Number Of Secretory Cells Research Articles

TRIENNIAL LACTATION SYMPOSIUM/BOLFA: Mammary growth during pregnancy and lactation and its relationship with milk yield.

The number of secretory cells in the mammary gland is often cited as a major determinant of milk production. However, literature data for proxy measures of secretory cell number do not fully support such a claim. In particular, measurements of total mammary DNA in livestock explain only <25% of variation in milk yield, probably because of tissue heterogeneity for DNA concentration. Relative to BW, measurements of udder size in dairy cattle, as total DNA or udder weight, are approximately double those seen in most other livestock classes. Therefore, selection for dairy production, not surprisingly, has resulted in cows with greater secretory capacity. There is limited evidence that genetic selection is still increasing udder size in some cattle populations, but more recent data are needed. It is contended that the most important period of mammary growth for determination of milk yield is that occurring in pregnancy and early lactation. Mammary development is largely complete, at term, in sheep, goats, and cattle, but in pigs, the udder continues to grow during the first 3 wk of lactation, depending, in part, on litter size. Increased litter size in sheep and goats will enhance the extent of mammary development at the end of gestation (and milk yield) by 20 to 25%. However, twinning in dairy cattle does not affect milk production and, by inference only, is not likely to affect numbers of secretory cells at term. Milking frequency and suckling intensity in very early lactation will increase milk yield in cows and increase mammogenesis and milk yield in sheep, indicating that even at term, the ruminant gland retains some capacity for further development, if demand requires it. There is limited understanding of the hormonal signals in pregnancy that regulate mammary development relative to the number of young carried. Furthermore, the genetic differences between dairy and beef cattle that lead to substantially greater udder size in the dairy breeds have not been identified. During lactation, the drivers for secretory cell loss in relation to milking frequency and nutritional status are still not known. Measurement of mammary development and using this phenotype in genomewide association studies to identify key genetic variants for mammogenesis will provide knowledge that is fundamental to understanding the quantitative regulation of milk production.

A 100-Year Review: Mammary development and lactation

What is old is new again-and with respect to the study of the mammary development and function in dairy animals, the expression resonates. Many of the mammary and milk production questions raised in the early years of the Journal of Dairy Science apply today. To be sure, scientists have filled in many details regarding, for example, identification of hormones and growth factors important in the control of mammary growth, the onset of copious milk production at calving, and maintenance of lactation. Early years focused on identification and subsequent availability of classic mammogenic, lactogenic, and galactopoietic hormones (e.g., steroids, prolactin, and growth hormone). The advent of sensitive assays to measure concentrations of these hormones and, subsequently, myriad growth factors in blood, milk, and tissues, allowed creation of multiple hypotheses to explain mammary cell proliferation and regulation of function. It is also apparent that we understand many of the fundamentals of milk removal, milking frequency, milking management, and milk ejection for successful lactation. However, some questions remain. Are the principles that were identified when cows produced markedly less milk still valid for the high-producing cows of today and the future? What mechanism(s) explain the positive effects of early increased milking frequency on subsequent milk production? Can the persistency of lactation be improved (secretory cell number vs. secretory cell function) or does early management "program" future mammary development or productivity (epigenetics, immune responsiveness, other)? The explosion of tools and techniques (Southern and Northern blots, PCR, and the "-omics" revolution) has driven an almost overwhelming evaluation of cellular and molecular functions in the mammary gland and other tissues. One key may be the discovery of a "Rosetta stone" that will allow understanding of this mass of detailed information on gene expression, cell signaling, and so on. Many scientists can now better appreciate the difficulty of the dairy farmer seeking to process DHIA or Dairy Comp 305 data, milking data, weights, feeding reports, pedometer readings, or genomic evaluations to manage their operations.

Neuropeptidergic integration of behavior in Trichoplax adhaerens, an animal without synapses.

ABSTRACTTrichoplax adhaerens is a flat, millimeter-sized marine animal that adheres to surfaces and grazes on algae. Trichoplax displays a repertoire of different feeding behaviors despite the apparent absence of a true nervous system with electrical or chemical synapses. It glides along surfaces to find food, propelled by beating cilia on cells at its ventral surface, and pauses during feeding by arresting ciliary beating. We found that when endomorphin-like peptides are applied to an animal, ciliary beating is arrested, mimicking natural feeding pauses. Antibodies against these neuropeptides label cells that express the neurosecretory proteins and voltage-gated calcium channels implicated in regulated secretion. These cells are embedded in the ventral epithelium, where they comprise only 4% of the total, and are concentrated around the edge of the animal. Each bears a cilium likely to be chemosensory and used to detect algae. Trichoplax pausing during feeding or spontaneously in the absence of food often induce their neighbors to pause as well, even neighbors not in direct contact. Pausing behavior propagates from animal to animal across distances much greater than the signal that diffuses from just one animal, so we presume that the peptides secreted from one animal elicit secretion from nearby animals. Signal amplification by peptide-induced peptide secretion explains how a small number of sensory secretory cells lacking processes and synapses can evoke a wave of peptide secretion across the entire animal to globally arrest ciliary beating and allow pausing during feeding.

