Duration of embryonic diapause in the brush-tailed bettong, Bettongia penicillata (Potoroidae): effect of age of quiescent corpus luteum

1996 ◽  
Vol 8 (4) ◽  
pp. 807 ◽  
Author(s):  
MJ Smith
Keyword(s):  
Corpus Luteum ◽  
Post Partum ◽  
Embryonic Diapause ◽  
Maximum Duration ◽  
Bettongia Penicillata ◽  
Diapause Embryo ◽  
Effect Of Age

It has been shown that changes to the frequency of sucking by the pouch young do not affect the time of reactivation of the quiescent corpus luteum and diapause embryo in Bettongia penicillata; these observations led to the suggestion that the corpus luteum may have an inherent maximum duration of quiescence. The aim of the present study was to investigate the effect of the age of the corpus luteum on the timing of its reactivation. Ovulation fails to occur post partum in female B. penicillata isolated from males, and the introduction of a male B. penicillata induces oestrus in females suckling a young in the pouch. Oestrus was induced from Day 23 of lactation to Day 76, in different females, and the corpus luteum became quiescent. All parturitions occurred between Day 95 and Day 103 of lactation (average, Day 98.8), at the time expected if the corpus luteum had been formed post partum. Duration of quiescence of the corpus luteum ranged from 60 days to 10 days, compared with 83.9 +/- 0.43 days in females that mated post partum. The results show that the age of the corpus luteum does not affect the timing of its redevelopment and release of the embryo from diapause near the end of the period of the young being suckled within the pouch.

Male-induced oestrus and ovulation in female brush-tailed bettongs (Bettongia penicillata) suckling a young in the pouch

1994 ◽  
Vol 6 (4) ◽  
pp. 445 ◽  
Author(s):  
MJ Smith
Keyword(s):  
Corpus Luteum ◽  
Adult Male ◽  
Post Partum ◽  
Suckling Period ◽  
Vaginal Smears ◽  
Induced Ovulation ◽  
Unusual Condition ◽  
Bettongia Penicillata ◽  
To Come ◽  
Diapause Embryo

Female brush-tailed bettongs isolated from males usually do not come into oestrus or ovulate. Individuals isolated during pregnancy and at parturition do not ovulate post partum and are in the unusual condition for a macropodoid of suckling a pouch young but lacking a quiescent corpus luteum or a diapause embryo. Females in this condition were tested for their ability to come into oestrus and to ovulate after re-introduction to the male. When returned to the male on Day 1 of lactation, females generally mated before Day 2 and ovulated; at all later stages of lactation, six or seven days after being returned to the male > or = 50% of females came into oestrus, mated and ovulated. The vaginal smears of most females in isolation were typical of post oestrus on Day 2; after being returned to the male on Day 11, these females came into oestrus in seven days, mated and ovulated. The results show that suckling a young in the pouch does not suppress ovulation in this species provided that an adult male is present. Moreover, the results indicate that the mechanism of male-induced ovulation 24 h post partum differs from that of the remainder of the pouch suckling period.

The reproductive system and embryonic diapause in the female kangaroo, Marcopodus giganteus

1967 ◽  
Vol 15 (3) ◽  
pp. 441 ◽  
Author(s):  
MJ Clark ◽  
WE Poole
Keyword(s):  
Corpus Luteum ◽  
Mitotic Activity ◽  
Reproductive System ◽  
Luteal Phase ◽  
Post Partum ◽  
Ovarian Follicle ◽  
Initial Period ◽  
Secretory Cells ◽  
Ovarian Activity ◽  
Embryonic Diapause

