Cell-based meat: the need to assess holistically.

Proof-of-principle for large-scale engineering of edible muscle tissue, in vitro, was established with the product's introduction in 2013. Subsequent research and commentary on the potential for cell-based meat to be a viable food option and potential alternative to conventional meat have been significant. While some of this has focused on the biology and engineering required to optimize the manufacturing process, a majority of debate has focused on cultural, environmental, and regulatory considerations.

Genome-wide survey of SNP variation uncovers the genetic structure of cattle breeds.

The imprints of domestication and breed development on the genomes of livestock likely differ from those of companion animals. A deep draft sequence assembly of shotgun reads from a single Hereford female and comparative sequences sampled from six additional breeds were used to develop probes to interrogate 37,470 single-nucleotide polymorphisms (SNPs) in 497 cattle from 19 geographically and biologically diverse breeds. These data show that cattle have undergone a rapid recent decrease in effective population size from a very large ancestral population, possibly due to bottlenecks associated with domestication, selection, and breed formation.

USDA Stakeholder Workshop on Animal Bioinformatics: Summary and Recommendations.

An electronic workshop was conducted on 4 November-13 December 2002 to discuss current issues and needs in animal bioinformatics. The electronic (e-mail listserver) format was chosen to provide a relatively speedy process that is broad in scope, cost-efficient and easily accessible to all participants. Approximately 40 panelists with diverse species and discipline expertise communicated through the panel e-mail listserver.

Identifying the future needs for long-term USDA efforts in agricultural animal genomics.

Agricultural animal research has been immensely successful over the past century in developing technology and methodologies that have dramatically enhanced production efficiency of the beef, dairy, swine, poultry, sheep, and aquaculture industries. In the past two decades, molecular biology has changed the face of agricultural animal research, primarily in the arena of genomics and the relatively new offshoot areas of functional genomics, proteomics, transcriptomics, metabolomics and metagenomics. Publication of genetic and physical genome maps in the past 15 years has given rise to the possibility of being able finally to understand the molecular nature of the genetic component of phenotypic variation.

Funding priorities in animal reproduction at the United States Department of Agriculture's Cooperative State Research, Education, and Extension Service.

The National Research Initiative (NRI) Competitive Grants Program is the U.S. Department of Agriculture's major competitive grants program and is administered by the Cooperative State Research, Education, and Extension Service (CSREES).

Allerton III. Beyond livestock genomics.

Throughout the Allerton III Conference, several consistent research needs were identified across scientific disciplines. First, additional basic research is needed to identify genomic mechanisms and novel genes/proteins in a variety of tissues under different conditions. Second, expansion of the infrastructure of the scientific community is needed.

Responsiveness of the ovine gonadotropin-releasing hormone receptor gene to estradiol and gonadotropin-releasing hormone is not detectable in vitro but is revealed in transgenic mice.

Although the ability of estradiol to enhance pituitary sensitivity to GnRH is established, the underlying mechanism(s) remain undefined. Herein, we find that approximately 9,100 bp of 5' flanking region from the ovine GnRH receptor (oGnRHR) gene is devoid of transcriptional activity in gonadotrope-derived cell lines and is not responsive to either estradiol or GnRH. In stark contrast, this same 9,100 bp promoter fragment directed tissue-specific expression of luciferase in multiple lines of transgenic mice.

Ovine prostaglandin F2alpha receptor: steroid influence on steady-state levels of luteal mRNA.

Expression of the receptor for prostaglandin F2alpha (PGF2alpha) is decreased in the ovine corpus luteum during regression and increased in early pregnancy. This study was designed to evaluate the influence of progesterone and/or 17beta-estradiol (E2) on this regulation. Circulating progesterone (functional regression) and luteal PGF receptor mRNA decreased (p < 0.

Insulin-like growth factor-I, insulin-like growth factor-binding proteins, and gonadotropins in the hypothalamic-pituitary axis and serum of nutrient-restricted ewes.

Body condition scores (BCS) of ovariectomized estradiol-treated ewes were controlled to examine effects of suboptimum BCS on insulin-like growth factor (IGF)-I, IGF-binding proteins (IGFBPs), and LH in the anterior pituitary gland, hypophyseal stalk-median eminence (SME), and circulation. Serum LH increased in ewes with BCS (1 = emaciated, 9 = obese) > 3 (HIGH-BCS), but not in ewes with BCS View Article and Find Full Text PDF

Accumulation of caspase-3 messenger ribonucleic acid and induction of caspase activity in the ovine corpus luteum following prostaglandin F2alpha treatment in vivo.

Caspase-3, a vertebrate homologue of the protein encoded by the Caenorhabditis elegans cell death gene, ced-3, induces apoptosis when overexpressed in eukaryotic cells. Since apoptosis occurs during corpus luteum (CL) regression in many species, including the ewe, these studies were conducted to 1) isolate a cDNA encoding ovine caspase-3, 2) measure steady state amounts of caspase-3 mRNA in the CL during luteolysis induced by prostaglandin F2alpha (PGF2alpha) and during the time of maternal recognition of pregnancy, and 3) measure changes in caspase activity during PGF2alpha-initiated luteal regression. Oligonucleotide primers corresponding to a human caspase-3 cDNA sequence were combined with total RNA from ovine CL in a reverse transcription-polymerase chain reaction-based procedure to amplify a 640-base pair partial cDNA with a nucleotide sequence 86% and 81% identical to the human and rat caspase-3 cDNAs, respectively.

Estradiol and gonadotropin-releasing hormone (GnRH) interact to increase GnRH receptor expression in ovariectomized ewes after hypothalamic-pituitary disconnection.

