13 STRATEGIES TO INCREASE OVULATORY FOLLICLE SIZE AND REDUCE OVULATION TIME IN LACTATING DAIRY COWS

2008 ◽  
Vol 20 (1) ◽  
pp. 87
Author(s):  
J. O. Giordano ◽  
J. L. Edwards ◽  
G. M. Schuenemann ◽  
N. Rohrbach ◽  
F. N. Schrick
Keyword(s):  
Oocyte Maturation ◽  
Elevated Temperatures ◽  
Animal Health ◽  
Ovarian Activity ◽  
Blastocyst Development ◽  
Sterile Saline ◽  
Ovulatory Follicle ◽  
To Receive

In vitro exposure of oocytes to elevated temperatures hastened oocyte maturation; furthermore, performing IVF of heat-stressed oocytes 5 h earlier than the usual 24 h resulted in blastocyst development similar to that of non-heat-stressed controls (Edwards et al. 2005 J. Dairy Sci. 88, 4326–4333). If elevated ambient temperatures in vivo alter oocyte maturation in a similar fashion, then new strategies are needed to induce earlier release of the oocyte from the ovulatory follicle. Current objectives were to examine follicular growth after FSH administration and examine whether treatment with FSH and an exogenously induced LH surge would hasten ovulation. On Day 0 (8 to 9 days after estrus) of the experimental period, lactating Holstein cows (n = 31; 65–115 days in milk; 1–6 lactations) received an EAZI-BREED CIDR (Pfizer Animal Health, New York, NY, USA) plus 100 µg of gonadotropin-releasing hormone (GnRH, IM; Cystorelin, Merial Ltd, Iselin, NJ, USA). On Day 7, CIDRs were removed and cows were administered 500 µg cloprostenol (IM; Estrumate, Schering-Plough Animal Health, Union, NJ, USA). Concurrently, cows were randomly allocated to receive either 80 mg FSH (FSH; n = 15; Folltropin-V, Bioniche Animal Health, Belleville, ON, Canada) or 4 mL of sterile saline (SAL; n = 16). Forty-eight h later (Day 9), cows within the FSH and SAL groups were randomly subdivided to receive either a 100-µg dose of Cysterolin (GnRH) or 3000 IU of hCG (hCG, IM; Chorulon, Intervet Inc., Millsboro, DE, USA) generating 4 treatment combinations (FSH/GnRH, n = 3; FSH/hCG, n = 7; SAL/GnRH, n = 8; and SAL/hCG, n = 8). Ovarian activity was assessed by ultrasonography to evaluate growth of the ovulatory follicle. Following CIDR removal, frequent ultrasonography was utilized to confirm ovulation (disappearance of the dominant follicle). Data were analyzed using the MIXED procedure of SAS (SAS Institute, Inc., Cary, NC, USA). Five cows from the FSH group were removed from the combination treatment due to ovulation occurring before 48 h post-CIDR removal. Size of the ovulatory follicle at time of GnRH or hCG administration was not different between FSH or SAL groups (16.7 � 0.7 v. 17.5 � 0.6 mm, respectively). Total growth of the ovulatory follicle from CIDR removal to ovulation did not differ between FSH (3.04 � 0.7 mm) and SAL (2.75 � 0.7 mm)-treated cows. As calculated from time of CIDR removal, ovulation occurred earlier in FSH (63.6 � 4.5 h) than in SAL (77.2 � 4.4 h; P < 0.05)-treated cows. Combination of FSH/GnRH produced the earliest ovulation (74 � 1.2 h) which was different only from FSH/hCG (78.6 � 0.8 h; P < 0.05), but not from SAL/GnRH or SAL/hCG (77 � 0.8 and 78 � 0.8 h, respectively). Regardless of FSH or SAL treatment, cows treated with GnRH ovulated earlier than those treated with hCG (75.5 � 0.7 v. 78.3 � 0.6 h, respectively; P < 0.05). In conclusion, while FSH was unable to increase the size of the ovulatory follicle, earlier ovulation occurred when given alone or in combination with GnRH.