The reproductive system of the female grey kangaroo consists as in other marsupiais, of two ovaries, two uteri, two lateral vaginae, and a median vaginal canal. The changes which occur during the oestrous cycle or pregnancy can be divided into three phases: (1) a proliferative phase characterized by maturation and rupture of an ovarian follicle and its subsequent transformation into a new corpus luteum, and by cell division in the uteri; (2) a luteal phase, when the corpus luteum is fully formed and the luteal cells attain their maximum size, and the uterine gland cells are tall columnar, with basally situated nuclei; and (3) a post-luteal phase when the secretory cells of the corpus luteum and uteri degenerate. Repair begins in the uteri before the end of pregnancy and this is supplemented by post-partum mitotic activity, but post-partum oestrus does not occur. The uterine glands are small, and ovarian activity is inhibited during the initial period of lactation. A small proportion of females with pouch young over 100 days old return to oestrus and mate. Mitotic activity then ceases in the uteri, in the newly formed corpus luteum, and the blastocyst until the pouch young is lost or approaches the end of pouch life, when mitotic activity is resumed in the corpus luteum and blastocyst. The occurrence of embryonic diapause has been confirmed in both wild and captive animals.

Control of pregnancy, parturition and luteolysis in marsupials

1990 ◽  
Vol 2 (5) ◽  
pp. 535 ◽  
Author(s):  
LA Hinds
Keyword(s):  
Life Span ◽  
Corpus Luteum ◽  
Post Partum ◽  
Secretory Activity ◽  
Extrinsic Factors ◽  
Pituitary Prolactin

In most eutherian species the function of the corpus luteum (CL) is influenced by extrinsic factors and it is subordinate to the pituitary, placenta, or uterus. In contrast, in marsupials the CL is relatively autonomous. Although the pituitary is essential for the formation of the CL, thereafter the secretory activity of the CL is independent of luteotrophic support, and the uterus is not luteolytic. Furthermore, the life span of the CL is unaffected by pregnancy, except in the Macropodidae (kangaroos and wallabies), in which the secretory activity of the CL is shortened under the influence of the fetus. At parturition the macropodid fetus, possibly via a release of glucocorticoids, causes the release of prostaglandins, presumed to be of uterine origin. The effect of the prostaglandin is to induce the release of prolactin from the maternal pituitary. Prolactin, and not prostaglandin, induces luteolysis and advances the events of post-partum oestrus. In the non-pregnant cycle, the mechanism of luteolysis is different; it does not involve prolactin, and the luteolytic signal is of non-uterine, possibly intrinsic, origin.

Reproductive Ecology of The Allied Rock-wallaby, Petrogale assimilis.

1996 ◽  
Vol 19 (2) ◽  
pp. 209
Author(s):  
R. Delaney
Keyword(s):  
Life History ◽  
Sex Ratio ◽  
Sexual Maturity ◽  
Post Partum ◽  
Reproductive Ecology ◽  
Oestrous Cycle ◽  
Embryonic Diapause ◽  
Minimum Age

Petrogale assimilis has a typical life history and reproductive ecology for a macropodid of its size. Both sexes are capable of reproducing continuously; gestation is about the same length as the oestrous cycle (approximately one month); a single young is born and, a post-partum oestrus and embryonic diapause probably occurs. The sex ratio of young is unbiased. Pouch young remain permanently attached to the teat until 110 - 143 days (n=11). Permanent exit from the pouch occurs at 180 - 231 days (mean=201 days, n=25), and weaning occurs between 267 - 387 days (n=5). Sexual maturity occurs at a minimum age of 17.5 months in females and 23 months in males.

A comparative study of the corpus luteum

1995 ◽  
Vol 7 (3) ◽  
pp. 303 ◽  
Author(s):  
RT Gemmell
Keyword(s):  
Corpus Luteum ◽  
Luteal Phase ◽  
Secretory Granules ◽  
Hormonal Control ◽  
Egg Laying ◽  
Oestrous Cycle ◽  
Corpora Lutea ◽  
Embryonic Diapause ◽  
Alternative Reproductive Strategy ◽  
Uterine Development

