial cells (BMECs) and compare them with milk-derived exosomes in the database. BMEC-derived exosomes were successfully separated from the culture supernatant of BMECs by a combined ultracentrifugation approach, and the purity of exosomes was identified by western blot analysis. Liquid chromatography with tandem mass spectrometry identified 638 proteins in BMEC-derived exosomes. The MS data were deposited into the PUBLIC repository ProteomeXchange, dataset identifier(s): https://www.iprox.org/page/PSV023.html;?url=1590961453176tKpa. Gene Ontology annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that these proteins were associated with specific biological processes and molecular functions of metabolism. Cross comparison of these proteins with the protein database of milk exosomes showed that 77 common expressed proteins (CEPs) were in both BMEC- and milk-derived exosomes. The KEGG pathway analysis for these CEPs showed that they were mainly involved in signaling pathways associated with milk biosynthesis in BMECs. Among these CEPs, six proteins have been previously reported to be associated with the lactation function. The western blot analysis detected that expression of these six proteins in BMEC-derived exosomes was increased after the stimulation of methionine and β-estradiol on BMECs. In summary, the proteome of BMEC-derived exosomes reveals that they are associated with milk biosynthesis in BMECs and might be a source of milk-derived exosomes.

Primary Mammary Organoid Model of Lactation and Involution.

Mammary gland development occurs mainly after birth and is composed of three successive stages: puberty, pregnancy and lactation, and involution. These developmental stages are associated with major tissue remodeling, including extensive changes in mammary epithelium, as well as surrounding stroma. Three-dimensional (3D) mammary organoid culture has become an important tool in mammary gland biology and enabled invaluable discoveries on pubertal mammary branching morphogenesis and breast cancer. However, a suitable 3D organoid model recapitulating key aspects of lactation and involution has been missing. Here, we describe a robust and straightforward mouse mammary organoid system modeling lactation and involution-like process, which can be applied to study mechanisms of physiological mammary gland lactation and involution as well as pregnancy-associated breast cancer.

Histological Characteristics of the Telocytes in the Mammary Glands of She-Camel (Camelus dromedarius)

ABSTRACT Telocytes are stromal stem cells located in different organs including the lactating and non-lactating mammary glands of she-camel. Fresh speciemens of mammary gland were obtained from 10 lactating and non-lactating she-camels of 8 years old directly after slaughtering for human consumption according to the rules of the Egyptian veterinary authorities. The specimens were processed for transmission electron microscopical examination. Telocytes were found around the ducts of lactating and non-lactating mammary glands and beside the mast cells. These telocytes communicate with other cells sometimes differentiate into fibroblasts. In the lactating mammary gland telocytes were found around the acini. The telocytes were spindle and slender in shape with two long cytoplasmic extension (telopodes). These telopodes had nano-vesicles. They had rods to pear shape nuclei. In a conclusion, the telocytes are stromal stem cells in both lactating and non-lactating she-camel mammary glands

Transcriptomic analysis investigating the interaction between peripheral serotonin and high-fat diet feeding on mammary gene expression in midlactation mice.

To understand the role of peripheral serotonin and its interaction with diet in midlactation mammary gene expression, our study uses tryptophan hydroxylase 1 knockout (Tph1-KO) mice fed a high-fat diet (HFD). It has previously been demonstrated that HFD feeding increases inflammatory and immune pathways in peak lactation mammary glands of mice and increases pup mortality in wild-type (WT) mice compared with dams fed a low-fat diet (LFD). Peripheral serotonin inhibition has been associated with resistance to obesity in male mice fed an HFD. Little is known about the function of Tph1 and how peripheral serotonin affects mammary gland function during pregnancy and lactation. In this study, WT and Tph1-KO models were used to investigate global transcriptomic changes in peak lactation mammary glands when dams were fed either an HFD or LFD. WT and Tph1-KO female mice were assigned to either an LFD or HFD beginning at 3 wk of age (n = 4/group). Dams were euthanized on lactation day 11. Differentially expressed genes (DEGs) were first filtered by adjusted P value (cutoff ≤ 0.05) and fold-change (FC, cutoff ≥2). Genes were further filtered by mean normalized read count with a cutoff 310. We did not observe many differentially expressed genes in WT and Tph1-KO dams fed LFD. However, 3,529 DEGs were observed between WT-HFD and Tph1-KO-HFD mice, including cell cycle regulation and MAPK pathways being significantly enriched. Further research is required to completely understand the physiological significance of our results on peak lactation mammary physiology and the contribution of serotonin.

