scholarly journals Null Mutation in Transforming Growth Factor β1 Disrupts Ovarian Function and Causes Oocyte Incompetence and Early Embryo Arrest

Endocrinology ◽  
2006 ◽  
Vol 147 (2) ◽  
pp. 835-845 ◽  
Author(s):  
Wendy V. Ingman ◽  
Rebecca L. Robker ◽  
Karen Woittiez ◽  
Sarah A. Robertson
Keyword(s):  
Transforming Growth Factor ◽  
Ovarian Function ◽  
Mutant Mice ◽  
Reproductive Capacity ◽  
Null Mutation ◽  
Null Mutant ◽  
Critical Determinant ◽  
Serum Progesterone ◽  
Null Mutant Mice

TGFβ1 is implicated in regulation of ovarian function and the events of early pregnancy. We have investigated the effect of null mutation in the Tgfβ1 gene on reproductive function in female mice. The reproductive capacity of TGFβ1 null mutant females was severely impaired, leading to almost complete infertility. Onset of sexual maturity was delayed, after which ovarian function was disrupted, with extended ovarian cycles, irregular ovulation, and a 40% reduction in oocytes ovulated. Serum FSH and estrogen content were normal, but TGFβ1 null mutant mice failed to display the characteristic proestrus surge in circulating LH. Ovarian hyperstimulation with exogenous gonadotropins elicited normal ovulation rates in TGFβ1 null mutant mice. After mating with wild-type stud males, serum progesterone content was reduced by 75% associated with altered ovarian expression of mRNAs encoding steroidogenic enzymes 3β-hydroxysteroid dehydrogenase-1 and P450 17 α-hydroxylase/C17–20-lyase. Embryos recovered from TGFβ1 null mutant females were developmentally arrested in the morula stage and rarely progressed to blastocysts. Attempts to rescue embryos by exogenous progesterone administration and in vitro culture were unsuccessful, and in vitro fertilization and culture experiments demonstrated that impaired development is unlikely to result from lack of maternal tract TGFβ1. We conclude that embryo arrest is due to developmental incompetence in oocytes developed in a TGFβ1-deficient follicular environment. This study demonstrates that TGFβ1 is a critical determinant of normal ovarian function, operating through regulation of LH activity and generation of oocytes competent for embryonic development and successful initiation of pregnancy.

The Liver in Transforming Growth Factor-Beta-1 (TGF-β1) Null Mutant Mice

1996 ◽  
Vol 20 (5) ◽  
pp. 477-490 ◽  
Author(s):  
A. Olufemi Williams ◽  
Alan D. Knapton ◽  
Andrew Geiser ◽  
John J. Letterio ◽  
Anita B. Roberts
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Mutant Mice ◽  
Null Mutant ◽  
Growth Factor Beta ◽  
Null Mutant Mice ◽  
Tgf Β1

scholarly journals Neurons Expressing the Highest Levels of γ-Synuclein Are Unaffected by Targeted Inactivation of the Gene

2003 ◽  
Vol 23 (22) ◽  
pp. 8233-8245 ◽  
Author(s):  
Natalia Ninkina ◽  
Katerina Papachroni ◽  
Darren C. Robertson ◽  
Oliver Schmidt ◽  
Liz Delaney ◽  
...  
Keyword(s):  
Es Cells ◽  
Culture Conditions ◽  
Sensory Function ◽  
Mutant Mice ◽  
Null Mutant ◽  
Wild Type ◽  
Complete Inactivation ◽  
Null Mutant Mice

ABSTRACT Homologous recombination in ES cells was employed to generate mice with targeted deletion of the first three exons of the γ-synuclein gene. Complete inactivation of gene expression in null mutant mice was confirmed on the mRNA and protein levels. Null mutant mice are viable, are fertile, and do not display evident phenotypical abnormalities. The effects of γ-synuclein deficiency on motor and peripheral sensory neurons were studied by various methods in vivo and in vitro. These two types of neurons were selected because they both express high levels of γ-synuclein from the early stages of mouse embryonic development but later in the development they display different patterns of intracellular compartmentalization of the protein. We found no difference in the number of neurons between wild-type and null mutant animals in several brain stem motor nuclei, in lumbar dorsal root ganglia, and in the trigeminal ganglion. The survival of γ-synuclein-deficient trigeminal neurons in various culture conditions was not different from that of wild-type neurons. There was no difference in the numbers of myelinated and nonmyelinated fibers in the saphenous nerves of these animals, and sensory reflex thresholds were also intact in γ-synuclein null mutant mice. Nerve injury led to similar changes in sensory function in wild-type and mutant mice. Taken together, our data suggest that like α-synuclein, γ-synuclein is dispensable for the development and function of the nervous system.

