Ultrastructural changes in the adenohypophysis during the ovarian cycle of the viviparous teleost Poecilia latipinna

Young, Graham; Ball, J.N.

doi:10.1016/0016-6480(83)90093-x

Cited by 17 publications

(6 citation statements)

References 115 publications

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“…Soon after delivery of the preceding brood (day 0), oocyte diameter rapidly increased to 1.4 mm, indicating that vitellogenesis became active. Similar patterns of growth in vitellogenic oocytes have been described for other poeciliids such as Xiphophorus helleri , 2 Poecilia latipinna , 10,11 and P. reticulata . 12 From day 0 to 5, the larger diameter group (forming the secondary peak in Fig.…”

Section: Discussionsupporting

confidence: 72%

Dynamics of oocyte and embryonic development during ovarian cycle of the viviparous mosquitofish Gambusia affinis

et al. 2000

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SUMMARY: The present study investigates the dynamics of oocyte and embryonic development between two successive parturitions (about 22‐day interval) under 16 Light : 8 Dark photoperiod at 25°C, in order to develop criteria for the ovarian cycle in the viviparous mosquitofish Gambusia affinis. On day 0 after parturition, the ovaries contained oocytes of various stages. Vitellogenic oocytes belonged mostly to a basal group and prominent group, each with two peaks and ranging 0.2 to 1.4 mm in diameter. The prominent group of oocytes increased in diameter by day 5, and the hepatosomatic index reached a peak on day 3, indicating active vitellogenesis. The oocyte maturation and fertilization did not occur simultaneously in an individual, but in order of oocyte size (oocytes over 1.7 mm in diameter were fertilized) between days 2 and 5. Mature oocytes were fertilized without ovulation, and then continued through embryonic development in the follicle. Many vitellogenic oocytes that did not reach fertilization degenerated and disappeared by day 10. Oil‐droplet stage oocytes seem to be recruited by this time. Yolk accumulation for the next gestation started from day 10, and advanced slowly after that.

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Section: Discussionsupporting

confidence: 72%

Dynamics of oocyte and embryonic development during ovarian cycle of the viviparous mosquitofish Gambusia affinis

et al. 2000

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“…These secretory granules are few in number and small in size in the post-spawning season, while they become numerous and larger in both prespawning and spawning seasons. These results are in accordance with those of Peute et al (1978) in Salmo gairdneri, Ueda and Takahashi, (1980) and Ueda (1981) in Misgurnus anguillicaudatus and Young and Ball (1982) in Poecilia latipinna. Furthermore, during the post-spawning season, the basophils (B1) of L. carinata are characterized by the presence of numerous vacuoles that containing fibrillar inclusions.…”

Section: Discussionsupporting

confidence: 90%

Morphological and histological studies on the pituitary gland of Liza carinata from the Suez Bay (Red Sea, Egypt), with special reference to the gonadotrophs

El-Rahman

El-Shabaka

et al. 2015

Egypt. J. of Aquatic Biolo. and Fish.

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The teleosts pituitary gland has a peculiar structure that shows wide variability of its morphology and cellular organization. Moreover, the pituitary gland usually displays seasonal changes during the reproductive cycle. So, the present study is designed to identify and localize the different cell types of the pituitary gland of mature male and female of Liza carinata from the Suez Bay and to study the possible variations that found during its reproductive cycle. The result revealed that the pituitary gland of L. carinata is of the platybasic type, which lacks a distinct hypophyseal stalk, and is differentiated into two main divisions, namely: the adenohypophysis and neurohypophysis. The glandular adenohypophysis consists of five main cell types, the lactotrophs, somatotrophs, gonadotrophs, thyrotrophs and melanotrophs. On the other hand, the neurohypophysis is formed of nerve fibres and contains a variable amount of neurosecretory granules. Moreover, the principal seasonal variations take place in the meso-adenohypophyseal gonadotrophs and the neurosecretory granules.

