Bovine Hormone Research Articles

Manipulation of growth of the Amazonian fish tambaqui, Colossoma macropomum (Characiformes: Serrasalmidae): analysis of physiological and zootechnical aspects

ABSTRACT Colossoma macropomum, known locally as tambaqui, is the native fish most farmed in Brazil, however, technological advances are needed to reach efficient production rates. Modulating growth factors, such as growth hormone, may be associated with improved growth rate and feed efficiency. The use of exogenous hormone for fish rearing is prohibited in Brazil, yet the experimental use of bovine hormone can be useful in research aimed at understanding how to stimulate endogenous growth hormones in fish. Therefore, the present study had the strict objective of understanding the effects of growth hormone on the physiology and zootechnical parameters of C. macropomum under experimental conditions. The animals were intraperitoneally injected every fifteen days with 1, 10 and 100 μg g-1 of bGH using 0.9% NaCl saline as diluent. The 10 and 100 μg g-1 bolus had a positive effect on the performance indexes of C. macropomum: weight gain (g), growing length (cm), daily weight gain (g), feed conversion and specific growth rate (% per day). The bGH promoted a greater increase in length than in mass, which caused a reduction in condition factor of the individuals receiving a bolus of 10 and 100 μg g-1. Furthermore, bGH caused no changes in glucose levels, cortisol, hematological parameters, plasma levels of Na+ and K+, and activity of gill’s H+-ATPase and Na+, K+-ATPase, at least during the experimental period considered in the present study.

Endocrine and hematological responses of beef heifers divergently ranked for residual feed intake following a bovine corticotropin-releasing hormone challenge.

The objective of this study was to determine if beef heifers divergently ranked on phenotypic residual feed intake (RFI) differed in their physiological stress response to an exogenous bovine corticotropin-releasing hormone (bCRH) challenge. Yearling Limousin × Friesian heifers ( = 86) were ranked by RFI. The 15 highest (mean 0.66 kg DM/d; high RFI) and 15 lowest (mean -0.72 kg DM/d; low RFI) ranking animals were used for this study. During the study period, heifers (mean age 485 ± 13 d; mean BW 408 ± 31.4 kg) were housed in a slatted-floor facility. To facilitate intensive blood collection, heifers were fitted aseptically with indwelling jugular catheters. All heifers received dexamethasone (DEX; 20 µg/kg BW i.m.) 12 h before the bCRH challenge (d 0). Heparinized blood samples were collected at -60 and 0 min before administration of DEX, and 12 h after DEX administration. Following DEX administration, cortisol and dehydroepiandrosterone (DHEA) concentrations similarly decreased ( ≥ 0.22) between high and low RFI groups. The response of the HPA axis to a standardized dose of bCRH (0.3 μg/kg BW) was examined. On d 0, serial blood samples were collected at -20, 0, 20, 40, 60, 80, 100, 120, 150, 180, 210, 240, 270, 330, and 390 min relative to the time of bCRH administration (0 min) and were analyzed for plasma cortisol and DHEA concentrations. Blood hematology variables were also determined at -20, 0, 20, 80, 150, 270, 330, and 390 min relative to bCRH administration. Neither an RFI × sampling time interaction nor a direct effect of RFI were detected ( ≥ 0.36) for plasma cortisol, DHEA concentrations, or cortisol:DHEA ratio. An effect of sample time was observed for cortisol ( < 0.001), DHEA ( = 0.04), and cortisol:DHEA ( = 0.02), with cortisol concentration peaking at 60 min post-CRH administration. The maximum concentration and rate of change in cortisol and DHEA concentrations following bCRH administration were not different ( ≥ 0.20) between the high and low RFI phenotypes. Similarly, an effect of RFI was not evident ( ≥ 0.16) for any of the hematology variables examined including neutrophil, lymphocyte, and leukocytes counts; white and red blood cell numbers; and hemoglobin concentrations. Our results suggest that responsiveness of the HPA to stress, at least at the level of the anterior pituitary gland, is not a significant contributor to variation in RFI among growing beef heifers.

