Deslorelin implants in free-ranging female eastern grey kangaroos (Macropus giganteus): mechanism of action and contraceptive efficacy

2013 ◽  
Vol 40 (5) ◽  
pp. 403 ◽  
Author(s):  
Michelle E. Wilson ◽  
Graeme Coulson ◽  
Geoff Shaw ◽  
Marilyn B. Renfree
Keyword(s):  
Follicular Development ◽  
Fertility Control ◽  
Ovarian Follicles ◽  
Management Technique ◽  
Contraceptive Efficacy ◽  
Effective Population ◽  
Contraceptive Effect ◽  
Reproductive Life ◽  
Lethal Management ◽  
Free Ranging

Context Fertility control offers a non-lethal management technique for iconic yet overabundant wildlife. Slow-release hormonal implants containing deslorelin show promise for managing free-ranging populations, particularly in peri-urban reserves, but most studies have been limited to captivity. Aims We investigated the efficacy and mechanism of deslorelin implants in free-ranging female eastern grey kangaroos (Macropus giganteus) under realistic management conditions. Methods We assigned females to a deslorelin (9.4 mg, n = 53) or placebo (n = 56) group at three peri-urban sites in Victoria, Australia, and monitored reproductive success for 3 years by observing young in the pouch. We tested the plasma LH response of control and treated females to exogenous GnRH, and compared the size of ovarian follicles between the two groups. Key results Deslorelin implants reduced fertility at all three sites. No deslorelin-treated females bred in Year 1 at Anglesea and Serendip versus 42% and 44% of control females respectively. At Plenty Gorge, 60% of deslorelin-treated females bred in Year 1 versus 100% of control females. In Year 2, between 11% and 39% of the treated females bred versus between 82% and 100% of control females at all sites. The contraceptive efficacy reduced by Year 3 when between 43% and 57% of the treated females bred versus between 85% and 100% of controls. A GnRH challenge elicited higher plasma LH concentrations in control than in treated females, and unlike untreated females, treated females lacked ovarian follicles >2 mm. Conclusions Deslorelin implants reduced fertility in free-ranging female eastern grey kangaroos over three successive breeding seasons. Chronic exposure to deslorelin desensitised the pituitary gland to GnRH and suppressed follicular development, but did not inhibit the development of a blastocyst, pregnancy or lactation in at least some females that had conceived before treatment. Implications Effective population management using deslorelin implants will require females to be re-treated on multiple occasions because the contraceptive effect lasts only a portion of their reproductive life. This would be practical only at sites where kangaroos are relatively easy to capture. The timing of treatment is also important in a species that undergoes embryonic diapause, particularly at sites providing high-quality habitat.

Levonorgestrel, not etonogestrel, provides contraception in free-ranging koalas

2010 ◽  
Vol 22 (6) ◽  
pp. 913 ◽  
Author(s):  
E. F. Hynes ◽  
K. A. Handasyde ◽  
Geoff Shaw ◽  
Marilyn B. Renfree
Keyword(s):  
Breeding Season ◽  
Follicular Development ◽  
Urogenital Sinus ◽  
Control Group ◽  
Phascolarctos Cinereus ◽  
Plasma Progesterone ◽  
Contraceptive Effect ◽  
Cytological Smear ◽  
Vaginal Cytology ◽  
Free Ranging

Management of high-density koala (Phascolarctos cinereus) populations is essential because of the browsing damage they inflict on their habitat. We have tested two types of gestagen implant, namely levonorgestrel and etonogestrel, as contraceptives for koalas. Free-ranging female koalas were given either a control, levonorgestrel (70 mg) or etonogestrel (34 or 68 mg) implant before the breeding season. Koalas were monitored every 4–12 weeks for births. Plasma progesterone was measured and a cytological smear of the urogenital sinus was taken. Fertility was high in the control group and the two etonogestrel-treated groups, with approximately 90% of females giving birth. In contrast, no levonorgestrel-treated female produced young during the study. Removal of levonorgestrel implants from six females reversed the contraceptive effect in the next breeding season, whereas the eight females in which the levonorgestrel implants were left in remained infertile for six breeding seasons. Vaginal cytology showed evidence of oestrous cycles during the breeding season in all females from all groups and there was no difference seen in the prevalence of cornified epithelial cells in the oestrous smears. This indirectly suggests that levonorgestrel does not prevent follicular development and oestrous cycling. Plasma progesterone in levonorgestrel-treated females remained low all year, but rose in controls concurrent with the onset of the breeding season. This suggests that levonorgestrel prevents pregnancy by blocking ovulation. Etonogestrel had absolutely no contraceptive effect at the two doses delivered and so is not suitable for controlling koala populations. In contrast, levonorgestrel was effective as a long-term, reversible contraceptive in wild koalas.

