The Ovary of the Giraffe, Giraffa Camelopardalis

Kayanja, F. I. B.; Blankenship, Lytle H.

doi:10.1530/jrf.0.0340305

Cited by 21 publications

(26 citation statements)

References 5 publications

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“…The maternal ovaries of both G1 and G2 exhibited a single large CL of pregnancy, thereby confirming the previous observations of Kayanja & Blankenship (1973), Hall-Martin & Rowlands (1980), Benirschke (2007) and Lueders et al (2009aLueders et al ( , 2009b. However, the ovaries also contained a number of small antral follicles with prominent thecal and granulosa cell layers plus atretic follicles with degenerating granulosa cells.…”

Section: Discussionsupporting

confidence: 88%

“…The presence of these luteal structures in the fetal ovary was subsequently confirmed by Kayanja & Blankenship (1973), Gombe & Kayanja (1974) and Skinner & Hall-Martin (1975) and, more recently, Benirschke (2007) also noted multiple, small CL-like structures in the ovaries of an aborted giraffe fetus and a 3-day-old neonate. Such unusual developments in the fetal ovaries has led to speculation that the multiple CL-like structures may play a role in pregnancy maintenance, although the persistence of follicular growth and luteinisation after birth in the pre-pubertal giraffe (Kellas et al 1958, Kayanja & Blankenship 1973, Gombe & Kayanja 1974, Hall-Martin & Rowlands 1980, Lueders et al 2009a would seem to argue against such a possibility. Interestingly, the newborn Okapi (Okapia johnstoni), the only other living giraffid species, does not display the same ovarian activity as the giraffe neonate (Bernirschke 2007).…”

Section: Introductionmentioning

confidence: 80%

“…Thus, luteinisation of relatively small and partly developed antral follicles was a prominent feature of both the maternal and the fetal ovaries in G1 and G2. In their original study of 27 pregnant giraffes, Kayanja & Blankenship (1973) reported only the single, large CL in Table 1 Progestagen concentrations measured in the maternal and fetal fluids of G1 and G2 pregnant giraffe. Pregnancy in the giraffe one of the two maternal ovaries with no mention of accessory CL, although they examined the ovaries only grossly.…”

Section: Discussionmentioning

confidence: 99%

“…Only a single, large (3-5 cm diameter) pregnancy CL is present in one of the maternal ovaries and it persists throughout gestation (Amoroso & Finn 1962, Kayanja & Blankenship 1973, Hall-Martin & Rowlands 1980, Lueders et al 2009a, 2009b. Progestins have been isolated from the ovaries of fetal, juvenile, pregnant and non-pregnant giraffe (Gombe & Kayanja 1974), and it was originally postulated that a placental gonadotrophin might be responsible for the follicular activity and luteinisation seen in the fetus (Kellas et al 1958) following a report of gonadotrophic hormones in the urine of a pregnant giraffe by Wilkinson & De Fremmery (1940).…”

Section: Introductionmentioning

confidence: 99%

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Ovarian and placental morphology and endocrine functions in the pregnant giraffe (Giraffa camelopardalis)

Wilsher¹,

Stansfield

Greenwood

et al. 2013

Reproduction

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Gross, histological and immunocytochemical examinations carried out on maternal and fetal reproductive tissues from two pregnant giraffes at an estimated 8 and 13.5 months of gestation (termZ15 months) revealed a typically ruminant macrocotyledonary placenta with binucleate trophoblast cells scattered sparsely in the placentome where they stained intensely with a prolactin antiserum. Binucleate cells were present in greater numbers in the intercotyledonary allantochorion where they did not stain for prolactin whereas the uninucleate trophoblast still did. A single large corpus luteum of pregnancy and several small luteinised follicles were present in the maternal ovaries while the fetal ovaries at 13.5 months gestation showed an assortment of enlarging antral follicles and partially and completely lutenised follicles, the granulosa and luteal cells of which stained positively for 3b-hydroxysteroid dehydrogenase (3b-HSD), 17,20 lyase, prolactin, progesterone receptor and androgen receptor, but negatively for aromatase. The uninucleate trophoblast of the placentome and intercotyledonary allantochorion, the epithelium of the maternal endometrial glands, the seminiferous epithelium in the fetal testis at 8 months of gestation and the zonae fasciculata and reticularis of the fetal adrenal at 13.5 months also stained positively for 3b-HSD and negatively for aromatase. Endocrinologically, it appears that the giraffe placenta is more similar to that of the sheep than the cow with a placental lactogen as the likely driver of the considerable degree of luteinisation seen in both the maternal and the fetal ovaries.