Abstract 1887: Calcium intake and milk product consumption in association with risk for colorectal adenomas

Abstract Calcium intake has been consistently, albeit modestly associated with lower risk of colorectal cancer and adenomas, and supplemental calcium reduced adenoma recurrence in large randomized controlled trials. Milk-based dairy products are the major source of dietary calcium in the US, but the association between milk product consumption and colorectal cancer is unclear. Conventionally produced milk contains significant levels of insulin-like growth factor 1 (IGF-1) from the use of bovine somatotropin hormone. Calcium intake has been positively associated with IGF-1 and IGF-1 binding protein 3 (IGFBP-3) levels. Higher circulating levels of IGF-1 and the IGF-1:IGFBP-3 ratio have been associated with higher risk of certain cancers, including breast, prostate, and colorectal, as well as with adenomatous polyps. To investigate associations of calcium and milk product intakes with risk for colorectal neoplasms, we pooled data from three colonoscopy-based case-control studies of incident, sporadic colorectal adenoma (n = 786 cases, 2,020 controls) conducted between 1991 and 2002, and analyzed the data using multivariable unconditional logistic regression. Dietary and supplemental intakes in all three studies were assessed using Willett food frequency questionnaires. For indirect indicators of IGF-1 intake from milk products, dietary calcium-adjusted residuals were calculated for total milk products and non-fat milk. For total, dietary, and supplemental calcium intakes, the multivariable-adjusted odds ratios (ORs) comparing the highest to the lowest quintiles of intake were 0.87 (95% confidence interval [CI] 0.63-1.20), 0.91 (95% CI 0.65-1.28), and 0.96 (95% CI 0.70-1.31), respectively. The corresponding ORs for consumption of total milk products, total milk, non-fat milk, total milk product residuals, and non-fat milk residuals were, 1.01 (95% CI 0.74-1.36), 0.97 (95% CI 0.73-1.29), 0.95 (95% CI 0.71-1.25), 0.92 (95% CI 0.70-1.22), and 0.97 (95% CI 0.70-1.34), respectively. For those who consumed any whole milk relative to those who consumed none, the OR was 1.15 (95% CI 0.89-1.50). These results are consistent with previous findings of modestly lower risk with higher total (dietary plus supplemental) calcium intakes, but suggest that neither the consumption of specific milk products nor all milk products combined, nor the non-calcium components of milk products are associated with risk for sporadic colorectal adenoma. Citation Format: Caroline Um, Veronika Fedirko, W Dana Flanders, Roberd M. Bostick. Calcium intake and milk product consumption in association with risk for colorectal adenomas. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1887. doi:10.1158/1538-7445.AM2015-1887