Passive and Active Microrheology of the Intestinal Fluid of the Larval Zebrafish

The fluids of the intestine serve as a physical barrier to pathogens, a medium for the diffusion of nutrients and metabolites, and an environment for commensal microbes. The rheological properties of intestinal mucus have therefore been the subject of many investigations, thus far limited to in vitro studies due to the difficulty of measurement in the natural context of the gut. This limitation especially hinders our understanding of how the gut microbiota interact with the intestinal space, since examination of this calls not only for in vivo measurement techniques, but for techniques that can be applied to model organisms in which the microbial state of the gut can be controlled. We have addressed this challenge with two complementary approaches. We performed passive microrheological measurements using thermally driven nanoparticles and active microrheology using micron-scale ellipsoidal magnetic microparticles, in both cases using light-sheet fluorescence microscopy to optically access the intestinal bulb of the larval zebrafish, a model vertebrate. We present viscosity measurements in germ-free animals (devoid of gut microbes), animals colonized by a single bacterial species, and conventionally reared animals, and find that in all cases, the mucin-rich intestinal liquid is well described as a Newtonian fluid. Surprisingly, despite known differences in the number of secretory cells in germ-free zebrafish and their conventional counterparts, the fluid viscosity for these two groups is very similar, as measured with either technique. Our study provides, to our knowledge, the first in vivo microrheological measurements of the intestinal space in living animals, and we comment on its implications for timescales of host-microbe interactions in the gut.

Circadian rhythm disruption impairs tissue homeostasis and exacerbates chronic inflammation in the intestine.

Endogenous circadian clocks regulate 24-h rhythms of physiology and behavior. Circadian rhythm disruption (CRD) is suggested as a risk factor for inflammatory bowel disease. However, the underlying molecular mechanisms remain unknown. Intestinal biopsies from Per1/2 mutant and wild-type (WT) mice were investigated by electron microscopy, immunohistochemistry, and bromodeoxyuridine pulse-chase experiments. TNF-α was injected intraperitoneally, with or without necrostatin-1, into Per1/2 mice or rhythmic and externally desynchronized WT mice to study intestinal epithelial cell death. Experimental chronic colitis was induced by oral administration of dextran sodium sulfate. In vitro, caspase activity was assayed in Per1/2-specific small interfering RNA-transfected cells. Wee1 was overexpressed to study antiapoptosis and the cell cycle. Genetic ablation of circadian clock function or environmental CRD in mice increased susceptibility to severe intestinal inflammation and epithelial dysregulation, accompanied by excessive necroptotic cell death and a reduced number of secretory epithelial cells. Receptor-interacting serine/threonine-protein kinase (RIP)-3-mediated intestinal necroptosis was linked to increased mitotic cell cycle arrest via Per1/2-controlled Wee1, resulting in increased antiapoptosis via cellular inhibitor of apoptosis-2. Together, our data suggest that circadian rhythm stability is pivotal for the maintenance of mucosal barrier function. CRD increases intestinal necroptosis, thus rendering the gut epithelium more susceptible to inflammatory processes.-Pagel, R., Bär, F., Schröder, T., Sünderhauf, A., Künstner, A., Ibrahim, S. M., Autenrieth, S. E., Kalies, K., König, P., Tsang, A. H., Bettenworth, D., Divanovic, S., Lehnert, H., Fellermann, K., Oster, H., Derer, S., Sina, C. Circadian rhythm disruption impairs tissue homeostasis and exacerbates chronic inflammation in the intestine.

Structure and development of the metapleural gland in Technomyrmex vitiensis

We studied the internal and external appearance of the metapleural gland in the five castes of Technomyrmex vitiensis. All castes do possess the gland, but with a clear gradient from queens (most developed gland), via intercastes, workers and wingless males to winged males (least developed). Also the size and the shape of the atrium differ among castes along the same gradient. The presence of a more developed gland in wingless males than in winged males may be linked with the much longer longevity of the former. The number of secretory cells in T. vitiensis is the lowest among ants known so far. The functional meaning of this is not yet known and calls for a functional study of the gland’s secretion.