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“…In immature males, the differentiation of TSH cells in the absence of GnRH-Rs suggests that GnRH might be important for release rather than synthesis of TSH hormone. On the other hand, in mature males, the activation of GnRH-Rs in TSH cells could have some role in gonadal maturation because thyroid hormones and TSH cells have been implicated in reproductive processes (37).…”

Section: Cellular and Functional Heterogeneity Of Gnrh-rsmentioning

confidence: 99%

Three GnRH receptor types in laser-captured single cells of the cichlid pituitary display cellular and functional heterogeneity

Parhar

Ogawa

Sakuma

2005

Proc. Natl. Acad. Sci. U.S.A.

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The role of multiple gonadotropin-releasing hormone receptor (GnRH-R) types in the regulation of gonadotropic and nongonadotropic cells remains speculative. To address this issue, we developed a technology integrating laser-captured microdissection of single digoxigenin-labeled pituitary cells coupled with real-time quantitative PCR to examine the expression profiles of three endogenous GnRH-R types (R1, R2, and R3) in immature and mature males of tilapia Oreochromis niloticus. Here, in addition to gonadotropes (luteinizing and folicle-stimulating hormone, FSH), we show GnRH-Rs are also present in lactotropes, somatotropes, thyrotropes, melanotropes (melanocyte-stimulating hormone, MSH), corticotropes and somatolactin cells. Subpopulations of pituitary cells express single (42.9%), multiple (32.4%) or lack (24.7%) GnRH-Rs. In immature males, the percentage of FSH cells containing combinations of GnRH-Rs was significantly higher (R1؉R2: 24%, P < 0.05; R1؉R2؉R3: 25%, P < 0.01) than in mature males, whereas the percentage showing only R1 and R1 and R3 transcripts (P < 0.05) was higher in mature males. Significantly greater copies of R1 and R3 transcripts were found in MSH cells of immature and mature males, respectively (P < 0.05). GnRH-R transcripts in other pituitary cells (lactotropes, R1 and R2; somatolactin cells͞thyrotropes͞corticotropes, R1, R2, and R3) were significantly higher in mature males (P < 0.05) but were unaltered in somatotropes and luteinizing hormone cells. Thus, FSH and MSH cells are required for both reproductive states, whereas other pituitary cells are recruited only during testicular maturation. The differential expression of GnRH-Rs in gonadotropic and nongonadotropic cells demonstrates cellular and functional heterogeneity of mechanisms controlling normal sexual development.G protein ͉ in situ hybridization ͉ tilapia G onadotropin-releasing hormone (GnRH) is now recognized as a family of 16 multifunctional neuropeptides in vertebrates (1-3). It is well documented that all vertebrate species ranging from fish to humans possess two (hypothalamus, GnRH1; midbrain, GnRH2) or, as in recently derived teleosts, three GnRH types (caudal olfactory bulbs, GnRH3) (1-3). GnRH1, GnRH2, and GnRH3, in addition to stimulating gonadotropes (follicle-stimulating hormone, FSH; luteinizing hormone, LH), are potent regulators of somatotropes [growth hormone (GH) cells], lactotropes [prolactin (PRL) cells], and somatolactin (SL)-containing cells in teleosts (4-9). Because GnRH exerts its actions through binding to GnRH receptors (GnRH-Rs) (10), it is, therefore, conceivable that the three GnRH types have their respective cognate receptors expressed in different pituitary cells. Multiple GnRH-Rs have been cloned (10) and their transcripts identified in LH and GH cells (11), and GnRH-R proteins in LH, GH, and PRL cells (4) of teleosts. However, the distribution of GnRH-R transcripts in other endocrine cell types of the adenohypophysis has never been evaluated. Besides, it is unknown whether transcripts of multip...

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Ultrastructural changes in the adenohypophysis during the ovarian cycle of the viviparous teleost Poecilia latipinna

Cited by 17 publications

References 115 publications

Dynamics of oocyte and embryonic development during ovarian cycle of the viviparous mosquitofish Gambusia affinis

Dynamics of oocyte and embryonic development during ovarian cycle of the viviparous mosquitofish Gambusia affinis

Morphological and histological studies on the pituitary gland of Liza carinata from the Suez Bay (Red Sea, Egypt), with special reference to the gonadotrophs

Three GnRH receptor types in laser-captured single cells of the cichlid pituitary display cellular and functional heterogeneity

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