Exogenous transforming growth factor beta1 replacement and fertility in male Tgfb1 null mutant mice

2009 ◽  
Vol 21 (4) ◽  
pp. 561 ◽  
Author(s):  
Leanne J. McGrath ◽  
Wendy V. Ingman ◽  
Rebecca L. Robker ◽  
Sarah A. Robertson
Keyword(s):  
Growth Factor ◽  
Reproductive Tract ◽  
Transforming Growth Factor ◽  
Mating Behaviour ◽  
Bovine Milk ◽  
Reproductive Function ◽  
Serum Testosterone ◽  
Mutant Mice ◽  
Null Mutant ◽  
Null Mutant Mice

Analysis of Tgfb1 null mutant mice has demonstrated that the cytokine transforming growth factor β1 (TGFB1) has essential non-redundant roles in fertility. The present study attempted to alleviate the infertility phenotype of Tgfb1 null mutant male mice by administration of exogenous TGFB1, either orally by colostrum feeding or subcutaneously by delivery of recombinant human latent TGFB1 (rhLTGFB1) via osmotic mini-pumps. Bovine colostrum and fresh unpasteurised bovine milk were found to be rich sources of TGFB1 and TGFB2; however, feeding Tgfb1 null mutant mice colostrum for 2 days failed to raise serum levels of TGFB1. Administration of rhLTGFB1 (~150 μg in total) over 14 days to Tgfb1 null mutant mice resulted in detectable TGFB1 in serum; however, mean levels remained 10-fold less than in Tgfb1 heterozygous mice. After 7 days and 14 days of rhLTGFB1 administration, serum testosterone, spontaneous non-contact erections and mating behaviour were assessed. Despite the increased serum TGFB1, administration of rhLTGFB1 to Tgfb1 null mutant mice failed to improve these fertility parameters. It is concluded that sustained restoration of circulating latent TGFB1 to levels approaching the normal physiological range does not rescue the infertility phenotype caused by TGFB1 deficiency. Reproductive function in male Tgfb1 null mutant mice may not respond to systemic TGFB1 supplementation due to a requirement for local sources of TGFB1 at the site of action in the reproductive tract, or perturbed development during the neonatal period or puberty such that adult reproductive function is permanently impaired.

301. Effect of exogenous transforming growth factor beta 1 on reproductive performance in male TGFβ1 null mice

2005 ◽  
Vol 17 (9) ◽  
pp. 128
Author(s):  
L. J. McGrath ◽  
R. Robker ◽  
S. A. Robertson
Keyword(s):  
Growth Factor ◽  
Reproductive Performance ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Mating Behaviour ◽  
Mutant Mice ◽  
Null Mutant ◽  
Exogenous Cytokine ◽  
Growth Factor Beta ◽  
Null Mutant Mice

The transforming growth factor beta 1 (TGFβ1) family are potent cytokines that regulate tissue development, inflammation and immunity. Our studies in null mutant mice implicate a key role for TGFβ1 in male reproductive function. The TGFβ1 null mutation results in profound infertility due to inability to copulate successfully associated with reduced testosterone synthesis, although penile erection and sperm production do occur. To investigate whether fertility status can be improved in TGFβ1 null mutant mice by exogenous cytokine replacement, we used Alzet mini-pumps implanted subcutaneously to deliver a constant supply of recombinant latent TGFβ1 to TGFβ–/– mice (n = 7, 2.1µg/day over 2 weeks). Control TGFβ–/– mice (n = 6) and +/+ mice (n = 10) received pumps containing BSA carrier only. Circulating levels of TGFß1 were increased in TGFβ–/– mice and reached levels comparable to those seen in fertile heterozygote littermates. Increased circulating testosterone was evident in a proportion of TGFβ–/– mice after exogenous TGFβ replacement compared with untreated control mice. However, serum testosterone content was widely variable within all groups, so statistical significance was not achieved. Videotaping of nocturnal mating behaviour while caging treated males with normal receptive female mice showed that unlike TGFβ+/+ mice, which successfully mounted and intromitted, untreated TGFβ–/– mice failed to engage in normal mating behaviour. TGFβ–/– mice treated with exogenous cytokine were occasionally seen to intromit but less frequently than TGFβ+/+ controls. Ejaculation did not occur in any of the TGFβ–/– mice regardless of TGFβ replacement, compared with TGFβ+/+ mice where 8/10 mice ejaculated during the 2 h observation period. The trend towards improvement in both testosterone levels and copulation activity of the TGFβ1 null mice treated with exogenous cytokine suggests that systemic TGFβ1 availability may influence reproductive performance in male mice. However, since fertility was not restored by cytokine replacement, locally produced TGFβ in the reproductive tract and/or hypothalamic pituitary axis are also implicated in regulating fertility.