195 RELATIVE mRNA EXPRESSION OF 4 CANDIDATES IN LAMB OOCYTES SELECTED BY BRILLIANT CRESYL BLUE STAINING

Brilliant cresyl blue (BCB) staining determines the activity of glucose-6-phosphate dehydrogenase (G6PDH), an enzyme in which activity decreases as the oocytes reach their growth phase. We have previously shown in lamb the effectiveness of this stain in selecting the largest and most competent oocytes to develop up to the blastocyst stage (Catala et al. 2011 Reproduction 142, 517–527). The aim of this study was to analyse the expression of 4 genes related to oocyte quality in BCB-selected oocytes. The 4 genes analyzed in this study were selected after a literature review in which they were associated with a better oocyte quality or embryo development; 2 of these genes were related to cell cycle: nuclear auto-antigenic sperm protein (NASP) and histone H2A (H2A.Z), and 2 genes with enzymatic functions: peroxiredoxin (PRDX1) and elongation factor-A1 (EEF1A1). Oocytes were recovered after slicing the surface of lamb ovaries (3 to 5 months old) obtained from a local slaughterhouse. Oocytes with more than 3 compact cumulus layers and homogenic cytoplasm were selected and exposed to 13 µM BCB during 1 h before IVM and classified according to oocyte coloration: oocytes with blue cytoplasm or grown oocytes (BCB+) and oocytes not coloured or growing oocytes (BCB–). Cumulus–oocyte complexes were then matured in conventional TCM199 medium supplemented with 10% fetal bovine serum and hormones during 24 h in a controlled atmosphere. Groups of 15 denuded oocytes (3 replicates) were taken before (0 h) and after maturation (24 h) and stored at –80°C in 100 mL of Trizol until use. After RNA extraction following manufacturer’s protocol (Promega, Madison, WI, USA), reverse transcription was performed by extended cDNA using Oligo (dT) primers during 5 min at 70°C and 1 h at 65°C using superscript III (200 U mM–1; Invitrogen). Relative qualitative PCR analyses were performed in duplicate using SYBR Green Fluorophore kit (Bio-Rad, Hercules, CA, USA). The specificity of each PCR product was determined by a melting curve analysis and the amplicon size determination by an agarose gel. A standard curve was also included, consisting of corresponding plasmid DNA fragments from 1 pg to 0.1 fg, purified with QIAquick PCR Purification Kit (Qiagen, Valencia, CA, USA). Correlation coefficients and PCR efficiencies were considered between 85 and 100%. Finally, the results for mRNA were normalized according to the relative concentration of the internal and external gene (luciferase and 18S, respectively). The statistical analysis was performed by One-way ANOVA in GraphPad Prism v 3 (GraphPad Software, San Diego, CA, USA). The analysis of gene expression showed no differences in relation to BCB classification. The only difference we found is a significant decrease (P ≤ 0.05) in the RE of PRDX observed in matured oocytes compared with immature ones. In conclusion, the expression of the mRNA expression of NASP, H2A.Z, PRDX1, and EEF1A1 were not affected by oocyte quality.

Long term use of bovine somatotropic (bST) on reproduction and health of Nili-Ravi buffaloes

The study was conducted to determine the effect of long term use of bovine somatotropic hormone (bST) on days to first oestrus post-partum, number of services per conception, pregnancy rate, lactation length, dry period and calving interval for a period of three years, from 2004 to 2007. Thirty Nili-Ravi lactating buffaloes with approximately similar milk yields and stage of lactation were selected and randomly allocated to two treatments, A and B, with 15 animals in each group. Group A served as control while animals in group B were given injections of bovine somatotropic hormone (250 mg intramuscular per animal) at intervals of 14 days over a period of three years. The calving interval, dry period and lactation length were shorter by 71, 63.9 and 7 days, respectively, in the treated compared with the control group. The days to first oestrus post-partum, service period and services per conception were 160 ± 56.9 vs.98.2 ± 76.4 days, 207.0 ± 85.0 vs. 115.1 ± 107.0 days and 1.47 ± 1.1 vs. 1.31 ± 0.5 in group A vs. B, respectively. Statistically, differences were significant for post-partum oestrous and service period but for services per conception the difference was non-significant. Prevalence of mastitis was significantly higher in the treated animals while differences in body weights of the animals in the groups were not significant.

Porcine prolactin receptor genotypes and production and reproduction traits in Hungarian Large White and Landrace sows (Brief Report)

Abstract. Prolactin is an anterior pituitary hormone involved in many endocrine activities and plays and essential role in reproduction. Its receptor (PRLR) was detected in various tissues including brain, ovary, placenta, an uterus in several mammalian species (BOLE-FEYSOT et al. 1998). Reproductive performance of sows is a crutial point in pig production with significant economic importance and may be estimated with the help of markers. Porcine prolactin receptor gene is said to be a candidate genetic marker for reproductive traits. It has been mapped to porcine chromosome 16 (Vincent et al. 1997). There is a C/G SNP in PRLR gene (KMIEC et al. 2001) at the position of 203 (GAN: U96306) which eliminates an AluI cleavage site. The effect of this polymorphism on litter size in various breeds has been estimated (VINCENT et al. 1998, ROTHSCHILD et al. 1998, VAN RENS et al. 2002, KMIEC and TERMAN, 2004, DRÖGEMÜLLER et al. 2001, KORWIN-KOSSAKOWSKA et al. 2003). The influence of the bovine hormone variant was also estimated (RATNA-KUMARI et al. 2008). The aim of the study was to estimate PRLR AluI polymorphism effects on litter size in Hungarian Large White (HLW) and Hungarian Landrace (HL) breeds.

