Age- and parity-dependent differences in ovarian activity and oocyte maturity in the african elephant (Loxodonta africana)

Kidson, A; Loskutoff, N.M.; Raath, Cobus; Wood, Carole; Williams, Kortney; Schalkwyk, J.O. van; Dyche, W.K.; Barry, D.M.; Bartels, Paul

doi:10.1016/0093-691x(95)92400-4

Cited by 7 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At 11 months gestation very few naked oogonia remain identifiable within the cortex of the fetal ovary and nearly all the germ cells are present as meiotic oocytes arrested at the dictyate stage of prophase I [ 23 ] and surrounded by a single layer of granulosa cells which vary in shape from flat to cuboidal. These follicles within the cortex appear to form the follicle reserve for future reproductive life.…”

Section: Discussionmentioning

confidence: 99%

Growth and development of the ovary and small follicle pool from mid fetal life to pre-puberty in the African elephant (Loxodonta africana)

Stansfield

Nöthling

Allen³

2012

BMC Vet Res

View full text Add to dashboard Cite

BackgroundFollicle numbers and developing ovarian morphology, particularly with reference to the presence of interstitial tissue, are intimately linked within the ovary of the African elephant during the period spanning mid-gestation to puberty. These have not been previously quantified in any studies. The collection of 7 sets of elephant fetal ovaries between 11.2 and 20.2 months of gestation, and 29 pairs of prepubertal calf ovaries between 2 months and 9 years of age during routine management off-takes of complete family groups in private conservancies in Zimbabwe provided an opportunity for a detailed study of this period.ResultsThe changing morphology of the ovary is described as the presumptive cortex and medulla components of the fetal ovary settled into their adult form. Interstitial tissue dominated the ovary in late fetal life and these cells stained strongly for 3β–hydroxysteroid dehydrogenase. This staining continued postnatally through to 4.5 years of age suggesting continued secretion of progestagens by the ovary during this period. The considerable growth of antral follicles peaked at 28% of ovarian volume at around 16.7 months of fetal age. The numbers of small follicles (primordial, early primary and true primary), counted in the cortex using stereological protocols, revealed fewer small follicles in the ovaries of animals aged 0 to 4.5 years of age than during either late fetal life or prepubertal life.ConclusionsThe small follicle populations of the late-fetal and prepubertal ovaries of the African elephant were described along with the changing morphology of these organs. The changes noted represent a series of events that have been recorded only in the elephant and the giraffe species to date. The expansion of the interstitial tissue of the fetal ovary and its continued presence in early post natal life may well contribute to the control of follicle development in these early years. Further research is required to determine the reasons behind the variation of numbers of small follicles in the ovaries of prepubertal calves.

show abstract

Section: Discussionmentioning

confidence: 99%

Growth and development of the ovary and small follicle pool from mid fetal life to pre-puberty in the African elephant (Loxodonta africana)

Stansfield

Nöthling

Allen³

2012

BMC Vet Res

View full text Add to dashboard Cite

show abstract

“…In contrast to AI, handling is reduced and more embryos may be produced with the same semen dose. IVM or IVF have been tried in various species such as the mink whale (Balaenoptera acutorostrata) [20], African elephant (Loxodonta africana) [36], gorilla (Gorilla gorilla) [53], and zebra (Equus burchelli, Equus zebra) [47]. In our deer preservation program, we developed a method for repeated immature oocyte recovery on live sika deer hinds by laparoscopic OPU.…”