339 OXYGEN CONCENTRATION DURING IN VITRO MATURATION OF MURINE OOCYTES INFLUENCES SUBSEQUENT FETAL AND PLACENTAL OUTCOMES

2007 ◽  
Vol 19 (1) ◽  
pp. 285
Author(s):  
K. M. Banwell ◽  
M. Lane ◽  
D. L. Russell ◽  
K. L. Kind ◽  
J. G. Thompson
Keyword(s):  
Oxygen Concentration ◽  
Oocyte Maturation ◽  
In Vitro Maturation ◽  
Weight Ratio ◽  
Average Weight ◽  
Intermediate Cell ◽  
Blastocyst Development ◽  
Oxygen Environment

Although the oxygen environment of the ovarian follicle is thought to influence oocyte developmental competence, little is known of the optimal oxygen environment for oocyte in vitro maturation (IVM). Previously, we found that oxygen concentration (either 2, 5, 10, or 20% O2; 6% CO2; and balance of N2) during IVM of murine oocytes had no effect on maturation rate or subsequent fertilization, cleavage, and blastocyst development rates. However, 2% O2 results in blastocysts with a higher (P &lt; 0.05) trophectoderm cell number (mean � SEM, 35.1 � 2.3) when compared to 20% (19.4 � 1.7), with 5 and 10% O2 yielding similar but intermediate cell numbers. When examined for cell apoptosis by TUNEL labelling, the 2% O2 IVM-derived embryos were also found to have a significantly higher percentage of cells undergoing apoptosis compared to the 5% O2 IVM-derived embryos and embryos derived from in vivo matured oocytes (unpublished data). Although the blastocyst development rate is not affected by varying oxygen environment during oocyte maturation, the resultant blastocysts exhibited signs of differing quality. The aim of this study was to investigate the effect of varying oxygen during IVM on post-transfer outcomes. Immature cumulus-oocyte complexes (COCs) were collected from the ovaries of eCG-stimulated CBAB6F1 females (21 days) and cultured for 17–18 h under 2, 5, or 20% O2, whereas in vivo-matured COCs were also collected post-hCG. After IVF/C (both under 5% O2), 6 blastocysts were transferred to each uterine horn of pseudopregnant Swiss recipients. Fetal and placental parameters were measured on Day 18 of pregnancy. The ability of the embryos to implant or develop was not altered by IVM oxygen concentration. However, the average weight of fetuses derived from 5% O2 matured oocytes was reduced (823.3 � 28.1 mg, P &lt; 0.05) compared to those in the 20% O2 group (928.5 � 26.1 mg). The average weight of the placenta in the 5% O2 group was also reduced (87.4 � 4.0 mg) compared to those derived from in vivo-matured oocytes (104.5 � 5.4 mg). In contrast, the fetal:placental weight ratio was unchanged in the 5% O2 treatment, suggesting these placentae, although small, are still efficient. This is the first evidence that programming of fetal/placental growth occurs from treatments applied during oocyte maturation.

Effects of Unfractionated and Low Molecular Weight Heparins on Platelet Thromboxane Biosynthesis “In Vivo”

1994 ◽  
Vol 72 (06) ◽  
pp. 942-946 ◽  
Author(s):  
Raffaele Landolfi ◽  
Erica De Candia ◽  
Bianca Rocca ◽  
Giovanni Ciabattoni ◽  
Armando Antinori ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Unfractionated Heparin ◽  
Low Molecular Weight Heparin ◽  
Primary Source ◽  
In Vivo Studies ◽  
Low Molecular Weight ◽  
Heparin Administration ◽  
To Receive

SummarySeveral “in vitro” and “in vivo” studies indicate that heparin administration may affect platelet function. In this study we investigated the effects of prophylactic heparin on thromboxane (Tx)A2 biosynthesis “in vivo”, as assessed by the urinary excretion of major enzymatic metabolites 11-dehydro-TxB2 and 2,3-dinor-TxB2. Twenty-four patients who were candidates for cholecystectomy because of uncomplicated lithiasis were randomly assigned to receive placebo, unfractionated heparin, low molecular weight heparin or unfractionaed heparin plus 100 mg aspirin. Measurements of daily excretion of Tx metabolites were performed before and during the treatment. In the groups assigned to placebo and to low molecular weight heparin there was no statistically significant modification of Tx metabolite excretion while patients receiving unfractionated heparin had a significant increase of both metabolites (11-dehydro-TxB2: 3844 ± 1388 vs 2092 ±777, p <0.05; 2,3-dinor-TxB2: 2737 ± 808 vs 1535 ± 771 pg/mg creatinine, p <0.05). In patients randomized to receive low-dose aspirin plus unfractionated heparin the excretion of the two metabolites was largely suppressed thus suggesting that platelets are the primary source of enhanced thromboxane biosynthesis associated with heparin administration. These data indicate that unfractionated heparin causes platelet activation “in vivo” and suggest that the use of low molecular weight heparin may avoid this complication.