251 EVALUATION OF mRNA POLYADENYLATION STATUS OF CELL CYCLE-RELATED GENES IN BOVINE OOCYTES DURING MATURATION: PARTIAL RESULTS

During oocyte growth, transcription activity results in the production of RNA and proteins, which are immediately used or stored. At this time, gene expression is, in part, controlled at the post-transcriptional level through deadenylation and polyadenylation processes. After fertilization, early embryonic cell cycles are mainly supported by maternal mRNA and proteins until the maternal embryonic transition. The extent of the poly A tail of mRNA is known as an important element to determine their stability and can be considered a key marker in embryonic development. Because cell cycle-related genes are implicated in the maturation process and early embryonic cell cycle, study of the poly A tail in oocytes during maturation and early embryonic development may be an useful marker of differential developmental competence. Thus, the aim of the present work was to determine the polyadenylation status of the cell cycle-related genes cdc2, CDK2, CDK4, and Cyclin A, B, D, and E during bovine oocyte in vitro maturation (IVM). A PCR-based technique previously developed by Salles and Strickland (1995 PCR Meth. Appl. 4, 317–321) was used, with some modifications. Cumulus–oocyte complexes obtained from 2- to 8-mm follicles were immediately frozen in liquid nitrogen or IVM for 24 h in TCM-199 supplemented with fetal bovine serum and hormones (LH, FSH, and estradiol). In both cases, cumulus cells were removed by pipetting after a 10-min 0.2% hyaluronidase incubation. The RNA was extracted from pools of 10 immature or IVM oocytes and incubated with phosphorylated oligo-dT and DNA ligase. Thereafter, an anchor adapter [poly(dT) anchor] was targeted to the 5 end of the oligo-dT and incubated with Superscript II (Invitrogen) for reverse transcription. Specific primers were designed at the end of a full known sequence of the genes described above, and PCR was conducted for each gene using a specific primer and the anchor primer. The PCR products were digested with restriction enzymes to verify their specificity and were submitted to polyacrylamide gel electrophoresis. All sequences were amplified in immature and matured oocytes from 2 replicates by using a very small sample. After the restriction enzyme treatment, the amplified products were digested as expected. Although differences in amplicon sizes could be observed between the immature and matured oocytes, these are preliminary results and a higher number of replicates are necessary to determine the changes in the polyadenylation status of these cell cycle-related genes and their biological function. In conclusion, the polyadenylation status of the cell cycle-related genes cdc2, CDK2, CDK4, and Cyclin A, B, D, and E could be effectively performed in small samples, and this may be a powerful tool for studying the differential developmental competence of bovine oocytes and early cleavage embryos. FAPESP.

FASB Proposal Protested; Monsanto Sells Bovine Hormone Franchise; Parallel Drug Distributors May Lose to Counterfeit Prevention Rules

Biotechnology Law ReportVol. 27, No. 6 Financial and Shareholder AffairsFASB Proposal Protested; Monsanto Sells Bovine Hormone Franchise; Parallel Drug Distributors May Lose to Counterfeit Prevention RulesPublished Online:23 Jan 2009https://doi.org/10.1089/blr.2008.9895AboutSectionsPDF/EPUB Permissions & CitationsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail "FASB Proposal Protested; Monsanto Sells Bovine Hormone Franchise; Parallel Drug Distributors May Lose to Counterfeit Prevention Rules." , 27(6), pp. 561–562FiguresReferencesRelatedDetails Volume 27Issue 6Dec 2008 InformationMary Ann Liebert, Inc.To cite this article:FASB Proposal Protested; Monsanto Sells Bovine Hormone Franchise; Parallel Drug Distributors May Lose to Counterfeit Prevention Rules.Biotechnology Law Report.Dec 2008.561-562.http://doi.org/10.1089/blr.2008.9895Published in Volume: 27 Issue 6: January 23, 2009PDF download

Effect of bovine somatotropic hormone on the productive performance of Nili-Ravi buffaloes