Comparative efficacy of levonorgestrel and deslorelin contraceptive implants in free-ranging eastern grey kangaroos (Macropus giganteus)

2016 ◽  
Vol 43 (3) ◽  
pp. 212 ◽  
Author(s):  
Michelle E. Wilson ◽  
Graeme Coulson
Keyword(s):  
Fertility Control ◽  
Control Group ◽  
Natural Fertility ◽  
Cost Of Treatment ◽  
Contraceptive Effect ◽  
Contraceptive Implants ◽  
The Cost ◽  
Free Ranging ◽  
Equivalent Field

Context Fertility control of females with levonorgestrel or deslorelin implants shows promise for managing populations of overabundant eastern grey kangaroos (Macropus giganteus). Although these implants have been tested separately in captive and free-ranging kangaroos, there has been no direct comparison under equivalent field conditions. Aims We investigated the long-term efficacy of levonorgestrel and deslorelin implants, together with the cost of treatment, ease of administration, and the welfare of the animals, in a side-by-side trial under realistic management conditions. Methods We captured 65 adult female kangaroos over 11 days at a golf course in Anglesea, Victoria, Australia. We assigned each female to one of the following three experimental groups: levonorgestrel (210 mg, n = 18), deslorelin (9.4 mg, n = 24) or procedural control (n = 23). We monitored reproductive success for 8 years, by observing young in the pouch in winter and spring. Key results Natural fertility was high; in most years, less than 20% of control females failed to reproduce. For deslorelin-treated females, the odds of failing to reproduce were four times higher than for the control group; for levonorgestrel-treated females, these odds were 74 times higher. Deslorelin was ineffective after 3 years, whereas levonorgestrel was effective for at least 5 years. Conclusions Levonorgestrel was markedly superior in efficacy, as shown by a stronger contraceptive effect persisting for longer. In other respects, the two implants were comparable, being similar in cost and ease of delivery, and equally safe. Implications Only levonorgestrel implants fulfill their promise for non-lethal, long-term control of kangaroo populations. Deslorelin implants cannot be recommended for this purpose.

The effect of acute immuno-neutralisation of inhibin in ewes during the early luteal phase of the oestrous cycle on ovarian hormone secretion and follicular development

1995 ◽  
Vol 145 (3) ◽  
pp. 479-490 ◽  
Author(s):  
B K Campbell ◽  
B M Gordon ◽  
C G Tsonis ◽  
R J Scaramuzzi
Keyword(s):  
Luteal Phase ◽  
Follicular Development ◽  
Experimental Period ◽  
Ovarian Follicles ◽  
Passive Immunisation ◽  
Follicle Development ◽  
Ovarian Steroid ◽  
Blood Samples ◽  
Steroid Secretion ◽  
Antibody Titres

Abstract Ewes with ovarian autotransplants received either inhibin antiserum (10 ml i.v. raised in sheep against recombinant 32 kDa human inhibin; n=6) or sheep serum (10 ml i.v.; n=5) on day 3 of the luteal phase with additional daily injections (1 ml i.v.) from 48 h after the initial bolus until day 13. Jugular and ovarian venous blood samples were taken 4-hourly over days 2–13 of the luteal phase. Blood samples were also taken at more frequent intervals (every 10–15 min for 2–3 h) to examine pulsatile secretory responses from the ovary to endogenous and gonadotrophin-releasing hormone-induced (150 ng i.m.) LH pulses on days 4, 6, 8, 10 and 12 of the luteal phase. Plasma FSH levels, ovarian steroid secretion and ovarian follicular development were measured. The ovarian follicle population was estimated daily by real time ultrasound scanning. Immunisation against inhibin resulted in a 3- to 4-fold increase (P<0·001) in plasma FSH levels within 8 h with levels remaining elevated over controls for 6–7 days. Within 24 h of immunisation there was an increase in the number of small ovarian follicles (P<0·05) and by 3 days after treatment immunised ewes had 4–6 large ovarian follicles/ewe with this increase in the total number of large follicles being maintained for the rest of the experimental period (P<0·05). Mean ovarian oestradiol secretion during intensive bleeds was not different from controls 24 h after immunisation, but by 3 days after immunisation it was elevated 4- to 5-fold (P<0·001) over controls with this increase being maintained throughout the experiment. Similar responses to immunisation against inhibin in androstenedione secretion were observed although mean androstenedione secretion was not elevated until 7 days after treatment. In vitro antibody titres in immunised ewes remained elevated but declined steadily (P<0·001) over the experimental period. We conclude that the initial stimulation of follicle development and ovarian steroid secretion following passive immunisation against inhibin can be attributed to increased blood FSH. However, the fact that with time FSH declined but increased follicle development was sustained, despite maintenance of high circulating antibody titres, suggests that on a longer term basis inhibin immunisation may stimulate ovarian function by interfering with the modulation of follicle development by inhibin at an ovarian level. Journal of Endocrinology (1995) 145, 479–490