Ameliorating effect of Erxian decoction combined with Fructus Schisandrae chinensis (Wu Wei Zi) on menopausal sweating and serum hormone profiles in a rat model.

BackgroundModified Erxian decoction (MEXD), i.e., Erxian decoction (EXD) with Fructus Schisandrae chinensis (Wu Wei Zi) added, has been used to alleviate menopausal symptoms. This study aimed to investigate the effects of MEXD on menopausal sweating and serum hormone levels in a rat model of menopause after oral administration of MEXD.MethodsQuality control of MEXD was conducted by employing a reversed-phase high performance liquid chromatography column. The three treatment groups received oral administration of MEXD in 0.5% sodium carboxylmethyl cellulose (CMC-Na) at three different doses (5.5, 11, and 22 g/kg body weight) once-daily for 6 consecutive weeks, with 10 animals per group. Huangqijing oral liquor (5 mL/kg) prepared from the roots of Huang qi (Astragalus membranaceus) with an antiperspirant effect was used as a positive control. The negative control group received the same volume of vehicle (0.5% CMC-Na). Ten 3-month-old Sprague–Dawley rats were used as a young group for comparison with the treatment groups (12–14 months old rats). Blood was collected from all animals after 3–6 weeks of treatment. At the end of the treatment, the uterine weight, ovarian weight, and body weight were recorded. Serum malondialdehyde contents and superoxide dismutase activities were determined by thiobarbituric acid colorimetric assays and chemoluminescence assays, respectively. Serum levels of estradiol, follicle-stimulating hormone, and luteinizing hormone were measured by radioimmunoassays. Rat foot pad assays were used to determine the antiperspirant activity of MEXD and histological examinations were conducted on plantar sweat glands.ResultsTreatment with MEXD (11 g/kg) significantly inhibited sweat excretion in the menopause model rats after treatment for 3 (P = 0.0026) and 6 (P < 0.0001) weeks. The decoction markedly decreased the number of secretory cells in plantar sweat glands. In addition, MEXD (11 g/kg) significantly increased the serum estradiol levels (P < 0.001) and superoxide dismutase activities (P = 0.0405). Furthermore, MEXD (11 g/kg) markedly decreased the serum levels of follicle-stimulating hormone (P = 0.001), luteinizing hormone (P = 0.0213), and malondialdehyde (P = 0.01).ConclusionModified Erxian decoction significantly inhibited sweat excretion, regulated serum levels of pituitary gonadotropins and estradiol, and exhibited antioxidative effects in a rat model of menopause.Electronic supplementary materialThe online version of this article (doi:10.1186/s13020-016-0117-6) contains supplementary material, which is available to authorized users.

A New Species of Rhodymeniaceae (Rhodophyta, Rhodymeniales) from the Northern Brazilian Coast: Botryocladia franciscana sp. nov.

A new species of marine macroalgae, Botryocladia franciscana sp. nov. (Rhodophyta, Rhodymeniaceae) is described for the south-west Atlantic Ocean. B. franciscana was collected from protected rocky crevices at Coqueiro Beach, Piaui, Brazil. Molecular characterization was based on two plastidial genes, the V domain of the 23S rRNA gene (UPA, universal plastid amplicon), and the large subunit of ribulose-1, 5-bisphosphate carboxylase oxygenase gene (rbcL), and the mitochondrial cytochrome oxidase I gene (cox1). Phylogenetic trees from rbcL sequences clearly set B. franciscana apart from morphologically similar B. bermudana and B. caraibica. Morphological description was performed using anatomical and morphological features, including vesicle medulla and wall thickness, shape and size of the mucous-filled vesicles, pattern of vesicles’ outer cortication, number of secretory cells and type of cell bearing the secretory cells. The observed morphological characters do not correspond to any previously described Botryocladia species and DNA sequence diverge values indicate it is distinct from B. franciscana and B. bermudana; therefore, we present B. franciscana as a new species from the Brazilian coast, with illustrations and morpho-anatomical characteristics.

