The Huck Institutes of the Life Sciences

Center for Reproductive Biology and Health Publications

Feed restriction inhibits early follicular development in broiler-breeder hens

Feed restriction inhibits early follicular development in broiler-breeder hens

Expression of adiponectin and its receptors in avian species

Adipose tissue is a dynamic endocrine organ secreting a variety of hormones that affect physiological functions within the central nervous system, cardiovascular system, reproductive, and immune systems. The endocrine role of avian adipose tissue remains enigmatic as many of the classical hormones found in mammalian adipose tissue have not been found in avians. This mini-review summarizes our current knowledge on avian adiponectin, one of the most abundant adipose tissue hormones, and its receptors.

Bone morphogenetic protein 4 supports the initial differentiation of hen (Gallus gallus) granulosa cells

In the hen ovary, selection of a follicle into the preovulatory hierarchy occurs from a small cohort of prehierarchal (6-8 mm) follicles. Prior to follicle selection the granulosa layer remains in an undifferentiated state despite elevated follicle-stimulating hormone receptor (FSHR) expression. The present studies describe a role for bone morphogenetic protein 4 (BMP4) in supporting FSHR mRNA expression in granulosa cells from prehierarchal follicles and promoting differentiation at follicle selection

Gonadotropin-releasing hormone, estradiol, and inhibin regulation of follicle-stimulating hormone and luteinizing hormone surges: implications for follicle emergence and selection in heifers

Mechanisms regulating gonadotropin surges and gonadotropin requirements for follicle emergence and selection were studied in heifers

Zinc-dependent lysosomal enlargement in TRPML1-deficient cells involves MTF-1 transcription factor and ZnT4 (Slc30a4) transporter.

Zinc is critical for a multitude of cellular processes, including gene expression, secretion and enzymatic activities. Cellular zinc is controlled by zinc-chelating proteins and by zinc transporters. The recent identification of zinc permeability of the lysosomal ion channel TRPML1 (transient receptor potential mucolipin 1), and the evidence of abnormal zinc levels in cells deficient in TRPML1, suggested a role for TRPML1 in zinc transport. In the present study we provide new evidence for such a role and identify additional cellular components responsible for it.

Role of immune cells in the corpus luteum

During the luteal phase, changes in the population of macrophages, eosinophils, neutrophils, and T lymphocytes occur at critical functional stages of the CL. In addition to their role in facilitating ovulation, immune cells may have an important role in luteal function. Evidence shows that cytokines secreted by immune cells modulate both luteotropic and luteolytic processes. However, the decision to pursue either function may depend on the environment provided by luteal cells. It is suggested that understanding the role immune cells play could lead to identification of new strategies to improve fertility in dairy cattle and other species.

Differential expression of PRAMEL1, a cancer/testis antigen, during spermatogenesis in the mouse

The objective of this study is to characterize the temporal and spatial expression of the mouse Pramel1 gene, and to determine the cellular localization of the PRAMEL1 protein during the mouse spermatogenesis. Our results indicated that the mouse Pramel1 was expressed in testis only. The mRNA and protein expression level was low in the newborn testes, and gradually increased from 1- to 3-week-old testes, and then remained constant after three weeks of age.

Oocytecumulus cell interactions regulate free intracellular zinc in mouse oocytes

Zinc increases in the oocyte during maturation and is required for progression and completion of meiosis. The objective of this study was to determine whether cumulus cells regulate the levels of free intracellular zinc in the oocyte during maturation. In the cumulus-oocyte complex (COC) the relative level of free intracellular zinc was almost fourfold higher in cumulus cells compared with the resident germinal vesicle-stage oocyte.

Progesterone effects on lymphocytes may be mediated by membrane progesterone receptors

Progesterone induces specific and rapid functional effects on T lymphocytes in the absence of PGR. The mPRs are potential intermediaries of the cell-surface actions of progesterone because they are expressed in lymphocytes, the actions of progesterone are mimicked by a cell-impermeable form of progesterone, and specific, saturable progesterone binding, which is characteristic of mPRs, is present on lymphocyte membrane

Life or death decisions in the corpus luteum

This review article summarizes the major concepts related to the fate of the CL, with particular focus on recent insights into the mechanisms associated with the ability of PGF(2o) to bring about complete luteolysis. It has become clear that the achievement of luteolysis depends on repeated exposure to PGF(2o) and involves coordinated actions of heterogeneous cell types within the CL. Together, these components of the process bring about not only the loss in progesterone production, but also the rapid demise of the structure itself.

Zinc networks: the cell-specific compartmentalization of zinc for specialized functions.