Role of components of the phagocytic NADPH oxidase in oxygen sensing

2002 ◽  
Vol 93 (4) ◽  
pp. 1357-1364 ◽  
Author(s):  
K. A. Sanders ◽  
K. M. Sundar ◽  
L. He ◽  
B. Dinger ◽  
S. Fidone ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Carotid Body ◽  
Minute Ventilation ◽  
Mutant Mice ◽  
Whole Body ◽  
Type I ◽  
Null Mutant ◽  
Wild Type ◽  
Null Mutant Mice

It has been hypothesized that O2sensing in type I cells of the carotid body and erythropoietin (EPO)-producing cells of the kidney involves protein components identical to the NADPH oxidase system responsible for the respiratory burst of phagocytes. In the present study, we evaluated O2sensing in mice with null mutant genotypes for two components of the phagocytic oxidase. Whole body plethysmography was used to study unanesthetized, unrestrained mice. When exposed to an acute hypoxic stimulus, gp91phox-null mutant and wild-type mice increased their minute ventilation by similar amounts. In contrast, p47phox-null mutant mice demonstrated increases in minute ventilation in response to hypoxia that exceeded that of their wild-type counterparts: 98.0 ± 18.0 vs. 20.0 ± 13.0% ( n = 11, P = 0.003). In vitro recordings of carotid sinus nerve (CSN) activity demonstrated that resting (basal) neural activity was marginally elevated in p47phox-null mutant mice. With hypoxic challenge, mean CSN discharge was 1.5-fold greater in p47phox-null mutant than in wild-type mice: 109.61 ± 13.29 vs. 72.54 ± 7.65 impulses/s ( n = 8 and 7, respectively, P = 0.026). Consequently, the hypoxia-evoked CSN discharge (stimulus-basal) was ∼58% larger in p47phox-null mutant mice. Quantities of EPO mRNA in kidney were similar in gp91phox- and p47phox-null mutant mice and their respective wild-type controls exposed to hypobaric hypoxia for 72 h. These findings confirm the previous observation that absence of the gp91phoxcomponent of the phagocytic NADPH oxidase does not alter the O2-sensing mechanism of the carotid body. However, absence of the p47phoxcomponent significantly potentiates ventilatory and chemoreceptor responses to hypoxia. O2sensing in EPO-producing cells of the kidney appears to be independent of the gp91phoxand p47phoxcomponents of the phagocytic NADPH oxidase.

The Mechanistic Basis for Sexual Dysfunction in Male Transforming Growth Factor  1 Null Mutant Mice

2009 ◽  
Vol 31 (2) ◽  
pp. 95-107 ◽  
Author(s):  
W. V. Ingman ◽  
L. M. Mcgrath ◽  
W. G. Breed ◽  
I. F. Musgrave ◽  
R. L. Robker ◽  
...  
Keyword(s):  
Growth Factor ◽  
Sexual Dysfunction ◽  
Transforming Growth Factor ◽  
Mutant Mice ◽  
Null Mutant ◽  
Mechanistic Basis ◽  
Null Mutant Mice

Blockade of AMPA Receptors and Volatile Anesthetics

2001 ◽  
Vol 94 (3) ◽  
pp. 478-488 ◽  
Author(s):  
Daisy T. Joo ◽  
Diane Gong ◽  
James M. Sonner ◽  
Zhengping Jia ◽  
John F. MacDonald ◽  
...  
Keyword(s):  
Ampa Receptors ◽  
Volatile Anesthetics ◽  
Genetically Engineered ◽  
Mutant Mice ◽  
General Anesthetics ◽  
Null Mutant ◽  
Increased Sensitivity ◽  
Drug Receptor ◽  
Null Mutant Mice

Background The alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) subtype of glutamate receptor mediates fast excitatory neurotransmission in the central nervous system. Many general anesthetics inhibit AMPA receptors in vitro; however, it is not certain if this inhibition contributes to the behavioral properties of these drugs. AMPA receptors lacking the GluR2 subunit are resistant to blockade by barbiturates in vitro. Paradoxically, GluR2 null mutant (-/-) mice are more sensitive to barbiturate-induced loss of the righting reflex (LORR) compared with wild-type (+/+) littermates. To determine if interactions between anesthetics and AMPA receptors account for the increased sensitivity of (-/-) mice, the effects of volatile anesthetics that do not directly inhibit AMPA receptors were examined. Methods Isoflurane, halothane, desflurane, or sevoflurane were administered to (-/-) and (+/+) littermate controls. Anesthetic requirements for LORR, movement to tail clamp (minimum alveolar concentration [MAC]), and hind-paw withdrawal latency (HPWL) were determined. Electrophysiologic methods examined the inhibition of AMPA receptors by isoflurane and halothane. Results Anesthetic requirements for LORR and HPWL were decreased, whereas MAC values were unchanged in (-/-) mice. Isoflurane and halothane caused minimal inhibition of AMPA receptors at clinically relevant concentrations. Conclusions Direct blockade of AMPA receptors did not account for the increased sensitivity to volatile anesthetics in GluR2 null mutant mice for HPWL or LORR. Thus, the deficiency of GluR2-containing AMPA receptors increases the sensitivity of neuronal circuitry mediating these end points, but not MAC. GluR2-containing receptors do not contribute appreciably to MAC in this mouse model. These results illustrate the difficulties in attributing behavioral responses to drug-receptor interactions in genetically engineered animals.

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