Induction of nasal polyps using house dust mite and Staphylococcal enterotoxin B in C57BL/6 mice

BackgroundThe murine polyp model was developed previously using ovalbumin and Staphylococcus aureus enterotoxin B (SEB). Here, we established a model mimicking key aspects of chronic eosinophilic rhinosinusitis with nasal polyps using the house dust mite (HDM), a clinically relevant aeroallergen, co-administered with SEB. We assessed the inflammatory response and formation of nasal polypoid lesions in an experimental murine model using intranasal delivery of HDM and ovalbumin. MethodsAfter induction of HDM-induced allergic rhinosinusitis in C57BL/6 mice, SEB (10ng) was instilled into the nasal cavity of mice for eight weeks. Phosphate-buffered saline-challenged mice served as control. Histopathological changes were evaluated using haematoxylin and eosin for overall inflammation, Sirius red for eosinophils, and periodic acid–Schiff stain for goblet cells. The distribution of mast cells in mouse nasal tissue was determined by immunohistochemistry. Serum total IgE was measured using enzyme-linked immunosorbent assay. ResultsCompared to mice treated with HDM only, the HDM+SEB-treated mice demonstrated nasal polypoid lesion formation and a significant increase in the number of secretory cells and eosinophilic infiltration. Moreover, mice challenged intranasally with HDM showed highly abundant mast cells in the nasal mucosa. In contrast, OVA+SEB-challenged mice showed a significantly lower degree of mast cell infiltration. ConclusionWe established an in vivo model of chronic allergic rhinosinusitis with nasal polypoid lesions using HDM aeroallergen. This study demonstrated that the HDM+SEB-induced murine polyp model could be utilised as a suitable model for nasal polyps, especially with both eosinophil and mast cell infiltration.

Comparative morpho-physiology of the metapleural glands of two Atta leaf-cutting ant queens nesting in clayish and organic soils

Queens of leaf-cutting ants found their nests singly, each consisting of a vertical tunnel and a final horizontal chamber. Because of the claustral mode of nest founding, the queen and/or her initial fungus garden are exposed to threats imposed by several soil pathogens, and the antibiotic secretions produced by their metapleural glands are considered a main adaptation to deal with them. Nests of two Atta leaf-cutting ant species, Atta vollenweideri and Atta sexdens rubropilosa, occur in different soil types, alfisols and oxisols. Their queens are known to excavate the initial nest in different soil horizons, clayish and organic, respectively, which differ in their fertility and associated microbiota. The aim of the present study was to comparatively investigate the morpho-physiology of the metapleural glands in queens of A. vollenweideri and A. sexdens rubropilosa, addressing the question whether the distinct selective pressure imposed by the microbiota in the two different soil types led to morpho-physiological differences in the metapleural glands that were consistent with their antiseptic function. The results revealed that metapleural glands of A. sexdens rubropilosa have a larger number of secretory cells, and consequently a higher production of antibiotic secretions, which may have been selected to allow nest founding at the superficial horizon of oxisols rich in organic matter and microorganisms. Glands of A. vollenweideri, on the contrary, presented fewer secretory cells, suggesting less production of antibiotic secretions. We argue that the excavation of deep founding nests in A. vollenweideri was primarily selected for during evolution to avoid the risk posed by flooding, and further hypothesize that a reduced number of cells in their metapleural glands occurred because of a weak pathogen-driven selective pressure at the preferred soil depth.

The effects of milking frequency on insulin-like growth factor I signaling within the mammary gland of dairy cows

In dairy cows, short-term changes in milking frequency (MF) in early lactation have been shown to produce both an immediate and a long-term effect on milk yield. The effect of MF on milk yield is controlled locally within mammary glands and could be a function of changes in either number or activity of secretory mammary epithelial cells (MEC). Insulin-like growth factor I (IGF-I) signaling is one candidate factor that could mediate these effects, as it can be controlled locally within mammary glands. Both MEC number and activity can be affected by IGF-I signaling by activating the phosphoinositide 3-kinase (PI3K)/Akt and extracellular-signal-regulated kinase (ERK)1/2 pathways. To investigate the relationship between MF and IGF-I signaling, udder halves of 17 dairy cows were milked either 4 times a day (4×) or once a day (1×) for 14 d in early lactation. On d 14, between 3 and 5 h following milking, mammary biopsies were obtained from 10 cows from both udder halves, and changes in the expression of genes associated with IGF-I signaling and the activation of the PI3K/Akt and ERK1/2 pathways were measured. The mRNA abundance of IGF type I receptor, IGF binding protein (IGFBP)-3, and IGFBP-5 were lower following 4× milking relative to 1× milking. However, the mRNA abundance of IGF-I was not affected by MF. Both IGFBP3 and IGFBP5 are thought to inhibit IGF-I; therefore, decreases in their mRNA abundance may serve to stimulate the IGF-I signal in the 4×-milked mammary gland. The activation of PI3K/Akt pathway was lower in response to 4× milking relative to 1×, and the activation of the ERK1/2 was unaffected by MF, suggesting that they do not mediate the effects of MF.