PGC-1α induced browning promotes involution and inhibits lactation in mammary glands.

The PPARγ coactivator 1α (PGC-1α) is a transcriptional regulator of mitochondrial biogenesis and oxidative metabolism. Recent studies have highlighted a fundamental role of PGC-1α in promoting breast cancer progression and metastasis, but the physiological role of this coactivator in the development of mammary glands is still unknown. First, we show that PGC-1α is highly expressed during puberty and involution, but nearly disappeared in pregnancy and lactation. Then, taking advantage of a newly generated transgenic mouse model with a stable and specific overexpression of PGC-1α in mammary glands, we demonstrate that the re-expression of this coactivator during the lactation stage leads to a precocious regression of the mammary glands. Thus, we propose that PGC-1α action is non-essential during pregnancy and lactation, whereas it is indispensable during involution. The rapid preadipocyte-adipocyte transition, together with an increased rate of apoptosis promotes a premature mammary glands involution that cause lactation defects and pup growth retardation. Overall, we provide new insights in the comprehension of female reproductive cycles and lactation deficiency, thus opening new roads for mothers that cannot breastfeed.

Effect of high-fat diet feeding and associated transcriptome changes in the peak lactation mammary gland in C57BL/6 dams.

Maternal consumption of a high-fat diet (HFD) during pregnancy has established adverse effects on the developing neonate. In this study, we aimed to investigate the effect of an HFD on the murine mammary gland during midlactation. Female C57BL/6J mice were placed on either a low-fat diet (LFD/10% fat) or HFD (60% fat) from 3 wk of age through peak lactation (lactation day 11/L11). After 4 wk of consuming either the LFD or HFD, female mice were bred. There were no significant differences in milk yield between treatment groups, which was measured from L1 to L9. On L10, mice were subjected to an overnight fast and then euthanized on the morning of L11. Total RNA was isolated from inguinal mammary glands for whole transcriptome sequencing. We found 628 genes that were differentially expressed between the treatment groups. Notably, HFD feeding resulted in expression alterations of genes involved in collagen and cytoplasmic components. Additionally, genes related to inflammatory and immune responses were also impacted. Differential expression in gene transcript isoforms between the treatment groups was detected in three genes related to mammary duct development. This study sheds light as to how an HFD may affect the mammary gland transcriptome during midlactation.

Transcriptome sequencing to detect the potential role of long non-coding RNAs in bovine mammary gland during the dry and lactation period

BackgroundIt is known that long non-coding RNAs (lncRNAs) play an important role in various biological processes, including cell proliferation, differentiation and apoptosis. However, their functions and profiles in lactation cycle of dairy cows are largely unknown. In this study, lncRNA-seq technique was employed to compare the expression profiles of lncRNAs and mRNAs from Chinese Holstein mammary gland in dry and lactation period.ResultTotally 3746 differentially expressed lncRNAs (DELs) and 2890 differentially expressed genes (DEGs) were identified from the dry and lactation mammary glands of Holstein cows. Functional enrichment analysis on target genes of lncRNAs indicated that these genes were involved in lactation-related signaling pathways, including cell cycle, JAK-STAT, cell adhesion, and PI3K-Akt signaling pathways. Additionally, the interaction between lncRNAs and their potential miRNAs was predicted and partly verified. The result indicated that the lactation-associated miR-221 might interact with lncRNAs TCONS_00040268, TCONS_00137654, TCONS_00071659 and TCONS_00000352, which revealed that these lncRNAs might be important regulators for lactation cycle.ConclusionThis study provides a resource for lncRNA research on lactation cycle of bovine mammary gland. Besides, the interaction between lncRNAs and the specific miRNA is revealed. It expands our knowledge about lncRNA and miRNA biology as well as contributes to clarify the regulation of lactation cycle of bovine mammary gland.