Zinc (Zn2+) is the most abundant trace element in cells and is essential for a vast number of catalytic, structural, and regulatory processes. Mounting evidence indicates that like calcium (Ca2+), intracellular Zn2+ pools are redistributed for specific cellular functions. Delineating the entire Zn2+ transporting network within the context of unique cellular Zn2+ needs is important in identifying critical gaps in our knowledge and improving our understanding of the consequences of Zn2+ dysregulation in human health and disease.

Impact of preovulatory estradiol concentrations on conceptus development and uterine gene expression.

This experiment was conducted to determine the effect of altering preovulatory estradiol concentrations, through manipulation of length of proestrus, on peripheral progesterone concentrations, conceptus development, interferon tau (IFNT) production and uterine gene expression in cattle. Follicular dynamics and estradiol concentrations were evaluated during proestrus and progesterone concentrations were analyzed in the subsequent estrous cycle.

A dominant negative heterozygous G87R mutation in the zinc transporter, ZnT-2 (SLC30A2), results in transient neonatal zinc deficiency.

Zinc is an essential mineral, and infants are particularly vulnerable to zinc deficiency as they require large amounts of zinc for their normal growth and development.We have recently described the first loss-of-function mutation (H54R) in the zinc transporter ZnT-2 (SLC30A2) in mothers with infants harboring transient neonatal zinc deficiency (TNZD). Here we identified and characterized a novel heterozygous G87R ZnT-2 mutation in two unrelated Ashkenazi Jewish mothers with infants displaying TNZD.

Bone morphogenetic protein 6 promotes FSH receptor and anti-Mullerian hormone mRNA expression in granulosa cells from hen prehierarchal follicles.

A growing body of literature provides evidence of a prominent role for bone morphogenetic proteins (BMPs) in regulating various stages of ovarian follicle development. Several actions for BMP6 have been previously reported in the hen ovary, yet only within postselection (preovulatory) follicles. The initial hypothesis tested herein is that BMP6 increases FSH receptor (FSHR) mRNA expression within the granulosa layer of prehierarchal (6-8mm) follicles (6-8 GC). BMP6 mRNA is expressed at higher levels within undifferentiated (1-8mm) follicles compared with selected (=>9mm) follicles.

The myxovirus-resistance protein, MX1, is a component of exosomes secreted by uterine epithelial cells.

Dairy cattle suffer from high percentages of early embryonic loss, and therefore, it is critical to study the function of the uterus at this time. We hypothesize that the antiviral protein, myxovirus resistance (MX)1, regulates secretion in uterine glandular cells during early pregnancy. This study is the first to characterize MX1-associated exosomes, and we postulate that MX1 regulates secretion in epithelial cells by playing a role in exosome formation or trafficking.

TLR4 activates NF in human ovarian granulosa tumor cells

Findings herein are the first to demonstrate a functional TLR-signaling pathway specifically in GCTs, and indicate that in contrast to OSE-derived cancers, inhibition of NF-kB does not sensitize GCTs to TRAIL or cisplatin.

Colony stimulating factor 1 is an extrinsic stimulator of mouse spermatogonial stem cell self-renewal

Colony stimulating factor 1 receptor (Csf1r) gene expression is enriched in Thy1+ germ cells. Addition of recombinant colony stimulating factor 1 (Csf1), the specific ligand for Csf1r, to culture media significantly enhanced the self-renewal of SSCs in heterogeneous Thy1+ spermatogonial cultures over a 63-day period without affecting total germ cell expansion. In vivo, expression of Csf1 in both pre-pubertal and adult testes was localized to clusters of Leydig cells and select peritubular myoid cells. Collectively, these results identify Csf1 as an extrinsic stimulator of SSC self-renewal and implicate Leydig and myoid cells as contributors of the testicular stem cell niche in mammals.

Receptor Transporter Protein 4 (RTP4) in Endometrium, Ovary, and Peripheral Blood Leukocytes of Pregnant and Cyclic Ewes

Interferon-tau (IFNT) is secreted by the conceptus trophoblast and signals pregnancy recognition in ruminants. IFNT regulates expression of genes in the endometrium, peripheral blood leukocytes (PBLs), and corpus luteum (CL). Microarray analysis identified that expression of (chemosensory) receptor transporter protein 4 (RTP4) increased in PBLs during early pregnancy in cows. These results indicate that RTP4 mRNA levels are induced in the ovine endometrium, PBLs, and CL by IFNT during early pregnancy and in cell culture in response to IFNT. If RTP4 expression affects G protein-coupled receptor function, it may be important for establishment of pregnancy in domestic ruminants.