The corpus luteum (CL) is a transitory organ which has a regulatory role in reproduction. Sharks, amphibians and reptiles have corpora lutea that produce progesterone which influences the rate of embryonic development. The egg-laying monotremes and the two major mammalian groups, eutherian and marsupial, have a CL that secretes progesterone. Most eutherians have allowed for the uterine development of their young by extending the length of the oestrous cycle and the CL or placenta actively secretes progesterone until birth. Gestation in the marsupial does not extend beyond the length of an oestrous cycle and the major part of fetal development takes place in the pouch. Where the extension of the post-luteal phase in the eutherian has allowed for the uterine development of young, the marsupial has extended the pre-luteal phase of the oestrous cycle and has evolved an alternative reproductive strategy, embryonic diapause. The mechanism for the secretion of hormones from the CL has been controversial for many years. Densely-staining secretory granules have been observed in the CL of sharks, marsupials and eutherians. These granules have been reported to contain relaxin, oxytocin or mesotocin, and progesterone. A hypothesis to suit all available data is that all hormones secreted by the CL are transported within such granules. In conclusion, although there are obvious differences in the mode of reproduction in the two main mammalian groups, it is apparent that there is a great deal of similarity in the hormonal control of regression of the CL and parturition.

Reproduction of the Red-Bellied Pademelon Thylogale billardierii (Marsupialia)

1982 ◽  
Vol 9 (1) ◽  
pp. 27 ◽  
Author(s):  
RW Rose ◽  
DJ McCatney
Keyword(s):  
Corpus Luteum ◽  
Post Partum ◽  
Oestrous Cycle ◽  
Seasonal Breeder ◽  
The Mean ◽  
Duration Of Gestation

'Thylogale billardierii, which is abundant in Tasmania, is a seasonal breeder with most births in the months April, May and June. Parturition is followed by mating, and the zygote so produced remains dormant until either sucking becomes intermittent near the end of pouch life or the young is lost. The mean length of the oestrous cycle was determined at 30.3 days, not significantly longer than the duration of gestation (30.2 days). Removal of pouch young results in the birth of a new young 28.7 days later. Removal of the corpus luteum results in oestrus 11 days later. Pouch life is 202 days, and vacation of the pouch by the young coincides precisely with parturition and post-partum mating. The young mature at about 14-15 months.

Comparison of reproductive responses after PGF2α and GnRH-PGF2α oestrous synchronisation schemes in Holstein cows

2001 ◽  
Vol 26 (2) ◽  
pp. 467-470
Author(s):  
J.F. Cox ◽  
F. Saravia ◽  
O. Torrealba ◽  
A. Zavala ◽  
A. Lobos
Keyword(s):  
Dairy Cows ◽  
Corpus Luteum ◽  
Detection Efficiency ◽  
Post Partum ◽  
Conception Rate ◽  
Milk Samples ◽  
Reproductive Response ◽  
Holstein Friesian ◽  
Breeding Schemes ◽  
Friesian Cows