The study was conducted on 21 Nili-Ravi lactating buffaloes with similar milk production and stage of lactation. They were randomly divided into three groups A, B and C with 7 animals in each group. The group A was injected with full dose of bST hormone (250 mg/animal) with trade name of Boostin-250 at an interval of 14 days, while animals in group B were given injection on alternate days with divided dose of 36 mg/animal. The group C was kept as control. The duration of study was 5 months and the animals were kept on green fodder supplemented with concentrate ration @ half of milk production. The concentrate ration had 17.2% CP and 72.0% TDN. The milk production was 8.06 ± 1.49, 7.85 ± 1.08 and 6.81 ± 1.80 liter in respective groups. The milk production increased by 18.35% and 15.27% in group A and B compared with group C (control). However, the increase was statistically non-significant (P>0.05). The difference in Fat, SNF, and TS percent was non-significant among the groups. The service period and services per conception were improved in both the treated groups. The body weight in sub-group A, B and C were similar and none of them lost weight over the study period. The difference among hematological and biochemical parameters was also non-significant.

21 EFFECT OF SEVERAL PARAMETERS ON PARTHENOGENETIC BOVINE EMBRYO DEVELOPMENT IN VITRO

The activation of oocytes is one of the most important steps for a successful cloning and has great importance on embryo development in vitro. The objective of this study was to examine the different parameters affecting parthenogenetic embryo development in vitro. In the first experiment, two activation protocols were compared to examine the effect of electrical pulse on activation. Bovine oocytes isolated from slaughterhouse ovaries were matured in TCM-199 supplemented with fetal bovine serum (FBS), sodium pyruvate, penicillin/streptomycin, rat insulin-like growth factor (rIGF-1), bovine follicle-stimulating hormone (bFSH), and bovine luteinizing hormone (bLH). A group of oocytes was exposed to a DC pulse of 133 V/500 �m for 25 �s, and then activated by calcium ionophore (5 �M) for 10 min, cytochalasin D (CD) (2.5 �g/mL) + cycloheximide (CHX, 10 �g/mL) for 1 h, and CHX alone for 5 h (Group 1). Another group of oocytes was activated only by chemicals without electrical pulse. Activated oocytes were cultured for 72 h in G1-3 and then 4-6 days in G2-3 medium. In the second experiment, oocytes activated by electrical pulse and chemicals were cultured in Barc medium for 7-9 days or 72 h in G1-3 and then 4-6 days in G2-3 medium. In the third experiment, oocytes activated by electrical pulse and chemicals were cultured for 48 h or 72 h in G1-3 and then 5-7 days or 4-6 days in G2-3 medium. The differences among groups were analyzed by one-way ANOVA after arcsin square transformation. In the first experiment, cleavage rate (75.6%), development rate (37.3%), and blastocyst cell number (78.4 � 3.2) of oocytes activated by electrical pulse was higher than for the group without electrical pulse (28.7%, 8.0%, 59.5 � 4.3, respectively; P &lt; 0.05). This result showed that activation was started more effectively by electrical pulse than by chemicals. In the second experiment, there was no significant difference on cleavage rate between the two groups (66.6%, 65.0%, respectively), and the blastocyst development rate of parthenogenetic embryos cultured in G1-3/G2-3 (36.6%) was higher than in the Barc medium group (16.6%; P &lt; 0.05). This result showed that G1-3/G2-3 medium was more effective for parthenogenetic embryo development than Barc medium. In the third experiment, although significant differences could not be found between the two groups in the development rate of parthenogenetic embryos cultured for a total of 7-9 days (30.8%, 39.2%, respectively), the development rate of embryos cultured for 72 h in G1-3 was higher (26.4%) than for the 48-h group (15%; P &lt; 0.05) on Day 7. This result showed that embryos developed more slowly when cultured for a shorter time in G1-3 medium before transfer to G2-3 medium. This study was supported by a grant from TUBITAK, Turkey (VHAG-1022).