Production and packaging of a biological arsenal: Evolution of centipede venoms under morphological constraint

Venom represents one of the most extreme manifestations of a chemical arms race. Venoms are complex biochemical arsenals, often containing hundreds to thousands of unique protein toxins. Despite their utility for prey capture, venoms are energetically expensive commodities, and consequently it is hypothesized that venom complexity is inversely related to the capacity of a venomous animal to physically subdue prey. Centipedes, one of the oldest yet least-studied venomous lineages, appear to defy this rule. Although scutigeromorph centipedes produce less complex venom than those secreted by scolopendrid centipedes, they appear to rely heavily on venom for prey capture. We show that the venom glands are large and well developed in both scutigerid and scolopendrid species, but that scutigerid forcipules lack the adaptations that allow scolopendrids to inflict physical damage on prey and predators. Moreover, we reveal that scolopendrid venom glands have evolved to accommodate a much larger number of secretory cells and, by using imaging mass spectrometry, we demonstrate that toxin production is heterogeneous across these secretory units. We propose that the differences in venom complexity between centipede orders are largely a result of morphological restrictions of the venom gland, and consequently there is a strong correlation between the morphological and biochemical complexity of this unique venom system. The current data add to the growing body of evidence that toxins are not expressed in a spatially homogenous manner within venom glands, and they suggest that the link between ecology and toxin evolution is more complex than previously thought.

The photoperiod and heat stress effects on histometrical structure of rat prostate gland

BACKGROUND: There is not enough information about theeffects of heat stress and photoperiod on different lobes structure.OBJECTIVES: The present study aims at determining thehistological changes and the rate of changes in each lobes of ratprostate, affected by photoperiod changes and heat stress.METHODS:To this end, 15 adult male wistar rats were divided tothree groups: 1. the control group in which the rats were kept in12L: 12D and 25°C temperature condition, 2. the heat stressgroup in which the rats were kept in 12L: 12D and 42+1 °Ctemperature condition for 4 to 5 hours per day, and 3. thephotoperiod group in which the rats were kept in 16L: 8D and25°C temperature condition. After 30 days, samples were takenfrom different lobes and sections with 5 to 6μ thickness weremade and stained by HE however, it increased by photoperiod.The maximum changes were seen in ventral lobe. The epithelialthickness, lumen diameter, and number of secretory units alsoincreased by photoperiod (16L:8D), but it decreased by heatstress. The number of secretory cells were increased by heatstress because the cell size decreased; however, they decreasedby long photoperiod regime. The number of folded secretoryunits increased by photoperiod, while heat stress has an adverseeffect (p<0.001). The serum testosterone increased by longphotoperiod and decreased by heat stress (p<0.01).CONCLUSIONS: This study shows that long photoperiod hasimportant effects on increasing the rat prostate parenchyma andits activity.

Influence of stage of lactation on quantitative and qualitative milk production parameters in goats

Goat lactation is synonymous to an agricultural production function with three distinct production regions namely: early, mid and late lactation. It is characterised by an increase in milk yield in early lactation to a possible peak in the mid lactation and then a decline in milk yield as it reaches the end of lactation. However, the other milk constituencies (protein, fat, lactose, etc ) do not follow the same trend as total milk yield through the 3 lactation stages. Therefore, it is suffice to suggest that the understanding of the physiological changes in these stages of lactation is crucial in maximizing milk production in goats. The present discussion explores the importance of different stages of lactation in milk production in influencing yield and milk composition. Milk yield and its composition are influenced by various factors, among these stage of lactation is very significant. The proportion of protein, lactose, fat and total solids declined slightly with advance in lactation and a steady fall in milk yield. This is on the basis that milk yield is a function of the number of mammary secretory cells and their metabolic activity change during the course of lactation. The significant stage of lactation effect in most studies may have practical implications in determining optimal feeding management to maximize total lactation yield and milk composition. Therefore, the knowledge of physiological activities during different stages of lactation is critical to dairy animal nutrition and management decision support systems for optimization of goat dairy flock production processes.

Oestrus synchronization treatment induces histomorphological changes on the uterine tube epithelium of the gilt.