Section: In Vitro Production Of Embryosmentioning

confidence: 99%

Reproductive biotechnologies for endangered mammalian species

2000

View full text Add to dashboard Cite

-Assisted reproductive techniques (gamete cryopreservation, artificial insemination, embryo transfer, and in vitro fertilization) allow to propagate small fragmented populations of wild endangered species or domestic breeds. There are the best way for producing several offspring from selected genitors in order to avoid inbreeding depression. However, few mammalian species have been well studied for their reproductive biology whereas huge differences have been observed between these species. Furthermore, materials, methods and experimental designs have to be adapted for each case and each limiting factor (wildness, poor quantity of biological material, disparate locations). Genome resource banking is currently arising and the most applied reproductive biotechnology remains artificial insemination. Assisted reproductive techniques currently developed in domestic species (intracytoplasmic sperm injection, nuclear transfer) may offer new opportunities for the propagation of endangered species. endangered species / artificial insemination / cryopreservation / in vitro fertilization / embryo Résumé -Biotechnologies de la reproduction appliquées aux mammifères en voie de disparition. Les techniques de reproduction assistée (cryoconservation des gamètes, insémination artificielle, transfert embryonnaire, fécondation in vitro) permettent d'accroître des populations, parfois dispersées géographiquement, d'espèces sauvages ou domestiques en voie de disparition. Ces méthodes sont le meilleur moyen pour produire plusieurs descendants à partir de géniteurs sélectionnés de façon à éviter la consanguinité. La biologie de la reproduction est connue pour peu d'espèces de mammifères alors que de grandes différences ont pourtant été mises en évidence entre ces espèces. En outre, les matériels, les méthodes, ainsi que les schémas expérimentaux doivent être adaptés à chaque cas et pour chaque facteur limitant (animaux sauvages, peu de matériel biologique, populations dispersées). Des banques génétiques sont actuellement en voie de constitution mais la technique la plus utilisée reste l'insémination artificielle. Cependant, des biotechnologies de la reproduction en cours de mise au point chez les animaux domestiques (injection intra-cytoplasmique de spermatozoïde, transfert nucléaire) pourraient offrir de nouvelles possibilités pour l'accroissement de populations menacées. espèces menacées / insémination artificielle / congélation / fécondation in vitro / embryon Reprod. Nutr. Dev. 40 (2000)

show abstract

“…Using a new guide system, an average recovery of 2.5 oocytes per aspiration has been reported and mean number of oocytes per aspiration in buffalo cows varies from 2.5-2.7 with a range of 0 to 9 (Gerber et al, 2000b). Studies using slaughter house ovaries however, report an average recovery of 12 COC's per ovary by slicing or mincing (Kidson et al, 2000). However, the percentage of good quality oocytes developing to morula stage was low and did not differ significantly when collected from ovaries of calves (27.3%), non-pregnant (38.9%) and pregnant buffalo cows.…”

Section: Embryo Technologies In Feral Buffaloesmentioning

confidence: 92%

“…Most of the work on IVM\F\C on feral buffaloes use media developed in cattle or water buffaloes. TCM 199 is the basic medium supplemented with hormones and serum source (Smith et al, 1999;Kidson et al, 2000;Gerber et al, 2000a). Such recent work is likely to play an important role in the preservation of wild species, like the bison.…”

Section: Embryo Technologies In Feral Buffaloesmentioning

confidence: 99%

Reproductive Biotechnologies for Improvement of Buffalo: The Current Status

Purohit¹,

Duggal²,

Dadarwal³

et al. 2003

Asian Australas. J. Anim. Sci

View full text Add to dashboard Cite

Reproductive biotechnologies continue to be developed for genetic improvement of both river and swamp buffalo.Although artificial insemination using frozen semen emerged some decades back, there are still considerable limitations. The major problem appears to be the lack of efficient methods for estrus detection and timely insemination. Controlled breeding experiments in the buffalo had been limited and similar to those applied in cattle. Studies on multiple ovulation and embryo transfer are essentially a replica of those in cattle, however with inherent problems such as lower number of primordial follicles on the buffalo ovary, poor fertility and seasonality of reproduction, lower population of antral follicles at all stages of the estrous cycle, poor endocrine status and a high incidence of deep atresia in ovarian follicles, the response in terms of transferable embryo recovery has remained low with 0.51 to 3.0 per donor and pregnancy rates between 15 to 30%. In vitro production of buffalo embryos is a valid alternative to recovery of embryos by superovulation. This aspect received considerable attention during the past decade, however the proportion of embryos that develops to the blastocyst stage is still around 25-30% and hence the in vitro culture procedures need substantial improvement. Embryo cryopreservation procedures for direct transfer post thaw need to be developed for bubaline embryos. Nuclear transfer and embryo cloning is a technique that has received attention in various species during recent years and can be of immense value in buffaloes as they have a low rate of embryo recoveries by both in vitro and in vivo procedures. Gender pre-selection, genome analysis, gene mapping and gene transfer are a few of the techniques that have been studied to a limited extent during recent years and are likely to be included in future studies on buffaloes. Very recently, reproductive biotechnologies have been applied to feral buffaloes as well, but the results obtained so far are modest. When fully exploited they can play an important role in the preservation of endangered species.

show abstract

Age- and parity-dependent differences in ovarian activity and oocyte maturity in the african elephant (Loxodonta africana)

Cited by 7 publications

References 0 publications

Growth and development of the ovary and small follicle pool from mid fetal life to pre-puberty in the African elephant (Loxodonta africana)

Growth and development of the ovary and small follicle pool from mid fetal life to pre-puberty in the African elephant (Loxodonta africana)

Reproductive biotechnologies for endangered mammalian species

Reproductive Biotechnologies for Improvement of Buffalo: The Current Status

Contact Info

Product

Resources

About