Regulatory Effect of Magnesium Ions on Interaction of Prolactin and Somatotropin with Receptors on Granulosum Cells of the Cow Bos taurus

A comparative study of effects of Mg2+ ions on specific and competitive binding of the bovine somatotropic hormone (STH) and bovine prolactin (PL) with cells of cow granulosum is carried out. It is found that Mg2+ increases the level of specific binding of 125I-PL with the cells at concentrations from 1 to 70 mM and decreases the level of specific binding of 125I-STH at a concentration of 70 mM. Analysis of the data by Scatchard's method has shown that the decrease of the level of specific binding of 125I-PL in the absence of MgCl2 and 125I-STH at a MgCl2 concentration of 70 mM is caused mainly by a decrease of the number of active binding sites on the cells. Oppositely directed effects of the studied divalent cations on the capability of unlabelled STH (25 µg/ml) and PL (25 µg/ml) for cross-suppression of specific binding of 125I-PL and 125I-STH, respectively, with the granulosum cells have been revealed. At the same time, with increase of Mg2+ ion concentration, the degree of replacement of 125I-STH and 125I-PL with unlabelled STH and PL, respectively, did not change. The obtained results are considered in connection with electrostatic model of participation of the divalent cations in interaction of PL and STH with receptors on cells.

Placentation in the alpaca Lama pacos.

Reproduction in South American camelids is poorly studied. To extend our knowledge of the development and cellular physiology of the placenta in the alpaca Lama pacos, we have examined specimens from day 150 of pregnancy to term. Morphological investigations using light, transmission and scanning electron microscopy, the histochemical localization of iron, alkaline and acid phosphatase activity, and the immunodetection of placental lactogen hormone were performed. Throughout pregnancy there was a progressive increase in the depths of folds on the uterine mucosa surface together with a thickening of the endometrium. Glandular cells exhibited PAS and acid phosphatase (AcP) positive secretion granules. In the chorion, giant trophoblast polyploid cells gradually became more numerous and larger. Non-giant cells exhibited positive granules for PAS, alkaline phosphatase (AkP) reaction and immunostaining for bovine placental lactogen hormone (PLH). SDS -PAGE electrophoresis and Western blotting procedures also confirmed the presence of a bovine PLH-like glycoprotein in the fetal alpaca placenta. Over the glandular openings, the chorion formed typical areolae, where the trophoblast exhibited AcP and PAS positive reactions. At these sites, the fetal endothelial cells contained iron-storage granules in their cytoplasm. The trophoblast-epithelial interface exhibited a complex microvillous interdigitation, in which an AkP reaction was very prominent. The chorionic capillaries progressively indented adjacent trophoblast cells. These data suggest that although the epitheliochorial alpaca placenta is diffuse, various trophoblast cell types and specialized areas of the maternofetal interface give the placenta micro-regional functions where histiotrophic nutrition, hormone production and molecular exchange are prevalent.

Secretion of biologically active glycoforms of bovine follicle stimulating hormone in plants.

We chose the follicle stimulating hormone (FSH), a pituitary heterodimeric glycoprotein hormone, as a model to assess the ability of the plant cell to express a recombinant protein that requires extensive N-glycosylation for subunit folding and assembly, intracellular trafficking, signal transduction and circulatory stability. A tobacco mosaic virus (TMV) based transient expression system was used to express a single-chain (sc) version of bovine FSH in the tobacco related species Nicotiana benthamiana. Preparations of periplasmic proteins from plants infected with recombinant viral RNA contained high levels of sc-bFSH, up to 3% of total soluble proteins. Consistently, in situ indirect immunofluorescence revealed that the plant cell secreted the mammalian secretory protein to the extracellular compartment (EC). By mass spectrometric analysis of immunoaffinity purified sc-bFSH derived from EC fractions, we found two species of the plant paucimannosidic glycan type, truncated forms of complex-type N-glycans. Stimulation of cAMP production in a CHO cell line expressing the porcine FSH receptor acknowledged the native-like structure of sc-bFSH and a sufficient extent of N-glycosylation required for signal transduction. Furthermore, in superovulatory treatments of mice, sc-bFSH displayed significant in vivo bioactivity, although much lower than that of pregnant mare serum gonadotropin. We conclude that plants may have a broad utility as hosts for the recombinant expression of proteins even where glycosylation is essential for function.