PSX-A-10 Late-Breaking: Effects of paternal high energy diets on blastocyst development during in vitro embryo production in the bovine

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 363-363
Author(s):  
Dylan B Davis ◽  
Zachary Seekford ◽  
Mackenzie Dickson ◽  
Lucas Gonçalves ◽  
Samir Burato ◽  
...  
Keyword(s):  
High Gain ◽  
High Energy ◽  
Carcass Composition ◽  
Adaptation Period ◽  
Blastocyst Development ◽  
Embryo Production ◽  
Ad Libitum ◽  
In Vitro Embryo Production ◽  
To Receive

Abstract The objective of this study was to evaluate the effect of paternal high energy diets on blastocyst development during in vitro embryo production (IVP). Eight sires were stratified by body weight (initial BW = 946 ± 85 kg) and randomly assigned to the same diet (NEm = 2.10, NEg = 1.44, CP = 14.1%, NDF = 16.6%, DM basis) fed at two different inclusion rates while having ad libitum access to bermudagrass hay (NEm = 1.02, NEg = 0.45, CP = 10.2%, NDF = 71.6). After a 10-d adaptation period, sires were individually fed to receive 0.5% (MAINT) or 1.25% [High gain (HG)] of their BW daily for 67 days. At the end of the feeding period, semen was collected through electroejaculation and frozen. Antral follicles were aspirated from ovaries obtained from a slaughterhouse and utilized for IVP in 4 independent replicates (n = 2,227 total oocytes). Cleavage rates were evaluated 48 h after fertilization and blastocyst development rates were evaluated after 7 days of embryo culture. The proposed treatments successfully induced differences in BW gain (P &lt; 0.01; 2.28 vs -0.04 kg/d) and carcass composition (Rump fat: 1.63 vs. 0.41 cm, P = 0.08; Rib fat: 1.06 vs. 0.41 cm, P = 0.02; intramuscular fat: 3.5 vs. 3.0%, P = 0.36; for HG vs. MAINT sires, respectively). There was a significant decrease in cleavage rates (69.9 ± 2.5 vs. 65.0 ± 2.7; P &lt; 0.04), blastocyst rate as a percentage of oocytes (16.7 ± 2.9 vs. 11.5 ± 2.1; P &lt; 0.01), and blastocyst rates as a percentage of cleaved structures (24.1 ± 3.8 vs. 11.5 ± 2.1; P &lt; 0.01) for HG compared with MAINT sires. In conclusion, sires fed diets that induce highly anabolic conditions had impaired blastocyst development compared to sires fed a maintenance diet.

scholarly journals An Overview of Structural Aspects and Health Beneficial Effects of Antioxidant Oligosaccharides

2020 ◽  
Vol 26 (16) ◽  
pp. 1759-1777 ◽  
Author(s):  
Tatiane F. Vieira ◽  
Rúbia C. G. Corrêa ◽  
Rosely A. Peralta ◽  
Regina F. Peralta-Muniz-Moreira ◽  
Adelar Bracht ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Sugar Content ◽  
Animal Health ◽  
Monosaccharide Composition ◽  
Degree Of Polymerization ◽  
Chemical Diversity ◽  
In Vivo Studies

Background: Non-digestible oligosaccharides are versatile sources of chemical diversity, well known for their prebiotic actions, found naturally in plants or produced by chemical or enzymatic synthesis or by hydrolysis of polysaccharides. Compared to polyphenols or even polysaccharides, the antioxidant potential of oligosaccharides is still unexplored. The aim of the present work was to provide an up-to-date, broad and critical contribution on the topic of antioxidant oligosaccharides. Methods: The search was performed by crossing the words oligosaccharides and antioxidant. Whenever possible, attempts at establishing correlations between chemical structure and antioxidant activity were undertaken. Results: The most representative in vitro and in vivo studies were compiled in two tables. Chitooligosaccharides and xylooligosaccharides and their derivatives were the most studied up to now. The antioxidant activities of oligosaccharides depend on the degree of polymerization and the method used for depolymerization. Other factors influencing the antioxidant strength are solubility, monosaccharide composition, the type of glycosidic linkages of the side chains, molecular weight, reducing sugar content, the presence of phenolic groups such as ferulic acid, and the presence of uronic acid, among others. Modification of the antioxidant capacity of oligosaccharides has been achieved by adding diverse organic groups to their structures, thus increasing also the spectrum of potentially useful molecules. Conclusion: A great amount of high-quality evidence has been accumulating during the last decade in support of a meaningful antioxidant activity of oligosaccharides and derivatives. Ingestion of antioxidant oligosaccharides can be visualized as beneficial to human and animal health.