The aim of this study was to determine the histomorphological changes that occurred in response to two treatments for oestrus synchronization in three different regions of the gilt's uterine tubes epithelium: the ampulla (AMP), ampulla-isthmic junction (AIJ) and isthmus (IST). Nine prepuberal gilts were divided into three groups (n=3): (1) eCG 400IU and hCG 200IU (eCG/hCG), (2) progesterone agonist (P4) and (3) control group. The number of secretory cells (stained with periodic acid-Schiff reaction or PAS-positive cells) decreased in the AMP in the P4 treated group when compared to the control group, whereas, no difference was observed in the number of PAS-negative cells in the AMP of the three groups. A significant decrease in the number of PAS-positive cells was observed in the AIJ and IST of the P4 treated group when compared to the eCG/hCG and control groups. An increase in the number of PAS-negative cells was observed in the AIJ and IST in the P4 treated group. The epithelium height in the AMP and AIJ was increased in the eCG/hCG group when compared to the control and P4 groups. In this last group, we observed a reduced height compared with the other two groups for the AIJ. In the IST, there were no significant changes in the epithelium height of the control or the other two groups (eCG/hCG and P4). The epithelial cells of the P4 treated group had the least amount of cytoplasmic granules and the lowest intensity of PAS staining in the AMP, AIJ and IST. Animals treated with eCG/hCG showed an intermediate number of cytoplasmic granules and intensity in all regions evaluated. These data show that P4 treatment for synchronization induces a significant (P<0.001) decrease of PAS-positive cells and staining intensity of cytoplasmic granules in the different regions studied and an increased number of PAS-negative cells in the AIJ and IST epithelium. Moreover, eCG/hCG treatment increased the height of the epithelium in the AMP and AIJ, while in this last region, the P4 treatment decreased the epithelium height. These results show that synchronization treatments with P4 and in a smaller proportion with eCG/hCG can modify the amount of PAS-positive and PAS-negative cells, and the epithelium height. This has influence in the secretory activity of the epithelium and possibly alters the fluid microenvironment of the gilt's uterine tube. The biological impact of regional variations in the epithelial cells of the gilt's uterine tube needs further investigation to understand the implications that the reproductive processes can have in the uterine tube.

Ultrastructure of the oviductal mucosa of Leptodactylus chaquensis. Analysis of the preovulatory and postovulatory periods.

In the present study we analysed the ultrastructural characteristics of the oviductal mucosa of Leptodactylus chaquensis during the preovulatory period and immediately after ovulation. Epithelial secretory cells, ciliated cells, basal cells and glandular secretory cells are described. During the preovulatory period, the oviduct exhibits its maximum degree of development at both the epithelial and the glandular levels, with numerous secretory cells that contain a large number of secretory granules whose contents are released into the oviductal lumen by apocrine and exocytotic secretory processes. The secretory cells present throughout the oviduct display considerable variability in the characteristics of their secretory granules, which show different shapes, sizes, organization of the material contained and electron density. The different cell types are distributed following a characteristic pattern for each oviductal zone, thus creating an ultrastructural mosaic along the oviduct. During the postovulatory period, the number of secretory cells decreases and the remaining ones exhibit a marked reduction in secretory granules. Ciliated cells show a typical ultrastructural organization that is not modified throughout the reproductive cycle. Basal cells, located at the basal region of the epithelium, are characterized by their heterochromatic nuclei and electron-lucent cytoplasm, while glandular secretory cells exhibit oval, round or polyhedric granules, most of them with a prominent core. Our results, which indicate a high heterogeneity of secretory cell contents, allow us to suggest differential synthesis and secretion of specific products in each oviductal zone.

Technical note: A noninvasive method for measuring mammary apoptosis and epithelial cell activation in dairy animals using microparticles extracted from milk