Molecular Cloning of Ovine and Bovine Growth Hormone-Releasing Hormone Receptors: The Ovine Receptor Is C-Terminally Truncated

Molecular Cloning of Ovine and Bovine Growth Hormone-Releasing Hormone Receptors: The Ovine Receptor Is C-Terminally Truncated

Effect of bovine somatotropic hormone on insulin response to glucagon-like peptide 1, in dogs

Effect of bovine somatotropic hormone on insulin response to glucagon-like peptide 1, in dogs

Identification of an attenuating region in the bovine follicle-stimulating hormone beta subunit mRNA that decreases its expression in E. coli.

Follicle-stimulating hormone (FSH) is one of the key regulators of gonadal function in mammals. Recombinant DNA expression of this hormone has proved to be a difficult task as expression levels are invariably low, irrespective of the expression system employed. In the present study, we have attempted to identify reasons for this low expression using bacterial expression vectors, and we report here the identification of a theoretically predicted hairpin structure in the mRNA corresponding to the N-terminal portion of the mature coding portion of bFSHbeta cDNA that is responsible for attenuating its expression in E. coli. When full-length FSHbeta was expressed using the bacterial expression vector, a very low expression was obtained. However, when fragments of FSHbeta with N-terminal deletions (amino acids 24-110 and 13-110) were expressed using the same expression strategy, a 30- to 40-fold higher expression was observed. This low expression of FSHbeta could be attributed to a hairpin structure present in the first 12 codons of mature FSHbeta mRNA. Disruption of this structure without changing the amino acid sequence resulted in a higher level of expression of FSHbeta. The predicted hairpin structure, though away from the transcriptional and translational start site, was able to downregulate the expression of FSHbeta probably by impeding the movement of ribosomes.

Mapping of the bovine growth hormone-releasing hormone receptor (GHRH-R) gene to chromosome 4 by linkage analysis using a novel PCR-RFLP.

Mapping of the bovine growth hormone-releasing hormone receptor (GHRH-R) gene to chromosome 4 by linkage analysis using a novel PCR-RFLP.

Phosphorylation of bovine prolactin eliminates luteotropic activity in the rat

Phosphorylated and nonphosphorylated prolactins were isolated from bovine pituitaries and their luteotropic activity determined in female rats. Three groups of rats in day 1 of diestrus were treated ip twice daily for three days with 0.25 mg of either prolactin preparation or vehicle. Rats were sacrificed each day of treatment. Serum progesterone concentrations of the groups receiving vehicle or phosphorylated prolactin were similar and the vaginal cytology of these animals indicated that phosphorylated bovine prolactin (bPRL) treatment had not prolonged diestrus. Treatment with nonphosphorylated bPRL significantly increased serum progesterone concentration and the vaginal cytology indicated a diestrus prolonged for up to 4 days. Nonphosphorylated and phosphorylated bPRLs were cleared from the blood at similar rates after ip injection. In vitro receptor binding studies demonstrated that phosphorylated bPRL did not bind the ovarian prolactin receptor. Nonphosphorylated, but not phosphorylated, bPRL competed with radiolabeled bovine hormone for occupancy of rat ovarian prolactin receptors. These data are the first to test the activities of phosphorylated bPRL in vivo and indicate; 1) nonphosphorylated bPRL is luteotropic, 2) phosphorylated bPRL is neither luteotropic nor a prolactin receptor agonist or antagonist and 3) phosphorylated bPRL is not dephosphorylated in vivo rapidly enough to provide sufficient biologicallyactive bPRL to maintain luteal function.

An invertebrate G-protein coupled receptor is a chimeric cannabinoid/melanocortin receptor

Analysis of a G-protein coupled receptor fragment isolated from the leech CNS reveals that it is a chimeric cannabinoid/melanocortin receptor. Two regions of the leech sequence display high levels of amino acid identity with mammalian cannabinoid receptors while a third region is 98% identical to part of the bovine adrenocorticotropic hormone receptor. The leech receptor may therefore resemble the putative ancestor of mammalian cannabinoid and melanocortin receptors.

Reproductive functions in Nili-Ravi buffaloes after short term treatment with recombinant bovine somatotropin hormone

Reproductive functions in Nili-Ravi buffaloes after short term treatment with recombinant bovine somatotropin hormone