Molecular cloning, expression analysis and developmental changes in ovarian follicles of goose 3β-hydroxysteroid dehydrogenase 1

2014 ◽  
Vol 54 (8) ◽  
pp. 992 ◽  
Author(s):  
Yingying Zhang ◽  
Hehe Liu ◽  
Mingjun Yang ◽  
Shengqiang Hu ◽  
Liang Li ◽  
...  
Keyword(s):  
Adrenal Gland ◽  
Follicular Development ◽  
Hydroxysteroid Dehydrogenase ◽  
Ovarian Follicles ◽  
Mrna Levels ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Human And Mouse ◽  
Main Factor

The enzyme 3β-hydroxysteroid dehydrogenase/isomerase1 (3βHSD1) can catalyse the conversion of pregnenolone to progesterone in the △4-3-ketosteroid metabolic pathway. The aim of the present study was to clone 3βHSD1 and to determine whether this enzyme in the follicular wall has an effect on yolk progesterone in geese (Anser cygnoides). A putative coding sequence of 3βHSD1, which was 1134 nucleotides in length, was successfully obtained by using reverse transcription polymerase chain reaction (RT–PCR). A comparison of the deduced amino acid sequence with chicken, quail, zebra finch, cattle, horse, pig, human and mouse 3βHSD1 showed 89.7%, 88.4%, 87.3%, 55.6%, 54.0%, 53.5%, 55.3% and 52.9% similarity, respectively. The detection of 3βHSD1 mRNA levels in several tissues by quantitative real-time PCR showed that the highest level of 3βHSD1 was in the adrenal gland, followed by the ovary, which indicated that the gene we obtained was the adrenal gland/gonad-specific one. We measured the level of 3βHSD1 mRNA in the follicular wall and determined the concentration of progesterone in the yolk of these ovarian follicles; the concentration of progesterone in the yolk had a pattern of expression similar to that of 3βHSD1 in the follicular wall during follicular development. This result suggests that the expression of 3βHSD1 in the follicular wall may be a main factor that contributes to the accumulation of yolk progesterone.

Follicular development, morphological integrity, and oxidative stress in bovine preantral follicles cultured in vitro with ascorbic acid

Zygote ◽  
2021 ◽  
pp. 1-7
Author(s):  
Larissa Zamparone Bergamo ◽  
Denis Vinicius Bonato ◽  
Camila Bizarro-Silva ◽  
Francieli Gesleine Capote Bonato ◽  
Tamires Korchovei Sanches ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Ascorbic Acid ◽  
Culture Medium ◽  
Bos Taurus ◽  
Follicular Development ◽  
Ovarian Follicles ◽  
Bos Taurus Indicus ◽  
Bonferroni Test ◽  
And Oxidative Stress

Summary The aim of this study was to evaluate the follicular development, morphological integrity, and oxidative stress of preantral ovarian follicles from Bos taurus indicus females grown in vitro with ascorbic acid. Ovaries (n = 20) from Bos taurus indicus females were collected, fragmented, and were cultured in vitro for 6 or 12 days in minimum essential medium (MEM), or MEM supplemented with 50 or 100 ng/ml ascorbic acid, with an extracellular matrix of agarose gel, in an incubator at 38.5°C; every 2 days, 100% of the culture medium was replaced. The data were analyzed using the chi-squared test and/or Fisher’s exact test. In the event of a significant effect, the proportions were compared using a 2 × 2 proportion test. The oxidative stress analysis data were submitted to analysis of variance followed by the Bonferroni test. Values were considered significant when P ≤ 0.05. The addition of 100 ng/ml of ascorbic acid to the in vitro culture medium of preantral ovarian follicles from bovine females promoted follicular development, was efficient in maintaining morphological integrity, as well as the stability of reactive oxygen species, after 6 days of in vitro culture.