Milk production from dairy animals has been described in terms of 3 processes: the increase in secretory cell numbers in late pregnancy and early lactation, secretion rate of milk per cell, and the decline in cell numbers as lactation progresses. This latter process is thought to be determined by the level of programmed cell death (apoptosis) found in the animal. Until now, apoptosis has been measured by taking udder biopsies, using magnetic resonance imaging scans, or using animals postmortem. This paper describes an alternative, noninvasive method for estimating apoptosis by measuring microparticles in milk samples. Microparticles are the product of several processes in dairy animals, including apoptosis. Milk samples from 12 Holstein cows, at or past peak lactation, were collected at 5 monthly samplings. The samples (n=57) were used to measure the number of microparticles and calculate microparticle density for 4 metrics: annexin V positive and merocyanine 540 dye positive, for both and total particles, in both whole milk (WM) and spun milk. Various measures of milk production were also recorded for the 12 cows, including daily milk yield, fat and protein percentage in the milk, somatic cell count, and the days in milk when the samples were taken. A high correlation was found between the 4 WM microparticle densities and days in milk (0.46 to 0.64), and a moderate correlation between WM microparticle densities and daily milk yield (−0.33 to −0.44). No significant relationships were found involving spun milk samples, somatic cell count, or fat and protein percentage. General linear model analyses revealed differences between cows for both level of microparticle density and its rate of change in late lactation. Persistency of lactation was also found to be correlated with the WM microparticle traits (−0.65 to −0.32). As apoptosis is likely to be the major contributor to microparticle numbers in late lactation, this work found a noninvasive method for estimating apoptosis that gave promising results. Further investigation is required to find out the factors affecting microparticle production and how it changes throughout lactation.

The acetylome regulators Hdac1 and Hdac2 differently modulate intestinal epithelial cell dependent homeostatic responses in experimental colitis

Histone deacetylases (Hdac) remove acetyl groups from proteins, influencing global and specific gene expression. Hdacs control inflammation, as shown by Hdac inhibitor-dependent protection from dextran sulfate sodium (DSS)-induced murine colitis. Although tissue-specific Hdac knockouts show redundant and specific functions, little is known of their intestinal epithelial cell (IEC) role. We have shown previously that dual Hdac1/Hdac2 IEC-specific loss disrupts cell proliferation and determination, with decreased secretory cell numbers and altered barrier function. We thus investigated how compound Hdac1/Hdac2 or Hdac2 IEC-specific deficiency alters the inflammatory response. Floxed Hdac1 and Hdac2 and villin-Cre mice were interbred. Compound Hdac1/Hdac2 IEC-deficient mice showed chronic basal inflammation, with increased basal disease activity index (DAI) and deregulated Reg gene colonic expression. DSS-treated dual Hdac1/Hdac2 IEC-deficient mice displayed increased DAI, histological score, intestinal permeability, and inflammatory gene expression. In contrast to double knockouts, Hdac2 IEC-specific loss did not affect IEC determination and growth, nor result in chronic inflammation. However, Hdac2 disruption protected against DSS colitis, as shown by decreased DAI, intestinal permeability and caspase-3 cleavage. Hdac2 IEC-specific deficient mice displayed increased expression of IEC gene subsets, such as colonic antimicrobial Reg3b and Reg3g mRNAs, and decreased expression of immune cell function-related genes. Our data show that Hdac1 and Hdac2 are essential IEC homeostasis regulators. IEC-specific Hdac1 and Hdac2 may act as epigenetic sensors and transmitters of environmental cues and regulate IEC-mediated mucosal homeostatic and inflammatory responses. Different levels of IEC Hdac activity may lead to positive or negative outcomes on intestinal homeostasis during inflammation.

Ankyrin-B Regulates Cav2.1 and Cav2.2 Channel Expression and Targeting

N-type and P/Q-type calcium channels are documented players in the regulation of synaptic function; however, the mechanisms underlying their expression and cellular targeting are poorly understood. Ankyrin polypeptides are essential for normal integral membrane protein expression in a number of cell types, including neurons, cardiomyocytes, epithelia, secretory cells, and erythrocytes. Ankyrin dysfunction has been linked to defects in integral protein expression, abnormal cellular function, and disease. Here, we demonstrate that ankyrin-B associates with Cav2.1 and Cav2.2 in cortex, cerebellum, and brain stem. Additionally, using in vitro and in vivo techniques, we demonstrate that ankyrin-B, via its membrane-binding domain, associates with a highly conserved motif in the DII/III loop domain of Cav2.1 and Cav2.2. Further, we demonstrate that this domain is necessary for proper targeting of Cav2.1 and Cav2.2 in a heterologous system. Finally, we demonstrate that mutation of a single conserved tyrosine residue in the ankyrin-binding motif of both Cav2.1 (Y797E) and Cav2.2 (Y788E) results in loss of association with ankyrin-B in vitro and in vivo. Collectively, our findings identify an interaction between ankyrin-B and both Cav2.1 and Cav2.2 at the amino acid level that is necessary for proper Cav2.1 and Cav2.2 targeting in vivo.