AbstractControlled breeding schemes for oestrous detection constitutes a proactive technical response that balances the infrastructural requirement for a profitable dairy operation and the demands for optimal animal performance. The present study compared (a) the reproductive response of a treatment based on a short vs longer-acting PGF2α analogue (tiaprost vs luprostiol), and (b) the reproductive response after a treatment of GnRH-PGF2α vs PGF2α alone for synchronizing dairy cows. Holstein-Friesian cows averaging 9000 kg milk/lactation and fed according to their requirements were used in the study. Cows were cyclic, at least 60 days post partum and were clinically sound before being considered for the experiments. In Experiment 1, animals were synchronised using an i.m. injection of either 15 mg of luprostiol or 0.75 mg of tiaprost, based on ultrasonic diagnosis of a corpus luteum. Animals were inseminated at observed oestrus. In Experiment 2, cows were synchronised, at random, by either an injection of 10pg ofbuserelin (day 0) followed by 0.75 mg of tiaprost at day 7 (GnRH-PGF2α) orjust 0.75 mg of tiaprost (PGF2α). For both treatments only cows with an ultrasonically detected corpus luteum were treated. Animals were inseminated at oestrus. At the time of treatment and again 3 days later, milk samples were collected and assayed for progesterone by RIA. Cows with progesterone concentrations >1 ng/ml were considered to have corpus luteum. Luteolysis was considered to have occurred when concentrations of progesterone were > 1 ng/ml at day 0 and <0.8 ng/ml at day 3. In Experiment 1, both analogues gave similar results in terms of induced luteolysis [luprostiol: 36/39 (92.3%) vs tiaprost: 36/41 (87.8%)], oestrous detection efficiency [luprostiol: 26/36 (72.2%) vs tiaprost: 30/36 (83.3%], oestrous distribution [day 2, 3 and 4, respectively: luprostiol: 26.9%, 50.0%, 19.2% vs tiaprost: 36.7%, 50.0%, 13.3%], and conception rates [luprostiol: 12/25 (48.0%) vs tiaprost: 14/28 (50.0%); P>0.05]. In Experiment 2, oestrous detection efficiency, interval to oestrus and conception rate were similar between treatments [97/149 (65.1%), 71.1 h, 43/95 (45.3%) for PGF2α vs 130/188 (69.1%), 68.2h, 65/126 (51.6%) for GnRH-PGF2α, respectively]. However the oestrous distribution was more concentrated in GnRH-PGF2α treated animals (P<0.01).

Development and regression of the corpus luteum in grey seal (Halichoerus grypus) ovaries and its use in determining fertility rates

1984 ◽  
Vol 62 (6) ◽  
pp. 1095-1100 ◽  
Author(s):  
I. L. Boyd
Keyword(s):  
Corpus Luteum ◽  
Adult Female ◽  
Halichoerus Grypus ◽  
Embryonic Diapause ◽  
Grey Seal ◽  
Fertility Rates ◽  
Reproductive Condition ◽  
Plasma Progesterone ◽  
Blood Samples ◽  
Foetal Growth

Adult female grey seals were sampled at the Fame Islands at monthly intervals from November 1980 to October 1981. The distribution, size, and number of ovarian corpora were recorded in each case and blood samples were obtained for progesterone analysis. The concentration of plasma progesterone was about 6 ng/mL for most of gestation, including embryonic diapause, and rose to about 10 ng/mL during the final month. Progesterone declined sharply to less than 1 ng/mL at parturition. The size of the corpus luteum was constant throughout embryonic diapause, but after implantation it grew continuously until parturition. Following parturition, it regressed rapidly at first, forming a corpus albicans, and then more slowly, regression being arrested during the period of foetal growth of the following reproductive cycle. Most corpora albicantia had disappeared 1 year after their formation. Corpora albicantia may be useful indicators of reproductive history in grey seals, providing that allowance is made for the reproductive condition of females at the time of sampling and for several other possible errors which could arise. Retrospective calculation of reproductive statistics by more than 1 year using corpora albicantia is not valid for grey seals.

scholarly journals The development and morphology of the gonads of the mouse.— Part I. The morphogenesis of the indifferent gonad and of the ovary

1927 ◽  
Vol 101 (711) ◽  
pp. 391-409 ◽  
Keyword(s):  
Corpus Luteum ◽  
Sexual Maturity ◽  
Post Partum ◽  
Subsequent Paper ◽  
Adult Ovary

The work described in this series of papers was carried out with a view to furnishing controls of the experiments on the mouse undertaken in collaboration with Dr. A. S. Parkes and others. This paper deals with the development of the indifferent gonad of the mouse, up to the stage at which it differentiates into an ovary or a testis. This takes place on the 12th day post coitum , when the testis can first be distinguished. The ovaries remain in the indifferent stage for some time longer, but can be identified by a process of elimination. The present paper is concerned also with the development of the ovary from the time when sex can be distinguished until sexual maturity (8 weeks post partum ). It is not proposed to consider here the structure of the maturing follicle, the process of atresia, or the formation of the corpus luteum. These problems will be reserved for a subsequent paper on the adult ovary of the mouse.

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