Ontogeny of the long form of leptin receptor gene expression in the porcine ovarian follicles

2013 ◽  
Vol 16 (1) ◽  
pp. 101-105
Author(s):  
N. Smolinska ◽  
T. Kaminski ◽  
G. Siawrys ◽  
J. Przala
Keyword(s):  
Energy Homeostasis ◽  
Leptin Receptor ◽  
Receptor Gene ◽  
Follicular Development ◽  
Ovarian Follicles ◽  
Antral Follicles ◽  
Long Form ◽  
Rb Gene ◽  
Receptor Gene Expression

Abstract Leptin is a polypeptide hormone produced predominantly in adipocytes. It has been found to be implicated in the regulation of satiety and energy homeostasis. A role for leptin in reproduction was later suggested by findings that this hormone may be involved in the regulation of the hypothalamic- pituitary-gonadal axis via endocrine, paracrine and/or autocrine pathways. The objective of the study was to investigate the ontogeny of the long isoform of leptin receptor (OB-Rb) gene in porcine ovarian follicles. The expression of OB-Rb gene was detected in porcine primordial, primary, secondary and antral follicles by in situ hybridization. In summary, our data suggest that leptin might have a direct effect on porcine follicles and plays an important role in the follicular development.

7 Pregnancy from a vitrified-warmed alpaca pre-implantation embryo

2020 ◽  
Vol 32 (2) ◽  
pp. 128 ◽  
Author(s):  
J. Lutz ◽  
S. Johnson ◽  
K. Duprey ◽  
P. Taylor ◽  
H. Vivanco ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Embryo Transfer ◽  
Follicular Development ◽  
Ovarian Follicles ◽  
Mature Female ◽  
Field Conditions ◽  
Embryo Cryopreservation ◽  
South American ◽  
Livestock Species ◽  
Ruminant Livestock

The alpaca (Vicugna pacos) is a ruminant livestock species in the South American camelid family. There are more than 9 million South American camelids globally that make important contributions to the livelihoods of rural farmers through conversion of low quality roughages to high quality food and fibre. Reproductive biotechnologies for alpacas are not well developed compared with those for other ruminant livestock species. In particular, embryo cryopreservation technologies are lacking. The objective of this study was to evaluate under field conditions a vitrification protocol originally developed for old world camels that we adapted for use in alpacas. Potential donors were evaluated for follicular development using a 7.5-MHz ultrasound probe. Hembras (sexually mature female alpacas) with ovarian follicles 7-10mm in diameter were behaviour tested to determine sexual receptivity, and receptive females were naturally mated to a proven herd sire. At the time of breeding, non-superovulated donors (n=4) received 30μg gonadorelin. Embryos were nonsurgically collected 7 days after breeding and handled at 20°C. Diameter of harvested embryos (n=4 quality grade 1 hatched expanded blastocysts) was measured using an eyepiece reticle. All recovered embryos were placed individually into 0.5-mL drops of vitrification solution (VS1: 1.4M glycerol) for 5min, 0.5-mL drops of VS2 (1.4 M glycerol + 3.6M ethylene glycol) for 5min, 0.05-mL drops of VS3 (3.4 M glycerol + 4.6M ethylene glycol) for 20s, and 0.05-mL drops of VS3 for 20s while loading into open-pulled straws (OPS). Each OPS was plunged directly into liquid nitrogen for storage for 29 days. At warming, each OPS was submerged into a 1-mL drop of warming solution 1 (WS1: 0.5M galactose) for 1min followed by 1min in WS2 (0.25 M galactose) for 5min before being incubated at 37°C in 5% CO2 in humidified air for 21h in 1mL of Syngro holding medium supplemented with 10% (vol/vol) alpaca serum. Embryos that grew during culture (n=2) were transferred individually into synchronous recipients, and embryos that did not appear to grow (n=2) were transferred together as a pair. Prior to embryo transfer, potential recipients were evaluated ultrasonographically as described previously. Hembras with ovarian follicles 7-10mm in diameter were behaviour tested, and sexually receptive females received 30μg gonadorelin 6 days before embryo transfer. Final selection of recipients (n=3) was based on presence of a corpus luteum and nonreceptive behaviour to a herd sire 24h before transfer. Pregnancy was detected ultrasonographically, and fetal heartbeat was detected 29 days post-transfer in one of the three recipients. Ultrasound at 177 days post-transfer revealed that the pregnancy, generated from a 400μm×375μm vitrified-warmed embryo that had grown in culture, was still ongoing. If this pregnancy results in the birth of a live cria (newborn alpaca), it would represent-to the best of our knowledge-the world's first cria born from a cryopreserved alpaca pre-implantation embryo. It would also demonstrate the potential utility of this protocol under field conditions.

scholarly journals Acetaminophen and zinc phosphide for lethal management of invasive lizards Ctenosaura similis