氨氮胁迫对日本蟳免疫生理指标及器官结构的影响

采用生物酶测定及组织学方法，研究了水体中不同浓度氨氮胁迫下日本蟳免疫相关指标的变化，以及对鳃、肝胰腺和胃等器官结构的影响。结果表明：在氨氮胁迫下，各实验组的血细胞密度（DHC）、血蓝蛋白含量、超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活力，以及低浓度胁迫组的酚氧化酶（PO）和溶菌酶（LSZ）活力呈“先升后降”的变化趋势；高浓度组LSZ活力持续下降。在低浓度氨氮胁迫下，过氧化代谢产物丙二醛（MDA）含量呈“先升后降再升”，而高浓度氨氮胁迫导致MDA含量持续上升。胁迫第15天，除低浓度组的DHC、血蓝蛋白含量和PO活力略高于对照组外，其他实验组所测指标均低于对照组；PO、LSZ、SOD和CAT等酶活力以及DHC均与氨氮胁迫浓度呈显著负相关，MDA含量则与胁迫浓度呈显著正相关（<em>P</em> < 0.01）。高浓度氨氮胁迫会导致鳃几丁质膜变薄、断裂，鳃上皮排列紊乱、染色质异固缩；鳃腔中血淋巴减少，密度降低，血细胞凝集、质膜破裂，胞质严重空泡化；肝胰腺上皮形态不规则，B细胞减少，腺细胞出现大量空泡，染色质凝聚；胃几丁质膜断裂，胃上皮排列不规则，胞质中出现大量残余体。研究表明高浓度氨氮胁迫对日本蟳免疫相关指标和器官结构产生显著影响，SOD活力和MDA含量长期变化情况可作为衡量日本蟳在氨氮胁迫下免疫状态的指标。;<em>Charybdis japonica</em> is an important marine crab, that is widely distributed in the China sea area. Enzymatic and histological methods were used to analyze changes in the activities of immune-related enzymes in the blood serum, and in the histology of major organs of this crab exposed to different levels of ammonia-N stress. The primary objective of the study was to provide a theoretical basis for research into ammonia-N toxicity in relation to the control of water quality in artificial cultures of this crab.<br>The crabs were exposed to ammonia-N concentrations of 0, 2, 5, 10, 15, and 20 mg/L for up to 15 days. After times of 0, 1, 3, 5, 10, and 15 days, blood samples were taken for measurement of changes in immunity-related indicators, including the density of hemocytes (DHC); hemocyanin concentration; the activities of phenoloxidase (PO), lysozyme (LSZ), superoxide dismutase (SOD) and catalase (CAT); and the malondialdehyde (MDA) concentration. On day 15, samples were taken of the gills, hepatopancreas and stomach tissue of the crabs in the 20 mg/L of ammonia-N medium, for observations of histological changes.<br>Many of the measured indices showed an initial increase in response to ammonia-N stress, which was followed by a decreasing trend over time. This was observed in the values of DHC and hemocyanin concentration, in the activities of the SOD and CAT in all treatments, and in the activities of the PO and LSZ in the experimental groups at low ammonia-N concentrations. In contrast, the LSZ activity declined continuously in crabs at high concentration of ammonia. At low ammonia-N concentrations, the MDA content initially increased, and then decreased, and finally rose again. At higher concentrations, MDA continuously increased. After exposure to ammonia-N for 15 days, most of the measured indices were lower in the ammonia-N treatments than in the control group, with the exception of DHC, hemocyanin concentration, and PO activity, which were slightly higher. There were significant negative correlations between ammonia-N concentration and DHC, and ammonia concentration and the activities of PO, LSZ, SOD, and CAT. In contrast, the MDA content was positively correlated with the ammonia-N concentration (<em>P</em> < 0.01). Noticeable changes were observed in the histological structure of some organs in crabs exposed to high concentrations of ammonia-N. The chitin layer of the gills became thin and was partly ruptured, the epithelial lamina became disorganized, and the chromatin condensed. The quantity of hemolymph in the gill cavity was reduced and its density decreased. Hemocytes were condensed with ruptured cytomembranes and abundant vacuoles in cytoplasm. The glandular epithelium exhibited an irregular morphology, the number of secretory cells (B-cells) decreased and numerous vacuoles appeared. There were fewer organelles and the chromatin was condensed. The chitin layer of the stomach ruptured and the gastric epithelium became disordered, with abundant residual bodies formed in the cytoplasm.<br>We conclude that high concentrations of ammonia-N have significant effects on the activities of immune-related enzymes and on organ morphology in <em>Charybdis japonica</em>. Changes in the activities of SOD and in the content of MDA, may be used as indices for evaluating the immune state of <em>C. japonica</em> under ammonia-N stress.