scholarly journals Investigating the Intrafollicular Factors Affecting Oocyte Developmental Competency

2021 ◽  
Author(s):  
◽  
Zaramasina Clark
Keyword(s):  
Gene Expression ◽  
Oocyte Maturation ◽  
Granulosa Cells ◽  
Embryo Quality ◽  
Cumulus Cells ◽  
Significant Finding ◽  
High Quality ◽  
Final Maturation

<p>The number of cycles of assisted reproductive technologies (ART) performed increased by ~9.5 % globally between 2008 and 2010. In spite of this, the success rate in terms of delivery was only ~19.0 % (Dyer et al., 2016). This discrepancy between the demand for, and success of, these technologies necessitates the development of tools to improve ART efficiency. To facilitate this, a better understanding of how the microenvironment changes within the developing follicle to culminate in a mature, developmentally-competent oocyte is required. This study employed an in vivo and in vitro ovine model to investigate the relationship between the surrounding microenvironment and oocyte maturation, and in particular, the attainment of oocyte developmental competency and high-quality embryos.  The first objective of this PhD study was to comprehensively investigate the changing microenvironment of in vivo matured, presumptive preovulatory (PPOV) follicles from wild-type (++) and high ovulation rate (OR; I+B+) ewes. The high OR ewes were heterozygous carriers of mutations in BMP15 (I+) and BMPRIB (B+). Functional differences in follicular somatic (granulosa and cumulus) cells between these genotypes, including differential gonadotropin responsiveness of granulosa cells, composition of follicular fluid and gene expression profiles in cumulus cells were evident. These differences emerged as part of a compensatory mechanism by which oocytes from smaller follicles, containing fewer granulosa cells, achieved developmental competency in I+B+ ewes.  The second objective of this PhD study was to develop new approaches for improving current in vitro maturation (IVM) strategies. The first approach utilised in this study focused on developing biomarkers that could be used to improve prediction of developmental competency in oocytes and in vitro produced embryos. This involved interrogating the hypothesis that a combination of molecular and morphokinetic biomarkers would better predict the developmental competency of oocytes and embryos compared to using these biomarkers alone. The second approach utilised in this PhD study tested the effects of modulating IVM conditions to better mimic the follicular microenvironment of a high, compared to a low, OR species on oocyte developmental competency and embryo quality. This involved supplementing IVM media with different ratios of two oocyte-secreted growth factors, i.e. GDF9:BMP15, that were representative of low or high OR species. These approaches demonstrated significant potential and warrant further investigation.  The most significant finding of this study was that despite variances in the surrounding microenvironment during in vivo and in vitro oocyte maturation that culminated in differential gene expression patterns in cumulus cells, and divergent gonadotropin-responsiveness of granulosa cells, the gene expression signatures of developmentally-competent oocytes and the morphokinetics of high-quality embryos were unaltered. This confirms the value of developing such biomarkers for oocyte development competency and embryo quality that remain unaltered despite a changing surrounding environment. Interestingly, simulating the ratio of GDF9:BMP15 that oocytes from high OR species are exposed to during maturation improved developmental competency in oocytes as demonstrated by increased blastocyst rates. Furthermore, this study has demonstrated that combinations of molecular (cumulus cell gene expression) and morphokinetic biomarkers improved the ability to predict developmental competency in oocytes and embryos. Overall, this study revealed novel information regarding the follicular microenvironment during final maturation and identified several novel approaches to improving the efficiency of ART.</p>

scholarly journals 183PREGNANCY RATE FOLLOWING TRANSFER OF IN VITRO- AND IN VIVO-PRODUCED BOVINE EMBRYOS TO LH-TREATED RECIPIENTS