2011 ◽  
Vol 57 (5) ◽  
pp. 625-629 ◽  
Author(s):  
Michael L. Avery ◽  
John D. Eisemann ◽  
Kandy L. Keacher ◽  
Peter J. Savarie
Keyword(s):  
Integrated Management ◽  
Test Dose ◽  
Zinc Phosphide ◽  
Rodent Control ◽  
Effective Population ◽  
Delivery Methods ◽  
Lethal Management ◽  
Selective Delivery ◽  
Dose Levels ◽  
Ctenosaura Similis

Abstract Reducing populations of invasive lizards through trapping and shooting is feasible in many cases but effective integrated management relies on a variety of tools, including toxicants. In Florida, using wild-caught non-native black spiny-tailed iguanas Ctenosaura similis, we screened acetaminophen and zinc phosphide to determine their suitability for effective population management of this prolific invasive species. Of the animals that received acetaminophen, none died except at the highest test dose, 240 mg per lizard, which is not practical for field use. Zinc phosphide produced 100% mortality at dose levels as little as 25 mg per lizard, equivalent to about 0.5% in bait which is lower than currently used in commercial baits for commensal rodent control. We conclude that zinc phosphide has potential as a useful tool for reducing populations of invasive lizards such as the black spiny-tailed iguana provided target-selective delivery methods are developed.

Ultrastructural features of atretic ovarian follicles in buffalo (Bubalus bubalis)

2016 ◽  
Author(s):  
P. Sreejalekshmi ◽  
R. V. Prasad ◽  
S. Selvaraju ◽  
K. V. Jamuna ◽  
S. Sivagnanam
Keyword(s):  
Free Radical ◽  
Early Stage ◽  
Morphological Changes ◽  
Follicular Development ◽  
Bubalus Bubalis ◽  
Oxygen Free Radical ◽  
Ovarian Follicles ◽  
Crescent Formation ◽  
Probable Role

The process of follicular development and features of morphological changes are essential to understand the factors involved during folliculogenesis and to improve fertility in buffalo. Hence the objective of the present study was to report ultrastructural features of atretic ovarian follicles in buffalo. In the early stage of atresia, the involvement of mitochondria was observed and whereas in the later stages of atresia, involvement of macrophages were observed. The granulosa cells of buffalo atretic tertiary follicles were observed to contain undulation of the nuclear membrane, crescent formation of the pyknotic nuclei and loopiness and undulations of the basal lamina. These features are similar to the reports in other species. The involvement of mitochondria in the early stage of atresia suggested the probable role of a reactive oxygen free radical induced damage.

The transmission rate of MCMV in house mice in pens: implications for virally vectored immunocontraception

2009 ◽  
Vol 36 (5) ◽  
pp. 386 ◽  
Author(s):  
A. D. Arthur ◽  
C. J. Krebs ◽  
R. P. Pech ◽  
L. N. Farroway ◽  
G. R. Singleton
Keyword(s):  
Transmission Rate ◽  
Wild Mouse ◽  
Fertility Control ◽  
Murine Cytomegalovirus ◽  
House Mice ◽  
Recombinant Viruses ◽  
Economic Thresholds ◽  
Rapid Transmission ◽  
Future Work ◽  
Free Ranging

Pest mammals have severe economic, environmental and social impacts throughout the world. Fertility control could reduce these impacts. Murine cytomegalovirus (MCMV) is being considered as an immunocontraceptive vector to control outbreaks of house mice (Mus domesticus) in Australian grain-growing regions. For successful control, a modified MCMV must transmit at a sufficient rate to keep populations of house mice below acceptable economic thresholds. We used disease models developed previously by using observations of free-ranging wild-mouse populations to assess the transmission rate of two laboratory strains of MCMV (N1 and G4) collected in a previous experiment. Mice contained in pens were deliberately infected with the N1 strain only, or with the N1 strain followed by the G4 strain. If we assume density-dependent transmission, which is the more likely mode of transmission, we found the N1 strain of MCMV transmitted at a rate ~1/300 of the rate of field strains, and hence too slowly for successful virally vectored immunocontraception (VVIC). If transmission was frequency-dependent, the rate of transmission was ~1/3 of the rate of field strains, and hence may allow successful VVIC. The G4 strain transmitted at least as slowly as the N1 strain, and possibly much more slowly; however, we could not determine whether this was an inherent property of the G4 strain or whether it was caused by competition with the N1 strain. Given the reliance of successful VVIC on rapid transmission, we recommend that future work in any VVIC system explicitly quantifies the transmission rate of recombinant viruses relative to field strains, both in the presence and absence of competing strains.

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