Morphological and morphometric changes in the ovaries of white‐footed mice (<i>Peromyscus leucopus</i>) following exposure to long or short photoperiod

Spanel‐Borowski, Katharina; Petterborg, Larry J.; Reíter, Russel J.

doi:10.1002/ar.1092050103

Cited by 12 publications

(2 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The ability of Smad3Ϫ/Ϫ and WT mice to ovulate was determined by morphological assessment of the number of corpora lutea in the ovary (64,72,73). Briefly, ovaries were collected from WT and Smad3Ϫ/Ϫ mice on PD 90, fixed in Kahle's solution and processed for histological evaluation as previously described.…”

Section: Measurement Of Ovulationmentioning

confidence: 99%

Ovarian Follicle Development Requires Smad3

Tomic

Miller

Kenny³

et al. 2004

Molecular Endocrinology

112

View full text Add to dashboard Cite

Smad3 is an important mediator of the TGF beta signaling pathway. Interestingly, Smad3-deficient (Smad3-/-) mice have reduced fertility compared with wild-type (WT) mice. To better understand the molecular mechanisms underlying the reduced fertility in Smad3-/- animals, this work tested the hypothesis that Smad3 deficiency interferes with three critical aspects of folliculogenesis: growth, atresia, and differentiation. Growth was assessed by comparing the size of follicles, expression of proliferating cell nuclear antigen, and expression of cell cycle genes in Smad3-/- and WT mice. Atresia was assessed by comparing the incidence of atresia and expression of bcl-2 genes involved in cell death and cell survival in Smad3-/- and WT mice. Differentiation was assessed by comparing the expression of FSH receptor (FSHR), estrogen receptor (ER) alpha, ER beta, and inhibin alpha-, beta(A)-, and beta(B)-subunits in Smad3-/- and WT mice. Because growth, atresia, and differentiation are regulated by hormones, estradiol, FSH, and LH levels were compared in Smad3-/- and WT mice. Moreover, because alterations in folliculogenesis can affect the ability of mice to ovulate, the number of corpora lutea and ovulated eggs in response to gonadotropin treatments were compared in Smad3-/- and WT animals. The results indicate that Smad3 deficiency slows follicle growth, which is characterized by small follicle diameters, low levels of proliferating cell nuclear antigen, and low expression of cell cycle genes (cyclin-dependent kinase 4 and cyclin D2). Smad3 deficiency also causes atretic follicles, degenerated oocytes, and low expression of bcl-2. Furthermore, Smad3 deficiency affects follicular differentiation as evidenced by decreased expression of ER beta, increased expression of ER alpha, and decreased expression of inhibin alpha-subunits. Smad3 deficiency causes low estradiol and high FSH levels. Finally, Smad3-/- ovaries have no corpora lutea, and they do not ovulate after ovulatory induction with exogenous gonadotropins. Collectively, these data provide the first evidence that reduced fertility in Smad3-/- mice is due to impaired folliculogenesis, associated with altered expression of genes that control cell cycle progression, cell survival, and cell differentiation. The findings that Smad3-/- follicles have impaired growth, increased atresia, and altered differentiation in the presence of high FSH levels, normal expression of FSHR, and lower expression of cyclin D2, suggest a possible interaction between Smad3 and FSH signaling downstream of FSHR in the mouse ovary.

show abstract

Section: Measurement Of Ovulationmentioning

confidence: 99%

Ovarian Follicle Development Requires Smad3

Tomic

Miller

Kenny³

et al. 2004

Molecular Endocrinology

112

View full text Add to dashboard Cite

show abstract

“…Note that in M. agrestis , corpora lutea were also absent in LD ovaries because this species is an induced ovulator, but the size and numbers of antral follicles were greater in LD than in SD ovaries (Breed and Clark, ). In P. leucopus , evidence of hypertrophied somatic cells in the ovaries was absent at 50 days of age (Johnston and Zucker, ), although hypertrophied interstitial gland cells were noted in SD‐regressed adult ovaries (Spanel‐Borowski et al, ). The California mouse‐eared bat ( Myotis californicus ) is a non‐rodent mammal that also appears to have hypertrophied interstitial gland cells in its ovaries during the non‐breeding season (Mossman and Duke, ).…”