2004 ◽  
Vol 16 (2) ◽  
pp. 213 ◽  
Author(s):  
J. Small ◽  
M. Colazo ◽  
D. Ambrose ◽  
R. Mapletoft ◽  
J. Reeb ◽  
...  
Keyword(s):  
Pregnancy Rate ◽  
Animal Health ◽  
Beef Cows ◽  
Water Bath ◽  
Bovine Embryos ◽  
Chi Square ◽  
Embryo Survival ◽  
Frozen Embryos

The objective was to evaluate the effect of pLH treatment on pregnancy rates in recipients receiving in vivo- or in vitro-produced bovine embryos. Heifers (n=37) and lactating (n=28) and non-lactating (n=150) beef cows were treated at random stages of the cycle with 100μg GnRH i.m. (Cystorelin, Merial Canada Inc., Victoriaville, Quebec, Canada) on Day −9, 500μg cloprostenol i.m. (PGF; Estrumate, Schering Plough Animal Health, Pointe-Claire, Quebec, Canada) on Day —2 and GnRH on Day 0 (66h post-PGF; without estrus detection). Cattle were placed at random, by class, into three groups: no further treatment (Control; n=71), or 12.5mg pLH (Lutropin-V, Bioniche Animal Health, Belleville, Ontario, Canada) on Day 5 (n=72) or on Day 7 (n=72) after the second GnRH. On Day 7, cattle with a CL &gt;10mm in diameter (determined ultrasonically) received in vivo-produced, fresh (Simmental) or frozen (Holstein), or in vitro-produced frozen (Holstein) embryos (embryo type balanced among groups). Embryos were cryopreserved in 10% ethylene glycol; in vivo-produced frozen embryos were thawed 5 to 10s in air, 15s in a water-bath at 30°C and then “direct-transferred” nonsurgically. In vitro-produced frozen embryos (donated by IND Lifetech Inc., Delta, British Columbia, Canada) were thawed in a water-bath at 27°C for 10s and placed in ViGro Holding Plus medium (AB Technology, Pullman, WA, USA) at room temperature, evaluated and then transferred nonsurgically. Pregnancy was determined by ultrasonography on Day 35. Data were analyzed with CATMOD, chi-square and GLM procedures (SAS Institute, Cary, NC, USA.). Twenty cattle (9.3%) did not receive embryos; five heifers had cervical problems, and five heifers and 10 cows did not have a CL &gt;10mm. Overall, 7.1% of the recipients had two CL on the day of embryo transfer. There was no effect (P&gt;0.05) of treatment, embryo type (or interaction) or class of recipient on pregnancy rate (overall, 44.1%, 86/195; Table 1). Similarly, mean (±SD) CL diameter and luteal area did not differ (P&gt;0.05) among groups or between pregnant and open recipients (overall, 22.0±3.4mm and 352.0±108.7mm, respectively). However, recipients with a CL diameter ≥18mm tended (P&lt;0.1) to have a higher pregnancy rate (45.8 vs 25.0%). In a subset of 40 recipients examined ultrasonically on Day 12, 50% of those treated on Day 5 and 70% of those treated with pLH on Day 7 had two CL. In summary, overall pregnancy rate in GnRH-synchronized recipients receiving in vitro- or in vivo-produced embryos by nonsurgical transfer was 44.1%. Embryo survival to Day 35 was not affected by type of embryo or treatment with pLH 5 or 7 days after ovulation. Table 1 Pregnancy rate in recipients on Day 35 based on pLH treatment and embryo-type

scholarly journals Antimicrobial Peptides Epinecidin-1 and Beta-Defesin-3 Are Effective against a Broad Spectrum of Antibiotic-Resistant Bacterial Isolates and Increase Survival Rate in Experimental Sepsis

Antibiotics ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 76
Author(s):  
Albert Bolatchiev
Keyword(s):  
Antibacterial Activity ◽  
Survival Rate ◽  
Antimicrobial Peptides ◽  
Lethal Dose ◽  
Experimental Models ◽  
Experimental Sepsis ◽  
Epinephelus Coioides ◽  
Sterile Saline