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Section: Discussionsupporting

confidence: 88%

Section: Introductionmentioning

confidence: 80%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Ovarian and placental morphology and endocrine functions in the pregnant giraffe (Giraffa camelopardalis)

Wilsher¹,

Stansfield

Greenwood

et al. 2013

Reproduction

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“…Samples of testicular tissue (25 g) were taken and processed individually or pooled (see Table 2), and the extraction methods of Short & Mann (1966), as modified by Skinner (1967) and detailed by Hall-Martin et al (1975) Amoroso, 1958 ;Kayanja & Blankenship, 1973) and fetal equids of both sexes (Amoroso & Rowlands, 1951 ;Smuts, 1976). (Trautmann & Fiebiger, 1957), consists mostly of a lobular pars disseminata which forms a glandular layer in the wall of the pelvic urethra, is wider dorsally than ventrally and has a thick striated urethral muscle along the ventral side.…”

Section: Methodsmentioning

confidence: 99%

The development of the reproductive organs of the male giraffe, Giraffa camelopardalis

Hall-Martin¹,

Skinner²,

Hopkins³

1978

Reproduction

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Summary. The reproductive organs of the male giraffe differ little in morphology and histology from those of other ungulates. There is some indication that gonadal hypertrophy occurs in late fetal life. Spermatogenesis begins at 3\p=n-\4 years of age and coincides with a rapid increase of testicular weight and seminiferous tubule diameter. In the fetal testis the main hormone is androstenedione (2\m=.\73\g=m\g/g) but in adult testes testosterone is predominant (<10\m=.\08\g=m\g/g) and \ g=D\ \ m=' \ testosterone may also be present.

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Urinary steroid evaluations to monitor ovarian function in exotic ungulates: II. Comparison between the giraffe (Giraffa camelopardalis) and the Okapi (Okapia johnstoni)

Loskutoff¹,

Walker²,

Ott‐Joslin

et al. 1986

Zoo Biology

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Ovarian activity in the female giraffe was evaluated during the nonfertile ovarian cycle and during the terminal stages of gestation. Progesterone metabolites, in the form of pregnanediol-3-glucuronide (PdG), were measured in daily random urine samples collected from four adult parous giraffes. The follicular phase averaged 4.0 + 0.1 days in length (N = 12; range 3-5 days) and peak PdG levels in the postovulatory period averaged 30.9 5 1.7 ng/mg Cr (N = 12). PdG levels during the latter half of gestation greatly exceeded average luteal phase levels, which is in contrast to domestic ruminants. Prior to parturition, a marked decline in PdG excretion was evident, which may be useful for anticipating this event. These data serve to elucidate ovarian function in the mature female giraffe and to provide information concerning the physiologic role of certain anomalous ovarian structures. In addition, observed similarities in the pattern of PdG excretion during the nonfertile cycles of the giraffe and the okapi indicate similar underlying physiologic processes.Key words: urinary steroid, immunoreactivity, ovarian function, giraffe, okapi, INTRODUCTION ungulatesReproductive assessments in nondomestic species traditionally have depended on opportunistic blood sample collections for gonadal steroid measurements. Given the acute physiologic response of the animal to stress imposed by physical or chemical immobilization and restraint, it is dubious whether or not the resultant hormonal 332Loskutoff et al profiles accurately represent normal endogenous endocrine patterns [Seal et al, 1972;Cumming et al, 1976; Moberg, 19761. Results from studies in domestic cattle and sheep suggest that adrenal corticosteroids, which are released during periods of stress, play regulatory roles in the release of luteinizing hormone and gonadotropin releasing hormone welsh and Johnson, 1981: Padmanabhan et al, 1983 Moberg, 19841. The prevailing body of literature describing the reproductive physiology of exotic species is limited to postmortem examinations of animals that either succumb to disease or trauma or are culled from wild or captive populations for management or research purposes. However, this approach is limited, providing only single point-in-time appraisals of reproductive function, and fails to provide adequate evaluations of normal, ongoing reproductive processes.The giraffe (Girafla camelopardalis) is a ruminant in which unusual ovarian structures have been observed and described in a number of postmortem reports. One example is the reported occurrence of steroidogenically active hemorrhagic follicles and multiple corpora lutea in the ovaries of fetal and neonatal giraffes [Kellas et al, 19581 that are similar in function to the corpora lutea of adult female giraffes [Gombe and Kayanja, 19741. Little information is presently available regarding ovarian function during the nonfertile or fertile reproductive cycles in the adult female giraffe. A recent report by Teare and French [ 19841 indicates that serum progesterone measurem...

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The Ovary of the Giraffe, Giraffa Camelopardalis

Cited by 21 publications

References 5 publications

Ovarian and placental morphology and endocrine functions in the pregnant giraffe (Giraffa camelopardalis)

Ovarian and placental morphology and endocrine functions in the pregnant giraffe (Giraffa camelopardalis)

The development of the reproductive organs of the male giraffe, Giraffa camelopardalis

Urinary steroid evaluations to monitor ovarian function in exotic ungulates: II. Comparison between the giraffe (Giraffa camelopardalis) and the Okapi (Okapia johnstoni)

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