Gonadotropin-releasing hormone (GnRH) receptor expression is regulated by estradiol and GnRH itself. The objective of this experiment was to determine the extent to which low levels of estradiol, similar to those observed during the transition from the luteal to the follicular phase of the estrous cycle, and GnRH interact to regulate expression of GnRH receptors and GnRH receptor mRNA. Ewes were ovariectomized (OVX) at least 2 wk prior to initiation of the experiment, and the pituitary gland was surgically disconnected from the hypothalamus to remove ovarian and hypothalamic inputs to the pituitary.

Estradiol increases relative amounts of insulin-like growth factor binding protein (IGFBP)-3 in serum and expression of IGFBP-2 in anterior pituitaries of ewes.

This study determined whether estradiol regulates insulin-like growth factor (IGF)-I and IGF binding proteins (IGFBPs) in the pituitary gland, hypophyseal stalk median eminence (SME), and circulation concomitantly with effects on LH. Ovariectomized ewes received an estradiol implant or no implant during the anestrous season and were slaughtered 80 days later. Estradiol suppressed serum LH to a greater extent during anestrus than after onset of the breeding season (Days 60 and 75).

Regulation of amounts of mRNA for GnRH receptors by estradiol and progesterone in sheep.

Expression of GnRH receptors increases prior to the onset of the preovulatory surge of LH in sheep. Two experiments were conducted to investigate the interactions of progesterone (P) and estradiol (E) on amounts of mRNA for GnRH receptors and the number of receptors for GnRH. The first study was designed as a 2 x 2 factorial arrangement of treatments to investigate effects of removal of P and the presence of E.

Gonadotropin secretion and development of ovarian follicles during oestrous cycles in heifers treated with luteinizing hormone releasing hormone antagonist.

The hypothesis tested was that reduced LHRH stimulation of the anterior pituitary would lead to attenuated development of ovarian follicles as a result of reduced gonadotropin secretion during oestrous cycles of cattle. Twenty heifers were randomly assigned to be treated ( n = 5/treatment) with an antagonist to LHRH (LHRH-Ant) 1) from Day 2 to 7 (Day 0 = behavioural oestrus), 2) Day 7 to 12, 3) Day 12 to 17, 4) or serve as untreated control animals. LHRH-Ant suppressed LH pulses of heifers in all treatment groups from treatment initiation through Day 17 as compared with untreated control heifers [Peters et al.

The estradiol-induced luteinizing hormone surge in the ewe is not associated with increased gonadotropin-releasing hormone messenger ribonucleic acid levels.

This experiment was undertaken to determine whether the estrogen-induced LH and GnRH surge in the ewe is associated with activation of a specific subpopulation of neurons in the mid-brain of the ewe as indicated by a change in GnRH mRNA levels. Fifteen ovariectomized ewes were assigned to treatment groups 3-4 wk after ovariectomy. One group of ewes served as controls (n = 2); 50 microg estradiol-17beta (E2) was administered to the remaining ewes.

The proximal 350 bp of 5'-flanking sequence of the human α-subunit glycoprotein hormone gene functions in the pituitary gland, but not the placenta, in transgenic mice.

To understand better the minimal DNA sequence requirements for regulated expression of the human α-subunit glycoprotein hormone gene (Hα), two lines of transgenic mice were constructed that contained a fusion gene (Hα-350CAT) consisting of only 350 bp of 5'-flanking sequence of Hα linked to the bacterial gene encoding chloramphenicol acetyltransferase (CAT). CAT activity was detectable in pituitary, but not in brain, heart, kidney, liver, lung, pancreas, or spleen in transgenic mice. Gonadectomy increased (p<0.

Pituitary relationship of gonadotropins and messenger ribonucleic acid for gonadotropin subunits in white composite and Meishan boars.

Two experiments were conducted to compare amounts of mRNAs for gonadotropin subunits in two breeds of pigs that are genetically distinct with respect to litter size: the Chinese Meishan and the white composite (a composite of four European white breeds: Yorkshire, Landrace, large white, and Chester white). In experiment 1, pituitaries were collected from mature Meishan (n = 5) and white composite (n = 6) boars. In experiment 2, boars were assigned to three groups according to peripheral concentrations of FSH: white composite (approximately 100 ng/ml; n = 8), Meishan with low FSH (< 500 ng/ml; n = 7), and Meishan with high FSH (> 750 ng/ml; n = 7).

Estradiol increases amounts of messenger ribonucleic acid for gonadotropin-releasing hormone receptors in sheep.

Two experiments were conducted simultaneously to investigate regulation of amounts of mRNA for GnRH receptors during the periovulatory period in sheep. In the first experiment, amounts of mRNA for GnRH receptors were measured before and after preovulatory surge of LH following regression of the CL by prostaglandin F2 alpha(PGF2 alpha). So that the time of the preovulatory surge of LH could be accurately predicted, ewes received two injections of PGF2 alpha on Day 14 of the estrous cycle.

Molecular biology of gonadotrophins.

Regulation of gonadotrophin synthesis involves a complex interaction between hypothalamic and gonadal hormones. Chronic administration of oestrogens and androgens to gonadectomized animals blocked the postcastration rise in amounts of mRNA encoding gonadotrophin subunits. Removal of endogenous GnRH decreased amounts of mRNA encoding gonadotrophin subunits.

Analysis of transcriptional activation of a cyclic AMP response element by 2,6,10,14-tetramethylpentadecane (pristane) in JB6 mouse epidermal cells.

Pristane is a naturally occurring isoprenoid that is believed to be derived from the phytyl moiety of chlorophyll. Thus, it is not surprising that pristane is present in many common fruits and vegetables. Furthermore, pristane can be detected in the tissues of fish and mammals.