Section: Discussionmentioning

confidence: 99%

Complementary histological and genomic analyses reveal marked differences in the developmental trajectories of ovaries in Siberian hamsters raised in long‐ and short‐day lengths

Sung-Un

Bernstein

Place

2014

Molecular Reproduction Devel

View full text Add to dashboard Cite

Siberian hamsters (Phodopus sungorus) delay sexual development when raised in short-day (SD; 10 hr light: 14 hr dark) conditions, which leads to delayed onset of estrous cycles and ovulations as compared to females raised in long-day (LD; 16 hr light: 8 hr dark) conditions. In addition to the absence of pre-ovulatory follicles and corpora lutea, the ovaries of SD-reared Siberian hamsters are characterized by an abundance of hypertrophied granulosa cells (HGCs) that surround atretic oocytes. To determine the age at which the histology of LD and SD ovaries first diverge, including the initial appearance of HGCs in SD conditions, we examined hamster ovaries histologically at 1, 2, 3, 4, 6, 8, 10, and 12 weeks of age. After identifying subtle differences in LD and SD ovarian histology at 4 weeks of age, we searched for differences in ovarian gene expression at 3 and 8 weeks of age, which correspond to the ages when ovarian histology do not differ (3 weeks) versus the earliest age when HGCs were observed (8 weeks). At 3 weeks, only 14 genes were differentially expressed in LD and SD ovaries, whereas 183 genes were differentially expressed at 8 weeks. Overall, our findings demonstrate that ovarian development under SD conditions is not simply arrested at an early stage of LD development, but rather utilizes a developmental path that is distinct from that used in LD ovaries.

show abstract

Follicular growth and intraovarian and extraovarian oocyte release after daily injections of melatonin and 6‐chloromelatonin in the Syrian hamster

et al. 1983

View full text Add to dashboard Cite

Groups of adult female Syrian hamsters (Mesocricetus auratus) were injected daily at 17:00 hr with 2.5, 15, or 25 micrograms of melatonin (Mel) or 6-chloro-melatonin (Cl-Mel) for 12 weeks. An ovary from each animal was completely serially sectioned for light microscopic investigation. Judging from the presence of corpora lutea, there were some animals in each group that continued to cycle, although the postestrous, white mucous discharge had disappeared. Noncycling animals were most often found in the 25-micrograms group of Cl-Mel. Only uterine weights of noncycling animals treated with either 25 or 15 micrograms of Mel or Cl-Mel were statistically significantly depressed versus controls. Cl-Mel (25 micrograms) significantly suppressed the total number and size of antral follicles (P less than 0.05). Follicular ruptures with incomplete or complete release of the oocyte out of the follicular compartment were observed. The oocyte release occurred either into the ovary ("intraovarian oocyte release: IOR") or outside of the ovary ("extraovarian oocyte release: EOR"). Compared with controls, the total number of IOR was increased in all experimental groups with the exception of the 2.5-micrograms group of Cl-Mel. IOR appeared in both preantral and antral follicles, and often IOR was complete. In controls, only preantral follicles were involved in IOR; these were primarily incomplete ones. IOR was seen in cycling and noncycling animals. By contrast, EOR was exclusively observed in noncycling hamsters. It is concluded that the cessation of postestrous, white mucous discharge is not necessarily an index for a halt in cyclic ovarian function. Injections of 25 micrograms of Cl-Mel are more effective than 25 micrograms of Mel in suppressing ovarian function. Both Mel and Cl-Mel increase the frequency of IOR. Finally, noncycling hamsters show EOR that is regarded as an abnormal ovulation.

show abstract

Morphological and morphometric changes in the ovaries of white‐footed mice (Peromyscus leucopus) following exposure to long or short photoperiod

Cited by 12 publications

References 27 publications

Ovarian Follicle Development Requires Smad3

Ovarian Follicle Development Requires Smad3

Complementary histological and genomic analyses reveal marked differences in the developmental trajectories of ovaries in Siberian hamsters raised in long‐ and short‐day lengths

Follicular growth and intraovarian and extraovarian oocyte release after daily injections of melatonin and 6‐chloromelatonin in the Syrian hamster

Contact Info

Product

Resources

About