Th-POK regulates mammary gland lactation through mTOR-SREBP pathway.

The Th-inducing POK (Th-POK, also known as ZBTB7B or cKrox) transcription factor is a key regulator of lineage commitment of immature T cell precursors. It is yet unclear the physiological functions of Th-POK besides helper T cell differentiation. Here we show that Th-POK is restrictedly expressed in the luminal epithelial cells in the mammary glands that is upregulated at late pregnancy and lactation. Lineage restrictedly expressed Th-POK exerts distinct biological functions in the mammary epithelial cells and T cells in a tissue-specific manner. Th-POK is not required for mammary epithelial cell fate determination. Mammary gland morphogenesis in puberty and alveologenesis in pregnancy are phenotypically normal in the Th-POK-deficient mice. However, Th-POK-deficient mice are defective in triggering the onset of lactation upon parturition with large cellular lipid droplets retained within alveolar epithelial cells. As a result, Th-POK knockout mice are unable to efficiently secret milk lipid and to nurse the offspring. Such defect is mainly attributed to the malfunctioned mammary epithelial cells, but not the tissue microenvironment in the Th-POK deficient mice. Th-POK directly regulates expression of insulin receptor substrate-1 (IRS-1) and insulin-induced Akt-mTOR-SREBP signaling. Th-POK deficiency compromises IRS-1 expression and Akt-mTOR-SREBP signaling in the lactating mammary glands. Conversely, insulin induces Th-POK expression. Thus, Th-POK functions as an important feed-forward regulator of insulin signaling in mammary gland lactation.

Histopathology of Lactating, Non-Lactating and Mastitis Buffalo Mammary Gland Tissue

Histopathology of Lactating, Non-Lactating and Mastitis Buffalo Mammary Gland Tissue

Effect of addition of dried blood plasma to feed on chemical composition of milk and health status of mink lactation mammary gland

The aim of the study was to evaluate the selected parameters of milk mulberry fed with plasma and to assess the health status of the mammary gland of animals. The studies were conducted on american mink (Neovison vison). Two groups of animals were set up: the experimental one which received 0.5% beef-pork plasma for daily dosage of feed and the control group - without plasma. It was determined the content of fat, protein, lactose, dry matter and somatic cells counts in 1 ml of milk. Diagnosis of mastitis was done three times (in 1, 2 and 3 weeks of lactation) in both groups.In the group of animals fedded by dried blood plasma, there were significant differences in fat content in milk, lactose, dry matter and somatic cell counts. Diagnosis of mastitis of mammary gland showed positive plasma effects. The obtained that data suggest that feeding by dried blood derivatives may favorably affect the animal's immune system and support the first line of defense against environmental microorganisms..

Screening of miRNA profiles and construction of regulation networks in early and late lactation of dairy goat mammary glands

In recent years, studies related to the expression profiles of miRNAs in the dairy goat mammary gland were performed, but regulatory mechanisms in the physiological environment and the dynamic homeostasis of mammary gland development and lactation are not clear. In the present study, sequencing data analysis of early and late lactation uncovered a total of 1,487 unique miRNAs, including 45 novel miRNA candidates and 1,442 known and conserved miRNAs, of which 758 miRNAs were co-expressed and 378 differentially expressed with P < 0.05. Moreover, 76 non-redundant target genes were annotated in 347 GO consortiums, with 3,143 candidate target genes grouped into 33 pathways. Additionally, 18 predicted target genes of 214 miRNAs were directly annotated in mammary gland development and used to construct regulatory networks based on GO annotation and the KEGG pathway. The expression levels of seven known miRNAs and three novel miRNAs were examined using quantitative real-time PCR. The results showed that miRNAs might play important roles in early and late lactation during dairy goat mammary gland development, which will be helpful to obtain a better understanding of the genetic control of mammary gland lactation and development.