The antimicrobial peptides human Beta-defensin-3 (hBD-3) and Epinecidin-1 (Epi-1; by Epinephelus coioides) could be a promising tool to develop novel antibacterials to combat antibiotic resistance. The antibacterial activity of Epi-1 + vancomycin against methicillin-resistant Staphylococcus aureus (22 isolates) and Epi-1 + hBD-3 against carbapenem-resistant isolates of Klebsiella pneumoniae (n = 23), Klebsiella aerogenes (n = 17), Acinetobacter baumannii (n = 9), and Pseudomonas aeruginosa (n = 13) was studied in vitro. To evaluate the in vivo efficacy of hBD-3 and Epi-1, ICR (CD-1) mice were injected intraperitoneally with a lethal dose of K. pneumoniae or P. aeruginosa. The animals received a single injection of either sterile saline, hBD-3 monotherapy, meropenem monotherapy, hBD-3 + meropenem, or hBD-3 + Epi-1. Studied peptides showed antibacterial activity in vitro against all studied clinical isolates in a concentration of 2 to 32 mg/L. In both experimental models of murine sepsis, an increase in survival rate was seen with hBD-3 monotherapy, hBD-3 + meropenem, and hBD-3 + Epi-1. For K. pneumoniae-sepsis, hBD-3 was shown to be a promising option in overcoming the resistance of Klebsiella spp. to carbapenems, though more research is needed. In the P. aeruginosa-sepsis model, the addition of Epi-1 to hBD-3 was found to have a slightly reduced mortality rate compared to hBD-3 monotherapy.

scholarly journals Use of Tannin-Containing Plants as Antimicrobials Influencing the Animal Health

2022 ◽  
Vol 45 (2) ◽  
pp. 33-40
Author(s):  
Mohammed M Dakheel ◽  
Afnan A Al-Mnaser ◽  
Jessica Quijada ◽  
Martin J Woodward ◽  
Caroline Rymer
Keyword(s):  
Nutritional Quality ◽  
Condensed Tannins ◽  
Animal Health ◽  
Degree Of Polymerization ◽  
Gram Negative Bacteria ◽  
Animal Feeding ◽  
The Subject

The antimicrobial effects of diverse tannin-containing plants, particularly condensed tannins (CTs) produced from various plants, are the subject of this study. CT components can be determined using CT-specific procedures such the HCl-Butanol Acetone assay, Thiolysis reaction, and HPLC/MS analysis. These methods indicate CT contents, including mean degree of polymerization, the procyanidins and prodelphinidins ratio (PC/PD%), the isomers of trans- and cis-, and CT concentration. Tannin-containing plants possess antibacterial action, which can be attributed to their protein linkage technique, and tannin-type variations, particularly CTs extract and their PC/PD%. The effects of CT components on the development of Gram-positive and Gram-negative bacteria have been documented for their relative PC/PD%; this is regarded to be a key predictor of tannin characteristics in terms of antimicrobials. In conclusion, tannins, more specific CT compositions, have significant impacts on in vivo trials of animal productions and utilization of metabolites and fermentation in vitro experiments. These findings need further investigations to fully understand how CT-types act on animal feeding in terms of enhanced nutritional quality of animal diets, which may have implications for human and animal health.

Sheep antiluteolytic interferon: cDNA sequence and analysis of mRNA levels

1989 ◽  
Vol 2 (1) ◽  
pp. 65-70 ◽  
Author(s):  
H.J. Stewart ◽  
S.H.E. McCann ◽  
A.J. Northrop ◽  
G.E. Lamming ◽  
A.P.F. Flint
Keyword(s):  
Amino Acid ◽  
Northern Blotting ◽  
In Vitro Translation ◽  
Major Constituent ◽  
Interferon Α ◽  
Mrna Levels ◽  
Blastocyst Development ◽  
Cdna Sequences

ABSTRACT A cloned cDNA has been isolated by probing a sheep blastocyst cDNA library using a synthetic oligonucleotide representing the N-terminal amino acid sequence of the antiluteolytic protein, ovine trophoblast protein-1. Sequence analysis of the cDNA confirms the 70% homology between the antiluteolysin and the interferon-α family of proteins; however, the sequence reported here differs at several points from previously reported amino acid and cDNA sequences for the antiluteolysin. In-vitro translation of day-16 poly(A)+ RNA indicated that antiluteolysin mRNA is a major constituent of total mRNA at this stage of blastocyst development, and Northern blotting confirmed that antiluteolysin mRNA production occurred between days 13 and 22 after oestrus. This is consistent with the stage at which embryonic extracts are antiluteolytic on administration in vivo. These and other data confirm that the ovine trophoblast antiluteolysin is an interferon, and suggest that at least five isoforms of this protein may exist.

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